Motorola BSS Planning Guide

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CHAPTER 2TRANSMISSION SYSTEMS

CHAPTER 3BSS CELL PLANNING

CHAPTER 4BTS PLANNING STEPS AND

RULES

CHAPTER 5BSC PLANNING STEPS AND

RULES

CHAPTER 1 INTRODUCTION

CHAPTER 7OMC-R PLANNING STEPS

AND RULES

CHAPTER 8PLANNING EXERCISE

CHAPTER 9STANDARD

CONFIGURATIONS

CHAPTER 10PREVIOUS BSC PLANNING

STEPS AND RULES

CHAPTER 6RXCDR PLANNING STEPS

AND RULES

INDEXCHAPTER 11PREVIOUS BTS PLANNING

Cellular Infrastructure Group

SYSTEM INFORMATIONBSS EQUIPMENT PLANNINGSOFTWARE RELEASE 1.6.1.3

68P02900W21-G

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68P02900W21-G

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SYSTEMINFORMATION

BSS EQUIPMENTPLANNING

SOFTWARE RELEASE1.6.1.3

SYSTEM INFORMATIONBSS EQUIPMENT PLANNING

14th Apr 00 System Information: BSS Equipment Planning

68P02900W21-G

SOFTWARE RELEASE 1.6.1.3

i

GSM-001-103

System InformationBSS Equipment Planning

� Motorola 1993 - 2000All Rights ReservedPrinted in the U.K.

GSM-001-103

14th Apr 00ii System Information: BSS Equipment Planning

SOFTWARE RELEASE 1.6.1.368P02900W21-G

Copyrights, notices and trademarks

CopyrightsThe Motorola products described in this document may include copyrighted Motorola computerprograms stored in semiconductor memories or other media. Laws in the United States and othercountries preserve for Motorola certain exclusive rights for copyright computer programs, including theexclusive right to copy or reproduce in any form the copyright computer program. Accordingly, anycopyright Motorola computer programs contained in the Motorola products described in this documentmay not be copied or reproduced in any manner without the express written permission of Motorola.Furthermore, the purchase of Motorola products shall not be deemed to grant either directly or byimplication, estoppel or otherwise, any license under the copyrights, patents or patent applications ofMotorola, except for the rights that arise by operation of law in the sale of a product.

RestrictionsThe software described in this document is the property of Motorola. It is furnished under a licenseagreement and may be used and/or disclosed only in accordance with the terms of the agreement.Software and documentation are copyright materials. Making unauthorized copies is prohibited bylaw. No part of the software or documentation may be reproduced, transmitted, transcribed, storedin a retrieval system, or translated into any language or computer language, in any form or by anymeans, without prior written permission of Motorola.

AccuracyWhile reasonable efforts have been made to assure the accuracy of this document, Motorolaassumes no liability resulting from any inaccuracies or omissions in this document, or from the useof the information obtained herein. Motorola reserves the right to make changes to any productsdescribed herein to improve reliability, function, or design, and reserves the right to revise thisdocument and to make changes from time to time in content hereof with no obligation to notify anyperson of revisions or changes. Motorola does not assume any liability arising out of the applicationor use of any product or circuit described herein; neither does it convey license under its patentrights of others.

Trademarks

and MOTOROLA are registered trademarks of Motorola Inc. M-Cell and Taskfinder are trademarks of Motorola Inc.All other brands and corporate names are trademarks of their respective owners.

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Issue status of this manual 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General information 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

First aid in case of electric shock 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Reporting safety issues 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Warnings and cautions 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General warnings 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Human exposure to radio frequency energy (PCS1900 only) 9. . . . . . . . . . . . . . . . . . . . . .

Beryllium health and safety precautions 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General cautions 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Devices sensitive to static 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Motorola GSM manual set 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GMR amendment 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GMR amendment record 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 1Introduction i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter overview 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to BSS planning 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Manual overview 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Contents 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BSS equipment overview 1–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . System architecture 1–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . System components 1–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Radio channel units 1–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BSS features 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Features that affect planning 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Diversity 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Frequency hopping 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Short message service, cell broadcast 1–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Code storage facility processor 1–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PCU for GPRS upgrade 1–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BSS planning overview 1–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 1–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Initial information required 1–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning methodology 1–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 2Transmission systems i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter overview 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BSS interfaces 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Interconnecting the BSC and BTSs 2–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 2–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interconnection rules 2–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Network topology 2–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 2–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Star connection 2–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Daisy chain connection 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Daisy chain planning 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Aggregate Abis 2–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RTF path fault containment 2–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 kbit/s RSL 2–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 kbit/s XBL 2–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BTS concentration 2–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 2–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Key terms 2–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DYNET – new device 2–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Blocking considerations 2–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Emergency call handling 2–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Radio Signalling Link (RSL) planning 2–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Network topologies 2–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Performance issue 2–32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Configuration and compatibility issues 2–32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recommended BTS concentration planning guidelines 2–33. . . . . . . . . . . . . . . . . . . . . Examples 2–35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Managed HDSL on micro BTS 2–41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 2–41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Integrated HDSL interface 2–42. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General HDSL guidelines 2–44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Microcell system planning 2–45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Picocell system planning 2–47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 3BSS cell planning i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSS cell planning 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Planning requirements 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning factors 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Planning tools 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GSM frequency spectrum 3–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The GSM900 frequency spectrum 3–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The DCS1800 frequency spectrum 3–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The PCS1900 frequency spectrum 3–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Absolute radio frequency channel capacity 3–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Modulation techniques and channel spacing 3–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Traffic capacity 3–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dimensioning 3–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Channel blocking 3–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic flow 3–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Grade of service 3–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Capacity calculations 3–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 3–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Typical call parameters 3–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Control channel calculations 3–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 3–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPRS control channel RF provisioning 3–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Number of CCCH per BTS cell 3–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Number of SDCCH per BTS cell 3–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Control channel configurations 3–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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The GPRS planning process 3–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview of the GPRS planning process 3–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction to the GPRS planning process 3–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview the GPRS planning process introduction 3–25. . . . . . . . . . . . . . . . . . . . . . . . . Determination of expected load 3–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Network planning flow 3–27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GPRS network traffic estimation and key concepts 3–28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview of the GPRS network traffic estimation and key concepts 3–28. . . . . . . . . . Introduction to the GPRS network traffic estimation and key concepts 3–29. . . . . . . . Dynamic timeslot mode switching 3–32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Carrier timeslot allocation examples 3–34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSS timeslot allocation methods 3–37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Provisioning the network with switchable timeslots 3–39. . . . . . . . . . . . . . . . . . . . . . . . . Recommendation 3–43. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GPRS Air interface planning process 3–45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview of the GPRS air interface planning process structure 3–45. . . . . . . . . . . . . . Introduction to the GPRS air interface planning process 3–46. . . . . . . . . . . . . . . . . . . . Air interface throughput 3–51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Step 1: throughput estimation process 3–52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Step 2: throughput estimation process 3–53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Throughput estimation process: step 3 (optional) 3–56. . . . . . . . . . . . . . . . . . . . . . . . . . Throughput estimation process: step 4 (optional) 3–57. . . . . . . . . . . . . . . . . . . . . . . . . .

Propagation effects on GSM frequencies 3–59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Propagation production 3–59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to decibels 3–60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fresnel zone 3–61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Radio refractive index 3–62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Environmental effects on propagation 3–66. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Multipath propagation 3–69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GSM900 path loss 3–82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Path loss GSM900 vs DCS1800 3–83. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Frequency re-use 3–84. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to re-use patterns 3–84. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Re-use pattern 3–85. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Carrier/ Interference (C/I) ratio 3–88. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Other sources of interference 3–89. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sectorization of sites 3–89. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Overcoming adverse propagation effects 3–90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hardware techniques 3–90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Error protection and detection 3–92. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Speech channel encoding 3–94. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Channel coding for enhanced full rate 3–96. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Control channel encoding 3–97. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Data channel encoding 3–98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mapping logical channels onto the TDMA frame structure 3–99. . . . . . . . . . . . . . . . . . . Voice Activity Detection – VAD 3–105. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Discontinuous Transmission – DTX 3–105. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Receive diversity 3–106. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Subscriber environment 3–108. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Subscriber hardware 3–108. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Environment 3–108. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Distribution 3–109. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Most demanding 3–110. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Future planning 3–111. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GSM-001-103

14th Apr 00vi System Information: BSS Equipment Planning


The microcellular solution 3–112. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Layered Architecture 3–112. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Combined cell architecture 3–113. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Combined cell architecture structure 3–114. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Expansion solution 3–115. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 4BTS planning steps and rules i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter overview 4–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction 4–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BTS planning overview 4–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Outline of planning steps 4–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Macrocell cabinets 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Horizonmicro 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-Cell6 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-Cell2 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Microcell enclosures 4–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Horizonmicro and Horizoncompact 4–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Receive configurations 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Receiver planning actions 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Transmit configurations 4–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transmit planning actions 4–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Antenna configurations 4–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Antenna planning actions 4–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Carrier equipment (CTU/TCU) 4–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CTU/TCU planning actions 4–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Micro base control unit (mBCU) 4–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . mBCU planning actions 4–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Network interface unit (NIU) and site connection 4–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NIU planning actions 4–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Main control unit, with dual FMUX (MCUF) 4–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MCUF planning actions 4–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Main control unit (MCU) 4–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MCU planning actions 4–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GSM-001-103


68P02900W21-G


vii

Cabinet interconnection (FOX/FMUX) 4–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FOX/FMUX planning actions 4–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Power requirements 4–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Power planning actions 4–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Network expansion using Macro/Micro/Picocell BTS 4–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Expansion considerations 4–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mixed site utilization 4–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

PCC cabinet 4–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cabinet planning actions 4–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Line interface modules (HIM-75, HIM-120) 4–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HIM-75/HIM-120 planning actions 4–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 5BSC planning steps and rules i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


BSC planning overview 5–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Outline of planning steps 5–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Capacity calculations 5–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BSC system capacity 5–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . System capacity summary 5–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scaleable BSC 5–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Determining the required BSS signalling link capacities 5–7. . . . . . . . . . . . . . . . . . . . . . . . . . BSC signalling traffic model 5–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Typical parameter values 5–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Assumptions used in capacity calculations 5–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Link capacities 5–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BSS planning for GPRS 5–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview of introduction to BSS planning for GPRS 5–12. . . . . . . . . . . . . . . . . . . . . . . Introduction to BSS planning for GPRS 5–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Feature compatibility 5–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSS statistics 5–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PCU-to-SGSN interface planning 5–23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GPRS upgrade provisioning rules 5–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview of provisioning rules 5–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSS upgrade provisioning rules 5–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPRS PCU provisioning rules 5–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPRS link provisioning rules 5–33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Redundancy planning 5–34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GSM-001-103

14th Apr 00viii System Information: BSS Equipment Planning


Determining the RSLs required 5–38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 5–38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Standard traffic model 5–38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Non-standard traffic model 5–39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BTS-BSC E1 links (Abis) 5–39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC to BTS E1 interconnect planning actions 5–50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC to BTS T1 interconnect planning actions 5–51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculate the number of LCFs for RSL processing 5–52. . . . . . . . . . . . . . . . . . . . . . . . . LCF GPROC2 provisioning for GPRS signalling 5–53. . . . . . . . . . . . . . . . . . . . . . . . . . .

Determining the number of MTLs required 5–56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 5–56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Standard traffic model 5–57. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Non-standard traffic model 5–58. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculate the number of LCFs for MTL processing 5–60. . . . . . . . . . . . . . . . . . . . . . . . MSC to BSC signalling over a satellite link 5–60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Generic processor (GPROC2) 5–61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC2 functions and types 5–61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC types 5–62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 5–62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC2 planning actions 5–64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cell broadcast link 5–64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OMF GPROC required 5–64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Code storage facility processor 5–65. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC redundancy 5–65. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Transcoding 5–66. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–66. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GDP/XCDR planning considerations 5–66. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T1 conversion 5–67. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning actions for transcoding at the BSC 5–68. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Multiple serial interface (MSI, MSI-2) 5–69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 5–69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MSI/MSI-2 planning actions 5–70. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Kiloport switch (KSW) 5–71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 5–71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . KSW planning actions 5–72. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BSU shelves 5–73. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–73. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 5–73. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSU shelf planning actions 5–73. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Kiloport switch extender (KSWX) 5–74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 5–74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . KSWX planning actions 5–74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Generic clock (GCLK) 5–76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 5–76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GCLK planning actions 5–76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Clock extender (CLKX) 5–77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 5–77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CLKX planning actions 5–77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

LAN extender (LANX) 5–78. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–78. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 5–78. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LANX planning actions 5–78. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Parallel interface extender (PIX) 5–79. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–79. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 5–79. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PIX planning actions 5–79. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Line interfaces (BIB, T43) 5–80. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–80. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 5–80. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BIB/T43 planning actions 5–80. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Digital shelf power supply 5–81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 5–81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Power supply planning actions 5–81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Battery backup board (BBBX) 5–82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 5–82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BBBX planning actions 5–82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Verify the number of BSU shelves and BSSC2 cabinets 5–83. . . . . . . . . . . . . . . . . . . . . . . . . . Verification 5–83. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 6RXCDR planning steps and rules i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter overview 6–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction 6–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Remote transcoder planning overview 6–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 6–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Outline of planning steps 6–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

RXCDR to BSC links 6–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 6–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E1 interconnect planning actions 6–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T1 interconnect planning actions 6–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

RXCDR to MSC links 6–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 6–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E1 interconnect planning actions 6–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T1 interconnect planning actions 6–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Generic processor (GPROC, GPROC2) 6–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 6–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 6–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC planning actions 6–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Transcoding 6–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 6–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GDP/XCDR planning considerations 6–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T1 conversion 6–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GSM-001-103

14th Apr 00x System Information: BSS Equipment Planning


Multiple serial interface (MSI, MSI-2) 6–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 6–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 6–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MSI planning actions 6–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


RXU shelves 6–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 6–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 6–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RXU shelf planning actions 6–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .









Verify the number of RXU shelves and BSSC cabinets 6–22. . . . . . . . . . . . . . . . . . . . . . . . . . . Verification 6–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 7OMC-R planning steps and rules i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Authorized OMC-R configurations 7–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction 7–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Terminology 7–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Capacity 7–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Outline of planning steps 7–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6560 planning rules 7–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scaleable OMC-R server and workstation composition 7–6. . . . . . . . . . . . . . . . . . . . .

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Chapter 8Planning exercise i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter overview 8–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction 8–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Order creation 8–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 8–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Initial requirements 8–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Requirements 8–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The exercise 8–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 8–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Determine the hardware requirements for BTS 2 8–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 8–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cabinet 8–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Summary 8–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Determine the hardware requirements for BTS 10 8–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 8–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cabinet 8–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Receiver requirements 8–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transmitter combining requirements 8–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Summary 8–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Determine the hardware requirements for the BSC 8–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 8–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Summary 8–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Determine the hardware requirements for the RXCDR 8–15. . . . . . . . . . . . . . . . . . . . . . . . . . . MSI requirements 8–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transcoder requirement 8–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Link interface 8–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC2 requirement 8–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . KSW requirement 8–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . KSWX requirement 8–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GCLK requirement 8–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CLKX requirement 8–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PIX requirement 8–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BBBX requirement 8–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LANX requirement 8–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Power supply 8–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Summary 8–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Determine the hardware requirements for the OMC-R 8–18. . . . . . . . . . . . . . . . . . . . . . . . . . . OMC-R example 8–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Determine the hardware requirements for the GPRS PCU 8–20. . . . . . . . . . . . . . . . . . . . . . . .

Calculations using alternative call models 8–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 8–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Parameters used in calculations 8–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Determine the number of CCCHs per cell 8–27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Determine the number of SDCCHs per cell 8–28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Determine the number of GPROC2s 8–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 9Standard configuration descriptions i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter overview 9–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction 9–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Standard configurations 9–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 9–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Typical BSS configurations 9–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC with 24 BTS 9–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC with full redundancy 9–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transcoder 9–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Picocell configurations (M-Cellaccess) 9–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Single site 9–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Two site cabinet 9–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

One cabinet configurations 9–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with one Horizonmacro cabinet 9–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with one M-Cell6 cabinet 9–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with one M-Cell2 cabinet 9–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Two cabinet configuration 9–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with two Horizonmacro cabinets 9–13. . . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with two M-Cell6 cabinets 9–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Three cabinet configuration 9–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with three Horizonmacro cabinets 9–15. . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with three M-Cell2 cabinets 9–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Four cabinet configuration 9–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with four Horizonmacro cabinets 9–17. . . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with four M-Cell6 cabinets 9–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Macrocell RF configurations 9–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview of configuration diagrams 9–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Horizonmacro cabinets 9–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-Cell6 cabinets 9–35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-Cell2 cabinets 9–98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-Cellarenamacro enclosure 9–107. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Microcell RF configuration 9–108. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-Cellarena enclosure 9–108. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 10Previous BSC planning steps and rules i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter overview 10–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction 10–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC planning overview 10–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction 10–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Outline of planning steps 10–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .



Determining the RSLs required 10–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 10–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 10–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Standard traffic model 10–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Non-standard traffic model 10–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC to BTS E1 interconnect planning actions 10–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC to BTS T1 interconnect planning actions 10–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculate the number of LCFs for RSL processing 10–13. . . . . . . . . . . . . . . . . . . . . . . . . Assigning BTSs to LCFs 10–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Generic processor (GPROC, GPROC2) 10–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 10–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC functions and types 10–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC types 10–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 10–23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC planning actions (GSR3) 10–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC planning actions (GSR2 and earlier) 10–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cell broadcast link 10–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OMF GPROC required 10–27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Code storage facility processor 10–27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC redundancy 10–28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Transcoding 10–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 10–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GDP/XCDR planning considerations 10–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T1 conversion 10–30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning actions transcoding at the BSC 10–31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .








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Chapter 11Previous generation BTS planning and equipment descriptions i. . . . . . . . Chapter overview 11–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction 11–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BTS planning steps and rules 11–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Outline of planning steps 11–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Control channel calculations 11–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Calculations for determining BTS GPROC, GPROC2 requirements 11–7. . . . . . . . . . . . . . . . Introduction 11–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Call processing functions 11–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC, GPROC2 management 11–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC, GPROC2 planning 11–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BTS shelf configurations 11–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Shelf configurations for typical call mix 11–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Shelf configurations for border location area call mix 11–12. . . . . . . . . . . . . . . . . . . . . . .

BTS equipment cabinets 11–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cabinet planning actions 11–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Receiver front end 11–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RFE in cabinet types EG, FG and BTS6 11–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RFE in cabinet types AG, BG and DG 11–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Distributing Rx signals between multiple cabinets 11–15. . . . . . . . . . . . . . . . . . . . . . . . . . RFE planning actions 11–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Transmit combiner shelf 11–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transmit combining equipment 11–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 11–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transmit combiner shelf planning actions 11–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Duplexer 11–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 11–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Duplexer planning actions 11–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Carrier equipment (DRCU/SCU/TCU, DRIM, DRIX) 11–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 11–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Carrier equipment planning actions 11–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .



Generic processor (GPROC, GPROC2) 11–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 11–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC, GPROC2 planning actions 11–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Timeslot switch (TSW) 11–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 11–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSW planning actions 11–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .




Local area extender (LANX) 11–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 11–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LANX planning actions 11–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Digital radio interface extender (DRIX3c) 11–31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 11–31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DRIX planning actions 11–31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GSM-001-103

14th Apr 00xvi System Information: BSS Equipment Planning




BTS RF configurations 11–34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Typical BTS configurations 11–35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BTS configuration 11–35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TopCell BTS configuration 11–36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Single cabinet RF configurations 11–37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Single cabinet, single DRCU/SCU without diversity 11–37. . . . . . . . . . . . . . . . . . . . . . . . Single cabinet, single DRCU/SCU with diversity 11–39. . . . . . . . . . . . . . . . . . . . . . . . . . . Single cabinet, five DRCU/SCUs with combining 11–40. . . . . . . . . . . . . . . . . . . . . . . . . . Single cabinet, six DRCU/SCUs with combining and diversity 11–42. . . . . . . . . . . . . . . Single cabinet, multiple antennas 11–45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Single cabinet, multiple antennas with diversity 11–47. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Multiple cabinet RF configurations 11–49. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Multiple cabinet, single antenna, four DRCU/SCUs 11–49. . . . . . . . . . . . . . . . . . . . . . . . Multiple cabinet, single antenna, ten DRCU/SCUs 11–51. . . . . . . . . . . . . . . . . . . . . . . . . Multiple cabinet, multiple antenna 11–53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Six sector configuration 11–54. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Six–sector BTS6 configuration 11–56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Index I–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GSM-001-103 Issue status of this manual


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Issue status of this manual

Introduction

The following shows the issue status of this manual since it was first released.

Versioninformation

The following lists the versions of this manual in order of manual issue:

Manualissue

Date ofissue

Remarks

O 30th Jun 94 Original issue

A 19th Dec 94 Issue A

B 30th Nov 95 Issue B

C 17th Dec 96 Issue C

D 16th Jun 97 Issue D – (also supersedes 68P02900W31-B)

E 2nd Mar 98 Issue E – includes GSM Software Release 3

F 1st Dec 98 Issue F – includes GSM Software Release 4

G 15th Apr 00 Issue G – includes GSM Software Release 4.1(1.6.1.3)

Resolution ofService Requests

The following Service Requests are now resolved in this manual:

ServiceRequest

GMRNumber

Remarks

N/A N/A

GSM-001-103General information



General information

Important notice

If this manual was obtained when you attended a Motorola training course, it will not beupdated or amended by Motorola. It is intended for TRAINING PURPOSES ONLY. If itwas supplied under normal operational circumstances, to support a major softwarerelease, then corrections will be supplied automatically by Motorola in the form ofGeneral Manual Revisions (GMRs).

Purpose

Motorola Global System for Mobile Communications (GSM) manuals are intended toinstruct and assist personnel in the operation, installation and maintenance of theMotorola GSM equipment and ancillary devices. It is recommended that all personnelengaged in such activities be properly trained by Motorola.

Failure to comply with Motorola’s operation, installation and maintenanceinstructions may, in exceptional circumstances, lead to serious injury or death.

WARNING

These manuals are not intended to replace the system and equipment training offered byMotorola, although they can be used to supplement and enhance the knowledge gainedthrough such training.

About thismanual

The manual contains information about planning a GSM network; using the Horizonrange, BSC/RXCDR, Scaleable OMC equipments and the GPRS Packet Control Unit.

The information in this manual will help you to:

� Identify the main effects of propagation on GSM frequencies.

� Calculate the power budget to balance a cellular system.

� Identify sources of interference.

� Understand the importance of the carrier to interference ratio.

� Determine the viable frequency re-use scheme.

� Understand the impact of microcellular equipment.

� Calculate the required number of traffic channels per cell.

� Calculate the required number of CCCHs per cell.

� Calculate the required number of SDCCHs per cell.

� Determine the hardware requirements for the Horizon range of equipment.

� Understand the network topology as utilized within a GSM network.

� Determine the BSC hardware requirements for a given GSM network plan.

� Determine the XCDR hardware requirements for a given GSM network plan.

� Produce a BSS sub-system plan for a network, given various system parameters.

GSM-001-103 General information


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Cross references

Throughout this manual, cross references are made to the chapter numbers and sectionnames. The section name cross references are printed bold in text.

This manual is divided into uniquely identified and numbered chapters that, in turn, aredivided into sections. Sections are not numbered, but are individually named at the top ofeach page, and are listed in the table of contents.

Text conventions

The following conventions are used in the Motorola GSM manuals to represent keyboardinput text, screen output text and special key sequences.

Input

Characters typed in at the keyboard are shown like this.

Output

Messages, prompts, file listings, directories, utilities, and environmentalvariables that appear on the screen are shown like this.

Special key sequences

Special key sequences are represented as follows:

CRTL–c Press the Control and c keys at the same time.

ALT–f Press the Alt and f keys at the same time.

| Press the pipe symbol key.

CR or RETURN Press the Return (Enter) key. The Return key isidentified with the ↵ symbol on both the X terminal andthe SPARCstation keyboards. The SPARCstationkeyboard Return key is also identified with the wordReturn.

GSM-001-103First aid in case of electric shock



First aid in case of electric shock

Warning

Do not touch the victim with your bare hands until the electric circuit isbroken.Switch off. If this is not possible, protect yourself with dry insulatingmaterial and pull or push the victim clear of the conductor.

WARNING

Artificialrespiration

In the event of an electric shock it may be necessary to carry out artificial respiration.Send for medical assistance immediately.

Burns treatment

If the patient is also suffering from burns, then, without hindrance to artificial respiration,carry out the following:

1. Do not attempt to remove clothing adhering to the burn.

2. If help is available, or as soon as artificial respiration is no longer required, coverthe wound with a dry dressing.

3. Do not apply oil or grease in any form.

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Reporting safety issues

Introduction

Whenever a safety issue arises, carry out the following procedure in all instances.Ensure that all site personnel are familiar with this procedure.

Procedure

Whenever a safety issue arises:

1. Make the equipment concerned safe, for example, by removing power.

2. Make no further attempt to tamper with the equipment.

3. Report the problem directly to GSM Customer Network Resolution Centre+44 (0)1793 565444 (telephone) and follow up with a written report by fax+44 (0)1793 430987 (fax).

4. Collect evidence from the equipment under the guidance of the Customer NetworkResolution Centre.

GSM-001-103Warnings and cautions



Warnings and cautions

Introduction

The following describes how warnings and cautions are used in this manual and in allmanuals of the Motorola GSM manual set.

Warnings

Definition

A warning is used to alert the reader to possible hazards that could cause loss of life,physical injury, or ill health. This includes hazards introduced during maintenance, forexample, the use of adhesives and solvents, as well as those inherent in the equipment.

Example and format

Do not look directly into fibre optic cables or optical data in/out connectors.Laser radiation can come from either the data in/out connectors orunterminated fibre optic cables connected to data in/out connectors.

WARNING

Cautions

Definition

A caution means that there is a possibility of damage to systems, or individual items ofequipment within a system. However, this presents no danger to personnel.

Example and format

Do not use test equipment that is beyond its calibration due date when testingMotorola base stations.

CAUTION

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General warnings

Introduction

Observe the following warnings during all phases of operation, installation andmaintenance of the equipment described in the Motorola GSM manuals. Failure tocomply with these warnings, or with specific warnings elsewhere in the Motorola GSMmanuals, violates safety standards of design, manufacture and intended use of theequipment. Motorola assumes no liability for the customer’s failure to comply with theserequirements.

Warning labelsPersonnel working with or operating Motorola equipment must comply with any warninglabels fitted to the equipment. Warning labels must not be removed, painted over orobscured in any way.

Specificwarnings

Warnings particularly applicable to the equipment are positioned on the equipment andwithin the text of this manual. These must be observed by all personnel at all times whenworking with the equipment, as must any other warnings given in text, on the illustrationsand on the equipment.

High voltageCertain Motorola equipment operates from a dangerous high voltage of 230 V ac singlephase or 415 V ac three phase mains which is potentially lethal. Therefore, the areaswhere the ac mains power is present must not be approached until the warnings andcautions in the text and on the equipment have been complied with.

To achieve isolation of the equipment from the ac supply, the mains input isolator mustbe set to off and locked.

Within the United Kingdom (UK) regard must be paid to the requirements of theElectricity at Work Regulations 1989. There may also be specific country legislationwhich need to be complied with, depending on where the equipment is used.

RF radiationHigh RF potentials and electromagnetic fields are present in the base station equipmentwhen in operation. Ensure that all transmitters are switched off when any antennaconnections have to be changed. Do not key transmitters connected to unterminatedcavities or feeders.

Refer to the following standards:

� ANSI IEEE C95.1-1991, IEEE Standard for Safety Levels with Respect to HumanExposure to Radio Frequency Electromagnetic Fields, 3kHz to 300GHz.

� CENELEC 95 ENV 50166-2, Human Exposure to Electromagnetic Fields HighFrequency (10kHz to 300GHz).

Laser radiationDo not look directly into fibre optic cables or optical data in/out connectors. Laserradiation can come from either the data in/out connectors or unterminated fibre opticcables connected to data in/out connectors.

GSM-001-103General warnings



Liftingequipment

When dismantling heavy assemblies, or removing or replacing equipment, the competentresponsible person must ensure that adequate lifting facilities are available. Whereprovided, lifting frames must be used for these operations. When equipments have to bemanhandled, reference must be made to the Manual Handling of Loads Regulations1992 (UK) or to the relevant manual handling of loads legislation for the country in whichthe equipment is used.

Do not ...... substitute parts or modify equipment.

Because of the danger of introducing additional hazards, do not install substitute parts orperform any unauthorized modification of equipment. Contact Motorola if in doubt toensure that safety features are maintained.

Battery supplies

Do not wear earth straps when working with standby battery supplies.

Toxic material

Certain Motorola equipment incorporates components containing the highly toxic materialBeryllium or its oxide Beryllia or both. These materials are especially hazardous if:

� Beryllium materials are absorbed into the body tissues through the skin, mouth, ora wound.

� The dust created by breakage of Beryllia is inhaled.

� Toxic fumes are inhaled from Beryllium or Beryllia involved in a fire.

See the Beryllium health and safety precautions section for further information.

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Human exposure to radio frequency energy (PCS1900 only)

IntroductionThis equipment is designed to generate and radiate radio frequency (RF) energy. Itshould be installed and maintained only by trained technicians. Licensees of the FederalCommunications Commission (FCC) using this equipment are responsible for insuringthat its installation and operation comply with FCC regulations designed to limit humanexposure to RF radiation in accordance with the American National Standards InstituteIEEE Standard C95.1-1991, IEEE Standard for Safety Levels with Respect to HumanExposure to Radio Frequency Electromagnetic Fields, 3kHz to 300GHz.

DefinitionsThis standard establishes two sets of maximum permitted exposure limits, one forcontrolled environments and another, that allows less exposure, for uncontrolledenvironments. These terms are defined by the standard, as follows:

Uncontrolled environment

Uncontrolled environments are locations where there is the exposure of individuals whohave no knowledge or control of their exposure. The exposures may occur in livingquarters or workplaces where there are no expectations that the exposure levels mayexceed those shown for uncontrolled environments in the table of maximum permittedexposure ceilings.

Controlled environmentControlled environments are locations where there is exposure that may be incurred bypersons who are aware of the potential for exposure as a concomitant of employment, byother cognizant persons, or as the incidental result of transient passage through areaswhere analysis shows the exposure levels may be above those shown for uncontrolledenvironments but do not exceed the values shown for controlled environments in thetable of maximum permitted exposure ceilings.

Maximumpermittedexposures

The maximum permitted exposures prescribed by the standard are set in terms ofdifferent parameters of effects, depending on the frequency generated by the equipmentin question. At the frequency range of this Personal Communication System equipment,1930-1970MHz, the maximum permitted exposure levels are set in terms of powerdensity, whose definition and relationship to electric field and magnetic field strengths aredescribed by the standard as follows:

Power density (S)

Power per unit area normal to the direction of propagation, usually expressed in units ofwatts per square metre (W/m2) or, for convenience, units such as milliwatts per squarecentimetre (mW/cm2). For plane waves, power density, electric field strength (E) andmagnetic field strength (H) are related by the impedance of free space, 377 ohms. Inparticular,

� ��

��

where E and H are expressed in units of V/m and A/m, respectively, and S in units ofW/m2. Although many survey instruments indicate power density units, the actualquantities measured are E or E2 or H or H2.

GSM-001-103Human exposure to radio frequency energy (PCS1900 only)



Maximumpermittedexposureceilings

Within the frequency range, the maximum permitted exposure ceiling for uncontrolledenvironments is a power density (mW/cm2) that equals f/1500, where f is the frequencyexpressed in MHz, and measurements are averaged over a period of 30 minutes. Themaximum permitted exposure ceiling for controlled environments, also expressed inmW/cm2, is f/300 where measurements are averaged over 6 minutes. Applying theseprinciples to the minimum and maximum frequencies for which this equipment is intendedto be used yields the following maximum permitted exposure levels:

Uncontrolled Environment Controlled Environment

1930MHz 1970MHz 1930MHz 1970MHz

Ceiling 1.287mW/cm2 1.313mW/cm2 6.433mW/cm2 6.567mW/cm2

If you plan to operate the equipment at more than one frequency, compliance should beassured at the frequency which produces the lowest exposure ceiling (among thefrequencies at which operation will occur).

Licensees must be able to certify to the FCC that their facilities meet the above ceilings.Some lower power PCS devices, 100 milliwatts or less, are excluded from demonstratingcompliance, but this equipment operates at power levels orders of magnitude higher, andthe exclusion is not applicable.

Whether a given installation meets the maximum permitted exposure ceilings depends, inpart, upon antenna type, antenna placement and the output power to which thisequipment is adjusted. The following example sets forth the distances from the antennato which access should be prevented in order to comply with the uncontrolled andcontrolled environment exposure limits as set forth in the ANSI IEEE standards andcomputed above.

GSM-001-103 Human exposure to radio frequency energy (PCS1900 only)


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11

Examplecalculation

For a base station with the following characteristics, what is the minimum distance fromthe antenna necessary to meet the requirements of an uncontrolled environment?

Transmit frequency 1930MHz

Base station cabinet output power, P +39.0dBm (8 watts)

Antenna feeder cable loss, CL 2.0dB

Antenna input power Pin P–CL = +39.0–2.0 = +37.0dB (5watts)

Antenna gain, G 16.4dBi (43.65)

Using the following relationship:

� ��

��

Where W is the maximum permissible power density in W/m2 and r is the safe distancefrom the antenna in metres, the desired distance can be calculated as follows:

� ��

��

��

��

where W = 12.87 W/m2 was obtained from table listed above and converting frommW/cm2 to W/m2.

The above result applies only in the direction of maximum radiation of theantenna. Actual installations may employ antennas that have defined radiationpatterns and gains that differ from the example set forth above. The distancescalculated can vary depending on the actual antenna pattern and gain.

NOTE

Power densitymeasurements

While installation calculations such as the above are useful and essential in planning anddesign, validation that the operating facility using this equipment actually complies willrequire making power density measurements. For information on measuring RF fields fordetermining compliance with ANSI IEEE C95.1-1991, see IEEE Recommended Practicefor the Measure of Potentially Hazardous Electromagnetic Fields - RF and Microwave,IEEE Std C95.3-1991. Copies of IEEE C95.1-1991 and IEEE C95.3-1991 may bepurchased from the Institute of Electrical and Electronics Engineers, Inc., Attn:Publication Sales, 445 Hoes Lane, P.O. Box 1331, Piscattaway, NJ 08855-1331,(800) 678-IEEE or from ANSI, (212) 642-4900. Persons responsible for installation of thisequipment are urged to consult these standards in determining whether a giveninstallation complies with the applicable limits.

Other equipmentWhether a given installation meets ANSI standards for human exposure to radiofrequency radiation may depend not only on this equipment but also on whether theenvironments being assessed are being affected by radio frequency fields from otherequipment, the effects of which may add to the level of exposure. Accordingly, the overallexposure may be affected by radio frequency generating facilities that exist at the timethe licensee’s equipment is being installed or even by equipment installed later.Therefore, the effects of any such facilities must be considered in site selection and indetermining whether a particular installation meets the FCC requirements.

GSM-001-103Beryllium health and safety precautions



Beryllium health and safety precautions

Introduction

Beryllium (Be), is a hard silver/white metal. It is stable in air, but burns brilliantly inOxygen.

With the exception of the naturally occurring Beryl ore (Beryllium Silicate), all Berylliumcompounds and Beryllium metal are potentially highly toxic.

Health issues

Beryllium Oxide is used within some components as an electrical insulator. Captive withinthe component it presents no health risk whatsoever. However, if the component shouldbe broken open and the Beryllium Oxide, which is in the form of dust, released, thereexists the potential for harm.

Inhalation

Inhalation of Beryllium Oxide can lead to a condition known as Berylliosis, the symptomsof Berylliosis are similar to Pneumonia and may be identified by all or any of thefollowing:

Mild poisoning causes fever, shortness of breath, and a cough that producesyellow/green sputum, or occasionally bloodstained sputum. Inflammation of the mucousmembranes of the nose, throat, and chest with discomfort, possibly pain, and difficultywith swallowing and breathing.

Severe poisoning causes chest pain and wheezing which may progress to severeshortness of breath due to congestion of the lungs. Incubation period for lung symptomsis 2-20 days.

Exposure to moderately high concentrations of Beryllium in air may produce a veryserious condition of the lungs. The injured person may become blue, feverish with rapidbreathing and raised pulse rate. Recovery is usual but may take several months. Therehave been deaths in the acute stage.

Chronic response. This condition is more truly a general one although the lungs aremainly affected. There may be lesions in the kidneys and the skin. Certain featuressupport the view that the condition is allergic. There is no relationship between thedegree of exposure and the severity of response and there is usually a time lag of up to10 years between exposure and the onset of the illness. Both sexes are equallysusceptible. The onset of the illness is insidious but only a small number of exposedpersons develop this reaction.

First aid

Seek immediate medical assistance. The casualty should be removed immediately fromthe exposure area and placed in a fresh air environment with breathing supported withOxygen where required. Any contaminated clothing should be removed. The casualtyshould be kept warm and at rest until medical aid arrives.

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Skin contact

Possible irritation and redness at the contact area. Persistent itching and blisterformations can occur which usually resolve on removal from exposure.

First aid

Wash area thoroughly with soap and water. If skin is broken seek immediate medicalassistance.

Eye contact

May cause severe irritation, redness and swelling of eyelid(s) and inflammation of themucous membranes of the eyes.

First aid

Flush eyes with running water for at least 15 minutes. Seek medical assistance as soonas possible.

Handlingprocedures

Removal of components from printed circuit boards (PCBs) is to take place only atMotorola approved repair centres.

The removal station will be equipped with extraction equipment and all other protectiveequipment necessary for the safe removal of components containing Beryllium Oxide.

If during removal a component is accidently opened, the Beryllium Oxide dust is to bewetted into a paste and put into a container with a spatula or similar tool. The spatula/toolused to collect the paste is also to be placed in the container. The container is then to besealed and labelled. A suitable respirator is to be worn at all times during this operation.

Components which are successfully removed are to be placed in a separate bag, sealedand labelled.

Disposalmethods

Beryllium Oxide or components containing Beryllium Oxide are to be treated ashazardous waste. All components must be removed where possible from boards and putinto sealed bags labelled Beryllium Oxide components. These bags must be given to thesafety and environmental adviser for disposal.

Under no circumstances are boards or components containing Beryllium Oxide to be putinto the general waste skips or incinerated.

Product life cycleimplications

Motorola GSM and analogue equipment includes components containing Beryllium Oxide(identified in text as appropriate and indicated by warning labels on the equipment).These components require specific disposal measures as indicated in the preceding(Disposal methods) paragraph. Motorola will arrange for the disposal of all suchhazardous waste as part of its Total Customer Satisfaction philosophy and will arrangefor the most environmentally ‘friendly’ disposal available at that time.

GSM-001-103General cautions



General cautions

Introduction

Observe the following cautions during operation, installation and maintenance of theequipment described in the Motorola GSM manuals. Failure to comply with thesecautions or with specific cautions elsewhere in the Motorola GSM manuals may result indamage to the equipment. Motorola assumes no liability for the customer’s failure tocomply with these requirements.

Caution labels

Personnel working with or operating Motorola equipment must comply with any cautionlabels fitted to the equipment. Caution labels must not be removed, painted over orobscured in any way.

Specific cautions

Cautions particularly applicable to the equipment are positioned within the text of thismanual. These must be observed by all personnel at all times when working with theequipment, as must any other cautions given in text, on the illustrations and on theequipment.

Fibre optics

The bending radius of all fibre optic cables must not be less than 30 mm.

Static discharge

Motorola equipment contains CMOS devices that are vulnerable to static discharge.Although the damage caused by static discharge may not be immediately apparent,CMOS devices may be damaged in the long term due to static discharge caused bymishandling. Wear an approved earth strap when adjusting or handling digital boards.

See Devices sensitive to static for further information.

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Devices sensitive to static

Introduction

Certain metal oxide semiconductor (MOS) devices embody in their design a thin layer ofinsulation that is susceptible to damage from electrostatic charge. Such a charge appliedto the leads of the device could cause irreparable damage.

These charges can be built up on nylon overalls, by friction, by pushing the hands intohigh insulation packing material or by use of unearthed soldering irons.

MOS devices are normally despatched from the manufacturers with the leads shortedtogether, for example, by metal foil eyelets, wire strapping, or by inserting the leads intoconductive plastic foam. Provided the leads are shorted it is safe to handle the device.

Special handlingtechniques

In the event of one of these devices having to be replaced observe the followingprecautions when handling the replacement:

� Always wear an earth strap which must be connected to the electrostatic point(ESP) on the equipment.

� Leave the short circuit on the leads until the last moment. It may be necessary toreplace the conductive foam by a piece of wire to enable the device to be fitted.

� Do not wear outer clothing made of nylon or similar man made material. A cottonoverall is preferable.

� If possible work on an earthed metal surface. Wipe insulated plastic work surfaceswith an anti-static cloth before starting the operation.

� All metal tools should be used and when not in use they should be placed on anearthed surface.

� Take care when removing components connected to electrostatic sensitivedevices. These components may be providing protection to the device.

When mounted onto printed circuit boards (PCBs), MOS devices are normally lesssusceptible to electrostatic damage. However PCBs should be handled with care,preferably by their edges and not by their tracks and pins, they should be transferreddirectly from their packing to the equipment (or the other way around) and never leftexposed on the workbench.

GSM-001-103Motorola GSM manual set



Motorola GSM manual set

IntroductionThe following manuals provide the information needed to operate, install and maintain theMotorola GSM and GSM Packet Radio Service (GPRS) equipment.

Generic GSMmanuals

The following are the generic manuals in the GSM manual set, these manuals arerelease dependent:

Classificationnumber Name Order number

GSM-100-101 System Information: General 68P02901W01. . . . . . . . . . . . . . . . . . . GSM-100-201 Operating Information: GSM System Operation 68P02901W14. . . GSM-100-202 Operating Information: OMC-R System

Administration 68P02901W19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GSM-100-311 Technical Description: OMC-R in a GSM System 68P02901W31. . GSM-100-313 Technical Description: OMC-R Database Schema 68P02901W34. GSM-100-320 Technical Description: BSS Implementation 68P02901W36. . . . . . . GSM-100-321 Technical Description: BSS Command Reference 68P02901W23. GSM-100-403 Installation & Configuration: GSM System

Configuration 68P02901W17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GSM-100-423 Installation & Configuration: BSS Optimization 68P02901W43. . . . GSM-100-413 Installation & Configuration: OMC-R Clean Install 68P02901W47. . GSM-100-501 Maintenance Information: Alarm Handling at

the OMC-R 68P02901W26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GSM-100-520 Maintenance Information: BSS Timers 68P02901W58. . . . . . . . . . . GSM-100-521 Maintenance Information: Device State Transitions 68P02901W57GSM-100-523 Maintenance Information: BSS Field

Troubleshooting 68P02901W51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GSM-100-503 Maintenance Information: GSM Statistics

Application 68P02901W56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GSM-100-721 Software Release Notes: BSS/RXCDR 68P02901W72. . . . . . . . . . GSM-100-712 Software Release Notes: OMC-R System 68P02901W74. . . . . . . .

Related GSMmanuals

The following are related Motorola GSM manuals:


GSM-001-103 System Information: BSS Equipment Planning 68P02900W21. . . . GSM-002-103 System Information: DataGen 68P02900W22. . . . . . . . . . . . . . . . . . GSM-002-703 Software Release Notes: DataGen 68P02900W76. . . . . . . . . . . . . . GSM-005-103 System Information: GSM Advance Operational

Impact 68P02900W25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GSM-008-403 Installation & Configuration: Network Health Analyst 68P02900W36GSM-008-703 Software Release Notes: Network Health Analyst 68P02900W77. GSM-006-202 Operating Information: OMC-R System

Administration (OSI) 68P02901W10. . . . . . . . . . . . . . . . . . . . . . . . . . GSM-006-413 Installation & Configuration: OSI Clean Install 68P02901W39. . . . . GSM-006-712 Software Release Notes: OMC-R OSI System 68P02901W70. . . .

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Generic GPRSmanuals

The following are the generic manuals in the GPRS manual set, these manuals arerelease dependent:


GPRS-300-101 System Information: GPRS Overview 68P02903W01. . . . . . . . . . . . GPRS-300-202 Operating Information: OMC-G System

Administration 68P02903W03. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPRS-300-222 Operating Information: GSN System Administration 68P02903W37GPRS-300-311 Technical Description: OMC-G in a GPRS System 68P02903W29. GPRS-300-313 Technical Description: OMC-G Database Schema 68P02903W46. GPRS-300-321 Technical Description: GSN Command Reference 68P02903W18. GPRS-300-423 Installation & Configuration: GSN Clean Install 68P02903W47. . . . GPRS-300-413 Installation & Configuration: OMC-G Clean Install 68P02903W04. GPRS-300-501 Maintenance Information: Alarm Handling at

the OMC-G 68P02903W19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPRS-300-503 Maintenance Information: GSN Statistics

Application 68P02903W20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPRS-300-722 Software Release Notes: GSN System 68P02903W76. . . . . . . . . . GPRS-300-712 Software Release Notes: OMC-G System 68P02903W70. . . . . . . .

Related GPRSmanuals

The following are related Motorola GPRS manuals:

GPRS-001-103 System Information: GPRS Equipment Planning 68P02903W02. . GPRS-005-103 System Information: GSN Advance Operational

Impact 68P02903W38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GSM-001-103Motorola GSM manual set



BSS servicemanuals

The following are the Motorola Base Station service manuals, these manuals are notrelease dependent. The internal organization and makeup of service manual sets mayvary, they may consist of from one to four separate manuals, but they can all be orderedusing the overall catalogue number shown below:


GSM-100-020 Service Manual: BTS 68P02901W37. . . . . . . . . . . . . . . . . . . . . . . . . . GSM-100-030 Service Manual: BSC/RXCDR 68P02901W38. . . . . . . . . . . . . . . . . . GSM-105-020 Service Manual: M-Cell2 68P02901W75. . . . . . . . . . . . . . . . . . . . . . . GSM-106-020 Service Manual: M-Cell6 68P02901W85. . . . . . . . . . . . . . . . . . . . . . . GSM-201-020 Service Manual: M-Cellcity and M-Cellcity+ 68P02901W95. . . . . . . GSM-202-020 Service Manual: M-Cellaccess 68P02901W65. . . . . . . . . . . . . . . . . . GSM-203-020 Service Manual: Horizonmicro 68P02902W36. . . . . . . . . . . . . . . . . . GSM-206-020 Service Manual: Horizoncompact 68P02902W15. . . . . . . . . . . . . . . GSM-205-020 Service Manual: Horizonmacro Indoor 68P02902W06. . . . . . . . . . . GSM-204-020 Service Manual: Horizonmacro Outdoor 68P02902W12. . . . . . . . . . GSM-207-020 Service Manual: Horizonoffice 68P02902W46. . . . . . . . . . . . . . . . . . GSM-208-020 Service Manual: Horizonmacro 12 Carrier Outdoor 68P02902W66GSM-101-SERIES ExCell4 Documentation Set 68P02900W50. . . . . . . . . . . . . . . . . . . . GSM-103-SERIES ExCell6 Documentation Set 68P02900W70. . . . . . . . . . . . . . . . . . . . GSM-102-SERIES TopCell Documentation Set (GSM900) 68P02901W80. . . . . . . . . . . GSM-104-SERIES TopCell Documentation Set (DCS1800) 68P02902W80. . . . . . . . . . GSM-200-SERIES M-Cellmicro Documentation Set 68P02901W90. . . . . . . . . . . . . . . . .

GPRS servicemanuals

The following are the Motorola GPRS service manuals, these manuals include thePacket Control Unit (PCU) service manual which becomes part of the BSS for GPRS:


GPRS-301-020 Service Manual:GPRS Support Nodes (GSN) 68P02903W05. . . . . GPRS-302-020 Service Manual: Packet Control Unit (PCU) 68P02903W10. . . . . . .

Classificationnumber

The classification number is used to identify the type and level of a manual. For example,manuals with the classification number GSM-100-2xx contain operating information.

Order number

The Motorola 68P order (catalogue) number is used to order manuals.

Orderingmanuals

All orders for Motorola manuals must be placed with your Motorola Local Office orRepresentative. Manuals are ordered using the order (catalogue) number. Remember,specify the manual issue required by quoting the correct suffix letter.

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GMR amendment

Introduction toGMRs

Changes to a manual that occur after the printing date are incorporated into the manualusing General Manual Revisions (GMRs). GMRs are issued to correct Motorola manualsas and when required. A GMR has the same identity as the target manual. Each GMR isidentified by a number in a sequence that starts at 01 for each manual at each issue.GMRs are issued in the form of loose leaf pages, with a pink instruction sheet on thefront.

GMR procedure

When a GMR is received, check on the GMR amendment record page of this manualthat previous GMRs, if any, have been incorporated. If not, contact your administrator orMotorola Local Office to obtain the missing GMRs. Remove and replace pages in thismanual, as detailed on the GMR pink instruction sheet.

GSM-001-103GMR amendment record



GMR amendment record

Instructions

When a GMR is inserted in this manual, the amendment record below must be filled in torecord the insertion. Retain the pink instruction sheet that accompanies each GMR andinsert it in a suitable place in this manual for future reference.

Amendmentrecord

Record the insertion of GMRs in this manual in the following table:

GMR number Incorporated by (signature) Date

01

02

03

04

05

06

07

08

09

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25


68P02900W21-G


i

Chapter 1

Introduction

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iii

Chapter 1Introduction i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter overview 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to BSS planning 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Manual overview 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Contents 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BSS equipment overview 1–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . System architecture 1–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . System components 1–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Radio channel units 1–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BSS features 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Features that affect planning 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Diversity 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Frequency hopping 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Short message service, cell broadcast 1–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Code storage facility processor 1–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PCU for GPRS upgrade 1–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BSS planning overview 1–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 1–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Initial information required 1–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning methodology 1–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GSM-001-103



GSM-001-103 Chapter overview


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1–1

Chapter overview

Introduction toBSS planning

This chapter provides an overview of this manual and the various elements of a BSS andthe BSS planning methodology. This chapter contains:

� Manual overview.

� BSS equipment overview.

– An overview of the BSS system architecture.

– An overview of the BSS system components.

� BSS features.

– A description of those BSS features that can affect BSS planning.

� BSS planning overview.

– A list of the information required before planning can begin.

– An overview of the BSS planning methodology.

GSM-001-103Manual overview

14th Apr 001–2 System Information: BSS Equipment Planning


Manual overview

Introduction

The manual contains information about planning a GSM network; utilizing a combinationof BTS and M-Cell BTS equipment.

Contents

The manual contains the following chapters:

� Chapter 1: Introduction

This chapter provides an overview of the various elements of a BSS and the BSSplanning methodology.

� Chapter 2: Transmission systems

This chapter provides an overview of the transmission systems used in GSM.

� Chapter 3: BSS cell planning

This chapter states the requirements and procedures used in producing a BSS cellsite plan.

� Chapter 4: BTS planning steps and rules

This chapter provides the planning steps and rules for the BTS, including ExCell,TopCell and the M-Cell range of equipments.

� Chapter 5: BSC planning steps and rules

This chapter provides the planning steps and rules for the BSC.

� Chapter 6: RXCDR planning steps and rules

This chapter provides the planning steps and rules for the RXCDR.

� Chapter 7: OMC-R planning steps and rules

This chapter provides the planning steps and rules for the OMC-R.

� Chapter 8: Planning exercise

This chapter provides a planning exercise designed to illustrate the use of the rulesand formulae provided in Chapter 3, Chapter 4, Chapter 5, Chapter 6, andChapter 7.

� Chapter 9: Standard configuration descriptions

This chapter provides diagrams of the logical interconnections of the componentsin various standard BSS and BTS site configurations, including Horizonmacro andthe M-Cell range.

� Chapter 10: Previous BSC planning steps and rules

This chapter (included for reference only) provides the planning steps and rulesfor the BSC up to software release GSR3.

� Chapter 11: Previous generation BTS planning steps and rules

This chapter (included for reference only) provides the planning steps and rulesfor the BSC up to software release GSR3.

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BSS equipment overview

Systemarchitecture

The architecture of the Motorola Base Station System (BSS) is extremely versatile, andallows many possible configurations for a given system. The BSS is a combination ofdigital and RF equipment that communicates with the Mobile Switching Centre (MSC),the Operations and Maintenance Centre Radio (OMC-R), and the Mobile Stations (MS)as shown in Figure 1-1.

BSC

BTS 1 BTS 5 BTS n

BSS

��

MSCLRs

OMC–R

A INTERFACE

O & M

MS MS ��

AIR INTERFACE

ABIS INTERFACE

BTS 8

BTS 2

BTS 3

BTS 4

BTS 6

BTS 7

BSSRXCDR

MS MS ��

NOTE: 1. THE OMC-R CAN BE LINKED THROUGH THE RXCDR AND/OR TO THE BSS/BSC DIRECT.2. THE EXAMPLE OF MULTIPLE MSs CONNECTED TO BTS 4 AND BTS 7, CAN BE ASSUMED

TO BE CONNECTED TO ALL OTHER BTSs SHOWN.

PCU

Figure 1-1 BSS block diagram

GSM-001-103BSS equipment overview



Systemcomponents

The BSS can be divided into a Base Site Controller (BSC), and one or more BaseTransceiver Station (BTS). These can be in-building BTS cabinets or externally locatedExCell, TopCell, M-Cell cabinets or M-Cell enclosures.

The Transcoder (XCDR) or Generic Digital Processor (GDP) provides 4:1 multiplexing ofthe traffic and can be located at the BSC or between the BSC and MSC. When theXCDR/GDP is located at the MSC it reduces the number of communication links to theBSC. When transcoding is not performed at the BSC, the XCDR is referred to as aremote transcoder (RXCDR). The RXCDR is part of the BSS but may serve more thanone BSS.

Radio channelunits

In the Motorola BTS product line, the radio transmit and receive functions are providedas listed in Table 1-1:

With the exception of the TCU, which is backwardly compatible by switchingfrom TCU to SCU on the front panel, all other radio channel units are onlycompatible with the equipment listed.

NOTE

Table 1-1 Radio channel unit usage

Radio channel unit Where used ...

Diversity Radio Channel Unit (DRCU) BTS4, BTS5, BTS6, TopCell, ExCell

Slim Channel Unit (SCU) BTS4, BTS5, BTS6, TopCell, ExCell

Transceiver Control Unit (TCU) M-Cell6, M-Cell2, BTS6

Picocell Control Unit (PCU) M-Cellaccess

RF Head Horizonoffice

Transceiver Control Unit, micro (TCU-m) M-Cellmicro, M-Cellcity and M-Cellcity+

Dual Transceiver Module (DTRX) M-Cellarena and M-Cellarenamacro

Compact Transceiver Unit (CTU) Horizonmacro

DRCU/SCU

Planning rules for the DRCU and SCU are provided in Chapter 11 of this manual. Thereceivers can support receive diversity.

TCU

Description and planning rules for the TCU is provided in Chapter 4 of this manual. Thereceivers can support receive diversity.

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TCU-m

In M-Cellmicro, M-Cellcity and M-Cellcity+ the radio transmit and receive functions areprovided by a pair of Transceiver Control Unit, micro (TCU-m).

Description and planning rules for the TCU-m are provided in Chapter 10, Chapter 16,and Chapter 4 of this manual. The receivers do not support receive diversity.

DTRX

In M-Cellarena and M-Cellarenamacro the radio transmit and receive functions areprovided by a Dual Transceiver Module (DTRX).

Description and planning rules for the DTRX are provided in Chapter 10 and Chapter 4 ofthis manual. The receivers do not support receive diversity.

PCU

Description and planning rules for the PCU is provided in Chapter 11 and Chapter 4 ofthis manual. The receivers can support receive diversity.

CTU

Description and planning rules for the CTU is provided in Chapter 9 and Chapter 4 of thismanual. The receivers can support receive diversity.

GSM-001-103BSS features



BSS features

Features thataffect planning

This section provides a description of the software features that might affect the requiredequipment, and that should be taken into consideration before planning actualequipment. Check with the appropriate Motorola sales office regarding softwareavailability with respect to these features.

� Diversity.

� Frequency hopping.

� Short message, cell broadcast.

� Code storage facility processor.

� Packet Control Unit (PCU) for General Packet Data Service (GPRS) upgrade.

Diversity

Diversity reception (spatial diversity) at the BTS is obtained by supplying twouncorrelated receive signals to the DRCU/SCU/TCUs. Each DRCU/SCU/TCU includestwo receivers, which independently process the two received signals and combine theresults to produce an output. This results in improved receiver performance whenmultipath propagation is significant and in improved interference protection.

Two Rx antennas are required for each sector. Equivalent overlapping antenna patterns,and sufficient physical separation between the two antennas are required to obtain thenecessary de-correlation.

Frequencyhopping

There are two methods of providing frequency hopping: synthesizer hopping andbaseband hopping. Each method has different hardware requirements.

The main differences are:

� Synthesizer hopping requires the use of wideband (hybrid) combiners for transmitcombining, while baseband hopping does not.

� Baseband hopping requires the use of one DRCU/SCU/TCU for each allocatedfrequency, while synthesizer hopping does not.

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Synthesizer hopping

Synthesizer hopping uses the frequency agility of the DRCU/SCU/TCU to changefrequencies on a timeslot basis for both receive and transmit. The DRCU/SCU/TCUcalculates the next frequency and re-programs its synthesizer to move to the newfrequency. There are three important points to note when using this method of providingfrequency hopping:

� Hybrid combining must be used; cavity combining is not allowed when usingsynthesizer hopping.

� The output power available with the use of the hybrid combiners must beconsistent with coverage requirements.

� It is only necessary to provide as many DRCU/SCU/TCUs as required by thetraffic. Note that one DRCU/SCU/TCU in each sector must be on a fixed frequencyto provide the BCCH carrier.

Baseband hopping

For baseband hopping each DRCU/SCU/TCU operates on preset frequencies in thetransmit direction. Baseband signals for a particular call are switched to a differentDRCU/SCU/TCU at each TDM frame in order to achieve frequency hopping. There arethree important points to note when using this method of providing frequency hopping:

� The number of DRCU/SCU/TCUs must be equal to the number of transmit (orreceive) frequencies required.

� Use of either remote tuning combiners or hybrid combiners is acceptable.

� Frequency redefinition procedures were incomplete in the Phase 1 GSMspecifications; this is addressed in the Phase 2 GSM procedures, but at this timethere are no Phase 2 MSs capable of implementing this. Consequently, calls couldbe dropped, if a single DRCU/SCU/TCU fails, due to the inability to inform theMSs.

Short messageservice, cellbroadcast

The Short Message Service, Cell Broadcast (SMS CB) feature, is a means of unilaterallytransmitting data to MSs on a per cell basis. This feature is provided, by a Cell BroadcastChannel (CBCH). The data originates from either a Cell Broadcast Centre (CBC) orOMC-R (operator-defined messages may be entered using the appropriate MMIcommand). The CBC or OMC-R downloads cell broadcast messages to the BSC,together with indications of the repetition rate, and the number of broadcasts required permessage. The BSC transmits these updates to the appropriate BTSs, which will thenensure that the message is transmitted as requested.

Code storagefacility processor

Beginning with software release 1.3.0.0, the BSS supports a GPROC acting as the CodeStorage Facility Processor (CSFP). The CSFP allows pre-loading of a new softwarerelease while the BSS is operational. When M-Cell BTSs are connected to the BSC, aCSFP is required at the BSC and a second CSFP should be equipped for redundancy asrequired.

If GPROC2 is used this feature will not require additional hardware.

NOTE

GSM-001-103BSS features



PCU for GPRSupgrade

GPRS introduces packet data services (with GSR4.1) and GPRS planning isfundamentally different from the planning of circuit swtiched networks. One of thefundamental reasons for the difference, is that a GPRS network allows the queing of datatraffic instead of blocking a call when a circuit is unavailble. Consequently, the use ofErlang B tables for estimating the number of trunks or timeslots required, is not a validplanning approach for the GPRS packet data provisioning process.

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BSS planning overview

Introduction

A brief overview of the planning process is provided in this section.

Initialinformationrequired

The information required, before planning can begin, can be categorized into three mainareas:

� Traffic model and capacity calculations.

� Category of service.

� Site planning.

Traffic model and capacity calculations

The following information is required to calculate the capacity required:

� Traffic information (Erlangs/BTS) over desired service area.

� Average traffic per site.

� Call duration.

� Number of handovers per call.

� Ratio of location updates to calls.

� Ratio of total pages sent to time in seconds (pages per second).

� Ratio of intra-BSC handovers to all handovers.

� Number of TCHs.

� Ratio of SDCCHs to TCHs.

� Link utilization (for C7 MSC to BSS links).

� SMS utilization (both cell broadcast and point to point).

� Expected (applied and effective) GPRS load.

GSM-001-103BSS planning overview



Category of service

The following information is required to decide what category of service is required:

� Category of service area urban, suburban, or rural:

– Cell configuration in each category, sector against omni.

– Frequency re-use scheme to meet traffic and C/I requirements.

– Number of RF carriers in cell/sector to support traffic.

� Grade of service of the trunks between MSC/BSC, typically Erlang B at 1%.

� Grade of service of the traffic channels (TCH) between MS and BTS, typicallyErlang B at 2%.

� Cell grid plan, a function of:

– Desired grade of service or acceptable level of blockage.

– Typical cell radio link budget.

– Results of field tests.

Site planning

The following information is required to plan each site.

� Where the BSC and BTSs will be located.

� Local restrictions affecting antenna heights, equipment shelters, and so on.

� Number of sites required (RF planning issues).

� Re-use plan (frequency planning) omni or sector:

– Spectrum availability.

– Number of RF carrier frequencies available.

– Antenna type(s) and gain specification.

� Diversity requirement. Diversity doubles the number of Rx antennas andassociated equipment.

� Redundancy level requirements, determined for each item.

� Supply voltage.

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Planningmethodology

A GSM digital cellular system is usually made up of several BSSs. The planning cyclebegins with defining the BSS cell, followed by the BTS(s), then the BSC(s), and finallythe RXCDR(s).

The text that follows provides a brief check-list of the steps in planning a BSS:

1. Choose the configuration, omni or sectored and the frequency re-use scheme thatsatisfies traffic, interference and growth requirements.

2. Plan all BTS sites first:

– Use an appropriate RF planning tool to determine the geographical locationof sites on and the RF parameters of the chosen terrain.

– Determine which equipment affecting features are required at each site. Forexample, diversity or frequency hopping.

– Plan the RF equipment portion and cabinets for each BTS site.

– Plan the digital equipment portion for each BTS site.

3. Plan the BSCs after the BTS sites are configured and determine:

– Sites for each BSC.

– Which BTSs are connected to which BSC.

– How the BTSs are connected to the BSCs.

– Traffic requirements for the BSCs.

– Digital equipment for each BSC site.

– Shelf/cabinets and power requirements for each BSC.

4. Plan the remote transcoder (RXCDR) requirements and, if required, subsequenthardware implementation.

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Chapter 2

Transmission systems

GSM-001-103



GSM-001-103


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iii

Chapter 2Transmission systems i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


BSS interfaces 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Interconnecting the BSC and BTSs 2–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 2–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interconnection rules 2–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Network topology 2–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 2–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Star connection 2–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Daisy chain connection 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Daisy chain planning 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Aggregate Abis 2–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RTF path fault containment 2–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 kbit/s RSL 2–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 kbit/s XBL 2–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BTS concentration 2–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 2–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Key terms 2–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DYNET – new device 2–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Blocking considerations 2–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Emergency call handling 2–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Radio Signalling Link (RSL) planning 2–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Network topologies 2–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Performance issue 2–32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Configuration and compatibility issues 2–32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recommended BTS concentration planning guidelines 2–33. . . . . . . . . . . . . . . . . . . . . Examples 2–35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Managed HDSL on micro BTS 2–41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 2–41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Integrated HDSL interface 2–42. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General HDSL guidelines 2–44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Microcell system planning 2–45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Picocell system planning 2–47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GSM-001-103





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Chapter overview

Introduction

This chapter provides diagrams of the logical interconnections and descriptions of BSSinterconnections.

This chapter contains:

� BSS interfaces.

� BSC to BTS interconnection rules.

� Network topology:

– Star connection.

– Daisy chain connection.

– Aggregate Abis.

– 16 kbit/s RSL.

– 16 kbit/s XBL.

� BTS concentration.

� Managed HDSL on micro BTS:

– Integrated HDSL interface.

– Microcell system planning.

– Picocell system planning.

GSM-001-103BSS interfaces



BSS interfaces

Introduction

Figure 2-1 and Table 2-1 indicate the type of interface, rate(s) and transmission systemsused to convey information around the various parts of the BSS system.

BTS BSC RXCDR

CBC

OMC-R

MS

MSC

Abis interface A interfaceAir interface

X.25(LAPB)

X.25(LAPB)OML

CBL

MTL (C7), XBL (LAPD)OML (X.25)

RSL (LAPD)(LAPDm)

PCU

GDS

Gb OPTION C

Gb OPTION B

SGSN

Gb OPTION A

Figure 2-1 BSS interfaces

Table 2-1 BSS interfaces

Interface From/To Signalling by ... Rate Using ...

Air MS – BTS RACH, SDCCH,SACCH, FACCH

LAPDm

E1/T1 links

Abis (Mobis) BTS – BSC RSL 16/64 kbit/s LAPD

A BSS – MSC MTL (OML, CBL) 64 kbit/s C7

A RXCDR – BSC XBL 16/64 kbit/s LAPD

MSC – OMC-R OML (X.25) 64 kbit/s LAPB

MSC – CBC CBL (X.25) 64 kbit/s LAPB

Gb PCU – SGSN

GDS PCU – BSC

GSM-001-103 Interconnecting the BSC and BTSs


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Interconnecting the BSC and BTSs

Introduction

Network topology is specified in terms of the path(s) between the BSC and the BTSsites. A path is determined by which E1 or T1 circuits, and possible intervening BTSsites are used to provide the connection. Transcoding may be carried out at the BSC orRXCDR.

Interconnectionrules

The following rules must be observed when interconnecting a BSC and BTSs:

� The BSC may share MSI boards between BTSs. When there are two or more E1or T1 circuits, at least two MSIs are recommended for redundancy.

� A minimum of one MSI is required at each BTS.

� There is a maximum of 8, and minimum of 1, signalling links per BTS6 site, eachrequiring one 64 kbit/s timeslot on a E1 or T1 circuit.

� The maximum number of carrier units is determined by available E1 or T1 circuitcapacity. A carrier unit will require two 64 kbit/s timeslots on a E1 or T1 circuit. Ina redundant connection, each carrier unit requires two 64 kbit/s timeslots on twodifferent E1 or T1 circuits.

� At the BSC, one E1 or T1 circuit is required to connect to a daisy chain. If theconnection is a closed loop daisy chain, two E1 or T1 circuits are required. Toprovide redundancy, the two E1 or T1 circuits should be terminated on differentMSIs.

� In a closed loop daisy chain the primary RSLs for all BTS sites should be routed inthe same direction with the secondary RSLs routed in the opposite direction. Theprimary RSL at each BTS site in the daisy chain should always be equipped on themultiple serial interface link (MMS) equipped in CAGE 15 slot 16 port A. Thesecondary RSL at each BTS site should be equipped on the MMS equipped ineither cage 15 slot 16 port B or cage 15 slot 14 port A or cage 14 slot 16 port A.

The following rules must be observed when interconnecting InCell and M-Cell equipment:

� Reconfigure the InCell BTS to have integral sector(s) in the cabinet.

� Install M-Cell cabinet(s) to serve the remaining sector(s).

� Daisy chain the M-Cell E1/T1 links to the BSC.

GSM-001-103Network topology



Network topology

Introduction

The user can specify what traffic is to use a specific path. Any direct route between anytwo adjacent sites in a network may consist of one or more E1 or T1 circuits. Figure 2-2shows a possible network topology.

Each BTS site in the network must obey the following maximum restrictions:

� Ten serial interfaces supported at a BTS6.

� Six serial interfaces supported at an M-Cell6 BTS.

� Four serial interfaces supported at an M-Cell2 BTS.

� Two serial interfaces supported at an M-Cellcity / M-Cellcity+ BTS.

� Two serial interfaces supported at an M-Cellarena / M-Cellarenamacro BTS.

� Six serial interfaces supported at an M-Cellaccess BTS.

� Six serial interfaces supported at a Horizonmacro.

� Ten BTS(s) in a path, including the terminating BTS for E1 circuit connection oreight BTS(s) in a path, including the terminating BTS for T1 circuit connection.

� Eight signalling links per BTS6 site.

� Four signalling links per M-Cell BTS site (maximum of two per path).

An alternative path may be reserved for voice/data traffic in the case of path failure. Thisis known as a redundant path, and is used to provide voice/data redundancy, that is loopredundancy The presence of multiple paths does not imply redundancy.

Each signalling link has a single path. When redundant paths exist, redundant signallinks are required, and the signalling is load shared over these links. In the case of apath failure, the traffic may be rerouted, but the signalling link(s) go out of service, andthe load is carried on the redundant link(s).

BSC

BTS 2

BTS 3

BTS 4

BTS 10

BTS 11

BTS 5

BTS 6

BTS 7 BTS 9

BTS 8

BTS 1

Figure 2-2 Possible network topology

GSM-001-103 Network topology


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Star connection

A star connection is defined by installing E1 or T1 circuits between each BTS site and theBSC, as shown in Figure 2-3.

A star connection may require more MSI cards at the BSC than daisy chaining for thesame number of BTS sites. The star connection will allow for a greater number of carrierunits per BTS site.

An E1 circuit provides for 15 carriers plus one signalling link. A T1 circuit provides for 11carriers plus 1 or 2 signalling links.

BTS 1

BTS 2BTS 3

BTS 4

BTS 5

BTS 9

BTS 7

BTS 8

MSC

BSC

Figure 2-3 Star connection




Daisy chainconnection

Daisy chaining multiple BTS sites together can better utilize the 64 kbit/s timeslots of oneE1 or T1 circuit from the BSC. Daisy chaining the sites together provides for the efficientutilization of the E1 or T1 circuit for interconnecting smaller sites back to the BSC.

The daisy chain may be open ended or closed looped back to the BSC as shown in Figure 2-4. The closed loop version provides for redundancy while the open ended doesnot. Note that longer daisy chains (five or more sites) may not meet the suggested roundtrip delay.

BTS 1

BTS 2

BTS 3

BTS 4

BTS 5

BTS 9BTS 7

BTS 8

MSC

BSC

BTS 10

BTS 6

BTS 11

BRANCH OF THEDAISY CHAIN

DAISY CHAINCLOSED LOOP

DAISY CHAINCLOSED LOOP

SINGLE MEMBERDAISY CHAIN, A STAR

Figure 2-4 Closed loop and open ended daisy chains

Daisy chainplanning

The introduction of multiple E1 or T1 circuits and branches increases the complexity ofthe network topology. Since the network can have multiple E1 or T1 circuits, branches,multiple paths over the same E1 or T1 circuit, and closed loop interconnections, each E1or T1 circuit should be individually planned.



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Simple daisy chain

A daisy chain with no branches and a single E1 or T1 circuit between each of the BTSs isreferred to as a simple daisy chain, a simple daisy chain is shown in Figure 2-5. Themaximum capacity supported in this connection is limited by the capacity of theconnection between the BSC and the first BTS in the chain.

......... ...

BSC BTS 1 BTS 2

BTS 3 BTS 4

RxTx

Rx

Tx Rx

Tx

RxTx

TxRx TxRxRx

Tx

TxRx

BTS X

RxTx

TxRx

USED IN CLOSED LOOPCONNECTION ONLY

Figure 2-5 Simple daisy chain

The capacity of a closed loop single E1 or T1 circuit daisy chain is the same as that foran open ended daisy chain. The closed loop daisy chain has redundant signalling linksfor each BTS, although they transverse the chain in opposite directions back to the BSC.

Maximum carrier capacity of the chain, with one signal link per BTS site is given by:

n �

31 – b2

for E1 links

n �

24 – b2

for T1 links.

Where: n is: the number of carriers.

b the number of BTS sites in the chain.

The results should be rounded down to the nearest integer.

Example

A single E1 circuit daisy chain with three BTSs, the maximum capacity of the chain isgiven by:

31 – 32

� 14 carriers

A single T1 circuit daisy chain with three BTSs, the maximum capacity of the chain is isgiven by:

24 – 32

� 10 carriers

These carriers can be distributed between the three sites. If the loop is closed, the BSChas additional signalling links, although the same number of carriers are supported.




Daisy chain with branch BTS site

The addition of a branch BTS site (BTS Y), as shown in Figure 2-6, affects the capacityof the links between the BSC and the site from which the branch originates as these areused for the path to the branched site.

BSC BTS 1 BTS 2

BTS 3 BTS 4

RxTx

Rx

Tx Rx

Tx

RxTx

TxRx TxRxRx

Tx

TxRx

BTS X

RxTx

TxRx

USED IN CLOSED LOOPCONNECTION ONLY

BTS Y

Rx

Tx

Figure 2-6 Daisy chain with branch

A branch may have multiple BTS sites on it. A branch may be closed, in which casethere would be redundant signalling links on different E1 or T1 circuits. In a closed loop,which requires redundant signalling links for each BTS site, with an open branch, the E1or T1 circuit to the branch needs to carry redundant signalling links.



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Aggregate Abis

This is an option designed to allow greater flexibility when network planning. It can alsohelp reduce leasing costs of E1/T1 links by optimizing the link usage over the greatestdistance between a BSC and BTS.

This is achieved by the introduction of third party multiplexer equipment enabled byMotorola software. This equipment allows timeslots on one E1/T1 link to be multiplexedto more than one BTS. Therefore if the situation arises where several single carrierBTSs would each require their own dedicated E1/T1 link, greatly under utilizing each linkcapacity.

Now providing the geographical locations of the sites and distances of the E1/T1 linkswork out advantageously, it is possible to send all the traffic channels for every siteinitially over one E1/T1 link to the third party multiplexer and then distribute them overmuch shorter distances to the required sites.

Providing the distance between the BSC and the multiplexer site is sufficiently large thisshould result in significant leasing cost savings over the original configuration. Below aretwo diagrams illustrating the before (Figure 2-7) and after (Figure 2-8) scenarios.

BSC

5x64 kbit/s TIMESLOTS USED

BTS

26x64 kbit/s TIMESLOTS UNUSED

TWO CARRIERONE RSL

BTS

TWO CARRIERONE RSL

BTS

TWO CARRIERONE RSL

5x64 kbit/s TIMESLOTS USED26x64 kbit/s TIMESLOTS UNUSED


Figure 2-7 Typical low capacity BSC/BTS configuration




BSC

5x64 kbit/s TIMESLOTS USED

BTS

26x64 kbit/s TIMESLOTS UNUSED

TWO CARRIERONE RSL

BTS

TWO CARRIERONE RSL

BTS

TWO CARRIERONE RSL



E1/T1MULTIPLEXER


BTS

TWO CARRIERONE RSL


MORE EFFICIENT USE OFLONGEST E1/T1 LINK

Figure 2-8 Example using a switching network

Another advantage of introducing the multiplexer is the improvement in the timeslotmapping onto the Abis interface.

Currently they are allocated from timeslot 1 upwards for RSLs and timeslot 31downwards for the RTF traffic channels. Most link providers lease timeslots incontiguous blocks (that is, no gaps between timeslots). Under the existing timeslotallocation scheme it often means leasing a whole E1/T1 link for a few timeslots. There isa new algorithm for allocating timeslots on the Abis interface. This is only used on thelinks connected directly to the new aggregate service, on the other links the existingalgorithm for allocating timeslots is used.

Under the new software the timeslots are allocated from timeslot 1 upwards, The RSLsallocated first and the RTF timeslots next with each site being equipped consecutively,thus allowing contiguous blocks of timeslots to be leased.

It is important that the sites are equipped in the order that they will be presented, alsothat the RSLs are equipped first on a per site basis to coincide with the default timeslotsfor the software downloads to the BTSs. Figure 2-9 is an example of timeslot allocationin a network using an aggregate service, with links to the aggregate service and linksby-passing it.



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BSC

BTS 2

ORIGINALALGORITHM

BTS 3

NEWALGORITHM

BTS 1

TWO CARRIERONE RSL

E1/T1MULTIPLEXER

BTS 4

ALLOCATIONUNAFFECTED

ORIGINALALGORITHM

ALLOCATIONUNAFFECTED

NEW ALGORITHM

ALLOCATIONAFFECTED

NEWALGORITHM

ALLOCATION AFFECTED

ALLOCATIONAFFECTED

12345

RSL1RTF1RTF1RTF2RTF2

1112131415


12345

RSL1RTF1RTF1RTF2RTF2 1

2345


6789

10


131302928


12345


131302928


1617181920


6789

10


ALLOCATION AFFECTED

NEW ALGORITHM

Figure 2-9 Timeslot allocation using new and old algorithms

Similar problems can be encountered when equipping redundant RSL devices onto pathscontaining aggregate services. Because of the new way of allocating timeslots whenconnecting to a aggregate service from timeslot 1 upwards there is no way of reservingthe default download RSL timeslot. This gives rise to the situation where the default RSLtimeslot has already been allocated to another device, RTF for example.

To avoid this happening the primary and redundant RSLs can be equipped first (in anorder that results in the correct allocation of default RSL timeslots), or reserve the defaultdownload RSL timeslot so that it may be allocated correctly when the primary orredundant RSL is equipped.

If it is envisaged to expand the site in future to preserve blocks of contiguous timeslotson the links, it is possible to reserve the timeslots needed for the expansion so that theycan be made free in the future.




Alarm reporting

This feature has an impact on the alarm reporting for the E1/T1 links. If the link isconnected to a third party switching network and is taken out of service, the BTS willreport the local alarm, but the remote alarm will only go to the third party aggregateservice supporting the E1/T1 link.

There may also be a case where the internal links within the E1/T1 switching network fail,causing the RSL to go out of service with no link alarms generated by GSM networkentities (BTS, BSC). In these cases it is the responsibility of the third party aggregateservice provider to inform the users of the link outage. The only indication of failure is theRSL state change to out of service.

Figure 2-10 shows a possible network configuration using several switching networks.

BSC

E1/T1MULTIPLEXER

BTS

BTS

BTS

BTS

E1/T1MULTIPLEXER

E1/T1MULTIPLEXER

E1/T1MULTIPLEXER

BTS BTS

BTS BTS

BTS BTS

BTS BTS

Figure 2-10 Alternative network configuration with E1/T1 switching network

Restrictions/limitations

The ability to nail path timeslots along a link containing an E1/T1 switching network issupported. The user is still able to reserve, nail and free timeslots.

The maximum number of sites within a path is ten, for E1/T1 networks. Even though it isa pseudo site, the aggregate service is counted as a site in the path. Hence the numberof BTSs that can be present in a path is reduce from ten to nine.

GCLK synchronization functions, but any BTS sites connected downlink from a switchingnetwork will synchronize to it and not the uplink GSM network entity (BTS, BSC).



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RTF path faultcontainment

Each radio at a BTS requires a receive/transmit function enabled which tells it variousoperating parameters to use. These include the ARFCN, type of carrier andprimary/secondary path among others. It is the path that is of concern here. An RTFmay be assigned different paths. The path is the route which the two 64 kbit/s timeslotsassigned to the radio from the E1/T1 link, take to get to and from the BTS/BSC. EachRTF can be assigned a different path for its two timeslots, even RTFs that are in thesame cell.

One path is designated the primary the other the secondary. In the event of the primarypath failing, the RTF would choose secondary path and the carrier would remain in callprocessing. At present, if all the paths to one RTF fail, the whole cell will be taken out ofcall processing, regardless if there are other radios/RTFs with serviceable paths in thesame cell.

This feature allows the cell to remain in call processing if the failure of all paths to oneRTF occurs, as described in the previous paragraphs. Any call in progress on the failedpath would be handed over to the remaining RTFs in the same cell, if there wereavailable timeslots. If there were not enough available timeslots, the call would bereleased. Also the timeslots on the radio of the failed path would be barred from trafficuntil the path was re-established, but any SDCCHs on the carrier would remain active.

If all paths to all RTFs in an active cell have failed and there is still an active RSL, thenthe cell will be barred from traffic.

Advantages

By using this feature, and removing any redundant paths that would normally beequipped to manage path failure, the customer could save on timeslot usage.Figure 2-11 shows the conventional redundant set-up, requiring in this case four extratimeslots to provide for redundant paths. Figure 2-12 shows the configuration using thenew software, which if one RTF path fails will allow call processing to continue via theother path, though with reduced capacity. This configuration only requires four timeslotsinstead of eight for Figure 2-11. The customer has to weigh up the cost savingadvantages of the new software against the reduced capacity in the event of failure of aRTF path.




RTF1 EQUIPPEDON PATH 1

(2 TIMESLOTS)


(2 TIMESLOTS)


(2 TIMESLOTS)


(2 TIMESLOTS)

BTS 3 BTS 1

BSC

BTS 2

Figure 2-11 A configuration with a BTS equipped with two redundant RTFs


(2 TIMESLOTS)


(2 TIMESLOTS)

BTS 3 BTS 1

BSC

BTS 2

Figure 2-12 A configuration with a BTS equipped with two non-redundant RTFs



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16 kbit/s RSL

The purpose of the 16 kbit/s RSL is to reduce the transmission costs between the BSCand BTS (Abis interface) for single carrier sites in particular.

At present, a single carrier BTS requires three E1/T1 64 kbit/s timeslots; one for the 64kbit/s RSL and two for the 16 kbit/s traffic channels. The two 64 kbit/s timeslotsdedicated to the traffic channels can accommodate eight traffic channels normally.

In the case of a single carrier site; it is not possible to use all eight traffic channels of thetwo 64 kbit/s timeslots the reason is that, in the case of a single carrier site, the carrierwill be the BCCH carrier and the air interface timeslot zero of the BCCH carrier isreserved for BCCH information. This information is generated at the BTS not the BSC.The TSW at the BTS routes the traffic channels from the two specified timeslots on theAbis interface to the dedicated radio for transmission.

Due to this the traffic channel on the Abis interface corresponding to the timeslot zero onthe air interface is unused and available to bear signalling traffic. This results in one 16kbit/s sub-channel unused on the Abis interface, a waste of resources.

With the introduction of the 16 kbit/s RSL it is possible to place it on this unusedsub-channel because the RSL is not transmitting on the air interface. The advantage isthat it frees up one 64 kbit/s timeslot on the Abis interface reducing the requirement toserve a single carrier system to only two 64 kbit/s timeslots. This operates with M-CellBTSs and InCell BTSs using KSW switching.

Figure 2-13 (Fully–equipped RTF) and Figure 2-14 (Sub-equipped RTF) show the eighttypes of RTF which are possible using the above options. They are shown in Table 2-2:

Table 2-2 RTF types

Type Options

1 A fully–equipped BCCH RTF with an associated 16 kbit/s RSL.

2 A fully–equipped BCCH RTF with no associated 16 kbit/s RSL.

3 A fully–equipped non-BCCH RTF with an associated 16 kbit/s RSL.

4 A fully–equipped non-BCCH RTF with no associated 16 kbit/s RSL.

5 A sub-equipped BCCH RTF with an associated 16 kbit/s RSL.

6 A sub-equipped BCCH RTF with no associated 16 kbit/s RSL.

7 A sub-equipped non-BCCH RTF with an associated 16 kbit/s RSL.

8 A sub-equipped non-BCCH RTF with no associated 16 kbit/s RSL.




Fully equipped RTF

NOASSOCIATED16 kbit/s RSL

ASSOCIATED16 kbit/s RSL

NON-BCCH

FULLY EQUIPPED RTF



BCCH

Timeslot X

Timeslot Y

KEY

Configuration 1 2 3 4

16 kbit/s sub-channel unavailable for use.16 kbit/s sub-channel used for 16 kbit/s RSL.16 kbit/s sub-channel available for voice traffic.

16 kbit/sBTS only

16 kbit/sBTS only

Figure 2-13 Fully–equipped RTF



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Sub-equipped RTF



NON-BCCH

SUB-EQUIPPED RTF



BCCH

Timeslot X

Timeslot Y

KEY

Configuration

16 kbit/s sub-channel used for 16 kbit/s RSL.16 kbit/s sub-channel available for voice traffic.

16 kbit/sBTS only

16 kbit/sBTS only

5 6 7 8

Figure 2-14 Sub-equipped RTF

Planning constraints

The following RSL planning constraints apply:

� A BTS shall support either 16 kbit/s RSLs or 64 kbit/s RSLs, not both.

� A BSC shall support both 16 kbit/s and 64 kbit/s RSLs.

� A BSU based BTS shall support up to eight 16 kbit/s RSLs.

� Up to two 16 kbit/s RSLs shall be supported by M-Cellmicro, M-Cellcity, andM-Cellarena.

� Up to six 16 kbit/s RSLs shall be supported by M-Cell6.

� Up to four 16 kbit/s RSLs shall be supported by M-Cell2.

� The BTS and BSC shall support a mix of both fully equipped and sub-equippedRTFs.

� A ROM download will be carried out over a 64 kbit/s RSL, even at a sitedesignated a 16 kbit/s RSL.

� A CSFP download shall utilize a 16 kbit/s RSL at a 16 kbit/s designated site.

� A KSW must be used at an InCell BTS where a 16 kbit/s RSL is equipped.

� The 16 kbit/s RSL shall only be able to be configured on CCITT sub-channel threeof a 64 kbit/s E1/T1 timeslot for BSU based sites.

� An associated 16 kbit/s RSL shall be supported on redundant RTF paths whereone exists on the primary path.




16 kbit/s XBL

The 16 kbit/s XBL has been introduced to provide a lower cost solution to the customerby reducing the interconnect costs between an RXCDR and BSC.

This is achieved by reducing the XBL data rate from its current 64 kbit/s to 16 kbit/s.This frees three 16 kbit/s sub-channels on the E1/T1 64 kbit/s timeslot to enable them tobe used as TCHs. The maximum number of XBLs able to be configured between asingle BSC and RXCDR remains the same as before, at two, with a total number of XBLsto an RXCDR of ten. There is no restriction on which timeslot an XBL can be configured.

It will be possible to select a rate of 16 kbit/s or 64 kbit/s on an XBL basis, so it would bepossible to have two different rates at the same BSC to RXCDR, although this would notbe considered a typical configuration. As a result of the introduction of the 16 kbit/s RSLthere will be no reduction in processing capacity of the BSC or RXCDR.

BSC

BSC

BSC

BSC

BSC RXCDR

XBL XBL

XBL XBL

XBL XBL

XBL XBL

XBL XBL

MAXIMUM OF TWO XBLs BETWEEN THE BSC AND XCDR OF EITHER 64 kbit/s OR 16 kbit/sON THE E1/T1 LINK.

MAXIMUM OF TEN XBLs PER RXCDR.

Figure 2-15 16 kbit/s XBL utilization

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BTS concentration

Introduction

The BTS Concentration feature is intended to reduce the number of BTS–BSC terrestrialbackhaul resources that are planned on the E1/T1 link between the BTS and BSC. Thisnew feature is made possible by dynamically allocating terrestrial backhaul resources forthe BTS radio channels, referred to as radio transmit function (RTF) resources, insteadof making static assignments on a one for one basis.

With this new feature, it will be very common to deploy more BTS carrier equipment(RTFs), for coverage purposes, than deployed terrestrial backhaul resources. This newplanning approach takes advantage of the trunking efficiencies gained by sharingterrestrial backhaul resources among multiple BTS RTFs. It is expected that this featurewill be particularly useful for in-building systems.

Prior to the introduction of this feature, terrestrial backhaul resources were staticallyallocated when RTFs were equipped. This feature preserves the existing mechanism(static allocation), but allows the operator the choice, on a per BTS site basis, of whetherto use the existing mechanism, or the new dynamic allocation method.

The BTS Concentration feature is particularly useful when a large BTS daisy chainconfiguration is planned. For a daisy chain network configuration using E1s, there canbe up to ten BTS sites connected together in a serial fashion to a serving BSC. The BTSConcentration feature will greatly increase the terrestrial backhaul trunking efficiency inthis large network configuration by allocating E1/T1 16 kbit/s backhaul resources over theentire daisy chain complex instead of allocating resources on a per BTS site basis.

The BTS Concentration feature introduces a new device referred to as the DYNETdevice. The control of the DYNET device enables a network operator to configure thedynamic allocation of terrestrial backhaul resources from the BSC to BTSs. Additionally,the process of creating a DYNET will cause automatic E1/T1 PATH assignments to bemade, where a PATH identifies the network topology of BSC to specific BTS connections.The DYNET is more fully described in a section to follow.

Key terms

Key networking concepts and terms used in the following sections are: network trafficload expressed in Erlangs, network blocking expressed as grade of service (GOS), andNetwork traffic modeling using the Erlang B formula. The concepts and terms that will beused to describe the BTS Concentration feature are defined below.

Table 2-3 BTS Concentration concepts and rules

Terminology DefinitionBTS Concentration Feature This is a software feature that can be installed on BTSs

supporting switching of 16 kbit/s backhaul resources. Itenables the terrestrial backhaul to be most efficientlyplanned by Dynamically Allocating these resources andrequires a significant software component to be installedon the BSC.

BTS site A BTS site may have one or more BTS Cells collocatedat the same site. The radio signalling link (RSL) planningis performed on a per BTS site basis.

BTS–BSC E1/T1 This is either an E1 or a T1 communication link betweenthe BTS site and the BSC. Additionally, thiscommunication link could be a daisy chain throughmultiple BTS sites connected to a serving BSC.

GSM-001-103BTS concentration



Common pool The common pool refers to the pool of resources that areavailable for unrestricted assignment on the BTS–BSCE1/T1 link to any cell or site requesting terrestrialbackhaul resources.

DYamic NETwork (DYNET)Device

This is a new device created for the BTS Concentrationfeature. A DYNET device is used to specify the BTSsites sharing of dynamic resources and how they areinterconnected. When a DYNET is equipped, using theequip command, the PATH devices for the BTSs thatsupport dynamic allocation are also equipped. See theDYNET section for more details.

Dynamic Allocation This is the way the BTS Concentration feature allocatesterrestrial backhaul between the BSC and BTS site on anas needed basis.

Erlang The Erlang is a measure of traffic loading; (for example,the percentage of time that a resource (channel or link) isbusy). One Erlang represents 3600 call-seconds in a onehour time period. This is equivalent to one call holding acircuit for one hour. Typically a cellular call is held in therange of 120 seconds. A 120 second hold time wouldcorrespond to 33 milli-Erlangs (0.033 Erlangs).

Erlang B Erlang B refers to the call model used to determine thenumber of circuits required in order to satisfy a givenGOS and call load measured in Erlangs. The formula isbased on a call arrival rate with a Poisson probabilitydistribution.

Grade of Service (GOS) The GOS is specified in percent. A 1% GOS means that,on average, 1 call out of 100 calls will be blocked, oftenreferred to as a 1% blocking rate. Typically, a 1% GOS isa desirable terrestrial backhaul design goal.

PATH devices This term refers to the E1/T1 connectivity from the BSCto the BTS site or multiple BTS sites in the case of a BTSdaisy chain.

Radio Signalling Link (RSL) This is the signalling link between the BSC and BTS. Itcan be allocated 16 kbit/s or 64 kbit/s resources over theE1/T1. Each BTS site has at least one 16 kbit/s or64 kbit/s RSL, and more than one can be allocated perBTS up to a maximum number specified by eachindividual BTS product.

Radio Transmit Function(RTF)

An RTF corresponds to one BTS carrier which cansupport up to a quantity of eight 16 kbit/s backhaulresources.

Reserved Allocation The BTS Concentration feature permits the ReservedAllocation of terrestrial backhaul resources. For example,in a daisy chain of BTS sites, each cell in a BTS site canhave a reserved number of terrestrial backhaulresources that cannot be allocated to the other BTS cellsor to other BTS sites in the daisy chain.

Reserve pool The reserved pool is a term used to describe the numberof available terrestrial backhaul resources that can beused by a specific BTS cell and cannot be dynamicallyallocated to another cell.



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Static Allocation Prior to the introduction of the BTS Concentration feature,the allocation of resources over the BTS–BSC E1/T1 linkwas by the use of the Static Allocation. Static Allocationpermits up to eight (sixteen with redundancy) terrestrialbackhaul resources to be assigned directly to one BTSRTF resource.

Subrate switching Subrate switching is the capability to switch 16 kbit/sbackhaul resources.

Terrestrial Backhaul The term terrestrial backhaul is used in the description ofthe BTS Concentration feature to describe the resourcesthat are available over the BTS–BSC E1/T1 link or AbisInterface. An E1 link is comprised of 32 64 kbit/s timeslots, of which up to 31 can be allocated to voice trafficand to RSL signaling channels. A T1 can be allocatedwith up to 24 64 kbit/s time slots. Each E1/T1 time slotcan carry up to 4 calls at 16 kbit/s per traffic channel.When terrestrial backhaul is used in the more generalsense, the term additionally refers to the E1/T1 linksbetween the BSC and RXCDR and to the links betweenthe RXCDR and the MSC.

Timeslot (TS) 64 kbit/s A timeslot is one 64 kbit/s channel on an E1 or T1 asprovided by terrestrial backhaul. A timeslot can carry upto 4 16 kbit/s traffic channels.

Traffic Channel (TCH) 16kbit/s

The term TCH refers to the BTS radio air interface trafficchannel. The bandwidth required to carry one cellular callover the terrestrial backhaul, in support of the TCH, is 16kbit/s.

Transcoder Rate AdaptationUnit (TRAU)

The TRAU corresponds to one transcoding hardware unitper traffic channel. The TRAU hardware unit processesTRAU frames from the BSS and performs thebidirectional conversion to PCM frames for transmissionto the MSC.

TRAU hardware allocation is not performed by the BSCas part of the dynamic allocation of terrestrial backhaulresources. Instead, TRAU allocation is performed whenthe MSC allocates a link from the MSC to the RXCDR,then to the BSC for a specific call.

DYNET – newdevice

DYNET description

To support the functionality of this feature, a new device has been added, the DYNETdevice. A DYNET device is used to specify the BTSs sharing dynamic resources andhow they are interconnected. This device exists as a construct to specify a BTS networkand does not exist as a managed device. A DYNET may be equipped or unequipped,but may not be locked, unlocked, or shut down. If third party timeslot multiplexer sites, ormarker sites, are used, they may be included in the definition of a DYNET.

All DYNETs that share the same first identifier must have exactly the same BTSs, ormarker sites, in the same order. These DYNETs must also have different links used bythe BTSs that use dynamic allocation within a BTS network. These limitations allowmultiple link BTS networks to be defined for sharing purposes, whilst limiting theconfiguration to simplify sharing.




Equipping DYNETs and PATHs

When a DYNET is equipped, using the equip command, the PATH devices for the BTSsthat support dynamic allocation are also equipped. PATH devices are not automaticallyequipped for BTSs that do not support dynamic allocation. A PATH equipped for a nonclosed loop daisy chain has a second identifier equal to the second identifier of theDYNET multiplied by two. In the case of a closed loop daisy chain, an additional PATHdevice is equipped automatically. This has a second identifier one greater than thesecond identifier of the first automatically equipped PATH device.

The indentifiers of the PATHS automatically equipped when a DYNET isequipped are not allowed to be used when equipping the PATH device.

NOTE

The amount of resources reserved for dynamic allocation is set to zero timeslots whenthe DYNET is initially equipped.

Equipping RSLs

RSLs for BTS sites that support dynamic allocation must be equipped to theautomatically equipped PATHs associated with the DYNET.

Blockingconsiderations

Dynamic allocation allows greater RF Channel capacity to be equipped (RTFs) than thereare terrestrial backhaul resources, whether at a BTS site, or within a BTS dynamicnetwork. This allows RTF equipage for coverage purposes rather than for networkcapacity purposes. Additionally, the dynamic allocation method allows terrestrialbackhaul resource capacity to move dynamically between radio units in the samenetwork based upon traffic considerations. The system planner needs to be aware that ifenough users try to gain access to a system planned with many more RTFs thanterrestrial backhaul resources, some of the call attempts will be blocked because of thelimited number of terrestrial backhaul resources.

Blocking control

The BTS Concentration feature provides a facility to reserve terrestrial backhaulresources on a per BTS cell basis along with the dynamic allocation of these resources.This reservation capability can be used to ensure that any given BTS cell has someE1/T1 resources available independent of the other BTS cells or other BTS site trafficloads, thereby providing a guaranteed method of blocking control. However, the best useof terrestrial backhaul resources is obtained by statistically planning the network, usingthe dynamic allocation method to achieve a low blocking probability (a good GOS).



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Reserved allocation algorithm

The feature allows reserved resources to be allocated to specific cells. In configuring anetwork with BTS concentration, a pool of terrestrial backhaul resources must be setaside for dynamically allocating to the relevant cells/BTS sites. This pool is called thedynamic pool in the following discussion. In addition, the feature allows each cell tospecify an amount of reserved resources, which are taken (dynamically allocated) fromthe dynamic pool. Once a number of resources are reserved for a cell, these resourcesare allocated specifically to the cell and, therefore, are not available for sharing.

To facilitate this discussion from the planning perspective, imagine that there is acommon pool that holds the remaining resources in the dynamic pool after resourcesare reserved for specific cells. Figure 2-16 shows what the dynamic pool of terrestrialbackhaul resources consists of from the planning perspective: a common pool and nreserved pools , one for each BTS site.

Each reserved pool consists of the resources associated with a 16 kbit/s RSL timeslot aswell as any additional resources that are specifically reserved on a per cell basis. The16 kbit/s RSL timeslot-associated resources are shared among the cells at the BTS site,but cannot be shared with other BTS sites. The reserved pool of an individual BTS sitecan be set to zero. For each 16 kbit/s RSL, there will always be three resources availablefor reserved allocation among cells at the same site. If there are two 16 kbit/s RSL, sixreserved resources are available, and so on. However, 16 kbit/s RSLs equipped forredundancy do not provide any reserved resources. For example, if there are six 16kbit/s RSLs and three of which are for redundancy, a total of nine RSL associatedresources are available to be included in the reserved pool.

When a new call arrives to a cell, the BSC always first allocates a resource from thereserved pool of the corresponding BTS site. Specifically, it will first attempt to allocate aRSL–associated resource. If none is available, it allocates a resource from the additionalresources specifically reserved for the cell. If all reserved resources are depleted, theBSC then allocates a resource from the common pool. If again no resource is available inthe common pool, the call is blocked.

If the BTS site is assigned a 64 kbit/s RSL instead of a 16 kbit/s RSL, then there are noRSL timeslot-associated resources available for dynamic allocation.




Emergency callhandling

BTS site 1 RESERVED POOL

COMMON POOL

BTS site n Cell 1 additionalreserved resources

RSL–associated reservedresources (Quantity = 0,

3, 6..)

BTS site 2 RESERVED POOL

BTS site n RESERVED POOL



Figure 2-16 A dynamic pool of terrestrial backhaul resources

With BTS Concentration, emergency calls take precedence over non-emergency calls inthe allocation of terrestrial backhaul resources. The emergency calls precedence inbackhaul resource allocation is independent of whether Emergency Call Pre-emption(ECP) is on or off. If no terrestrial backhaul resources are available when an emergencycall requests a resource, the oldest existing non-emergency call is terminated in order toprovide the needed resource. In addition, emergency calls take precedence overreserved resources allocated to specific cells. Emergency calls use whatever freeterrestrial backhaul resource becomes available first. The BSC will pre-emptnon-emergency calls in the same cell. The BSC next pre-empts non-emergency calls atthe site. Finally, the BSC will terminate non-emergency calls from other sites within thesame DYNET. If all available terrestrial backhaul resources are in use by emergencycalls or if no terrestrial backhaul resources are available, then the new emergency call isblocked.



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Radio SignallingLink (RSL)planning

When a BTS daisy chain is configured during the configuration management phase, theoperator has to equip each BTS site in the daisy chain at least one 64 kbit/s timeslot forRSL use. This is necessary so that when a BTS site is initialized it can communicatewith the BSC at 64 kbit/s. After the initialization process concludes, the BTS site canthen be allocated this 64 kbit/s E1/T1 timeslot as one 16 kbit/s RSL and three 16 kbit/sterrestrial backhaul resources. These three 16 kbit/s resources are always consideredpart of a reserved resources on a per site basis and can be used by any cell within a site.These three RSL associated resources may not be shared from one BTS site to another.A site always allocates RSL associated 16 kbit/s resources before allocating otherreserved resources or before requesting allocation from the common pool of resources.

Alternatively, the BTS site can continue to use this 64 kbit/s E1/T1 timeslot as one64 kbit/s RSL. When the RSL is used as a 64 kbit/s signalling link, there are no RSLassociated resources to be used as reserved resources at the site.




Networktopologies

BTS Concentration does not support all possible network topologies. Dynamic allocationis limited to spoke, daisy chain, and closed loop daisy chain network configurations. Thefollowing figures illustrate the network configurations to which these terms apply.

BSC BTS 1

Figure 2-17 Spoke configuration

BSC

BTS 1 BTS 2 BTS 3

Figure 2-18 Daisy chain configuration

BSC

BTS 1 BTS 2 BTS 3

Figure 2-19 Closed loop daisy chain configuration



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Links between BTSs

Even with dynamic allocation, greater bandwidth than that provided by a single link maybe required. To provide this, networks following the configurations shown in Figure 2-20,Figure 2-21, and Figure 2-22 and may have one to three links between each BTS–BSCor BTS–BTS pair in the configuration. The same number of links must be specifiedbetween each pair to maintain the simplicity needed to provide dynamic allocation. Thefollowing figures illustrate configurations with multiple links between BTSs.

BSC BTS 1

Figure 2-20 Spoke configuration with three links

BSC

BTS 1 BTS 2 BTS 3

Figure 2-21 Daisy chain configuration with two links

BSC

BTS 1 BTS 2 BTS 3

Figure 2-22 Closed loop daisy chain configuration with three links

This feature allows BTSs within a configuration to use the existing allocation mechanism.Such BTSs continue to reserve terrestrial backhaul resources when RTFs are equipped.Capacity in a network configuration is reserved for use for dynamic allocation by theBTSs that use dynamic allocation. This capacity forms the pool from which terrestrialbackhaul resources are allocated.




Third party multiplexer equipment

This feature supports the use of third party multiplexer equipment within a networkconfiguration. Such equipment defines a terrestrial network outside of the knowledge ofthe BSS. To the BSS, this terrestrial network appears as a timeslot multiplexer site (alsoknown as a marker site) within the BSS configuration. The following example illustratesthe use of third party multiplexer equipment in a closed loop configuration.

BSC

BTS 1 BTS 2 BTS 3

THIRD PARTYMULTIPLEXEREQUIPMENT

THIRD PARTYMULTIPLEXEREQUIPMENT

Figure 2-23 Closed loop daisy chain configuration with third party multiplexer

Nailed paths

It may be required to declare additional paths to a BTS that uses dynamic allocation fornail connection purposes. This feature supports this functionality.

BSC

BTS 1 BTS 2 BTS 3

Additional path definition

Figure 2-24 Extra path definition for nailed connections

Figure 2-24 shows a closed loop daisy chain with an additional path (shown as a dashedline) to BTS 2. No BSS managed resources can be placed on this additional path, itexists solely as a convenience for defining nailed connections.



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RTF path fault containment

Additional functionality introduced allows the RTF to be used for non TCH channels whenthe path(s) for the RTF are not available, leaving the cell for the RTF in service.However, the cell is still taken out of service when all RTFs in the cell lose their paths tothe BSC. A dynamic allocation site may use any of the path(s) to the site that appear inthe dynamic allocation network definition. If all of these path(s) are out of service, adynamic allocation site cannot be allocated any terrestrial backhaul resources. Hence,the cell(s) at this site are taken out of service under these conditions.

Additional paths to dynamic allocation sites, as described previously, may be declared asa convenience. Since these paths are not used for terrestrial backhaul resources, theirstate does not influence the state of the cells at a dynamic allocation site.




Allocating and freeing terrestrial backhaul resources

This feature attempts to minimize the BTS interaction needed to allocate or free aterrestrial backhaul resource. The terrestrial backhaul resources are initially a set ofnailed connections throughout a BTS network. When a resource is allocated to a BTS,that BTS breaks its nailed connection. A connection to the TCH is made in place of thenailed connection. When the resource is freed, the BTS re-establishes the nailedconnection. No change in connections is required at any other BTS in the BTS network.

BSC

BTS 1 BTS 2 BTS 3

Figure 2-25 Terrestrial backhaul resource nailed connection before a call

BSC

BTS 1 BTS 2 BTS 3

Figure 2-26 Terrestrial backhaul resource connections during a call

Figure 2-26 shows a resource allocated to BTS 2. BTS 2 connects the resource to theTCH using one of the two possible paths to the BSC. BTS 2 changes the connection ifthe path being used fails during the call. BTS 2 connects the unused path to the Abisidle tone.



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RedundancyThis feature does not support the use of closed loop daisy chains for additional capacitywhen all links are available. This feature treats the closed loop nature of the closed loopdaisy chain as existing for purposes of redundancy. Such a design ensures that no callsare dropped when a link becomes unavailable in a closed loop configuration. This designalso simplifies the tracking of terrestrial backhaul resources. (See Figure 2-27.)

BSC

BTS 1 BTS 2 BTS 3

Call 1

Call 2

Figure 2-27 Using redundancy for extra capacity before failure

BSC

BTS 1 BTS 2 BTS 3

Call 1

Failed link

Figure 2-28 Using redundancy for extra capacity after failure

For the purposes of this feature, the configuration shown in Figure 2-27 is considered aclosed loop daisy chain configuration.

BSC BTS 1

Figure 2-29 Closed loop daisy chain configuration with 1 BTS

The closed loop daisy chain has the potential to use the same resource in both portionsof the loop. For example, in Figure 2-28, both BTS 1 and BTS 3 could be using thesame resource. BTS 1 could use the resource on the link between the BSC and BTS 1.BTS 3 could use the resource on the link between the BSC and BTS 3. If either link fails,one of the calls is no longer able to use the resource.




Performanceissue

The use of satellites to carry links introduces an additional 600 millisecond one way delayto messages sent on the links. Dynamic allocation requires a BTS to BSC request and aBSC to BTS response. These messages incur an 1.2 second delay beyond the normaltransmit and queuing delay times. These delay times affect call setup and handoverdelay times, especially if retransmission of the request/reply scenario is necessary due tomessage loss. This feature addresses this problem by adding an operator specifiedparameter that provides the retry time for dynamic allocation requests. For non-satellitesystems, the retry time should be set to its minimum value. For satellite systems, theretry should be set to 1.2 seconds plus the minimum retry value. The minimum retry timechosen is 150 milliseconds to account for transmit and queuing delay times (for 16 kbit/slinks, longer retry time is recommended to avoid excessive retries).

Configurationand compatibilityissues

The BTS Concentration feature is supported for BSS GSR4 software releases onwardson BTS4, BTS5, BTS6, ExCell and TopCell (with TSW) and in-building picocellularsystem products. BTS products that support subrate switching (switching of 16 kbit/sterrestrial backhaul resources) are essential for the feature. While the feature operateson 16 kbit/s switching, it can coexist with 64 kbit/s static switching in a mixed setup.

The BTS Concentration feature allows up to three E1/T1s to be allocated between theBSC and BTS site as terrestrial backhaul resources. This rule applies to all BTSproducts that support the BTS Concentration feature. The maximum BTS daisy chainlength served by one BSC is 10 BTS sites.

The BTS Concentration feature limits call congestion handling and priority call handling toradio resource call management. The existing functionality for call congestion handling,priority call handling, and emergency call handling allocates radio resources dynamically.Hence, the BTS Concentration feature interacts with these existing call handling methodsbecause the new feature dynamically allocates terrestrial backhaul resources. Thehandling of emergency calls is discussed at length in the Emergency call handlingsection.



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RecommendedBTSconcentrationplanningguidelines

This section recommends some planning guidelines for planning the BTS Concentrationfeature and discusses some uses for the reserved allocation algorithm of the feature.Applications of the guidelines are illustrated by the examples in the next section.

The BTS Concentration feature allows terrestrial backhaul resources to be shared amongmultiple BTS sites and cells (as if the resources are allocated to a common resource poolfor sharing). In addition, a number of resources can be optionally reserved for specificBTS cells. It is recommended that network planning favours sharing resources and thatthe reserved allocation be used more sparingly, unless reserved resources are availableby default due to the use of 16 kbit/s RSL (see the Radio Signalling Link Planningsection in this chapter). This strategy will allow more efficient use of the terrestrialbackhaul resources.

Guideline 1

For a common pool of terrestrial backhaul resources that is to be shared among anumber of cells with different GOSs, enough resources should be allocated to meet themost stringent GOS among all relevant cells.

This guideline addresses the case when a daisy chain is planned and not all of the BTSsin the daisy chain need to have the same GOS. For example, in a daisy chain of threeBTS sites the planning objective may be to plan BTS 1 with a 1% GOS, BTS 2 with a 2%GOS, and BTS 3 with a 1% GOS.

However, when the BTS Concentration feature allows terrestrial backhaul resources tobe shared among these three BTS sites, only one GOS may be used for the purposes ofplanning the resources. Therefore, Guideline 1 recommends that the best GOSneeded in the daisy chain, that is 1% over 2%, be specified when planning.

Guideline 1 is used in the first example in the following section.

Guideline 2

Due to trunking efficiency, resources are more efficiently utilized if allocated to thecommon pool than if reserved for individual cells. Therefore, share the resources amongcells by putting as many of them in the common pool as possible.

The exception to this guideline is when reserved resources are available by default;those 16 kbit/s circuits that are associated with the same timeslot (on E1 or T1) with the16 kbit/s RSL/s. In this case, follow Guideline 3 to estimate the overflow traffic from thedefault reserved resources and then to determine the required number of resources inthe common pool for meeting the most stringent GOS.

Reserved allocation is intended only as a safeguard mechanism, as implemented in theBTS Concentration feature. Therefore, Guideline 2 recommends that the dynamicallocation from the common pool be used almost exclusively in order to minimize therequired terrestrial backhaul resources.




Guideline 3

If resources are reserved for specific cells (either by default or by design), the trafficoverflowed from the reserved resources are handled by the resources in the commonpool. The size of the common pool for meeting a certain GOS can be determined usingthe following steps:

1. Use the Erlang B model to determine the blocking probability of the reservedresources, given the offered traffic load at each cell.

2. The traffic overflowed from reserved resources is simply the product of theexpected traffic load and the blocking probability of the reserved resources.

3. Sum the traffic overflowed from all cells.

4. Use the Erlang B model again to determine the number of resources needed to bein the common pool, in order to handle the total overflow traffic at the moststringent GOS requirement among all cells (according to Guideline 1).

Although the call arrival process at the resources might not be Poisson, the use of ErlangB model in steps 1 and 4 are reasonable approximations and has been verified insimulations.

The application of these steps is illustrated in Examples 1 and 2 in next section.

Uses of Reserved Allocation Algorithm

The following are a few possible applications of the Reserved Allocation Algorithm, whichallows the operators to reserve resources for specific BTS cells:

� If there is insufficient knowledge of the traffic load on the individual BTS sites of arecently deployed network, resources may be allocated to reserved pools untilsome traffic statistics can be accumulated.

� As a transition strategy for moving from the static allocation planning method to thedynamic allocation of terrestrial backhaul resources out of a common resourcepool, the BTS Concentration feature can be added to an existing network and thenplanned by allocating resources to only the reserved pools resulting in no effectivechange in the planned terrestrial backhaul resources. A follow-up planningprocess can later be taken to take advantage of dynamic allocation of terrestrialbackhaul resources out of a common resource pool.

� Suppose in an existing system with BTS concentration, better GOSs are deemednecessary for some specific and important cells, but for whatever reason it is notfeasible to immediately deploy more terrestrial backhaul resources to the commonpool to achieve the required GOSs. A possible strategy might be to re-allocatesome resources from the common pool to the reserved pools of the important cellsto improve their GOSs. However, as a trade-off, reducing the size of the commonpool will result in worst GOS for the other cells that rely on the common pool.Nonetheless, the more extensive use of the reserved pool could be considered atransition strategy until more terrestrial backhaul resources become available.



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Examples

The following examples provide a better understanding for how the guidelines in theprevious section might be applied when planning a network with the BTS Concentrationfeature.

The first two examples, Examples 1 and 2 , demonstrate the trunking efficiency gainedby the BTS Concentration feature as well as the use of Guidelines 1, 2, and 3 .Additionally, Guideline 2 is applied by limiting the use of reserved facilities to only thosereserved facilities that are planned as part of the RSL 64 kbit/s timeslot.

The third example, Example 3 , demonstrates the case when a combination of reservedresources and call loading causes blocking to occur at a particular cell, even thoughthere is still some terrestrial backhaul resource available.

All examples are worked using the Erlang B formula/model.

Example 1

The number of required 16 kbit/s terrestrial backhaul resources between the BSC andBTS or daisy chain of BTSs depends on the amount of traffic (in Erlangs) expected ateach BTS cell/site and the blocking probability for the resources. (A new call is blockedwhen all resources have been allocated to other on-going calls.) This example illustrateshow planning can be carried out. The DYNET in Figure 2-28 is used in the examples andeach BTS site is assumed to have only one cell. Suppose 3 Erlangs of traffic is expectedto come through the cell in BTS 1, 2 Erlangs through BTS 2, and 5 Erlangs throughBTS 3.

It is important not to confuse the blocking at the terrestrial backhaul resourceswith the blocking at the channels over the air (TCHs) and the blocking at thelinks between a MSC and a BSC.

NOTE

If choosing to share the pool of terrestrial backhaul resources freely among all BTSs, andto allow an 1% blocking probability for these resources, a total of 18 resources areneeded to handle the 10 Erlangs of expected traffic, according to Erlang B formula.

However, to reserve some resources for each BTS site, to provide the required blockingprobability, calculate the required number of resources for each BTS site. Assume thatthe desired blocking probabilities for the terrestrial backhaul resources are 1%, 2% and1% for BTS 1, BTS 2 and BTS 3, respectively. Again, using the Erlang B formula,reserve eight resources to handle the 3 Erlangs of expected traffic through BTS 1 with1% blocking. Also reserve six resources to handle the 2 Erlangs through BTS 2 at 2%blocking. Finally, 11 resources are needed at BTS 3 to handle the 5 Erlangs at 1%.Therefore, 25 resources in total are needed.

Table 2-4 summarizes these key results.




Table 2-4 Summary of required resourcesBTS Expected Traffic

(Erlangs)Blocking Probability

(GOS)Required number of

resources1 3 1% 82 2 2% 63 5 1% 11

Total(100%

reserved)

10 25

Total(100%

common)

10 1% 18

The expected traffic refers to the amount of traffic arriving at the backhaulresources. Since the limited number of TCHs gives rise to another level ofblocking (GOS), the traffic expected at the backhaul resources is in generalsmaller than the traffic generated by the subscribers. For example, with 1%blocking at the TCHs, on average only 99% of the traffic make it to thebackhaul resources. Therefore, the expected or offered traffic at the backhaulresources is the product of the expected traffic from the subscribers and (1 –blocking probability).

NOTE

Note that when the 100% reserved planning approach is used, more resources (25instead of 18) are required and, in addition, BTS 2 is planned at a higher blocking (aworse GOS). This example demonstrates the power of trunking efficiency and the reasonwhy allocation to the common pool should be favoured over allocation to the reservedpool when planning terrestrial backhaul resources for individual BTS sites or cells.

Reserving terrestrial backhaul resources for individual cells, however, does isolate thecell from the statistical traffic fluctuation of other cells. When other cells experiencehigher call arrivals than average, a cell with its own n reserved terrestrial backhaulresources will never be in a situation where all its calls are blocked. The cell isguaranteed that it has at least n ongoing calls before a new call is blocked. The tradeoff,however, is that a greater number of terrestrial backhaul resources are necessary.

As described in the Radio Signalling Link Planning section in this chapter, somereserved resources may exist by default if 16 kbit/s RSLs are used at the BTS site. The16 kbit/s backhaul resources associated with the same timeslot on the E1/T1 as the 16kbit/s RSL are considered reserved resources for all cells in the BTS site. Suppose eachof the BTS 1 and BTS 2 in this example uses one 16 kbit/s RSL and, therefore, each hasthree backhaul resources available by default. Follow Guideline 3 to determine thenumber of resources needed in this situation:

1. For BTS 1, given that it has three reserved resources and 3 Erlangs of offeredtraffic, the calculated blocking probability for the resources is 0.35. Similarly, forBTS 2, three reserved resources handling 2 Erlangs gives a blocking probability of0.21.

2. The traffic overflowed from the reserved resources is 3 x 0.35 = 1.04 Erlangs forBTS 1 and is 2 x 0.21 = 0.42 Erlangs for BTS 2.

3. The total traffic to be handled by the common pool is, therefore, the sum of theoverflow traffic from BTS 1 and BTS 2 and the 5 Erlangs from BTS 3. The sumturns out to be 6.46 Erlangs



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4. Using the Erlang B model, the calculated common pool needs to have 13 backhaulresources in order to meet the 1% GOS.

As a result, a total of 19 resources are needed in this case. Although this approachrequires one more resource than the 100% common allocation approach, six of theresources are available by default. Only 13 additional resources are really needed.

In summary, it has been demonstrated that the 100% reserved approach resulted in lessefficient use of resources and, therefore, required the most number of resources to meetthe design requirements. The 100% common approach resulted in the most efficientutilization of resources. However, if reserved resources are readily available, using theplanning approach given in Guideline 3 can make use of them and reduce the number ofadditional resources needed to be provisioned. (See Table 2-5.)

Table 2-5 Summary of common pool planning when BTSs 1 and 2 have reservedresources

BTS Offeredtraffic

(Erlangs)

Number ofreserved

resources

Blockingprobability

for reserved

Overflowed trafficfrom reserved

(Erlangs)

1 3 3 0.35 1.04

2 2 3 0.21 0.42

3 5 0 – 5

6.46

Number of resources needed in common pool to meet 1% GOS = 13

Therefore, the total number of resources, including reserved = 19




Example 2

As Example 2 demonstrates, the trunking efficiency gain by the BTS Concentrationfeature can be rather significant. To show the advantage in a large system, this examplelooks into the planning of BTS Concentration for a daisy chain of 10 single-cell BTS sites.The following table summarizes the expected amount of traffic at the backhaul resourcesand the GOS requirement associated with each cell.

Table 2-6 Summary of traffic and GOS requirementsBTS Expected Traffic

(Erlangs)Blocking Probability

(GOS)Required number of

resources1 5 1% 112 10 1% 183 15 1% 244 20 1% 305 25 1% 366 30 1% 427 35 1% 478 40 1% 539 50 1% 64

10 60 1% 75Total

(100%reserved)

290 400

Total(100%

common)

290 1% 314

Table 2-6 also shows the results of the 100% reserved and 100% common planningapproaches (the rightmost column). The total traffic load of the 10 BTS sites is290 Erlangs. If each BTS resource allocation is planned as in the static allocation or100% reserved methods (resources are actually reserved for the cell in thecorresponding BTS site, since they are reserved on a per-cell basis), the resources thatneed to be planned over the terrestrial backhaul are 400. However, if the resourceallocation is performed over all 10 BTS sites, the number of required terrestrial backhaulresources drops to 314, a saving of 86 resources.

The saving of 86 resources is significant because, without it, the daisy chain would haverequired 400 resources (using the 100% reserved approach) and would not be able to fitinto three E1 links, the most a DYNET can have. Note that three E1 links together canprovide only 372 (= 3 x 31 x 4) 16 kbit/s channels, and, inevitably, some of which will beallocated for 16 and 64 kbit/s RSLs. The 100% common approach of planning BTSConcentration reduces the number of required resources and makes it possible to offer1% blocking to the entire daisy chain with three E1 links.

To expand this example further, assume that each BTS site has some default reservedbackhaul resources ranging from 1 to 3 (see Table 2-4). Following Guideline 3, thecalculation in Table 2-7 shows that about a total of 272 Erlangs of traffic will beoverflowed to the common pool. Therefore, the common pool needs 295 additionalresources in order to provide an 1% GOS, making a total of 315 backhaul resources inthis scenario.



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Table 2-7 Summary of common pool planning when BTSs have reserved resources

BTS Offeredtraffic

(Erlangs)

Number ofreserved

resources

Blockingprobability

for reserved

Overflowed trafficfrom reserved

(Erlangs)

1 5 3 0.53 2.65

2 10 3 0.73 7.32

3 15 3 0.81 12.21

4 20 2 0.90 18.10

5 25 2 0.92 23.08

6 30 2 0.94 28.07

7 35 2 0.94 33.06

8 40 1 0.98 39.02

9 50 1 0.98 49.02

10 60 1 0.98 59.02

271.54

Number of resources needed in common pool to meet 1% GOS = 295

Therefore, the total number of resources, including reserved = 315




Example 3

This example uses a call blocking situation in a three-cell BTS site to illustrate theoperation of the BTS Concentration feature. First, the assumptions about theconfiguration and the state of the three-cell BTS site:

� There are 24 terrestrial backhaul resources (that is six timeslots) in the dynamicpool, 12 of which are in the common pool for assignment to any of the three cellsand the other 12 are reserved as illustrated in Table 2-7.

� All RSLs are 64 kbit/s and, hence, no RSL associated resources.

� Cell 1 has three calls in progress and all three calls are counted against Cell 1reserved pool. Cell 1 cannot take any more new calls without getting resourceallocation from the common pool.

� Cell 2 has 17 calls in progress, five of which are counted against Cell 2 reservedpool and 12 were counted against the common pool. As a result, the commonpool is depleted.

� Cell 3 has three calls in progress, and all three calls are counted against Cell 3reserved pool. Cell 3 has the reserved pool capacity to take one more call beforeneeding resources from the common pool.

Suppose a new call arrives to Cell 1. Since resources in both Cell 1 reserved pool andthe common pool are in use, the new call attempt will be blocked. This blocking occurseven though there is one available resource in the dynamic pool. This remaining resourcecan only be allocated to Cell 3 since it has not used up its reserved pool. (SeeTable 2-8.)

Table 2-8 Blocking activityBTS New Call

AttemptCalls in

ProgressReserved Pool

resourcesResources used out

of common pool1 X 3 3 02 17 5 123 3 4 0

GSM-001-103 Managed HDSL on micro BTS


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Managed HDSL on micro BTS

Introduction

This new feature brings the benefits of full OMC Management to those products thatsupport integrated HDSL technology. Specifically, it allows remote configuration, status,control, and quality of service information to be handled by the OMC. External HDSLmodems configured as slave devices may also be managed by the same mechanism aslong as they are connected to an integrated master HDSL port.

This feature enables such an HDSL link to be managed entirely from the OMC.Following introduction of this feature, the initial basic version of the product will no longerbe supported.

To ensure compatibility, external modems should be sourced from Motorola.

NOTE

GSM-001-103Managed HDSL on micro BTS



Integrated HDSLinterface

HDSL cable selection

The cabling needs to comply with the following selection guidelines:

� Correct number of pairs for an application.

� Each Tip and Ring pair must be of a twisted construction.

� The Tip and Ring must not be mixed between the pairs, that is, Tip1 must not beused as a pair with Ring2.

� Either unshielded twisted pair (UTP) or shielded twisted pair (STP) may be used.

� The cable gauge should be between 0.4mm and 0.91mm (AWG 26 to AWG19).

� Attenuation at 260 kHz should be less than 10.5 dB/km.

� Cable runs should be limited to a length depending on the product.

Some types of cable are known to perform suitably in HDSL applications, provided theyare correctly installed and the guidelines for selection and installation are observed.Recommendations for types of cable follow:

� Unshielded twisted pair

– BT CW1308 and equivalents.

– Category 3 UTP.

– Category 4 UTP.

– Category 5 UTP.

� Shielded twisted pair

– Category 3 STP.

– Category 4 STP.

– Category 5 STP.

The performance of some types of cable is known to be unacceptable for HDSLapplications. The following cable types should be avoided:

� Twisted quad cable is unsuitable for use in HDSL applications and must not beused.

� Drop wire that consists of two parallel conductors with supporting steel cable. Thiswill work with HDSL but because it is not twisted, it provides little immunity fromnoise, and is therefore not recommended.

� Information cable is typically of non-twisted, multicore construction, for exampleribbon cable. Its use is not recommended.



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HDSL cable installation

If cabling does not exist between two end sites, guidelines follow for the installation ofcable, that must meet the selection guidelines given above:

� The conductor pair(s) should be connected point-to-point only, not point tomultipoint.

� The use of different gauges of cable in one link should be avoided.

� Bridge taps in the cable run should be avoided.

� Loading coils in the cable run must be removed.

� The isolation between Tip and Ring should be greater than 1 M ohm (at SELVvoltage levels).

� The isolation between Tip and earth should be greater than 1 M ohm (at SELVvoltage levels).

� The isolation between Ring and earth should be greater than 1 M ohm (at SELVvoltage levels).

HDSL range

HDSL range is affected by many factors which should be taken into account whenplanning the system.

� Picocell systems should have distances of less than 1 km due to the link qualityrequirements of these systems.

� Microcell systems can have longer distances, typically 2 km or so, because of theirdifferent link error requirements.

� The following factors will reduce the available distances:

– Bridge gaps add unwanted loads on to the cables.

– Gauge changes add unwanted signal reflections.

– Small gauge cables increase the signal attenuations.

– Other noise sources.

HDSL is specified not to affect other digital subscriber link systems and voicetraffic.

However, standard E1 traffic will affect, and be affected by, HDSL systemsrunning in the same cable binder, if unshielded from each other.

NOTE




General HDSLguidelines

Conversion of E1 to HDSL at a site away from the BSC requires either an externalmodem or a microsite. It may be better to utilize the microsite to do this conversion, ifpossible.

BSC

EXTERNALMODEM

M

M = MASTER S = SLAVE

EXTERNALMODEM

E1 LINK HDSL

HDSL

HDSL

E1 LINK

E1 LINK

M-Cell6

SLAVE

MSLAVE

S M S M M

M SM SHDSL

HDSL

HDSL

E1 LINK

E1 LINK

BTS

Horizonmicroor Horizoncompact







Microcell BTS have a maximum of two 2.048 Mbit/s links. If the HDSL equipped versionis purchased the links are automatically configured as either E1 or HDSL via acombination of database settings and auto-detection mechanisms. The setting ofmaster/slave defaults can be changed by database settings for those scenarios, such asa closed loop daisy chain, where the defaults are not appropriate.



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Microcell systemplanning

Network configurations from the BSC can be a combination of daisy chain and star.

Links can be either E1 or HDSL, and can be mixed as appropriate within the network.

Daisy chain

Here a BSC connected to an external modem which then connects from its slave port tothe master port of the Horizonmicro or Horizoncompact. The slave port of theM-Cellarena or M-Cellarenamacro connects to the next M-Cellarena or M-Cellarenamacro

master port and so on, until the last M-Cellarena or M-Cellarenamacro port is connected.


EXTERNALMODEM

HDSLMSLAVE MS MSBSC

HDSL HDSLE1 LINK




Star configuration

Here a BSC is again connected to an external modem which then connects from its slaveport to the master port of a Horizonmicro or Horizoncompact. In this configuration anexternal modem is used every time a link to a Horizonmicro or Horizoncompact is used,hence the star formation.

BSC

EXTERNALMODEM

M

M = MASTER

EXTERNALMODEM

M

EXTERNALMODEM

MSLAVE

E1 LINK HDSL

HDSL

HDSL

E1 LINK

E1 LINK

SLAVE

SLAVE







E1 link

Here the an E1 link is used from the BSC to the first Horizonmicro or Horizoncompact,from there onwards HDSL links are used running from master to slave in eachHorizonmicro or Horizoncompact; or conversion can be at any BTS, in either direction.


M S MS

BSC

E1 LINK HDSLHDSL






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Picocell systemplanning

The Picocell (M-Cellaccess) system comprises a cabinet housing a maximum of two sitecontrollers which can each control up to six single remote RF heads which operates in allfrequency bands that adopt the GSM standard (GSM900 and DCS1800).

The considerations for Picocell planning are:

� Links are all point to point.

� Run from site controller to the remote RF head.

� Frequency bands must not be mixed on the same site controller.

� Can be either optical of HDSL.

� If HDSL, two twisted pairs of wires for each RF head.

No daisy chaining of RF heads is allowed.

NOTE

RF HEAD

SITECONTROLLER

PCC CABINET SITE B

SITE A

SITECONTROLLER

RF HEAD

RF HEAD

RF HEAD

RF HEAD

RF HEAD

RF HEAD

RF HEAD

RF HEAD

RF HEAD

RF HEAD

RF HEAD





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i

Chapter 3

BSS cell planning

GSM-001-103



GSM-001-103


68P02900W21-G


iii

Chapter 3BSS cell planning i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BSS cell planning 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning requirements 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning factors 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Planning tools 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GSM frequency spectrum 3–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The GSM900 frequency spectrum 3–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The DCS1800 frequency spectrum 3–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The PCS1900 frequency spectrum 3–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Absolute radio frequency channel capacity 3–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Modulation techniques and channel spacing 3–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Traffic capacity 3–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dimensioning 3–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Channel blocking 3–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Traffic flow 3–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Grade of service 3–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Control channel calculations 3–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 3–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPRS control channel RF provisioning 3–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Number of CCCH per BTS cell 3–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Number of SDCCH per BTS cell 3–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Control channel configurations 3–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The GPRS planning process 3–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview of the GPRS planning process 3–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction to the GPRS planning process 3–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview the GPRS planning process introduction 3–25. . . . . . . . . . . . . . . . . . . . . . . . . Determination of expected load 3–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Network planning flow 3–27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GPRS network traffic estimation and key concepts 3–28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview of the GPRS network traffic estimation and key concepts 3–28. . . . . . . . . . Introduction to the GPRS network traffic estimation and key concepts 3–29. . . . . . . . Dynamic timeslot mode switching 3–32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Carrier timeslot allocation examples 3–34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSS timeslot allocation methods 3–37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Provisioning the network with switchable timeslots 3–39. . . . . . . . . . . . . . . . . . . . . . . . . Recommendation 3–43. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GPRS Air interface planning process 3–45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview of the GPRS air interface planning process structure 3–45. . . . . . . . . . . . . . Introduction to the GPRS air interface planning process 3–46. . . . . . . . . . . . . . . . . . . . Air interface throughput 3–51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Step 1: throughput estimation process 3–52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Step 2: throughput estimation process 3–53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Throughput estimation process: step 3 (optional) 3–56. . . . . . . . . . . . . . . . . . . . . . . . . . Throughput estimation process: step 4 (optional) 3–57. . . . . . . . . . . . . . . . . . . . . . . . . .

GSM-001-103



Propagation effects on GSM frequencies 3–59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Propagation production 3–59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to decibels 3–60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fresnel zone 3–61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Radio refractive index 3–62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Environmental effects on propagation 3–66. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Multipath propagation 3–69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GSM900 path loss 3–82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Path loss GSM900 vs DCS1800 3–83. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Frequency re-use 3–84. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction to re-use patterns 3–84. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Re-use pattern 3–85. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Carrier/ Interference (C/I) ratio 3–88. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Other sources of interference 3–89. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sectorization of sites 3–89. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Overcoming adverse propagation effects 3–90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hardware techniques 3–90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Error protection and detection 3–92. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Speech channel encoding 3–94. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Channel coding for enhanced full rate 3–96. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Control channel encoding 3–97. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Data channel encoding 3–98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mapping logical channels onto the TDMA frame structure 3–99. . . . . . . . . . . . . . . . . . . Voice Activity Detection – VAD 3–105. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Discontinuous Transmission – DTX 3–105. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Receive diversity 3–106. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Subscriber environment 3–108. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Subscriber hardware 3–108. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Environment 3–108. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Distribution 3–109. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Most demanding 3–110. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Future planning 3–111. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The microcellular solution 3–112. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Layered Architecture 3–112. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Combined cell architecture 3–113. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Combined cell architecture structure 3–114. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Expansion solution 3–115. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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BSS cell planning

Planningrequirements

� ��

��

� ��

� Offers good frequency efficiency.

� Implemented at low cost.

� High grade of service.

These requirements, when analyzed, actually conflict with one another. Therefore theoperating network is always a solution achieved through compromise.

The cost of different network configurations can vary considerably. From an engineeringpoint of view it would be worth while using the most frequency efficient solutions despitetheir high cost, but a mobile telephone network is so huge an investment that thefinancial factors are always going to limit the possibilities. The effect of limited funds isparticularly obvious when the first stage of the network is being built. Consequently,economical planning is a condition for giving the best possible service from the start.

The use of the GSM900, EGSM, and DCS1800 frequency bands, create manypropagation based problems. Because the channel characteristics are not fixed, theypresent design challenges and impairments that must be dealt with to protect MStelephone users from experiencing excessively varying signal level and lack of voicequality.

It is important to be able to predict the RF path loss between the BTS and the MS withinthe coverage area in different types of environment. To do this it is necessary to haveknowledge of the transmitter and receiver antenna heights, the nature of the environmentand the terrain variations.

GSM-001-103BSS cell planning



Planning factors

When planning the network there are a number of major factors which must beconsidered to enable the overall system requirements to be met.

1. Planning tools.

2. GSM frequency spectrum:

Modulation techniques and channel spacing.

3. Traffic capacity:

Unit of measure and grade of service.

4. Capacity calculations:

Typical call parameters.

5. Control channel calculations:

Number of CCCH per BTS cell.Number of SDCCH per BTS cell.Control channel configurations.

6. GPRS effective load.

7. Propagation effects on GSM frequencies:

Introduction to decibels.Fresnel zoneRadio refractive index.Environmental effects on propagation.Multipath propagation.Free space loss.Plane earth loss.Antenna gain.Clutter factor.Power budget and system balance.

8. Frequency re-use:

Re-use patterns.Carrier to interference ratio.Co-channel interference.Adjacent channel interference.Sectorization of sites.

9. Overcoming adverse propagation effects:

Frequency/baseband/synthesizer hopping.Block and diagonal interleaving.Directional antennas, sectorization.Uplink and downlink power control.Discontinued transmissions.Receive diversity.Equalization.

10. Subscriber environment:

Environment.Future planning.

11. The microcellular solution.

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Planning tools

Introduction

In order to predict the signal strength in a cell area it would be necessary to make manycalculations, at regular intervals, from the BTS. The smaller the interval the moreaccurate the propagation model. Also the calculations would need to be performed atregular distances along each radial arm from the BTS, to map the signal strength as afunction of distance from the BTS.

The result, is the necessity to perform hundreds of calculations for each cell. This wouldbe time consuming in practice, but for the intervention of the software planning tool.

This can be fed with all the details of the cell, such as:

� Type of terrain.

� Environment.

� Heights of antennas.

It can perform the necessary number of calculations needed to give an accurate pictureof the propagation paths of the cell.

Several planning tools are available on the market, such as Netplan or planet, and it is upto the users to choose the tool(s) which suit them best.

After calculation and implementation of the cell, the figures should then be checked bypractical measurements. This is because, with all the variable factors in propagationmodelling, an accuracy of 80% would be considered excellent.

GSM-001-103GSM frequency spectrum



GSM frequency spectrum

The GSM900frequencyspectrum

The original GSM frequency spectrum was allocated in 1979. This consisted of twosub-bands 25 MHz wide. The frequency range is:

� Uplink range 890 MHz – 915 MHz.

� Downlink range 935 MHz – 960 MHz.

It is usual for the uplink frequencies – mobiles transmit to the BTS – to be on the lowestfrequency band . This is because there is a lower free space path loss for lowerfrequencies. This is more advantageous to the mobile as it has a reduced transmit outputpower capability compared to the BTS.

The two bands are divided into channels, a channel from each band is then paired withone of the pair allocated for uplink and one for the downlink. Each sub-band is dividedinto 124 channels, these are then given a number known as the Absolute RadioFrequency Channel Number (ARFCN). So a mobile allocated an ARFCN will have onefrequency to transmit on and one to receive on. The frequency spacing between the pairis always 45 MHz for GSM. The spacing between individual channels is 200 kHz and atthe beginning of each range is a guard band. It can be calculated that this will leave 124ARFCNs for allocation to the various network operators. These ARFCNs are numbered 1to 124 inclusive

To provide for future network expansion more frequencies were allocated to GSM as theybecame available. An extra 10 MHz was added on to the two GSM bands and thisbecame known as Extended GSM (EGSM). The EGSM frequency range is:–



This allows another 50 ARFCNs to be used bringing the total to 174. These additionalARFCNs are numbered 975 to 1023 inclusive.

One thing to note is that original Phase 1 MSs can only work with the original GSMfrequency range and it requires a Phase 2 MS to take advantage of the extra ARFCNs.As the operator cannot guarantee that his network will have a significant number ofPhase 2 MS, care must be taken when using EGSM frequencies not to make holes in thenetwork for Phase 1 MSs.

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The DCS1800frequencyspectrum

As GSM evolved it was decided to apply the technology to the Personal CommunicationsNetworks. This required changes to the air interface to modify the frequency range overwhich it operates. The modified frequency range is:



This provides 374 ARFCNs with a frequency separation of 95 MHz between uplink anddownlink frequencies.

In the UK these ARFCNs have been shared out between the four network operators,refer to Figure 3-1. Two of these, Orange and One to One operate exclusively in theDCS1800 range while the other two, Vodafone and Cellnet have been allocatedDCS1800 channels on top of their GSM900 networks. ARFCNs are numbered from 512to 885 inclusive

The portion at the top of the band is used by Digital enhanced Cordless telephony(DECT).

DECT

Orange

One – 2 – One

Vodafone/Cellnet

DownlinkUplink

1785MHz

1781.5MHz

1721.5MHz

1710MHz

1880MHz

1876.5MHz

1816.5MHz

1805MHz

DECT

Orange

One – 2 – One

Vodafone/Cellnet

Figure 3-1 UK network operators

GSM-001-103GSM frequency spectrum



The PCS1900frequencyspectrum

This is another adaptation of GSM into the 1900 MHz band. It is used in the UnitedStates where the Federal Communications Commission has divided the band into 300ARFCNs and issued licences to various operators to implement GSM networks. Thefrequency separation is 80 MHz. The frequency range is :



Absolute radiofrequencychannel capacity

Each RF carrier supports eight time division multiplexed physical channels and each ofthese is capable of supporting speech or signalling information. The maximum number ofRF carriers at any one BTS site is 24 for M-Cell6 and 25 for BTS6. Therefore themaximum number of physical channels available at a BTS site is 24 x 8 = 192, forM-Cell6 and 25 x 8 = 200, for BTS6.

BTSMaximum 24 carriers for M-Cell6

Maximum 25 carriers for BTS6

72 410 653

Figure 3-2 Eight TDMA timeslots per RF carrier

GSM-001-103 GSM frequency spectrum


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Modulationtechniques andchannel spacing

The modulation technique used in GSM is Gaussian minimum shift keying. This works byshaping the data to be modulated with a Gaussian filter. The filter removes some of theharmonics from the data square wave producing a more rounded shape. When this isapplied to a phase modulator the result is a modified envelope shape at the output of themodulator. The bandwidth of this envelope is narrower than that of a comparable oneproduced from non-filtered data. With each modulating carrier occupying a narrowerbandwidth, more efficient use can be made of the overall bandwidth available.

The bandwidth allocated to each carrier frequency in GSM is 200 kHz. The actualbandwidth occupied by a transmitted GSM carrier is far greater than 200 kHz, even withGaussian filtering. The signal therefore overlaps into surrounding frequencies, asillustrated in Figure 3-3. If two carriers from the same or adjacent cells are allocatedadjacent frequencies or channel numbers they will interfere with each other because ofthe described overlapping. This interference is unwanted signal noise. All noise iscumulative, so starting with a large amount by using adjacent channels our wanted signalwill soon deteriorate below the required quality standard. For this reason adjacentfrequencies should never be allocated to carriers in the same or adjacent cells.

Figure 3-3 illustrates the fact that the actual bandwidth of a GMSK modulated signal isconsiderably wider than the 200 kHz channel spacing specified by GSM. At the channeloverlap point the signal strength of the adjacent channel is only –10 dB below that of thewanted signal. While this just falls within the minimum carrier to interference ratio of 9 dB,it is not insignificant and must be planned around so that allocation of adjacentfrequencies in adjacent cells never occurs.

One other consideration about channel spacing that must be considered is when usingcombiners. If a cavity combining block is used the frequencies for combining must beseparated by at least three ARFCNs otherwise it could cause intermodulation productsand spurious frequency generation. These could interfere with other carriers further awayin the radio spectrum, possibly in adjacent cells, so they would not necessarily be aproblem to the home cell so the source of interference becomes more difficult to locate.

CHANNEL 1 CHANNEL 2 CHANNEL 3

200 kHz

–10 dB POINT

0

–10

–20

–30

–40

–50–60

–70

dBs

Figure 3-3 Modulation techniques and channel spacing

GSM-001-103Traffic capacity



Traffic capacity

Dimensioning

One of the most important steps in cellular planning is system dimensioning. Todimension a system correctly and hence all the supporting infrastructure, some idea ofthe projected usage of the system must be obtained (for example; the number of peoplewishing to simultaneously use the system). This means traffic engineering.

Consider a cell with N voice channels, the cell is therefore capable of carrying Nindividual simultaneous calls. The traffic flow can be defined as the average number ofconcurrent calls carried in the cell. The unit of traffic intensity is the Erlang, traffic definedin this way can be thought of as a measure of the voice load carried by the cell. Themaximum carried traffic in a cell is N Erlangs, which occurs when there is a call on eachvoice channel all of the time.

If during a time period T (seconds), a channel carries traffic is busy for t (seconds), thenthe average carried traffic, in Erlangs, is t/T. The total traffic carried by the cell is the sumof the traffic carried by each channel. The mean call holding time is the average time achannel is serving a call.

GSM-001-103 Traffic capacity


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Channel blocking

The standard model used to dimension a system is the Erlang B model, which modelsthe number of traffic channels or trunks required or a given grade of service and givenoffered traffic. There will be times when a call request is made and all channels or trunksare in use, this call is then blocked. The probability of this happening is the grade ofservice of the cell. If blocking occurs then the carried traffic will be less than the offeredtraffic. If a call is blocked, the caller may try again within a short interval.

Repeated call attempts of this type increase the offered traffic above the level if there hadbeen an absence of blocking. Because of this effect the notion of offered traffic issomewhat confused, however, if the blocking probability is small, it is reasonable toignore the effect of repeated call attempts and assume that blocked calls are abandoned.

The number of calls handled during a 24 hour period varies considerably with time. Thefigure opposite shows the type of traffic load that might be expected on a typical call.There are usually two peaks during week days, although the pattern can change fromday to day. Across the typical day the variation is such that a one–hour period showsgreater usage than any other. From the hour with the least traffic to the hour with thegreatest traffic, the variation can exceed 100:1.

To add to these fairly regular variations, there can also be unpredictable peaks caused bya wide variety of events (for example; the weather, natural disasters, conventions, sportsevents). In addition to this, system growth must also be taken into account. There are aset of common definitions to describe this busy hour traffic loading.

Busy Hour: The busy hour is a continuous period during which traffic volume or numberof call attempts is the greatest.

Peak Busy Hour: The busy hour each day it is not usually the same over a number ofdays.

Time Constant Busy Hour: The one–hour period starting at the same time each dayfor which the average traffic volume or call attempts count is greatest over the daysunder consideration.

Busy Season Busy Hour: The engineering period where the grade of service criteria isapplied for the busiest clock hour of the busiest weeks of the year.

Average Busy Season Busy Hour: The average busy season busy hour is used fortrunk groups and always has a grade of service criteria applied. For example, for theAverage Busy Season Busy Hour load, a call requiring a circuit in a trunk group shouldnot encounter All Trunks Busy (ATB) no more than 1% of the time.

Peak loads are of more concern than average loads when engineering traffic routes andswitching equipment.

GSM-001-103Traffic capacity



Traffic flow

If mobile traffic is defined as the aggregate number of MS calls (C) in a cell with regard tothe duration of the calls (T) as well as their number, then traffic flow (A) can be definedas:

Traffic Flow (A) = C x T

Where: C is: the calling rate per hour.

T the average holding time per call.

Suppose an average hold time of 1.5 minutes is assumed and the calling rate in the BusyHour is 120, then the traffic flow would be 120 x 1.5 = 180 call-minutes or 3 call hours.One Erlang of traffic intensity on one traffic channel means a continuous occupancy ofthat particular traffic channel.

Considering a group of traffic channels, the traffic intensity in Erlangs is the number ofcall-seconds per second or the number of call-hours per hour. As an example; if therewere a group of 10 traffic channels which had a call intensity of 5 Erlangs, then half of thecircuits would be busy at the time of measurement.

Grade of service

One measure of the quality of service is how many times a subscriber is unsuccessful insetting up a call (blocking). Blocking data states what grade of service is required and isgiven as a percentage of the time that the subscriber is unable to make a call. Typicalblocking for the MS–BSC link is 2% with 1% being acceptable on the BSC–MSC link.There is a direct relationship between the grade of service required and the number ofchannels. The customers desired grade of service has a direct affect on the number ofchannels needed in the network.

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Capacity calculations

Introduction

This section provides information on how to determine the number of control channelsrequired at a BTS.

This information is required for the sizing of the links to the BSC, and is required whencalculating the exact configuration of the BSC required to support a given BSS.

Typical callparameters

The number of control channels and GPROC2s required at a BTS depend on a set of callparameters; typical call parameters for BTS planning are given in Table 3-1.

Table 3-1 Typical parameters for BTS call planning

Parameter Assumed Value

Call duration T = 120 seconds

Ratio of SMSs per call S = 0.1

Ratio of location updates to calls: non-border location area l = 2

Ratio of location updates to calls: border location area l = 7

Ratio of IMSI detaches to calls �d = 0

Location update factor: non-border location area (see below) L = 2

Location update factor: border location area (see below) L = 7

Number of handovers per call H = 2.5

Paging Rate in pages per second P = 3

Time duration for location update TL = 4 seconds

Time duration for SMSs TSMS = 6seconds

Time duration for call set-ups TC = 5 seconds

Guard time for SDCCHs Tg = 4 seconds

GSM-001-103Capacity calculations





Probability of blocking for TCHs PB-TCH < 2%

Probability of blocking for SDCCHs PB-SDCCH < 1%

The location update factor (L) is a function of the ratio of location updates to calls (I), theratio of IMSI detaches to calls (�d) and whether the short message sequence (type 1) orlong message sequence (type 2) is used for IMSI detach; typically �d = 0 (that is IMSIdetach is disabled) as in the first formula given below. When IMSI detach is enabled, thesecond or third of the formulas given below should be used. The type of IMSI detachused is a function of the MSC.

If IMSI detach is disabled:

L = I

If IMSI detach type 1 is enabled:

L = I + 0.2 * �d


L = I + 0.5 * �d

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Control channel calculations

Introduction

There are four types of air interface control channels, they are:

� Broadcast control channel (BCCH).

� Common control channel (CCCH).

� Standalone dedicated control channel (SDCCH).

� Cell broadcast channel (CBCH), which uses one SDCCH.

There are three configurations of control channels, each occupies one radio timeslot:

� A combined control channel.

One BCCH plus three CCCH plus four SDCCH.

or

� A non-combined control channel.

One BCCH plus nine CCCH (no SDCCH).

plus

� An SDCCH control channel.

Eight SDCCH.

Each sector/cell requires a BCCH, so one of the configurations is always required.

The number of air interface control channels required for a site, is dependent on the:

� Number of pages.

� Location updates.

� Short message services.

� Call loading.

� Setup time.

Only the number of pages and access grants affects the CCCH. The other informationuses the SDCCH.

GPRS controlchannel RFprovisioning

Control channels can be equipped to a GPRS carrier or to a circuit switched GSM carrierto support GPRS traffic channels. If the control channel timeslot(s) are assigned to aGPRS carrier, this reduces the number of available GPRS timeslots from eight to asmaller number in direct proportion to the number used as control channels. Alternatively,by equipping the control channels to the circuit switched GSM carrier, all eight timeslotson the GPRS carrier remain available for use as GPRS timeslots.

The network planner needs to combine the GSM circuit switched signalling requirementswith the GPRS signalling requirements in order to plan the appropriate level of controlchannel support. This planning guide provides the planning rules that enable the network

GSM-001-103Control channel calculations



planner to evaluate whether a combined BCCH can be used, or if a non-combined BCCHis required. The decision to use a non-combined BCCH is a function of the combinedGPRS and GSM signalling load on the PAGCH ,and on the number of SDCCH channelsrequired to support the GSM circuit switched traffic.

The use of a combined BCCH is desirable because it may permit the use of only onetimeslot on a carrier that is used for signalling. A combined BCCH can offer 4 moreSDCCH blocks for use by the GSM circuit switched signalling traffic. If more than anaverage of three CCCH blocks, or more than four SDCCH blocks, is required to handlethe signalling load, more control channel timeslots are required.

The planning approach for GPRS/GSM control channel provisioning is to determinewhether a combined BCCH is possible, given the combined GPRS and GSM load on theCCCH control channel. When more than three CCCH blocks and less than nine CCCHblocks are required to handle the combined load, the use of a combined BCCH is notpossible. When more than nine CCCH blocks are needed, one or more timeslots arerequired to handle the CCCH signalling. In this case, it may be advantageous to use acombined BCCH again, depending on the CCCH and SDCCH load. The determination ofhow many CCCH and SDCCH blocks are required to support the circuit switched GSMtraffic is deferred to the network planning that is performed with the aid of the relevantplanning information for GSM. The network planning that is performed using the planninginformation determines how many CCCH and SDCCH blocks are required, andsubsequently how many timeslots in total are required, to support the CCCH and SDCCHsignalling load.

The downlink control channels are: FCCH, SCH, BCCH, PAGCH. The Paging AccessGrant CHannel (PAGCH) consists of paging messages and access grant messages. Thedownlink control channel load is determined by evaluating the combined GSM circuitswitched signalling traffic load and the GPRS signalling traffic load on the PAGCH.

The uplink control channel is the Random Access CHannel (RACH). It is assumed thatby adequate provisioning of the downlink portion of the Common Control CHannel(CCCH), the uplink portion is implicitly provisioned with sufficient capacity.

The provisioning of the Paging Access Grant CHannel (PAGCH) is estimated bycalculating the combined load from the GPRS pages, GSM pages, GPRS access grantmessages, and GSM access grant messages. The calculation is performed by addingthe estimated GPRS and GSM paging blocks for the BTS cell to the estimated number ofGPRS and GSM access grant blocks for the BTS cell, and dividing that sum by theCCCH utilization factor.

Equation 19 should be evaluated to determine whether the number of PAGCHs isgreater than three. If the evaluation is greater than three, three CCCH blocks are notsufficient: a non-combined BCCH must be used, independent of the number of SDCCHchannels that are calculated as part of the BSS GSM circuit switched planning. If morethan nine CCCH blocks are needed, more non-combined timeslots may be required.Example control channel configurations are shown in Table 3-2.



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Table 3-2 Control channel configurations

Timeslot 0 Other timeslots Comment

1 BCCH + 3 CCCH +

4 SDCCH

N x 8 SDCCH One combined BCCH. Theother timeslot may or maynot be required dependingon the support of circuitswitched traffic, where thevalue of N can be >=0.

1 BCCH + 9 CCCH N x 8 SDCCH Non-combined BCCH. Thevalue of N is >=1.

1 BCCH + 9 CCCH N x 8 SDCCH, 9 CCCH Non-combined BCCH. Thisis an example of one extratimeslot of CCCHs added insupport of GPRS traffic.The value of N is >= 1.

The number of GPRS and GSM paging blocks are summed together in Equation 20 .

Equation 19

NPAGCH � (NPCH � NAGCH)�UCCCH

Each term in the above equation is determined as per Equation 21 and Equation 22 .

Where: NPAGCH is: The average number ofpaging / Access Grantblocks rounded up to aninteger.

NPCH The average number ofpaging blocks required ata cell.

NAGCH The average number ofAccess Grant blocksrequired at a cell.

UCCCH This is a utilization factorbased on the percentageof the CCCH bandwidththat can be reliably used.A typical value for UCCCHis 30%.

The number of GPRS and GSM paging blocks are summed together in Equation 20 .




Equation 20

NPCH � NPCH_GPRS � NPCH_GSM

Each term in the above equation is determined as per Equation 21 and Equation 22 .

Where: NPCH is: The average number ofpaging blocks in support ofGPRS and GSM trafficrequired at a cell.

NPCH_GPRS The average number ofpaging blocks in support ofGPRS traffic.

NPCH_GSM The average number ofpaging blocks in support ofGSM traffic.

Equation 21

NPCH_GPRS � GPRS_Page_Rate�(1.5 * 4.25)

Where: NPCH_GPRS is: The average number ofpaging blocks in support ofGPRS traffic required at acell.

GPRS_Page_Rate The number of GPRSpages transmitted to aBTS cell per second.

Equation 22

NPCH_GSM � GSM_Page_Rate�(1.5 * 4.25)

Where: NPCH_GSM is: The average number ofpaging blocks in support ofGSM traffic required at acell.

GSM_Page_Rate The number of GSMpages transmitted to aBTS cell per second.

Where the denominator factor of 1.5 in Equation 21 and Equation 22 reflects that onepage can be used for an average of 1.5 mobiles. The factor of 4.25 is the number ofpaging messages per second supported by one CCCH block.

The factors of 1.5 in Equation 21 and in Equation 22 take into account the pagingmessage packing efficiency experienced at the cell.

The number of GPRS and GSM access grant channel blocks is summed in Equation 23 .



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Equation 23

NAGCH � NAGCH_GPRS � NAGCH_GSM

Where: NAGCH is: The average number ofaccess grant blocksrequired at a cell.

NAGCH_GPRS The average number ofGPRS access grantblocks required at a cell.

NAGCH_GSM The average number ofGSM access grant blocksrequired at a cell.

Each term in Equation 23 above is determined by Equation 24 and Equation 25respectively.

Equation 24

NAGCH_GPRS �

(�BURST_GPRS)(4.25)

Where: NAGCH_GPRS is: The number of GPRSaccess grant blocksrequired at a cell.

lBURST_GPRS This number includes alldownlink bursts persecond in support of alluplink and downlink GPRStemporary data flow (TBF)originations. GPRS datatraffic includes all SMStraffic carried by theGPRS infrastructure.Additionally, this factorincludes routeing areaupdates and cell updates.

Before the GPRS network is operational, the above values in Equation 24 must bedetermined by the operator. Once the network is operational, these values can beobtained by inspecting the BSS busy hour statistics.

Equation 25

NAGCH_GSM �

�CALL_GSM � �L_GSM � �S_GSM

1.5 * 4.25

The factors in the above Equation 25 are defined as follows.

Where: NAGCH_GSM is: The average number ofGSM access grant blocksrequired at a cell.

λCALL_GSM The call arrival rate persecond.

λL_GSM The location update rateper second.

λS_GSM The number of SMSmessages per second.




Number of CCCHper BTS cell

The following factors should be considered when calculating the number of CCCH perBTS cell:

� The CCCH channels comprise the paging and access grant channel (PAGCH) inthe downlink, and the random access channel (RACH) in the uplink. The PAGCHis subdivided into access grant channel (AGCH) and paging channel (PCH).

� If the CCCH has a low traffic requirement, the CCCH can share its timeslot withSDCCHs (combined BCCH). If the CCCH carries a high traffic a non-combinedBCCH must be used:

– Combined BCCH (with four SDCCH).

Number of CCCH blocks = 3.

Number of CCCH blocks reserved for AGCH ag_blks_res is 0 to 2.

Number of CCCH blocks available for PCH/AGCH is 3 to 1.

– Non combined BCCH.

Number of CCCH blocks = 9.

Number of CCCH blocks reserved for AGCH ag_blks_res is 0 to 7.

Number of CCCH blocks available for PCH is 9 to 2.

� When a non-combined BCCH is used, it is possible to add additional CCCH controlchannels (in addition to the mandatory BCCH on timeslot 0). These additionalCCCH control channels are added, in order, on timeslots 2, 4, and 6 of the BCCHcarrier. Thus creating cells with 18, 27, and 36 CCCH blocks. These configurationswould only be required for very high capacity cells or in large location areas with alarge number of pages.

� Each CCCH block can carry one message. The message capacity of each CCCHblock is 4.25 messages/second.

� The AGCH is used to send immediate assignment and immediate assignmentreject messages. Each AGCH immediate assignment message can conveychannel assignments for up to two MSs. Each AGCH immediate assignment rejectmessage can reject channel requests from up to four MSs.

� The PCH is used to send paging messages. Each PCH paging message cancontain pages for up to four MSs using TMSI or two MSs using IMSI. If no pagingmessages are to be sent in a particular CCCH block, then an immediateassignment/immediate assignment reject message can be sent instead.

The current Motorola BSS implementation applies the following priority (highest tolowest) for downlink CCCH messages:

– Paging message (if not reserved for AGCH).

– Immediate assignment message.

– Immediate assignment reject message.

Thus, for example, if for a particular PAGCH sub-channel there are always pagingmessages (that is high paging load) waiting to be sent, no immediate assignmentor immediate assignment reject messages will be sent on that PAGCHsub-channel. Hence the option to reserve CCCH channels for AGCH.



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� It can normally be assumed that sufficient capacity exists on the uplink CCCH(RACH) once the downlink CCCH (PAGCH) is correctly dimensioned.

� A number of other parameters may be used to configure the CCCH channels.Some of these are:

– Number of paging groups. Each MS is a member of only one paging groupand only needs to listen to the PCH sub-channel corresponding to thatgroup. Paging group size is a trade off between MS idle-mode battery lifeand speed of access (for example, a lot of paging groups, means the MSneed only listen very occasionally to the PCH but as a consequence it takeslonger to Page that MS resulting in slower call setup as perceived by aPSTN calling party).

– Number of repetitions for MSs attempting to access the network on theRACH.

– Time MS must wait between repetitions on the RACH.

� Precise determination of the CCCH requirements may be difficult; however, anumber of statistics can be collected (for example ACCESS_PER_PCH,ACCESS_PER_AGCH by the BSS and these may be used to determine theCCCH loading and hence perform adjustments.

Calculate the number of CCCHs per BTS cell The following planning actions are required:

� Determine the number of CCCHs per BTS.

The average number of blocks required to support AGCH and PCH is given by:

NPAGCH = (NAGCH + NPCH) 1UCCCH

The average number of blocks required to support AGCH only is given by:

NAGCH � �AGCH1

2 � 4.25

The average number of blocks required to support TMSI paging only isgiven by:

NPCH �P

4 � 4.25

The average number of blocks required to support IMSI paging only is givenby:

NPCH �P

2 � 4.25

The access grant rate is given by:

�AGCH � �call � �L � �S

Where: UCCCH is: the CCCH utilization.

�AGCH the access grant rate (per second).

P the paging rate per second.

�call the call arrival rate per second.

�L the location update rate per second.

�S the number of SMSs per second.




Number ofSDCCH per BTScell

Determining the SDCCH requirement is an important part of the planning process. TheSDCCH is where a large portion of call setup messaging takes place. As the number ofcalls taking place in a BTS increases, greater demand is placed on the control channelfor call setup.

The following factors should be considered when calculating the number of SDCCH perBTS cell:

� To determine the required number of SDCCHs for a given number of TCHs persector, the call, location update, and SMS (point to point) rates must bedetermined.

Refer to the equations below for information on calculating these rates. Oncethese rates are determined, the required number of SDCCHs for the given numberof TCHs can be determined. Refer to the equations below for information oncalculating the required number of SDCCHs.

� The rates for SMS are for the SMSs taking place over an SDCCH. For MSsinvolved in a call, the SMS may take place over the TCH, and may not require theuse of an SDCCH.

� Calculating the number of SDCCHs required is necessary for each cell at a BTSsite.

� The equation below for NSDCCH is used to determine the average number ofSDCCHs. The number of Erlangs, e, is the number of Erlangs supported by agiven sector based on the number of TCHs in that sector. To determine thenumber Erlangs support by a sector use Erlangs B. Use Erlang B to determine therequired number of SDCCHs necessary to support the desired grade of service.

� The number of location updates will be higher for sites located on the borders oflocation areas, as compared to inner sites of a location area. See Figure 3-4.

LOCATION AREA

BORDER BTS =

INNER BTS =

Figure 3-4 Location area diagram



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Calculate the number of SDCCHs per BTS cell The following planning actions are required:

� Determine the number of SDCCHs per BTS.

The average number of SDCCHs is given by:

NSDCCH = �call � Tc � �LU � �TL � Tg� � �S ��TS � Tg�

The call rate (calls per hour) is given by:

�call = eT

The location update rate (LU per hour) is given by:

�LU = L �eT

The SMS rate (SMS per hour) is given by:

�S = S �eT

Where: NSDCCH is: the average number of SDCCHs.

�call the call arrival rate per second.

Tc the time duration for call setup.

�LU the location update rate.

TL the time duration of location updates.

Tg the guard time for SDCCH.

�S the number of SMSs per second.

TS the time duration of SMS (short message servicesetup).

e the number of Erlangs per cell.

T the average call length in seconds.

L the ratio of location updates to calls.

S the ratio of SMSs to calls.




Control channelconfigurations

Table 3-3 and Table 3-4 give typical control channel configurations based on the typicalBTS planning parameters given in Table 3-1.

Control channel configurations for non-border location area

Table 3-3 is for the non-border location area cell, where the ratio of location updates tocalls is 2.

Table 3-3 SDCCH planning for typical parameters (non-border location area)

Numberof

RTF

Numberof

TCH

Numberof

E l

Numberof

SDCCH

Timeslot utilization

RTFs TCHs Erlangs SDCCHs Timeslot 0 Other timeslots

1 7 2.94 4 1 BCCH + 3 CCCH+ 4 SDCCH

2 14 8.20 8 1 BCCH + 9 CCCH 8 SDCCH

3 22 14.9 8 1 BCCH + 9 CCCH 8 SDCCH

4 30 21.9 12 1 BCCH + 3 CCCH+ 4 SDCCH

8 SDCCH

5 38 29.2 12 1 BCCH + 3 CCCH+ 4 SDCCH

8 SDCCH

6 45 35.6 16 1 BCCH + 9 CCCH 2 x 8 SDCCH

7 53 43.1 16 1 BCCH + 9 CCCH 2 x 8 SDCCH

8 61 50.6 20 1 BCCH + 3 CCCH+ 4 SDCCH

2 x 8 SDCCH

9 69 58.2 20 1 BCCH + 3 CCCH+ 4 SDCCH

2 x 8 SDCCH

10 77 65.8 20 1 BCCH + 3 CCCH+ 4 SDCCH

2 x 8 SDCCH

11

12

The CBCH reduces the number of SDCCHs by one and may require anotherchannel.

NOTE



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Control channel configurations for border location area

Table 3-4 is for the border location area cell, where the ratio of location updates to calls is7.

Table 3-4 SDCCH planning for typical parameters (border location area)

Numberof

RTFs

Numberof

TCHs

Numberof

Erlangs

Numberof

SDCCHs

Timeslot utilization

RTFs TCHs Erlangs SDCCHsTimeslot 0 Other timeslots

1 6 2.28 8 1 BCCH + 9 CCCH 8 SDCCH

2 14 8.20 12 1 BCCH + 3 CCCH+ 4 SDCCH

8 SDCCH

3 21 14.0 16 1 BCCH + 9 CCCH 2 x 8 SDCCH

4 29 21.0 20 1 BCCH + 3 CCCH+ 4 SDCCH

2 x 8 SDCCH

5 36 27.3 24 1 BCCH + 9 CCCH 3 x 8 SDCCH

6 44 34.7 28 1 BCCH + 3 CCCH+ 4 SDCCH

3 x 8 SDCCH

7 51 41.2 36 1 BCCH + 3 CCCH+ 4 SDCCH

4 x 8 SDCCH

8 59 48.7 36 1 BCCH + 3 CCCH+ 4 SDCCH

4 x 8 SDCCH

9 66 55.3 40 1 BCCH + 9 CCCH 5 x 8 SDCCH

10 74 62.8 44 1 BCCH + 3 CCCH+ 4 SDCCH

5 x 8 SDCCH

GSM-001-103The GPRS planning process



The GPRS planning process

Overview of theGPRS planningprocess

The GPRS planning process documentation has the following structure:

� Introduction to the planning process .

� GPRS network traffic estimation and key concepts .

� Air interface planning process .

GSM-001-103 Introduction to the GPRS planning process


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Introduction to the GPRS planning process

Overview theGPRS planningprocessintroduction

The Introduction to the GPRS planning process has the following structure:

� Determination of expected load or overload .

� Network planning flow .

GSM-001-103Introduction to the GPRS planning process



Determination ofexpected load

The planning process begins by determining the expected GPRS load (applied load ) tothe system. The next step is to determine the effective load to the system by weightingthe applied load by network operating parameters. These parameters consist of theexpected BLock Error Rate (BLER) based on the cell RF plan, the protocol overhead(GPRS protocol stack, that is TCP/IP, LLC, SNDCP, RLC/MAC), the expected advantagefrom V.42bis compression and TCP/IP header compression, and the multislot operationof the mobiles and infrastructure.

The effective load at a cell is used to determine the number of GPRS timeslots requiredto provision a cell. The provisioning process can be performed for a uniform loaddistribution across all cells in the network or on an individual cell basis for varying GPRScell loads. The number of GPRS timeslots is the key piece of information that drives theBSS provisioning process in support of GPRS.

The planning process also uses network generated statistics, available after initialdeployment, for replanning a network. The statistics fall into two categories: PCU specificstatistics, and GSN (SGSN + GGSN) statistics. In a later section of this document, all ofthe statistics collected from the GPRS infrastructure are listed. The statistics that areexpected to be useful for network replanning are identified. In this planning document,the statistics used for planning purposes are grouped into four categories: Stats_A,Stats_B, Stats_C, and Stats_D, as indicated in Figure 3-5.

ENTER USER PROFILE(APPLIED LOAD)

CALCULATE BLER ANDPROTOCOL OVERHEAD

IMPACT ON APPLIEDLOAD

BSS/PCU STATS_DGSN (SGSN, GGSN,

OMC-G)

BSS/PCU/GSN STATS_A

BSS/PCU/GSN STATS_B

BSS/PCU GSN STATS_CCONFIGURE

INFRASTRUCTURE

Figure 3-5 GPRS network planning flowchart

GSM-001-103 Introduction to the GPRS planning process


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Networkplanning flow

The remaining chapters of the planning guide are presented in support of the GPRSnetwork planning flowchart (Figure 3-5). The network planning flow is as follows:

� GPRS network traffic estimation and key concepts : This text is intended tointroduce the key concepts involved in planning a network. Because GPRSintroduces the concept of a switchable timeslot that can be shared by both theGSM circuit switched infrastructure and by the GPRS infrastructure, much of thefollowing text is dedicated to the discussion of this topic.

� Customer inputs to the planning process : This chapter provides a table ofinputs that can serve as a guide in the planning process. In subsequent planningsections, references are made to parameters in this table of inputs. A key piece ofinformation that is needed for the planning process is the RF cell plan. Thissubsection discusses the impact of different cell plans on the GPRS provisioningprocess, and how to use this information in order to determine the number ofGPRS timeslots that are required on a per cell basis.

� BSS planning : The hardware and communication link provisioning rules aredetailed in this section based on the number of timeslots required. The number oftimeslots is determined from the applied cell load requirements (cell throughput)that are provided by the network planner.

� GSN complex planning : The hardware and communication links are determinedin this section.

� GPRS network statistics for network replanning : The statistics collected by theBSS and GSN are listed in tabular form, and the statistics that could be valuablefor network replanning are identified.

� Planning examples : A planning example is provided for both the BSS and GSNportions of the GPRS infrastructure.

� Recommended planning guidelines : Based on the network planning rules, a fewrecommended planning guidelines are provided in this section.

GSM-001-103GPRS network traffic estimation and key concepts



GPRS network traffic estimation and key concepts

Overview of theGPRS networktraffic estimationand keyconcepts

The GPRS network traffic estimation and key concepts section has the followingstructure:

� Introduction to the GPRS network traffic estimation and key concepts .

� Dynamic timeslot mode switching .

� Carrier timeslot allocation examples .

� BSS timeslot allocation methods .

� Provisioning the network with switchable timeslots .

� Recommendation .

GSM-001-103 GPRS network traffic estimation and key concepts


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Introduction tothe GPRSnetwork trafficestimation andkey concepts

The GPRS network planning is fundamentally different from the planning of circuitswitched networks. One of the fundamental reasons for the difference is that a GPRSnetwork allows the queuing of data traffic instead of blocking a call when a circuit isunavailable. Consequently, the use of Erlang B tables for estimating the number of trunksor timeslots required is not a valid planning approach for the GPRS packet dataprovisioning process.

The GPRS traffic estimation process starts by looking at the per cell GPRS data trafficprofile such as fleet management communications, email communications, webbrowsing, and large file transfers. Once a typical data traffic profile mix is determined, therequired network throughput per cell can be calculated as measured in kbits per second.The desired network throughput per cell is used to calculate the number of GPRStimeslots required to support this throughput on a per-cell basis.

The estimated GPRS network delay is derived based on computer modeling of the delaybetween the Um interface and the Gi interface. The results are provided in the planningguide. The network delay can be used to determine the mean or average time it takes totransfer a file of arbitrary length. In order to simulate the delay, the following factors areconsidered: traffic load per cell, mean packet size, number of available GPRS carriertimeslots, distribution of CS-1 and CS-2 rate utilization, distribution of Mobile Station(MS) multislot operation (1,2,3, or 4), and BLER.

Use of timeslots

The use of timeslots on a GPRS carrier is different from how they are used in the GSMcircuit switched case. In circuit switched mode, an MS is either in the idle mode ordedicated mode. In the dedicated mode, a circuit is assigned through the infrastructurewhether or not a subscriber is transporting voice or data. In the Idle mode, the networkknows where the MS is, but there is no circuit assigned. In the GPRS mode, a subscriberuses the infrastructure timeslots for carrying data only when there is data to be sent.However, the GPRS subscriber can be attached and not sending data and this stillpresents a load to the GSN portion of the GRPS system, and must be accounted forwhen provisioning the GPRS infrastructure, that is, in state 2 as explained below.

The GPRS mobile states and conditions for transferring between states are provided inTable 3-5 and shown in Figure 3-6 in order to specify when infrastructure resources arebeing used to transfer data. The comment column specifies what the load on theinfrastructure equipment is for that state and only in state 3 does the infrastructureequipment actually carry user data. The infrastructure equipment is planned such thatmany more MSs can be attached to the GPRS network, that is in state 2, than there isbandwidth available to simultaneously transfer data. One of the more significant inputdecisions for the network planning process is to determine and specify how many of theattached MSs are actively transmitting data in the Ready state 3. In the Standby state 2,no data is being transferred but the MS is using network resources to notify the networkof its location. The infrastructure has equipment limits as to how many MSs can be instate 2. When the MS is in state 1, the only required infrastructure equipment support isthe storage of MS records in the HLR.

Network provisioning requires planning for traffic channels and for signalling channelsalso referred to as control channels. The BSS GSR 4.1 release combines the circuitswitched and GPRS control channels together as BCCH/CCCH. This planning guideprovides a planning procedure in a later section for determining the BCCH/CCCH controlchannel capacity needed.




Table 3-5 MM State Model of MS

Presentstate #

Presentstate

Next state Condition forstate transfer

Comments(Present state)

1 IDLE READY(3) GPRS Attach Subscriber is notmonitored by theinfrastructure, that isnot attached toGPRS MM, andtherefore does notload the systemother than the HLRrecords.

2 STANDBY READY(3) PDU Transmission Subscriber isattached to GPRSMM and is beingactively monitoredby theinfrastructure, that isMS and SGSNestablish MMcontext forsubscriber IMSI, butno datatransmission occursin this state.

3 READY IDLE(1) GPRS Detach Data transmissionthrough theinfrastructure occursin the Ready state

3 READY STANDBY(2) Ready timer expiry

or

force to Standby

(The network or theMS can send aGMM signallingmessage to invokeforce to Standby .)

The ready timer(T3314) default timeis 32 seconds. Thetimer value can bemodified during thesignalling processby MS request.

2-60 sec. in 2 sec.increments

or

61-1800 sec. in 60sec. increments.



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PDU transmission

orCancel Location

GPRS Attach

READY timer expiryorForce to STANDBY

STANDBY timerexpiry

GPRS Detach GPRS Attach

PDU reception

GPRS Detachor

Cancel Location

MM State Model of MS MM State Model of SGSN

IDLE

READY

STANDBY

IDLE

READY

STANDBY

READY timer expiryorForce to STANDBYor

Abnormal RLC condition

STANDBY timer expiry

Figure 3-6 MM state models for MS and SGSN




Dynamic timeslotmode switching

This section proposes a network planning approach when utilizing dynamic timeslotmode switching of timeslots on a GPRS carrier. The radio interface resources can beshared dynamically between the GSM circuit switched services and GPRS data servicesas a function of service load and operator preference.

The timeslots on a GPRS carrier can be reserved for GPRS use, for circuit switched useonly, or allocated as switchable . Motorola uses the term switchable to describe atimeslot that can be dynamically allocated for GPRS Data service or for circuit switchedservice.

The timeslot allocation is performed such that the GPRS reserved timeslots areallocated for GPRS use before switchable timeslots. GSM circuit switched timeslots areallocated to the circuit switched calls before switchable timeslots. The switchabletimeslots are allocated with priority given to circuit switched calls.

Motorola has a BSS feature called Concentration at BTS . This feature enables theterrestrial backhaul resources to be dynamically assigned over the E1 links between theBSC and BTS. The terrestrial backhaul resources are managed and allocated inincrements of 16 kbit/s.

When the concentration-at-BTS feature is enabled, it is important to have a sufficientlevel of terrestrial backhaul resources provisioned. This feature has the concept ofreserved and switchable BSC-to-BTS resources. This concentration-at-BTS featureallows the network planner to allocate dedicated or reserved backing pools to reservedGPRS timeslots so that there is a guaranteed level of terrestrial backing available toGPRS traffic. It is recommended that the reserved backing pool is made large enough toserve the expected busy hour GPRS traffic demands on a per BTS site basis.

It is possible for the circuit switched portion of the network to be assigned all of theswitchable terrestrial backing under high-load conditions and, in effect, block GPRSaccess to the switchable timeslots at the BTS. In addition, the reserved GPRS pool ofbacking resources can be taken by the circuit switched portion of the network whenBSC-to-BTS E1 outages occur, and when emergency pre-emption type of calls occur andcannot be served with the pool of non-reserved resources. The concentration-at-BTSfeature does not take the last switchable backhaul timeslot until all of the GPRS traffichas be transmitted, in the case when there are no provisioned reserved GPRS timeslotsat the cell site. Provisioning rules for the concentration-at-BTS feature are described inthe planning information.



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Background and discussion

The initial Motorola BSS GPRS infrastructure product permits up to one carrier per cell tobe provisioned as a GPRS carrier. The GPRS carrier can also be the BCCH/CCCHcarrier. Alternatively, the GPRS carrier can be specified to use all eight timeslots forGPRS traffic and one of the GSM circuit switched carriers in the cell can be designatedas the BCCH/CCCH carrier.

The GPRS carrier can be provisioned to carry a mix of circuit switched traffic and GPRStraffic. There are three provisioning choices:

� Reserved GPRS timeslots allocated only for GPRS use.

� Switchable timeslots dynamically allocated for either GSM circuit switched traffic orGPRS traffic (designated as switchable timeslots by Motorola).

� Remaining GPRS carrier timeslots, if any, only for circuit switched use.

The BSS supports a user definable number of GPRS timeslots and reserved GPRStimeslots. The BSS calculates the number of switchable timeslots by taking the numberof operator allocated GPRS timeslots minus the number of operator allocated reservedGPRS timeslots. The number of circuit switched timeslots on a non-BCCH GPRS carrieris equal to eight timeslots minus the number of GPRS timeslots, that is GPRS timeslotsinclude reserved plus switchable timeslots.

The network planner may have some of the following network planning goals in mindwhen trying to determine when to use reserved timeslots versus and when to useswitchable :

� Use reserved timeslots to guarantee a minimum GPRS quality of service.

� Use switchable timeslots to provide low circuit mode blocking and high GPRSthroughput when the voice busy hour and the GPRS busy hour do not coincide.

� Use switchable timeslots to provide higher GPRS throughput without increasingthe circuit switched blocking rate.

If all the GPRS carrier timeslots are provisioned as switchable , the last availabletimeslot is not given to a circuit switched call until transmission of all the GPRStraffic on that last timeslot is completed. Therefore, there is a circuit switchedblocking on that last timeslot until the timeslot becomes free.

� Use switchable timeslots to provide some GPRS service coverage in low GPRStraffic volume areas.

� Use switchable timeslots to provide extra circuit switched capacity in spectrumlimited areas.

In order to make the decision on how to best allocate reserved and switchabletimeslots, the network planner needs to have a good idea of the traffic level for bothservices. The proposal in this planning guide is to drive the allocation of switchabletimeslots and reserved GPRS timeslots from a circuit switched point of view.

Start by looking at the circuit switched grade of service objectives and the busy hourtraffic level, as measured in Erlangs. Once the circuit switched information is known, thepotential impact on switchable timeslots can be analysed. The GPRS quality of servicecan be planned by counting the number of available reserved GPRS timeslots, and byevaluating the expected utilization of the switchable timeslots by the circuit switchedportion of the network during the GPRS busy hour.




Carrier timeslotallocationexamples

The following two-carrier configuration examples explore different ways a two-carriersystem may provision switchable and reserved GPRS timeslots. All blank timeslots inthe following figures are available only for circuit switched traffic use. The BSS starts thereserved GPRS timeslot allocation at the top of the carrier (timeslot 7), and thenallocates the switchable timeslots, followed by circuit-switched-use-only timeslots.

When GPRS and GSM signalling requirements are added together to be served by atwo-carrier cell, it is highly likely that one timeslot will be used for BCCH and anothertimeslot allocated as an SDCCH timeslot. Therefore, the following examples A toexample E assume that there is an extra timeslot allocated as an SDCCH timeslot (SD)for GSM signalling purposes.

In Example A, Figure 3-7, only four timeslots are used for GPRS on carrier 1; two arereserved GPRS timeslots (R), and two are switchable timeslots (S). One timeslot isused for BCCH (B) and another timeslot for SDCCH (SD), and two timeslots for circuit-switched-only use (blank).

In Example B, Figure 3-8, the GPRS signalling information is carried on the BCCH (B) ofcarrier 1 and SDCCH GSM signalling on a separate timeslot (SD). A separate carrier(carrier 2) is used to carry the GPRS data traffic. In this example, three timeslots arereserved GPRS timeslots and two are switchable . The remaining three timeslots on thesecond carrier are for circuit-switched-only use(blank).

In Example C, Figure 3-9, all GPRS timeslots are configured as switchable timeslots onthe BCCH carrier 1 and no reserved GPRS timeslots are configured. Again, one timeslotis assigned for SDCCH signalling use.

In Example D, Figure 3-10, all GPRS timeslots are configured as switchable timeslotson the non-BCCH carrier, carrier 2.

In Example E, Figure 3-11, all eight GPRS timeslots are configured as reservedtimeslots on the non-BCCH carrier, carrier 2.



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Timeslot allocation for examples A and B

B: BCCH/CCCH timeslot for GPRS/GSM signalling

SD: SDCCH timeslot for GSM signalling

R: Reserved GPRS timeslot

S: Switchable timeslot

Blank: Circuit-switched-use-only timeslots

Figure 3-7 provides a timeslot allocation example A.

CARRIER 1

CARRIER 2 (CIRCUIT SWITCHED ONLY)

B SD S R RS

TS0

Figure 3-7 Example A

Figure 3-8 provides a timeslot allocation example B.


CARRIER 2

B SD

R R RS

TS0

S

Figure 3-8 Example B




Timeslot allocation for examples C, D, and E

B: BCCH/CCCH for GPRS/GSM signalling

SD: SDCCH for GSM signalling

R: Reserved PDCH

S: Switchable PDCH


Figure 3-9 provides a timeslot allocation example C.

CARRIER 1


B SD S S SS

TS0

Figure 3-9 Example C

Figure 3-10 provides a timeslot allocation example D.


CARRIER 2

B SD

S S SS

TS0

S

Figure 3-10 Example D

Figure 3-11 provides a timeslot allocation example E.


CARRIER 2

B SD

R R RR

TS0

RRRR

Figure 3-11 Example E



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BSS timeslotallocationmethods

The BSS algorithm that is used in order to determine allocation of switchable timeslotsgives priority to circuit switched calls. Consequently, if a switchable timeslot is beingused by a GPRS mobile and a circuit switched call is requested after all other circuitswitched timeslots are used, the BSS takes the timeslot away from the GPRS mobile andgives it to the circuit switched mobile.

The switchable timeslot can be re-allocated back to the GPRS mobile when the circuitswitched call ends. The number of reserved GPRS timeslots can be changed by theoperator in order to guarantee a minimum number of dedicated GPRS timeslots at alltimes. The operator provisions the GPRS carrier by selecting the number of timeslotsthat are allocated as reserved and switchable , and not by specifically assigningtimeslots on the GPRS carrier.

Motorola has implemented an idle circuit switched parameter that enables the operator tostrongly favour circuit switched calls from a network provisioning perspective. By settingthe idle parameter to 0, this capability is essentially turned off.

The use of the idle circuit switched parameter is as follows. When a circuit switched callends on a switchable GPRS timeslot and the number of idle circuit switched timeslots isgreater than an operator settable threshold, the BSS re-allocates the borrowed timeslotfor GPRS service. When the number of idle timeslots is less than or equal to aprogrammable threshold, the BSS does not allocate the timeslot back for GPRS service,even if it is the last available timeslot for GPRS traffic.

If the BSS needs to use the last switchable timeslot in a cell for a circuit switched callwhen all of the timeslots are allocated as switchable , re-allocation of the timeslot tocircuit switched must wait until there is no GPRS traffic in the cell. There is no GPRStraffic in the cell when all of the GPRS uplink and downlink BSS infrastructure queues areempty. At this point, the BSS can re-allocate the last switchable timeslot back as acircuit switched timeslot. If one or more timeslots in a cell are allocated as reserved , thelast switchable timeslot is allocated immediately on demand for a circuit switched call.

Multislot mobile operation requires that contiguous timeslots are available. The BSSltakes the lowest numbered switchable timeslot in such a manner as to maintaincontiguous GPRS timeslots for multislot GPRS operation. The BSS attempts to allocateas many timeslots as requested in multislot mode, and then backoff from that number astimeslots are not available. For example, suppose that timeslots 3 and 4 are switchable ,and timeslots 5,6, and 7 are GPRS reserved (see Figure 3-12). When the BSS needs tore-allocate a switchable timeslot from GPRS mode to circuit switched mode, the BSSassigns timeslot 3 before it assigns timeslot 4 for circuit switched mode.




Timeslot allocation for Figure 3-12



R: Reserved PDCH

S: Switchable PDCH


Figure 3-12 provides a timeslot allocation with reserved and switchable timeslots.

R R RS

TS0

S

TS7

Figure 3-12 GPRS carrier with reserved and switchable timeslots

If the Emergency Call Pre-emption feature is enabled, the BSS selects the air timeslotthat carries the emergency call from the following list: (most preferable listed first)

1. Idle circuit switched.

2. Idle or in-service switchable GPRS timeslot (from lowest to highest).

3. In-service circuit switched.

4. Idle or in-service reserved GPRS timeslot (from lowest to highest).



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Provisioning thenetwork withswitchabletimeslots

Provisioning the network with switchable timeslots can offer flexibility in the provisioningprocess for combining circuit switched and GPRS service. This flexibility is in the form ofadditional available network capacity to both the circuit switched and GPRS subscribers,but not simultaneously. Because the BSS favours circuit switched use of the switchabletimeslots, the network planner should examine the demand for switchable timeslotsduring the circuit switched busy hour and during the GPRS busy hour.

Normally the operator provisions the circuit switched radio resource for a particular GradeOf Service (GOS) such as 2%. This means that 2 out of 100 circuit switched calls areblocked during the busy hour. If the operator chooses to use the new switchabletimeslot capability, it is now possible to share some GPRS carrier timeslots between thecircuit switched calls and the GPRS calls.

During the circuit switched busy hour, the circuit switched use of these switchabletimeslots may dominate their use. The circuit switched side of the network has priorityuse of the switchable timeslots, and attempts to provide a better grade of service as aresult of the switchable timeslots being available.

The example in Table 3-6 assumes that the planning is being performed for a cell thathas two carriers. The first carrier is for circuit-switched-only use as shown in Table 3-6.The second carrier is a GPRS carrier; all eight timeslots are configured as switchable asshown in Figure 3-13.

The table was created using the Erlang B formula in order to determine how many circuitswitched timeslots are required for a given grade of service. The table covers the rangeof 2 Erlangs to 9 Erlangs of circuit switched traffic in order to show the full utilization oftwo carriers for circuit switched calls. The purpose of the table is to show how the circuitswitched side of the network allocates switchable timeslots during the circuit switchedbusy hour in an attempt to provide the best possible GOS, assumed to be 0.1% for thepurposes of this example.

The comments column in the table is used to discuss what is happening to the availabilityof switchable timeslots for GPRS data use as the circuit switched traffic increases, asmeasured in Erlangs.

This example does show some Erlang traffic levels that cannot be adequately served bytwo carriers at the stated grade of service listed in the tables. This occurs at the 7 and 8Erlang levels for 0.1% GOS. In these cases, all of the switchable timeslots are used upon the second carrier in an attempt to reach a 0.1% GOS. For the 9 Erlang traffic level, 2carriers is not enough to serve the circuit switched traffic at a 2% GOS. This wouldindicate a need for a second circuit switched carrier, in addition to the first circuitswitched carrier and the GPRS carrier.




Timeslot allocation for



R: Reserved PDCH

S: Switchable TCH


Assumptions: 2 Carrier site.

Figure 3-13 shows one circuit switched carrier with one BCCH/CCCH timeslot, oneSDCCH timeslot, and six TCH timeslots.

TS0 TS7

B SD

Figure 3-13 1 circuit switched carrier with 1 BCCH/CCCH timeslot, 1 SDCCH timeslotand 6 TCH timeslots

Figure 3-14 shows one GPRS carrier with all timeslots (eight TCHs) designated asswitchable.

S S SS

TS0

S

TS7

S S S

Figure 3-14 One GPRS carrier with all timeslots (eight TCHs) designated as switchable

Table 3-6 shows part of the switchable timeslot utilization.



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Table 3-6 Switchable timeslot utilization (part A)

GOS Plannedcircuit

switchedErlangs/cell

Totalnumber of

circuitswitchedtimeslotsrequiredincluding

switchable

Number ofswitchabletimeslotsnecessaryto provide

GOS

Comments

2% 2 6 0 During off busy hour timeperiods, the GPRS carriermost likely carries onlyGPRS traffic. Therefore,GPRS network planningshould be performedassuming there are 8timeslots available forGPRS traffic.

0.1% 2 8 2 During circuit switchedbusy hour at least 2 of theswitchable timeslots areoccasionally used by thecircuit switch side of thenetwork in an attempt toprovide the best possibleGOS - assumed to be onthe order of 0.1%.

2% 3 8 2 During the circuit switchedbusy hour, 2 of theswitchable timeslots areoccasionally used by thecircuit switch side of thenetwork in an attempt toprovide the 2% GOS.

0.1% 3 10 4 During the circuit switchedbusy hour, 4 of theswitchable timeslots areoccasionally used by thecircuit switch side of thenetwork in an attempt toprovide the best possibleGOS - assumed to be onthe order of 0.1%.

2% 4 9 3

0.1% 4 12 6

2% 5 10 4

0.1% 5 14 8 All of the switchabletimeslots are occasionallyused to satisfy the 0.1%GOS.

Table 3-7 shows more switchable timeslot utilization.




Table 3-7 Switchable timeslot utilization (part B)

GOS Plannedcircuit

switchedErlangs/cell

Totalnumber of

circuitswitchedtimeslotsrequiredincluding

switchable

Number ofswitchabletimeslotsnecessaryto provide

GOS

Comments

2% 6 12 6

0.1% 6 15 9 There are not enoughswitchable timeslots toreach 0.1% GOS.

2% 7 13 7


2% 8 14 8 All of the switchabletimeslots are occasionallyused to satisfy the 2%GOS.


2% 9 15 9 There are not enoughswitchable timeslots toreach 2% GOS




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RecommendationThe following recommendation is offered when using switchable timeslots. It isimportant to determine the GOS objectives for circuit switched traffic and QoS objectivesfor GPRS traffic prior to selecting the number of switchable timeslots to deploy.

During the circuit-switched-busy-hour, potentially all switchable timeslots areoccasionally used by the circuit switched calls. The circuit switched timeslot allocationmechanism continues to assign switchable timeslots as circuit switched timeslots as thecircuit switched traffic continues to increase. Therefore, if there is a minimum capacityrequirement for GPRS services, the network planner should plan the GPRS carrier withenough reserved timeslots in order to handle the expected GPRS data traffic. Thisensures that there is a minimum guaranteed network capacity for the GPRS data trafficduring the circuit switched busy hour.

During the circuit-switched-off-busy-hours, the switchable timeslots could be consideredas available for use by the GPRS network. Therefore, in the circuit switched off busyhours potentially all switchable timeslots could be available for the GPRS network traffic.The BSS call statistics should be inspected to determine the actual use of theswitchable timeslots by the circuit switched services.

The circuit-switched-busy-hour and the GPRS-busy-hour should be monitored to see ifthey overlap when switchable timeslots are in use. If the busy hours overlap, anadjustment may be needed to the number of reserved timeslots allocated to the GPRSportion of the network in order to guarantee a minimum GPRS quality of service asmeasured by GPRS throughput and delay. Furthermore, one or more circuit switchedcarriers may need to be added to the cell being planned or replanned so that theswitchable timeslots are not required in order to offer the desired circuit switched gradeof service.

In conclusion, assume switchable timeslots are occasionally unavailable for GPRStraffic during the circuit switched portion of the network busy hour. Provision enoughreserved timeslots for GPRS traffic during the circuit switched busy hour to meet thedesired minimum GPRS quality of service objectives, as measured by GPRS datathroughput.

The following step-wise process is proposed when determining how best to allocateGPRS carrier timeslots.

AssumptionsThe process assumptions are:

� A GPRS carrier can be added to a cell in addition to circuit switched carriers.

� A circuit switched carrier can be used to provide the control channels(BCCH/CCCH/SDCCH) on one or more timeslots as needed.

� The number of circuit switched timeslots are determined as part of the BSSplanning effort prior to the GPRS planning effort.

� When the concentration-at-BTS feature is enabled, a sufficient pool of reservedbacking resources is provisioned in support of the number of reserved GPRStimeslots in order to meet the GPRS QoS objectives.

Step 1Determine how many reserved GPRS timeslots are needed on a per-cell basis in orderto satisfy a GPRS throughput QoS. The GPRS reserved timeslots should equal the sumof the active and standby timeslots that are allocated to a carrier.

Step 2If there are any timeslots left on the GPRS carrier after step 1, consider using them asswitchable timeslots. The use of switchable timeslots can potentially offer increasedcapacity to both the GPRS and circuit switched traffic if the traffic is staggered in time.




Step 3

If there is a need to use some timeslots on the GPRS carrier to satisfy the circuitswitched GOS objectives and the timeslot requirement overlaps with the number ofreserved GPRS timeslots, consider adding another circuit switched carrier to the cell.

Step 4

After deploying the GPRS carrier, review the network statistics listed in the Networkstatistics section on a continuous basis in order to determine whether the reservedGPRS timeslots, switchable GPRS timeslots, and circuit switched timeslots are trulyserving the GOS and QoS objectives. As previously discussed, the use of switchabletimeslots can offer network capacity advantages to both circuit switched traffic and GPRStraffic as long as the demand for these timeslots is staggered in time.

GSM-001-103 GPRS Air interface planning process


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GPRS Air interface planning process

Overview of theGPRS airinterfaceplanning processstructure

The air interface planning process is documented as follows:

� Introduction to the air interface planning process.

� Air interface interface throughput.

� Throughput estimation process: step 1.




GSM-001-103GPRS Air interface planning process



Introduction tothe GPRS airinterfaceplanning process

The air interface planning process uses the range of values listed in Table 3-8 toTable 3-13. If network values are not available at the time a network is planned, typicalor recommended values are provided where appropriate. The minimum values are givenfor the maximum capacity of a minimum system, and the typical values are used asstandard model parameters.

Table 3-8 Air interface planning inputs (part A)

Variable Minimumvalue

Typicalvalue

Maximumvalue

Assumptions/variable use

CS rate ratio,

CS-1/CS-2

Approx. 0 % 10% 100 % CS rate ratio isdetermined by theCell plan, meanTBF size and use ofAcknowledgemode. Refer to cellplan tables:Table 3-14,Table 3-15 andTable 3-16.

V.42 biscompressionratio

1 2.5 4 A ratio of 1 meansthere is nocompression and aratio of 4 is thetheoreticalmaximum, which ismost likely neverrealized. Most userssee a compressionadvantage in therange of 2-to-3 overthe air interfacebetween the MSand the SGSN. Thecompression ratio isused in Equation 3 .

The air interface planning process uses the range of values listed in Table 3-8 toTable 3-13.



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Table 3-9 Air interface planning inputs (part B)


Typicalvalue

Maximumvalue


BLER 0 10% 100% The BLock ErrorRate (BLER) islargely determinedby the cell RF plan.The typical value isan average rate.There are separateBLERs for CS-1and CS-2 rates thatare RF planspecific.

FTD 0.7 second 3 seconds fora 3 kbyte file,subject tonetwork loadand multislotoperation.

File sizedependent

This is the FileTransit Delay (FTD)objective measuredin seconds from theUm interface to theGi interface. Theminimum delay isthe approximatedelay for a RLCblock of 23 bytes orless, which is theminimum systemlimit with only oneuser on the system.The FTD value isdetermined byEquation 4 .

The number ofGPRS timeslotsper cell

0 Networkdependent

8 This number canrepresent reservedand/or switchabletimeslots asexplained fromFigure 3-7 toFigure 3-14.

Number of activeGPRS timeslotsper PCU withredundancy

30 Networkdependent

240 This is the numberof timeslotssimultaneously inuse with N+1redundancy. Thisnumber is used tocalculate thenumber of PRP andPICP boards toequip at the PCUusing the PCUplanning rulestabled in Chapter 5.





Table 3-10 Air interface planning inputs (part C)


Typicalvalue

Maximumvalue


Number ofGPRS usersmonitored at thePCU withredundancy

90 Networkdependent

720 This is the numberof mobiles that canbe monitored inaddition to themobiles actuallyusing timeslots.This value reflectsN+1 redundancy.This numberreflects thecoverage capabilityof the PCU.

Number of activeGPRS timeslotsper PCU withoutredundancy

30 Networkdependent

270 This is the numberof timeslotssimultaneously inuse without N+1redundancy. Thisnumber is used tocalculate thenumber of PRP andPICP boards toequip at the PCUusing the PCUplanning rulestabled in Chapter 5.

Number ofGPRS usersmonitored at thePCU withoutredundancy

90 Networkdependent

810 This is the numberof mobiles that canbe monitored inaddition to themobiles actuallyusing timeslotswithout N+1redundancy. Thisnumber reflects thecoverage capabilityof the PCU.




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Table 3-11 Air interface planning inputs (part D)


Typicalvalue

Maximumvalue


Mean LLC PDUpacket size(bytes)

20 435 1,580 This parameter isused in determiningthe cell andsubscriberthroughputcapacities.

Data traffic/subscriber(peak)

0 98kbytes/hour

No maximumlimit otherthan what thenetwork isprovisioned tosupport.

This parameter isthe expected GPRSload of a subscriber.This figure shouldinclude the SMStraffic carried asGPRS data.





Table 3-12 Air interface planning inputs (part E)


Typicalvalue

Maximumvalue


Total number ofGPRS pages perattachedsubscriber

0 0.6 No maximumlimit otherthan what thenetwork isprovisioned tosupport.

This effects thesignalling traffic loadover theSGSN-to-PCU (Gb)interface, thePCU-to-BSCinterface(GSL), andthe BSC-to-BTSinterface(RSL). TheGPRS paging trafficmust be added tothe circuit switchedsignalling traffic atthe BSC in order todetermine the totalsignalling trafficbetween the BSCand reporting BTSs.This parameter isalso used todetermine theGPRS load on theCCCH.

Number of datatransfers perhour persubscriber

0 No maximumlimit otherthan what thenetwork isprovisioned tosupport

This number is usedto determine theprovisioning of thecontrol channels(CCCHprovisioning).

Number of BSCssupportingGPRS perOMC-R servingarea

1 Networkdependent

64 This establisheshow many PCUsare required perOMC-R servingarea. The size ofthe PCU isdetermined from theGPRS subscriberprofile.

(Provision 1 PCUper BSC.)




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Table 3-13 Air interface planning inputs (part F)


Typicalvalue

Maximumvalue


Equipmentredundancy

(BSS PCU &GSN)

No Yes More equipmentcan be deployedwhen redundancy isdesired.

E1 redundancy No Yes Extra E1 lines aredeployed for GSL,GDS, GBL, and Gilinks whenredundancy isdesired. The extraE1 lines providelogical redundancybecause the trafficis load shared overthe redundant links.

Air interfacethroughput

The GPRS data throughput estimation process given in this planning guide is basedupon the Poisson process for determining the GPRS mobile packet transfer arrivals tothe network and for determining the size of GPRS data packets generated or received bythe GPRS mobiles.

A number of wired LAN/WAN traffic studies have shown that packet interarrival rates arenot exponentially distributed. Recent work argues that LAN traffic is much bettermodelled using statistically self-similar processes instead of Poisson or Markovianprocesses. Self-similar traffic pattern means the interarrival rates appear the sameregardless of the timescale at which it is viewed (in contrast to Poisson process, whichtends to be smoothed around the mean in a larger time scale). The exact nature ofwireless GPRS traffic pattern is not known due to lack of field data.

In order to minimize the negative impact of underestimating the nature of the GPRStraffic, it is proposed in this planning guide to limit the mean GPRS cell loading value to50% of the system capacity. Using this cell loading factor has the following advantages:

� Cell overloading due to the bursty nature of GPRS traffic is minimized.

� The variance in file transit delay over the Um-to-Gi interface is minimized such thatthe delay can be considered a constant value for the purposes of calculating thetime to transfer a file of arbitrary size.

LAN/WAN wireline studies have also shown that even when statistically valid studies areperformed, the results come out very different in follow-up studies. It turns out that webtraffic patterns are very difficult to predict accurately and, therefore, it is highlyrecommended that the network planner makes routine use of the GPRS networkstatistics.

About the stepsThe following steps 1 and 2 are used for dimensioning the system. Step 1 needs to beperformed prior to step 2 in order to calculate the number of GPRS timeslots that shouldbe provisioned on a per cell basis.

Steps 3 and 4 are optional. These steps are included in this section so that anover-the-air file transfer time can be calculated for any size file. The results from steps 3and 4 are dependent upon the choices made in steps 1 and 2.




Step 1:throughputestimationprocess

Choose a cell plan in order to determine the expected BLER and percentage of time datais transferred at the CS-1 rate and at the CS-2 rate. The cell plan that is chosen forGPRS may be determined by the plan currently in use for the GSM circuit switchedportion of the network. However, it may be necessary to change an existing cell planused for GSM circuit switched in order to get better BLER performance for the GPRSportion of the network.

After the cell plan is chosen, the network planner can move on to step 2.

The PCU dynamically selects the best CS-1 or CS-2 rate in order to maximize the GPRSdata throughput on a per mobile basis. The CS-1 and CS-2 rate selection is performedperiodically during the TBF.

Simulations were performed (see Impact of the Radio Interface on GPRS SystemDimensioning – a Simulation Study , Draft 0.1 of June 1999) for two typical frequencyhopping cell configurations; results for a 1x3 cell reuse pattern with 2/6 hopping areshown in Table 3-14 (which is hopping on 2 carriers over 6 frequencies) and results for a1x1 cell reuse pattern with 2/18 hopping are shown in Table 3-15 (which is hopping on 2carriers over 18 frequencies). Results for a non-hopping cell configuration with a TU-3model is shown in Table 3-17 provide a chart of the cell coverage area and cell C/Iperformance for the non-hopping case. The following tables were created, based on thesimulations, in order to indicate the percentage of the time the CS-2 rate would bechosen over the CS-1 rate and at what mean BLER. The simulation results indicate thatthe higher data rate of the CS-2 more than offsets its higher BLER rate in the majority ofthe cell coverage area, resulting in the CS-2 rate being chosen most of the time.

Reviewing the following tables it can be seen that under good cell C/I conditions, betterthroughput may be obtained by provisioning the GPRS timeslots on the BCCH carrier asindicated by Table 3-16.

Table 3-14 1 x 3 2/6 hopping

Parameter CS-1 rate CS-2 rate

% Rate chosen 10 90

% Mean BLER 50 20

Table 3-15 1 x 1 2/18 hopping


% Rate chosen 10 90

% Mean BLER 56 14

Table 3-16 Non–hopping TU-3 model


% Rate chosen 0 100

% Mean BLER 10 3

Table 3-17 provides the cell C/I performance, as measured in dBs, as a function of cellarea coverage for the TU-3 model.



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Table 3-17 Cell coverage versus carrier-to-interface (C/I)

% cell coverage 90 80 70 60 50 40

C/I 12 16 18 20 22 24

The cell plans assume a regular cell reuse pattern for the geographic layout and for theallocation of frequencies. The computer simulation generated the above cell plan using atypical urban 3 kph model, a propagation law with a Radius (R) exponent of -3.7 and ashadowing function standard deviation of 5 db.

If non-regular patterns are used, a specific simulation study may be required to match theparticular cell characteristics. The simulation process is outside the scope of this planningguide and the network planner should contact Motorola for additional simulation results.

Step 2:throughputestimationprocess

Step 2 determines the number of GPRS timeslots that need to be provisioned on a percell basis. Timeslot provisioning is based on the expected per-cell mean GPRS trafficload, as measured in kbit/s. The GPRS traffic load includes all SMS traffic routed throughthe GSN. The SMS traffic is handled by the GPRS infrastructure in the same manner asall other GPRS traffic originating from the PDN. The cell BLER and CS ratecharacteristics chosen in step 1 provide the needed information for evaluating thefollowing Equation 1 .

Equation 1

No_PDCH_TS � Roundup�Mean_trf_ld

(Denom_1) * TBF_SETUP_REL_FACTOR�

Equation 1 is based on the DL traffic load and it is assumed that the DLprovisioning would be sufficient to handle UL traffic, without additionalprovisioning.

NOTE




Equation 2

Denom_1 � ��%CS1100

* (1 � CS1BLER) * 9.05 * �1 �

323��

%CS2100

* (1 � CS2BLER) * 13.4 * �1 �

333�� * �

Mean_ld_f

100�

Where: is:

Mean_trf_ld The mean traffic load, as measured inkbit/s, is defined at the LLC layer thereforeall the higher layer protocol overheads (forexample, TCP, UDP, IP, SNDCP, LLC) areencapsulated in this load figure.

Denom_1 Denominator 1 is used in Equation 1 .

PDCH The number of timeslots per cell,maximum 8.

%CS1 The percent of time data transmissionoccurs using the CS-1 coding scheme.

CS1BLER The mean BLER rate for CS-1.

%C2S The percent of time data transmissionoccurs using the CS-2 coding scheme.

CS2BLER The mean BLER rate for CS-2.

3/23 The CS-1 RLC/MAC overheadpercentage, that is 20 bytes payload.

3/33 The CS-2 RLC/MAC overheadpercentage, that is 30 bytes payload.



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Mean_ld_f The mean load factor for the number ofactive timeslots to provision at a cell. Therecommended value is 50% of the numberGPRS timeslots provisioned at a cell.

TBF SETUPREL factor

TBF SETUP and Release Factor. Therecommended value 0.45. This factor isan interim solution whilst the OverlappingTPF feature is being completed.

The number of PDCH timeslots calculated in Equation 1 includes the number of activetimeslots and the number of standby timeslots. The Mean_load_factor of 50%determines the ratio of active timeslots to standby timeslots. For example, if Equation 1evaluated to 8 timeslots, 4 timeslots would be counted as active timeslots and 4 timeslotsas standby timeslots.

It is important to differentiate between the required number of active timeslots and therequired number of standby timeslots because it directly effects the provisioning of thecommunication links and the PCU hardware. The active timeslots are timeslots that aresimultaneously carrying data. The standby timeslots are timeslots that are beingmonitored by the PCU for an uplink or downlink timeslot request. A request on a standbytimeslot for an active timeslot is granted for an active timeslot as soon as one becomesavailable at the PCU. For example, when the PCU is provisioned to handle 30 activetimeslots and all of them are in use, at least one of these 30 active timeslots mustbecome available in order to move a standby timeslot to active state.

The use of active timeslots and standby timeslots enables several cells to share the PCUresource. While one cell is experiencing a high load condition, using all eight GPRStimeslots for instance, another cell operating below its mean load averages out theGPRS traffic load at the PCU.

The E1s between the BTS and BSC must be provisioned to handle the number oftimeslots calculated in Equation 1 because all of the timeslots can become active underhigh load conditions.




Throughputestimationprocess: step 3(optional)

Step 3 is optional, and the results can be used in optional step 4. Step 3 is intended to beused as an aid in determining the size of a file that is to be transferred as an LLC PDUfrom the mobile to the SGSN, by using Equation 3 .

The file size consists of the application file to be transferred, which includes anyapplication-related overhead. In addition to the application file, there is transport andnetwork layer protocol overhead, TCP and IP. Finally, there is GPRS Link Layer Control(LLC) and SubNetwork Convergence (SNDCP) protocol overhead. The application fileplus all of the protocol overhead summed together makes up the one or more LLC_PDUframes that constitute the file to be transferred.

The percentage of protocol overhead depends on the transport layer used, such as TCPor UDP. For example, the TCP/IP protocol overhead is 40 bytes when TCP/IP headercompression is not used. When TCP/IP header compression is used, the TCP/IP headercan be reduced to 5 bytes from 40 bytes after the first LLC frame is transferred. The useof header compression continues for as long as the IP address remains the same.

Figure 3-15 illustrates the typical LLC_PDU frame with the user application payload andall of the protocol overhead combined for the case of no TCP/IP header compression.

4

64 BYTES<L<1580 BYTES

207 2 20

LLC SNDCP IP TCP APPLICATION CRC

Figure 3-15 LLC PDU layout

If V.42bis application data compression is used, the effective file size for transmission isreduced by the data compression factor which can range from 1 to 4. Typically, V.42bisyields a 2.5 compression advantage on a text file, and close to no compressionadvantage (factor=1) on image files and very short files.



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Equation 3

File_size_LLC �

ApplnV.42bis_factor

� roundup�Appln

V.42bis_factor * LLC_payload� * protocol_overhead

Where: File_size_LLC is: The files size in bytes to betransferred measured at the LLClayer.

Appln The user application data file sizemeasured in bytes.

LLC_payload The maximum LLC PDU payload of1527 bytes.

protocol_overhead The protocol overhead forTCP/IP/SNDCP/LLC/CRC is 53bytes without header compressionand 18 bytes with headercompression.

V.42bis_factor Application data compression isover the range of 1 to 4, a typicalvalue is equal to 2.5.

Example

A 3 kbytes application file transfer requires the following number of bytes to betransferred at the LLC_PDU layer:

Application= 3 kbytes

Assume V.42bis_factor = 1, that is no application data compression

No header compression:

File_size_LLC = 3000 + roundup (3000/1527) x 53 = 3106 bytes

With header compression:

The first LLC_PDU the header is not compressed, and all subsequent LLC_PDUs arecompressed. For this size file of 3000 bytes, only 2 LLC_PDU transmissions are requiredso the File_size_LLC is:

File_size_LLC = 3000 + 53+18 = 3071 bytes

Throughputestimationprocess: step 4(optional)

The network planner can use step 4 to determine how long it takes to transfer a file of anarbitrary size over the Um-to-Gi interface. The application file is segmented into LLCPDU frames as illustrated previously. The File Transit Delay (FTD) is calculated inEquation 4 by using the following information: total number of RLC blocks of the file,BLER, number of timeslots used during the transfer, and mean RLC Transit Delay (RTD)value.

Equation 4 does not include the effects of acknowledgement messages. The reason isthat the largest effect is in the uplink direction, and it is expected that the downlinkdirection will dominate the cell traffic. The DL sends an acknowledgement message onan as-needed basis, whereas the uplink generates an acknowledgement message every2 out of 12 RLC_Blocks. It is expected that the downlink acknowledgement messageswill not significantly effect the file transit delay in the downlink direction.




Equation 4

FTD � RTD �

RLC_Blocks * 0.02 * (1 � CSBLER)mslot

Where: FTD is: The file transit delay measured inseconds.

RTD This is the transit delay time from theUm interface to the Gi interface for afile size of only 1 RLC/MAC block ofdata. RTD is estimated to be 0.9seconds when system running at 50%capacity. This parameter will beupdated when field test data isavailable.

RLC_Blocks This is the total number of RLC blocksof the file. This can be calculated bydividing file_size_LLC by thecorresponding RLC data size of 20bytes for CS-1 and 30 bytes for CS-2.

mslot This is the mobile multislot operatingmode; the value can be from 1 to 4.

CSBLER This is the BLER for the specific CSrate. The value is specified in decimalform. Typical values range form 0.1 to0.2.

The RTD parameter is directly correlated to the system utilization and the mean packetsize. When the cell approaches its throughput capacity limit, the RTD value increasesdramatically, and the infrastructure starts to drop packets. Simulation data indicates thatwhen traffic load is minimal, the RTD value is at a minimum limit of 0.7 seconds. At a cellthroughput capacity of 50%, the RTD increases to 0.9 seconds. It is recommended thatcell throughput provisioning be performed at the mean cell capacity level of 50%.Provisioning for a mean cell throughput greater than 50% greatly increases the likelihoodof dropped packets, and RTD values of over 2.6 seconds can occur. The assumptionsused in the simulation to determine the RTD value at a mean cell throughput level of 50%are: 25% of the cell traffic at the CS-1 rate and 75% of the cell traffic at the CS-2 rate,BLER 10%, mobiles multislot distribution 1:2:3:4 = 20:50:20:10, 8 PDCH, DL, meanLLC_PDU packet size of 435 bytes.

For example, a 3 kbyte application file transit time at the CS-2 rate, using one timeslot,BLER = 10%, and no header or V.42 bis compression is:

3 Kbyte file transit time over Um-to-Gi interface =

0.9 + Roundup (3106/30) x 0.02 x 1.1 / 1 = 3.2 seconds

Where: File_size_LLC is: = 3106 bytes (ascalculated in the previousexample)

CS-2 payload = 30 bytes

Air time for one RLC/MACblock

= 0.02 seconds

(1+CSBLER) = 1.1

Multislot operation = 1

GSM-001-103 Propagation effects on GSM frequencies


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Propagation effects on GSM frequencies

Propagationproduction

Most of the methods used to predict propagation over irregular terrain are actually terrainbased, since they are designed to compute the diffraction loss and free space loss basedupon the path profile between the transmitter and the receiver. A widely used techniquein the United Kingdom is the prediction method used by the Joint Radio Committee of theNationalized Power Industries (JRC). This method utilizes a computerized topographicalmap in a data base, providing some 800,000 height reference points at 0.5 km intervalscovering the whole of the UK. The computer predicts the received signal level byconstructing the ground path profile between the transmitter and receiver using the database. The computer then tests the path profile for a line of sight path and whetherFresnel-zone clearance is obtained over the path. The free space and plane earthpropagation losses are calculated and the higher value is chosen. If the line of sight andFresnel-zone clearance test fails, then the programme evaluates the loss caused by anyobstructions and grades them into single or multiple diffraction edges. However, thismethod fails to take any buildings into account when performing its calculation, thecalculations are totally based upon the terrain features.

Although the use of topographical based calculations are useful when designing mobilecommunication systems, most mobile systems are centred around urban environments.In these urban environments, the path between transmitter and the receiver maybeblocked by a number of obstacles (for example; buildings), so it is necessary to resort toapproximate methods of calculating diffraction losses since exact calculations for eachobstacle then become extremely difficult.

GSM-001-103Propagation effects on GSM frequencies



Introduction todecibels

Decibels are used to express power output levels, receiver input levels and path losses.The reason they are used is to simplify the calculations used when planning radiosystems. Any number maybe expressed as a decibel (dB). The only requirement is thatthe original description and scale of unity is appended to the dB, so indicating a valuewhich can be used when adding , subtracting, or converting dBs.

For example for a given power of 1 mW it may be expressed as 0 dBmW, the mW refersto the fact that the original scale of measurement was in thousandths of a watt. For apower of 1 W the equivalent in dBs is 0 dBW.

The decibel scale is logarithmic and this allows very large or very small numbers to bemore easily expressed and calculated. For example take a power of 20 watts transmittedfrom a BTS which was .000000001 W at the receiver. It is very difficult to accuratelyexpress the total power loss in a simple way.

By converting both figures to decibels referenced to 1 mW, 20 W becomes 32 dBmWand .000000001 W is –60 dBmW. The path loss can now be expressed as 92 dBmW.

Multiplication and division also become easier when using dBs. For figures expressed asdBs to multiply them together simply add the db figures together. This is the equivalent indecimal of multiplying. For division simply take one dB figure from the other. Anotherexample is for every doubling of power figures the increase in dBs is 3 dB and for everyhalving of power the decrease is 3 dB. Table 3-18 gives examples of dB conversions.

Table 3-18 dBmW and dBW to Power conversion

dBmW dBW Power dBmW dBW Power

+ 59 29 800 W + 7 – 23 5 mW

+ 56 26 400 W + 4 – 26 2.5 mW

+ 53 23 200 W + 1 – 29 1.25 mW

+ 50 20 100 W 0 – 30 1 mW

+ 49 19 80 W – 3 – 33 0.5 mW

+ 46 16 40 W – 6 – 36 0.25 mW

+ 43 13 20 W – 9 – 39 0.125 mW

+ 40 10 10 W – 10 – 40 0.1 mW

+ 39 9 8 W – 20 – 50 0.01 mW

+ 36 6 4 W – 30 – 60 1 �W

+ 33 3 2 W – 40 – 70 0.1 �W

+ 30 0 1 W – 50 – 80 0.01 �W

+ 27 – 3 500 mW – 60 – 90 1 nW

+ 24 – 6 250 mW –70 –100 0.1 nW

+ 21 – 9 125 mW – 80 – 110 0.01 nW

+ 20 – 10 100 mW – 90 – 120 1 pW

+ 17 – 13 50 mW – 100 – 130 0.1 pW

+ 14 – 16 25 mW –103 – 133 0.01 pW

+ 11 – 19 12.5 mW – 106 – 136 0.001 pW

+ 10 – 20 10 mW



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Fresnel zone

The Fresnel (pronounced Fresnel) actually consists of several different zones, each oneforming an ellipsoid around the major axis of the direct propagation path. Each zonedescribes a specific area depending on the wavelength of the signal frequency. If a signalfrom that zone is reflected of an obstacle which protrudes into the zone, it means that areflected signal as well as the direct path signal will arrive at the receiver. Radio wavesreflected in the first Fresnel zone will arrive at the receiver out of phase with those takingthe direct path and so combine destructively. This results in a very low received signalstrength. It is important when planning a cell to consider all the radio paths for obstacleswhich may produce reflections from the first Fresnel zone because if they exist it is likeplanning permanent areas of no coverage in certain parts of the cell.

In order to calculate wether or not this condition exists the radius of the first Fresnel zoneat the point where the object is suspected of intruding into the zone must be calculated.The formula, illustrated in Figure 3-16, is as follows:

F1 �d1 � d2�

� �

d

Where: F1 is: the first Fresnel zone.

d1 distance from Tx antenna to the obstacle.

d2 distance from Rx antenna to the obstacle.

� wavelength of the carrier wave.

d total path length.

Once the cell coverage has been calculated the radio path can be checked for anyobjects intruding into the first Fresnel zone. Ideally the link should be planned for nointrusions but in some cases they are unavoidable. If that is the case then the next bestclearance for the first Fresnel zone is 0.6 of the radius.

When siting a BTS on top of a building care must be taken with the positioning andheight of the antenna to ensure that the roof edge of the building does not intrude into thefirst Fresnel zone.

d1 d2

d

FREQUENCY = 900 MHzWAVELENGTH = 30 cm

F1

Figure 3-16 First Fresnel zone radius calculation




Radio refractiveindex

It is important when planning a cell or microwave radio link to have an understanding ofthe effects changes in the Radio Refractive Index (RRI) can have on microwavecommunications, also what causes these changes.

RRI measurements provide planners with information on how much a radio wave will berefracted by the atmosphere at various heights above sea level. Refraction, Figure 3-17,is the changing of direction of propagation of the radio wave as it passes from a moredense layer of the atmosphere to a less dense layer, which is usual as one increases inheight above sea level. It also occurs when passing from a less dense layer to a denselayer. This may also occur under certain conditions even at higher altitudes.

REFRACTION OCCURS AS THE RADIO WAVE PASSES THROUGHLAYERS OF DIFFERENT ATMOSPHERIC DENSITY

EARTH

Figure 3-17 Refraction

The main effect to cell planners is that changes in the RRI can increase or decrease thecell radius depending on conditions prevailing at the time.

The RRI is normally referenced to a value n at sea level. The value will vary with seasonsand location but for the UK the mean value is 1.00034. This figure is very cumbersome towork with so convention has converted n to N.

Where: N is: (n–1) x 10 to the power of 6.

The value of N now becomes 340 units for the UK. The actual seasonal and globalvariations are only a few 10 s of units at sea level.

The value of N is influenced by the following :

� The proportion of principle gasses in the atmosphere such as nitrogen, oxygen,carbon dioxide, and rare gasses. These maintain a near constant relationship asheight is increased so although they affect the RRI the affect does not vary.

� The quantity of water vapour in the atmosphere. This is extremely variable and hassignificant effects on the RRI.

� Finally the temperature, pressure, and water vapour pressure have major effectson the RRI.

All the above will either increase or decrease the RRI depending on local conditions,resulting in more or less refraction of a radio wave. Typically though for a well mixedatmosphere the RRI will fall by 40 N units per 1 km increase in height above sea level.



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Measurement of the RRI

There are two main ways of measuring the RRI at any moment in time. Firstly by use ofRadio Sonds. This is an instrument which is released into the atmosphere, normallyattached to a balloon. As it rises it measures the temperature, pressure, and humidity.These are transmitted back to the ground station with a suitable reference value. Themeasurements of pressure are made every 35 m, humidity every 25 m, and temperatureevery 10 m. These together provide a relatively crude picture of what the value of theRRI is over a range of heights.

The second method is a more serious means of measuring the RRI. It uses fastresponse devises called refractometers. These maybe carried by a balloon , aircraft, orbe spaced apart on a high tower. These instruments are based upon the change inresonant frequency of a cavity with partially open ends caused by the change in RRI ofair passing through the cavity. This gives a finer measurement showing variations in theRRI over height differences of a little over one meter. This is illustrated by the graph inFigure 3-18. The aircraft mounted refractometer can give a detailed study over severalpaths and heights.

RRI (N)

340

HEIGHT (km)

1

0

Figure 3-18 Measurement of the RRI




Effects of deviations from the normal lapse rate

The lapse rate of 40 N per km is based on clear sky readings with good atmospheremixing. Normally a radio system is calibrated during these conditions and the heightalignment in the case of a microwave point to point link is determined.

It is easier to see the effects on a microwave point to point system when examining theeffects of uneven variations of the RRI. Figure 3-19A shows an exaggerated curved radiopath between two antennas under normal conditions. The signal is refracted by theatmosphere and arrives at the receiving antenna. Figure 3-19B illustrates the conditionknown as super refraction where the radio waves are not diffracted enough. This occurswhen the lapse rate is less than 40 N per km. Under these conditions the main signalpath will miss the receive antenna. Similar effects on a cell would increase the cell sizeas the radio waves would be propagated further resulting in co-channel and adjacentchannel interference.

The second effect is where the RRI increases greater than 40 N per km. This results inthe path being refracted too much and not arriving at the receive antenna. This conditionis known as sub-refraction. While this will not cause any interference as with superrefraction, it could result in areas of no coverage. See Figure 3-19C.

The last effect is known as ducting and occurs when the refraction of the radio waveproduces a path which matches the curvature of the Earth. If this happens radio wavesare propagated over far greater distances than normal and can produce interference inplaces not normally subjected to any.

NORMAL REFRACTIONEARTH

SUPER REFRACTION

SUB-REFRACTION

A

B

C

EARTH

EARTH

Figure 3-19 Effects on a microwave system



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Events which can modify the clear sky lapse rate

There are four main events which can modify the clear sky lapse rate and they are asfollows:

Radiation nights

This is the result of a very sunny day followed by clear skies overnight. The Earthabsorbs heat during the day and the air temperature rises. After sunset the Earthradiates heat into the atmosphere and its surface temperature drops. This heat loss isnot replaced resulting in air closer to the surface cooling faster than air higher up. Thiscondition causes a temperature inversion and the RRI profile no longer has a uniformlapse rate. This effect will only occur overland and not water as water temperaturevariations are over a longer period of time.

Advection effects

This effect is caused by high pressure weather fronts moving from land to the sea orother large expanses of water. The result is warm air from the high pressure frontcovering the relatively cool air of the water. When this combination is then blown backover land a temperature inversion is caused by the trapped cool air. It will persist until theair mass strikes high ground where the increase in height will mix and dissipate theinversion.

Subsidence

This occurs again in a high pressure system this time overland when air descending fromhigh altitude is heated by compression as it descends. This heated air then spreads overthe cooler air below. This type of temperature inversion normally occurs at an altitude of1 km but may occasionally drop to 100 m where it cause severe disruption to radiosignals.

Frontal systems

This happens when a cold front approaching an area forces a wedge of cold air under thewarmer air causing a temperature inversion. These disturbances tend to be short lived asthe cold front usually dissipate quickly.

Although those described above are the four main causes of RRI deviations, localpressure, humidity and temperature conditions could well give rise to events which willaffect the RRI.




Environmentaleffects onpropagation

At the frequency range used for GSM it is important to consider the effects that objectsin the path of the radio wave will have on it. As the wave length is approximately 30 cmfor GSM900 and 15 cm for GSM1800, most objects in the path will have some effect onthe signal. Such things as vehicles, buildings, office fittings even people and animals willall affect the radio wave in one way or another.

The main effects can be summarized as follows:

� Attenuation.

� Reflection.

� Scattering.

� Diffraction.

� Polarization changes.

Attenuation

This will be caused by any object obstructing the wave path causing absorption of thesignal. The effects are quite significant at GSM frequencies but still depend on the type ofmaterials and dimensions of the object in relation to the wavelength used. Buildings,trees and people will all cause the signal to be attenuated by varying degrees.

OBJECTABSORBS

THEENERGYIN THERADIOWAVE

OUTGOING WAVEATTENUATED BY THE OBJECT

INCOMING WAVE

Figure 3-20 Attenuation

Reflection

This is caused when the radio wave strikes a relatively smooth conducting surface. Thewave is reflected at the same angle at which it arrived. The strength of the reflectedsignal depends on how well the reflector conducts. The greater the conductivity thestronger the reflected wave. This explains why sea water is a better reflector than sand.

INCIDENT WAVE

EQUAL ANGLES

REFLECTED WAVE

AMOUNT OF REFLECTION DEPENDS ONCONDUCTIVITY OF THE SURFACE

SMOOTH SURFACE, SUCH AS WATER,VERY REFLECTIVE

Figure 3-21 Reflection



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Scattering

This occurs when a wave reflects of a rough surface. The rougher the surface and therelationship between the size of the objects and the wave length will determine theamount of scattering that occurs.

ROUGH STONY GROUND

INCIDENT WAVEENERGY IS

SCATTERED

Figure 3-22 Scattering

Diffraction

Diffraction is where a radio wave is bent off its normal path. This happens when the radiowave passes over an edge, such as that of a building roof or at street level that of acorner of a building. The amount of diffraction that takes place increases as thefrequency used is increased.

Diffraction can be a good thing as it allows radio signals to reach areas where they wouldnot normally be propagated.

PLAN VIEW

MICRO BTS ATSTREET LEVEL

DIFFRACTED WAVE GIVINGCOVERAGE AROUND THE CORNER

DIFFRACTED WAVE GIVINGCOVERAGE AROUND THE CORNER

SIDE VIEW

EXPECTED PATH

DIFFRACTEDWAVE

SHADOWAREA

Figure 3-23 Diffraction




Polarization changes

This can happen any time with any of the above effects of due to atmospheric conditionsand geomagnetic effects such as the solar wind striking the earths atmosphere. Thesepolarisation changes mean that a signal may arrive at the receiver with a differentpolarisation than that which the antenna has been designed to accept. If this occurs thereceived signal will be greatly attenuated by the antenna.

ELECTRICAL PART OF WAVEVERTICALLY POLARIZED

ÎÎÎÎÎÎ

ÎÎÎÎÎÎ

ÎÎÎÎÎÎ

ÎÎÎÎÎÎ

ÎÎÎÎÎÎ

ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ

ELECTRICAL PART OF WAVEHORIZONTALLY POLARIZED

(CHANGED BY ELECTRICAL STORM)

ELECTRICAL STORM

Tx Rx

Figure 3-24 Polarization



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Multipathpropagation

Rayleigh and Rician fading

As a result of the propagation effects on the transmitted signal the receiver will pick upthe same signal which has been reflected from many different objects resulting in what isknown as multipath reception. The signals arriving from the different paths will all havetravelled different distances and will therefore arrive at the receiver at different times withdifferent signal strengths. Because of the reception time difference the signals may ormay not be in phase with each other. The result is that some will combine constructivelyresulting in a gain of signal strength while others will combine destructively resulting in aloss of signal strength.

The receiving antenna does not have to be moved very far for the signal strength to varyby many tens of dBs. For GSM900 a move of just 15 cm or half a wavelength will sufficeto observe a change in signal strength. This effect is known as multipath fading. It istypically experienced in urban areas where there are lots of buildings and the only signalsreceived are from reflections and refractions of the original signal.




Rayleigh environment

This type of environment has been described by Rayleigh. He analysed the signalstrength along a path with a moving receiver and plotted a graph of the typical signalstrength measured due to multipath fading. The plot is specifically for non line of sight,Figure 3-25, and is known as Rayleigh distribution, Figure 3-26.

Rx

Tx

Figure 3-25 Propagation effect – Rayleigh fading environment

SIGNALSTRENGTH

DEEP NULLS � 1/2 WAVELENGTH

THRESHOLD

DISTANCE

Figure 3-26 Rayleigh distribution



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Rician environment

Where the signal path is predominantly line of sight, Figure 3-27, with insignificantreflections of refractions arriving at the receiver, this is know as Rician distribution,Figure 3-28. There are still fades in signal strength but they rarely dip below the thresholdbelow which they will not be processed by the receiver.

Rx

Tx

Figure 3-27 Propagation effect – Rician environment

SIGNALSTRENGTH

THRESHOLD

DISTANCE

Figure 3-28 Rician distribution

Comparison of DCS1800 and GSM900: From a pure frequency point of view it wouldbe true to say that DCS1800 generally has more fades than GSM900. However, they areusually less pronounced.




Receive signal strength

A moving vehicle in an urban environment seldom has a direct line of sight path to thebase station. The propagation path contains many obstacles in the form of buildings,other structures and even other vehicles. Because there is no unique propagation pathbetween transmitter and receiver, the instantaneous field strength at the MS and BTSexhibits a highly variable structure.

The received signal at the mobile is the net result of many waves that arrive via multiplepaths formed by diffraction and scattering. The amplitudes, phase and angle of arrival ofthe waves are random and the short term statistics of the resultant signal envelopeapproximate a Rayleigh distribution.

Should a microcell be employed, where part of a cell coverage area be predominantlyline of sight then Rician distribution will be exhibited.

Free space loss

This is the lose of signal strength that occurs as the radio waves are propagated throughfree space. Free space is defined as the condition where there are no sources ofreflection in the signal path. This is impossible to achieve in reality but it does give a goodstarting point for all propagation loss calculations.

Equally important in establishing path losses is the effect that the devices radiating thesignal have on the signal itself. As a basis for the calculation it is assumed the device isan isotopic radiator. This is a theoretical pin point antenna which radiates equally in everydirection. If the device was placed in the middle of a sphere it would illuminated the entireinner surface with an equal field strength.

In order to find out what the power is covering the sphere, the following formula used:

P �Pt

4 �� d2

Where: Pt is: the input power to the isotopic antenna.

d the distance from the radiator to thesurface of the sphere.

This formula illustrates the inverse square law that the power decreases with the squareof the distance.

In order to work out the power received at a normal antenna the affective aperture (Ae)of the receiving antenna must be calculated.

Ae ��2

4 �

The actual received power can be calculated as follows:

Pr � P � Ae

Now if P is substituted with the formula for the power received over the inner surface ofa sphere and Ae with its formula the result is:

Pr � � Pt4 �� d2

�� 2

4 �



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Free space path loss

This is the ratio of the actual received power to the transmitted power from an isotopicradiator and can be calculated by the formula:

20 log �4 �� d

��

Logs are used to to make the figures more manageable. Note that the formula isdependant on distance and frequency. The higher the frequency the shorter thewavelength and therefore the greater the path loss.

The formula above is based on units measured in metres. To make the formula moreconvenient it can be modified to use kilometre and megahertz for the distance andfrequency. It becomes:

Free space loss � 32 � 20 log d � 20 log f dBs

Where: d is: the distance in km.

f the frequency in MHz.

Plane earth loss

The free space loss as stated was based solely on a theoretical model and is of no useby itself when calculating the path loss in a multipath environment. To provide a morerealistic model, the earth in its role as a reflector of signals must be taken into account.When calculating the plane earth loss the model assumes that the signal arriving at thereceiver consists of a direct path component and a reflective path component. Togetherthese are often called the space wave. The formula for calculating the plane earth loss is:

L � 20 log � d 2

h1 � h2� dBs

This takes into account the different antenna heights at the transmitter and receiver.Although this is still a simple representation of path loss. When this formula is used isimplies the inverse fourth law as opposed to the inverse square law. So for everydoubling of distance there is a 12 dB loss instead of 6 db with the free space losscalculation.

The final factors in path loss are the ground characteristics. These will increase the pathloss even further depending on the type of terrain, refer to Figure 3-29. The groundcharacteristics can be divided into three groups:

1. Excellent ground . For example sea water, this provides the least attenuation soa lower path loss.

2. Good ground . For example rich agricultural land, moist loamy lowland andforests.

3. Poor ground . For example Industrial or Urban areas, rocky land. These give thehighest losses and are typically found when planning Urban cells.




PATH LOSS INCREASES 6dB FOR A DOUBLING OF d.

1d

FREE SPACE LOSSTx Rx

PLANE EARTH LOSS INCLUDES ONE EARTH REFLECTOR.PATH LOSS INCREASES 12dB FOR A DOUBLING OF d.

2

d

Tx

Rx

h1

h2

PLANE EARTH + CORRECTION FACTOR FOR TYPE OF TERRAIN.PATH LOSS INCREASES 12dB FOR A DOUBLING OF d + A FACTORFOR TYPE OF TERRAIN.

3

d

Tx

Rx

h1

h2

Figure 3-29 Plane earth loss



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Clutter factor

The propagation of the RF signal in an urban area is influenced by the nature of thesurrounding urban environment. An urban area can then be placed into two subcategories; the built up area and the suburban area. The built up area contains tallbuildings, office blocks, and high–rise residential tower blocks, whilst a suburban areacontains residential houses, playing fields and parks as the main features. Problems mayarise in placing areas into one of these two categories, so two parameters are utilised, aland usage factor describing the percentage of the area covered by buildings and a’degree of urbanization’ factor describing the percentage of buildings above storeys in thearea.

B(db) � 20 � � F40�� 0.18L � 0.34H � K

Where: B is: the clutter factor in dBs.

F the frequency of RF signal.

L the percentage of land within 500m square occupied bybuildings.

H the difference in height between the squares containingthe transmitter and receiver.

K 0.094U – 5.9

U the percentage of L occupied by buildings above 4storeys.

A good base station site should be high enough to clear all the surrounding obstacles inthe immediate vicinity. However, it should be pointed out that employing high antennasincreases the coverage area of the base station. However, it will also have adverseeffects on channel re-use distances because of the increased possibility of co-channelinterference.

Antenna gain

The additional gain provided by an antenna can be used to enhance the distance that theradio wave is transmitted. Antenna gain is measured against an isotopic radiator. Anyantenna has a gain over an isotopic radiator because in practice it is impossible toradiate the power equally in all directions. This means that in some directions theradiated power will be concentrated. This concentration or focusing of power is whatenables the radio waves to travel further than those that if it were possible were radiatedfrom an isotopic radiator. See Figure 3-30.

ISOTOPIC RADIATOR(A SPHERICAL PATTERN)

VERTICAL DIPOLE RADIATION PATTERN(SIDE VIEW)

TRANSMITTER

Figure 3-30 Focusing of power




The gain of a directional antenna is measured by comparing the signal strength of acarrier emitted from an isotopic antenna and the directional antenna. First the power ofthe isotopic radiator is increased so that both receive levels are the same. The emittedpowers required to achieve that are then compared for both antennas. The difference isa measure of gain experienced by the directional antenna. It will always have some gainwhen compared to an isotopic radiator. See example in Figure 3-31.

10 W

MEASUREMENT POINT

TRANSMITTER

1000 W

MEASUREMENT POINT

Figure 3-31 Measurement of gain

In this example to achieve a balanced receive level the isotopic radiator must have aninput power of 1000 W as opposed to the directional antenna which only requires 10 W.The gain of the directional antenna is 100 or 20 dBi.

Where: i is: for isotopic.

The more directional the antenna is made the more gain it will experience. This isapparent when sectorizing cells . Each sectored cell will require less transmit power thanthe equivalent range omni cell due to the gain of its directional antenna, typically 14 to17 dBi.

The gain is also present in the receive path though in all cases the gain decreases as thefrequency increases. That is why the uplink mobile to BTS frequency is usually thelowest part of the frequency range. This gives a slight gain advantage to the lower powermobile transmitter.



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Propagation in buildings

With the increased use of hand portable equipment in mobile cellular systems combinedwith the increased availability of cordless telephones, it has become essential to studyRF propagation into and within buildings.

When calculating the propagation loss inside a building, Figure 3-32, a building lossfactor is added to the RF path loss. This building loss factor is included in the model toaccount for the increase in attenuation of the received signal when the mobile is movedfrom outside to inside a building. This is fine if all users stood next to the walls of thebuilding when making calls, but this does not happen, so the internal distance throughwhich the signal must pass which has to be considered. Due to the internal constructionof a building, the signal may suffer form spatial variations caused by the design of theinterior of the building.

The building loss tends to be defined as the difference in the median field intensity at theadjacent area just outside the building and the field intensity at a location on the mainfloor of the building. This location can be anywhere on the main floor.

This produces a building median field intensity figure which is then used for plotting cellcoverage areas and grade of service.

When considering coverage in tall buildings, coverage is being considered throughout thebuilding, if any floors of that building are above the height of the transmitting antenna apath gain will be experienced.

XdBmWdBm

XdBm = SIGNAL STRENGTH OUTSIDE BUILDING

WdBm = SIGNAL STRENGTH INSIDE BUILDING

BUILDING INSERTION LOSS (dBm) = X –W = BdBm

TRANSMITTER

GAIN

REFERENCE POINT

TRANSMITTER

Figure 3-32 In building propagation




The Okumura method

In the early 1960’s a Japanese engineer named Okumura carried out a series of detailedpropagation tests for land mobile radio services at various different frequencies. Thefrequencies were 200 MHz in the VHF band and 453, 922, 1310, 1430, and 1920 MHz inthe UHF band. The results were statistically analyzed and described for distance andfrequency dependencies of median field strength, location variabilities and antennaheight gain factors for the base and mobile stations in urban, suburban, and open areasover quasi-smooth terrain.

The correction factors corresponding to various terrain parameters for irregular terrain,such as rolling hills, isolated mountain areas, general sloped terrain, and mixed land/seapath were defined by Okumura.

As a result of these tests carried out primarily in the Tokyo area, a method for predictingfield strength and service area for a given terrain of a land mobile radio system wasdefined. The Okumura method is valid for the frequency range of 150 to 2000 MHz, fordistances between the base station and the mobile stations of 1 to 100 km, with basestation effective antenna heights of 30 to 100m.

The results of the median field strength at the stated frequencies were displayedgraphically. Different graphs were drawn for each of the test frequencies in each of theterrain environments (for example; urban, suburban, hilly terrain) Also shown on thesegraphs were the various antenna heights used at the test transmitter base stations. Thegraphs show the median field strength in relation to the distance in km from the site.

As this is a graphical representation of results it does not transfer easily into a computerenvironment. However, the results provided by Okumura are the basis on which path lossprediction equations have been formulated. The most important work has been carriedout by another Japanese engineer named Hata. Hata has taken Okumura’s graphicalresults and derived an equation to calculate the path loss in various environments. Theseequations have been modified to take into account the differences between the Japaneseterrain and the type of terrain experienced in Western Europe.



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1 2 3 7 10 20 30 40 50 60 70 80 90 1000.6

–10

0

10

20

30

40

50

60

70

80

90

100

110

Free Space

�

�

��

�

��

��

��

�

��

�

�

�

��

�

LOG SCALELINEAR SCALE

DISTANCE (km)

922 MHz

h.= 320 m

h.= 3 m

�

PROPAGATION GRAPH FOR 922 MHz

5

h.= 220 m

h.= 140 m

h.= 45m

��

��

Figure 3-33 Okumura propagation graphs




Hata’s propagation formula

Hata used the information contained in Okumura’s propagation loss report of the early1960’s, which presented its results graphically, to define a series of empirical formulas toallow propagation prediction to be done on computers. The propagation loss in an urbanarea can be presented as a simple formula of:

A � B log 10R

Where: A is: the frequency.

B the antenna height function.

R the distance from the transmitter.

Hata using this basic formula which is applicable to radio systems is the UHF and VHFfrequency ranges, added an error factor to the basic formula to produce a series ofequations to predict path loss. To facilitate this action Hata has set a series of limitationswhich must be observed when using this empirical calculation method:

Where: Frequency range (fc) is: 100 – 1500 MHz

Distance (R) 1 – 20 km

Base station antenna height (hb) 30 – 200 M

Vehicular antenna height (hm) 1 – 10 M

Hata defined three basic formulas based upon three defined types of coverage area;urban, suburban and open. It should be noted that Hata’s formula predicts the actual pathloss, not the final signal strength at the receiver.

Urban Area:

Lp = 69.55 + 26.16 log10fc – 13.82.log10hb – a (hm)# + (44.9 – 6.66. log10hb).log10R dB

Where: # is: Correction factor for vehicular station antenna height.

Medium – Small City:

a(hm) = (1.1 . log10fc – 0.7).hm – (1.56.log10fc – 0.8)

Large City:

a(hm) = 3.2 (log10 11.75 hm)2 – 4.97

Where: fc is: >400 MHz.

Suburban Area:

Lps = Lp [Urban Area] – 2.[log10 (f/28)]2 – 5.4 dB

Rural Area:

Lpr = Lp [Urban Area] – 4.78.(log10fc)2 + 18.33.log10fc – 40.94 dB



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Power budget and system balance

In any two–way radio system the radio path losses and equipment output powers mustbe taken into account for both directions. This is especially true in a mobile networkwhere there are different characteristics for the uplink and downlink paths. These includereceive path diversity gain in the uplink only, the possibility of mast head amplifiers in theuplink path, the output power capability of the mobile is a lot less than that of the BTSand the sensitivity of the BTS receiver is usually better than the mobiles.

If these differences are not considered it is possible that the BTS will have a service areafar greater than that which the mobile will be able to use due to its limited output power.Therefore the path losses and output powers in the uplink and downlink must be carefullycalculated to achieve a system balance. One where the power required of the mobile toachieve a given range is equitable to the range offered by the power transmitted by theBTS. The output powers of the BTS and mobile are unlikely to be the same for any givendistances due to the differences in uplink and downlink path losses and gains asdescribed above.

Once the area of coverage for a site has been decided the calculations for the powerbudget can be made. The system balance is then calculated which will decide the outputpowers of the BTS and mobile to provide acceptable quality calls in the area of coverageof the BTS. The BTS power level must never be increased above the calculated level forsystem balance. Although this seems a simple way to increase coverage, the systembalance will be different and the mobile may not be able to make a call in the newcoverage area.

To increase the cell coverage, an acceptable way is to increase the gain of the antenna.This will affect both the uplink and downlink therefore maintaining system balance.Where separate antennas are used for transmit and receive they must be of similar gain.If the cell size is to be reduced then this is not a problem as the BTS power can bealtered and the mobiles output power is adaptive all the time.

There is a statistic in the BTS that checks the path balance every 480 ms for each call inprogress. The latest uplink and downlink figures reported along with the actual mobileand BTS transmit powers are used in a formula to give an indication of the path balance.




GSM900 pathloss

Figure 3-34 and Figure 3-35 compare the path losses at different heights for the BTSantenna and different locations of the mobile subscriber between one and 100 km cellradius.

CELL RADIUS (km)

1 10 100

PA

TH

LO

SS

(dB

)

90

100

110

120

130

140

150

160

170

180

190

200

210

220

URBAN INDOOR

URBAN

SUBURBAN

RURAL (OPEN)

RURAL (QUASI OPEN)

Figure 3-34 BTS antenna height of 50 m, MS height of 1.5 m (GSM900)

CELL RADIUS (km)

1 10 100

PA

TH

LO

SS

(dB

)

90

100

110

120

130

140

150

160

170

180

190

200

210

220

URBAN INDOOR

URBAN

SUBURBAN

RURAL (OPEN)

RURAL (QUASI OPEN)

Figure 3-35 BTS antenna height of 100 m, MS height of 1.5 m (GSM900)



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Path lossGSM900 vsDCS1800

Figure 3-36 illustrates the greater path loss experienced by the higher DCS1800frequency range compared to the GSM900 band. The cell size is typical of that found inurban or suburban locations. The difference in path loss for the GSM900 band at 0.2 kmcompared with 3 km is 40 dB, a resultant loss factor of 10,000 compared to themeasurement at 0.2 km.

CELL RADIUS (km)

0.1 1.0 3.0

PA

TH

LO

SS

(dB

)

100

110

120

130

140

150

160

170

GSM900

0.3

DCS1800(MEDIUM SIZED CITIES AND

SUBURBAN CENTRES)

DCS1800(METROPOLITAN CENTRES)

Figure 3-36 Path loss vs cell radius for small cells

GSM-001-103Frequency re-use



Frequency re-use

Introduction tore-use patterns

The network planner designs the cellular network around the available carriers orfrequency channels. The frequency channels will be allocated to the network providerfrom the GSM, EGSM, or DCS1800 band as shown below:

GSM = Tx 935 – 960 MHz

DCS1800 = Tx 1805 – 1880 MHzRx 1710 – 1785 MHz

Rx 890 – 915 MHz

EGSM = Tx 925 – 960 MHzRx 880 – 915 MHz

124 RF carriers

174 RF carriers

374 RF carriers

Within this range of frequencies only a finite number of channels may be allocated to theplanner. The number of channels will not necessarily cover the full frequency spectrumand there has to be great care taken when selecting/allocating the channels.

Installing a greater number of cells will provide greater spectral efficiency with morefrequency re-use of available frequencies. However, a balance must be struck betweenspectral efficiency and all the costs of the cell. The size of cells will also indicate how thefrequency spectrum is used. Maximum cell radius is determined in part by the outputpower of the mobile subscriber (MS) (and therefore, its range) and interference causedby adjacent cells.

Remember that the output power of the MS is limited in both the GSM900 and DCS1800systems. Therefore to plan a balanced transmit and receive radio path the planner mustmake use of the path loss and thus the link budget.

The effective range of a cell will vary according to location, and can be as much as 35 kmin rural areas and as little as 1 km in a dense urban environment.

CARRIERF 33

INTERFERING CARRIERF 33

DISTANCE

RECEIVESIGNALLEVEL

SERVING BTS INTERFERING BTS

MOBILEPOSITION

– 75dBm

– 100dBm

Figure 3-37 Frequency re-use

GSM-001-103 Frequency re-use


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Re-use pattern

The total number of radio frequencies allocated is split into a number of channel groupsor sets. These channel groups are assigned on a per cell basis in a regular pattern whichrepeats across all of the cells. Thus, each channel set may be re-used many timesthroughout the coverage area, giving rise to a particular re-use pattern (for example; 7cell re-use pattern, Figure 3-38).

6

2

7

7 CELL RE-USE

3

4 1

5

EACH USINGCHANNEL SETS

1

1

1

1

2

2

2

3

3

3

4

4

4 5

5

5

6

6

6

7

7

7

Figure 3-38 7 cell re-use pattern

Clearly, as the number of channel sets increases, the number of available channels percell reduces and therefore the system capacity falls. However, as the number of channelsets increases, the distance between co-channel cells also increases, thus theinterference reduces. Selecting the optimum number of channel sets is therefore acompromise between quality and capacity.




4 site – 3 cell re-use pattern

Due to this increase in frequency robustness within GSM, different re-use frequencypatterns can be adopted, which gives an overall greater frequency efficiency.

The most common re-use pattern is 4 site with 3 cells. With the available frequencyallocation divided into 12 channels sets numbered a1–3, b1–3, c1–3, and d1–3. There-use pattern is arranged so that the minimum re-use distance between cells is at least2 to 1.

The other main advantage of this re-use pattern is if a new cell is required to be insertedin the network, then there is always a frequency channel set available which will notcause any adjacent channel interference.

b1

b3

b2

d3

c2

c1

c3

a2

d2

d1

a1

a3

EXAMPLE

NEW CELL CANUSE d1–3 FREQ

ALLOCATION

a1

a1

a1

a2

a2

a3

a3

a3

a2

b1

b1 b1

b1

b2

b2b2

b2

b3

b3b3

b3

c1c1

c1

c2

c2

c2

c3

c3

c3

d1 d1

d1

d2d2

d2

d3

d3 d3

a2

Figure 3-39 4 site – 3 cell re-use pattern



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2 site – 6 cell re-use pattern

Another solution to possible network operators capacity problems may be an even higherfrequency re-use pattern. The re-use pattern, shown in Figure 3-40, uses a 2 site – 6 cellre-use.

Therefore: 2 sites repeated each with 6 cells = 2 x 6 = 12 groups.

If the operator has only 24 carriers allocated for their use, they are still in a position touse 2 carriers per cell. However this may be extremely difficult and may not be possibleto implement. It also may not be possible due to the current network configuration.However, the subscribers per km ratio would be improved.

b6b1

b4

b2

b3b5b6

b5

b2

b4

b3b1

a6a1

a4

a2

a3a5

a5a4

a1

a3

a2a6

60� SECTORS

Figure 3-40 2 site – 6 cell re-use pattern




Carrier/Interference (C/I)ratio

When a channel is re-used there is a risk of co-channel interference which is where otherbase stations are transmitting on the same frequency.

As the number of channel sets increases the number of available channels per cellreduces and therefore capacity reduces. But the interference level will also reduce,increasing the quality of service.

The capacity of any one cell is limited by the interference that can be tolerated for a givengrade of service. A number of other factors, apart from the capacity, effect theinterference level:

� Power control (both BTS and MS).

� Hardware techniques.

� Frequency hopping (if applied).

� Sectorization.

� Discontinuous transmission (DTX).

Carrier/Interference measurements taken at different locations within the coverage of acell can be compared to a previously defined acceptable criterion. For instance, thecriterion for the C/I ratio maybe set at 8 dB with the expectation that the C/Imeasurements will be better than that figure, for 90% of cases (C/I90).

For a given re-use pattern, the predicted C/I ratio related to the D/R ratio can bedetermined, to give overall system comparison. For example:

GSM System : 9dB �CI� � 7.94

�

(D�R)4

6� 7.94

Therefore ( DR

)4� 47.66

Thus �DR� � 47.664�

� 2.62

MS

BS BSR

DISTANCE BETWEEN CELLS

D

C/I CAN BE RELATED TO D/R(2 CELLS USING THE SAME BCCH FREQUENCY)

ANALOGUE SYSTEM D/R = 4.4GSM SYSTEM D/R= 2.62

Figure 3-41 Carrier interference measurements



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Other sources ofinterference

Adjacent Channel Interference: This type of interference is characterised by unwantedsignals from other frequency channels ‘spilling over’ or injecting energy into the channelof interest.

With this type of interference being influenced by the spacing of RF channels, its effectcan be reduced by increasing the frequency spacing of the channels. However, this willhave the adverse effect of reducing the number of channels available for use within thesystem.

The base station and the mobile stations receiver selectivity can also be designed toreduce the adjacent channel interference.

Environmental Noise: This type of interference can also provide another source ofpotential interference. The intensity of this environmental noise is related to localconditions and can vary from insignificance to levels which can completely dominate allother sources of noise and interference.

There are also several other factors which have to be taken into consideration. Theinterfering co-channel signals in given cell would normally arise from a number ofsurrounding cells not just one.

What effect will directional antennas have when employed?

Finally, if receiver diversity is to be used, what type and how is implementation to beachieved?

Sectorization ofsites

As cell sizes are reduced, the propagation laws indicate that the levels of carrierinterference tend to increase. In a omni cell, co-channel interference will be received fromsix surrounding cells all using the same channel sets. Therefore, one way of significantlycutting the level of interference is to use several directional antennas at the basestations, with each antenna radiating a sector of the cell, with a separate channel set.

Sectorization increases the number of traffic channels available at a cell site whichmeans more traffic channels available for subscribers to use. Also by installing morecapacity at the same site there is a significant reduction in the overall implementation andoperating costs experienced by the network operator.

By using sectorized antennas, sectorization allows the use of geographically smaller cellsand a tighter more economic re-use of the available frequency spectrum. This results inbetter network performance to the subscriber and a greater spectrum efficiency.

The use of sectorized antennas allows better control of any RF interference which resultsin a higher call quality and an improved call reliability. More importantly for the networkdesigner sectorization extends and enhances the cells ability to provide the in-buildingcoverage that is assumed by the hand portable subscriber.

Sectorization provides the flexibility to meet uneven subscriber distribution by allowing ifrequired an uneven distribution of traffic resources across the cells on a particular site.This allows a more efficient use of both the infrastructure hardware and the availablechannel resources.

Finally, with the addition of diversity techniques an improved sensitivity and increasedinterference immunity are experienced in a dense urban environment.

GSM-001-103Overcoming adverse propagation effects



Overcoming adverse propagation effects

Hardwaretechniques

Multipath fading is responsible for more than just deep fades in the signal strength. Themultipath signals are all arriving at different times and the demodulator will attempt torecover all of the time dispersed signals. This leads to an overlapping situation whereeach signal path influences the other, making the original data very hard to distinguish.The example opposite shows three component paths of the original signal which afterdemodulation should give three examples of the original data. This is not the case inreality as the output will be the result of the combination of the three inputs. As is shownin the diagram the output is very different making it difficult to decide wether the datashould represent a 1 or a 0. This problem is known as inter symbol interference (ISI) andis made worse by the fact that the output from the demodulator is rarely a square wave.The sharp edges are normally rounded off so that when time dispersed signals arecombined it makes it difficult to distinguish the original signal state.

Another factor which makes things even more difficult is that the modulation techniqueGaussian minimum shift keying, itself introduces a certain amount of ISI. Although this isa known distortion and can under normal conditions be filtered out, when it is added tothe ISI distortion caused by the time delayed multipath signals it makes recovery of theoriginal data that much harder.

Frequency hopping

Frequency hopping is a feature that can be implemented on the air interface, (forexample; the radio path to the MS), to help overcome the effects of multipath fading.GSM recommends only one type of frequency hopping, baseband hopping; but theMotorola BSS will support an additional type of frequency hopping called synthesizerhopping.

Baseband hopping

Baseband Hopping is used when a base station has several DRCU/TCUs available. Thedata flow is simply routed in the baseband to various DRCU/TCUs, each of whichoperates on a fixed frequency, in accordance with the assigned hopping sequence. Thedifferent DRCU/TCUs will receive a specific individual timeslot in each TDMA framecontaining information destined for different MSs. There are important points to notewhen using this method of providing frequency hopping.

� There is a need to provide as many DRCU/TCUs as the number of allocatedfrequencies.

� The use of remote tuning combiners, cavity combining blocks or hybrid combinersis acceptable in BTS6 applications.

� Within M-Cell equipment applications the use of either combining bandpassfilter/hybrid or cavity combining block is acceptable.

GSM-001-103 Overcoming adverse propagation effects


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Synthesizer hopping

Synthesizer hopping uses the frequency agility of the DRCU/TCU to change frequencieson a timeslot basis for both transmit and receive. The SCB in the DRCU and the digitalprocessing and control board in the TCU calculates the next frequency and programmesone of the pair of Tx and Rx synthesizers to go to the calculated frequency. As theDRCU/TCU uses a pair of synthesizers for both transmit and receive, as one pair ofsynthesizers is being used the other pair are returning. There are important points to notewhen using synthesizer hopping:

� Instead of providing as many DRCU/TCUs as the number of allocated frequencies,there is only a need to provide as many DRCU/TCUs as determined by traffic plusone for the BCCH carrier.

� The output power available with the use of hybrid combiners must be consistentwith coverage requirements.

Therefore as a general rule, cells with a small number of carriers will make goodcandidates for synthesizer hopping, whilst cells with many carriers will be goodcandidates for baseband hopping. There is also the other rule. There can only be onetype of hopping on a BTS site, not a combination of the two.




Error protectionand detection

To protect the logical channels from transmission errors introduced by the radio path,many different coding schemes are used. Figure 3-43 illustrates the coding process forspeech, control and data channels; the sequence is very complex.

The coding and interleaving schemes depend on the type of logical channel to beencoded. All logical channels require some form of convolutional encoding, but sinceprotection needs are different, the code rates may also differ.

The coding protection schemes,shown in Figure 3-42, are:

Speech channel encoding

The speech information for one 20 ms speech block is divided over eight GSM bursts.This ensures that if bursts are lost due to interference over the air interface the speechcan still be reproduced.

Common control channel encoding

20 ms of information over the air will carry four bursts of control information, for exampleBCCH. This enables the bursts to be inserted into one TDMA multiframe.

Data channel encoding

The data information is spread over 22 bursts. This is because every bit of datainformation is very important. Therefore, when the data is reconstructed at the receiver, ifa burst is lost, only a very small proportion of the 20 ms block of data will be lost. Theerror encoding mechanisms should then enable the missing data to be reconstructed.

20 msINFORMATION

BLOCK

SPEECH (260 BITS)

CONTROL (184 BITS)

DATA (240 BITS)

ENCODING INTERLEAVING

0.577 msINFORMATION

BURSTS

SPEECH (8 BURSTS)

CONTROL (4 BURSTS)

DATA (22 BURSTS)

Figure 3-42 The coding process



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EFR SPEECHFRAME

244 BITS

TCH/2.4

FR SPEECHFRAME

244 BITS

BCCH, PCH, AGCH, SDCCH,FACCH, SACCH, CBCH

184 BITS

DATA TRAFFIC9.6/4.8/2.4 k

N0 BITS

RACH + SCHP0 BITS

CYCLIC CODE+ REPETITION

IN: 244OUT: 260

CLASS 1aCYCLIC CODE

+ TAILIN: 260

OUT: 267

FIRECODE + TAILIN: 184

OUT: 228

ADD IN TAILIN: N0 BITS

OUT: N1 BITS

CYCLIC CODE + TAILIN: P0 BITS

OUT: P1 BITS

CONVOLUTION CODEIN: P1 BITS

OUT: 2 x P1 BITS

CONVOLUTION CODE+ PUNCTURE

IN: N1 BITSOUT: 456 BITS

CONVOLUTION CODEIN: 248 BITS

OUT: 456 BITS

CONVOLUTION CODEIN: 267 BITS

OUT: 456 BITS

RE-ORDERING & PARTITIONING+ STEALING FLAG

IN: 456 BITSOUT: 8 SUB-BLOCKS DIAGONAL INTERLEAVING +

STEALING FLAGIN: BLOCKS OF 456 BITS

OUT: 22 SUB-BLOCKS

BLOCK DIAGONALINTERLEAVINGIN: 8 BLOCKS

OUT: PAIRS OF BLOCKS

BLOCK RECTANGULARINTERLEAVING

IN: 8 SUB-BLOCKSOUT: PAIRS OF SUB-BLOCKS

19 x TCH 9.6 kBIT/S (BURST)

1 x RACH1 x SCH (BURST)

8 x TCH FR (BURSTS)8 x TCH EFR (BURSTS)8 x FACCH/TCH (BURSTS)8 x TCH 2-4 kBIT/S (BURSTS)

4 x BCCH, PCH, AGCH4 x SDCCH, SACCH4 x CBCH (BURSTS)

Figure 3-43 Error protection and detection




Speech channelencoding

The BTS receives transcoded speech over the Abis interface from the BSC. At this pointthe speech is organized into its individual logical channels by the BTS. These logicalchannels of information are then channel coded before being transmitted over the airinterface.

The transcoded speech information is received in frames, each containing 260 bits. Thespeech bits are grouped into three classes of sensitivity to errors, depending on theirimportance to the intelligibility of speech.

Class 1a

Three parity bits are derived from the 50 Class 1a bits. Transmission errors within thesebits are catastrophic to speech intelligibility, therefore, the speech decoder is able todetect uncorrectable errors within the Class 1a bits. If there are Class 1a bit errors, thewhole block is usually ignored.

Class 1b

The 132 Class 1b bits are not parity checked, but are fed together with the Class 1a andparity bits to a convolutional encoder. Four tail bits are added which set the registers inthe receiver to a known state for decoding purposes.



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Class 2

The 78 least sensitive bits are not protected at all.

The resulting 456 bit block is then interleaved before being sent over the air interface.

Over the Abis link, when using full rate speech vocoding, 260 bits aretransmitted in 20 ms equalling a transmission rate of 13 kbit/s. If enhanced fullrate is used then 244 bits are transmitted over the Abis link for each 20 mssample. The EFR frame is treated to some preliminary coding to build it up to260 bits before being applied to the same channel coding as full rate.

NOTE

The encoded speech now occupies 456 bits, but is still transmitted in 20 ms thus raisingthe transmission rate to 22.8 kbit/s.

CLASS 1a CLASS 1b CLASS 250 BITS 132 BITS 78 BITS

50 3 132 4

PARITYCHECK

TAILBITS

CONVOLUTIONAL CODE

378 78

456 BITS

260 BITS

Figure 3-44 Speech channel encoding




Channel codingfor enhanced fullrate

The transcoding for enhanced full rate produces 20 ms speech frames of 244 bits forchannel coding on the air interface. After passing through a preliminary stage which adds16 bits to make the frame up to 260 bits the EFR speech frame is treated to the samechannel coding as full rate.

The additional 16 bits correspond to an 8 bit CRC which is generated from the 50Class 1a bits plus the 15 most important Class 1b bits and 8 repetition bits correspondingto 4 selected bits in the original EFR frame of 244 bits.

Preliminary channel coding for EFR

EFR Speech Frame

� 50 Class 1a + 124 Class 1b + 70 Class 2 = 244 bits

Preliminary Coding

� 8 bit CRC generated from 50 Class 1a + 15 Class 1b added to Class 1b bits

� 8 repetition bits added to Class 2 bits

Output from preliminary coding

� 50 Class 1a + 132 Class 1b + 78 Class 2 = 260 bits

EFR frame of 260 bits passed on for similar channel coding as Full Rate.

244 BITS

CLASS 1a50 BITS

CLASS 1b124 BITS

CLASS 270 BITS

CLASS 1a50 BITS

CLASS 278 BITS

CLASS 1b132 BITS

8 BIT CRC ADDED TOCLASS 1b BITS

8REPETITIONBITS ADDEDTO CLASS 2

BITS

260 BITS

Figure 3-45 Preliminary coding for enhanced full rate speech



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Control channelencoding

Figure 3-46 shows the principle of the error protection for the control channels. Thisscheme is used for all the logical signalling channels, the synchronization channel (SCH)and the random access burst (RACH). The diagram applies to SCH and RACH, but withdifferent numbers.

When control information is received by the BTS it is received as a block of 184 bits.These bits are first protected with a cyclic block code of a class known as a Fire Code.This is particularly suitable for the detection and correction of burst errors, as it uses 40parity bits. Before the convolutional encoding, four tail bits are added which set theregisters in the receiver to a known state for decoding purposes.

The output from the encoding process for each block of 184 bits of signalling data is 456bits, exactly the same as for speech. The resulting 456 bit block is then interleavedbefore being sent over the air interface.

184

184

4

FIRE CODE TAIL BITS

CONVOLUTIONAL CODE

456

40

PARITY BITS

456 BITS

184 BITS

Figure 3-46 Control channel coding




Data channelencoding

Figure 3-47 shows the principle of the error protection for the 9.6 kbit/s data channel.The other data channels at rates of 4.8 kbit/s and 2.4 kbit/s are encoded slightlydifferently, but the principle is the same.

Data channels are encoded using a convolutional code only. With the 9.6 kbit/s datasome coded bits need to be removed (punctuated) before interleaving, so that like thespeech and control channels they contain 456 bits every 20 ms.

The data traffic channels require a higher net rate (‘net rate’ means the bit rate beforecoding bits have been added) than their actual transmission rate. For example, the9.6 kbit/s service will require 12 kbit/s, because status signals (such as the RS-232 DTR(data terminal ready)) have to be transmitted as well.

The output from the encoding process for each block of 240 bits of data traffic is 456 bits,exactly the same as for speech and control. The resulting 456 bit block is theninterleaved before being sent over the air interface.

Over the PCM link 240 bits were transmitted in 20 ms equalling a transmissionrate of 12 kbit/s. 9.6 kbit/s raw data and 2.4 kbit/s signalling information.

NOTE

The encoded control information now occupies 456 bits but is still transmitted in 20 msthus raising the transmission rate to 22.8 kbit/s.

CONVOLUTIONAL CODE

488

PUNCTUATE

456

DATA CHANNEL 9.6 kbit/s

240

4

TAILBITS

240 BITS

456 BITS

240

Figure 3-47 Data channel encoding



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Mapping logicalchannels ontothe TDMA framestructure

Interleaving

Having encoded, or error protected the logical channel, the next step is to build itsbitstream into bursts that can then be transmitted within the TDMA frame structure. It isat this stage that the process of interleaving is carried out. Interleaving spreads thecontent of one traffic block across several TDMA timeslots. The following interleavingdepths are used:

� Speech – 8 blocks

� Control – 4 blocks

� Data – 22 blocks

This process is an important one, for it safeguards the data in the harsh air interfaceradio environment.

Because of interference, noise, or physical interruption of the radio path, bursts may bedestroyed or corrupted as they travel between MS and BTS, a figure of 10–20% is quitenormal. The purpose of interleaving is to ensure that only some of the data from eachtraffic block is contained within each burst. By this means, when a burst is not correctlyreceived, the loss does not affect overall transmission quality because the errorcorrection techniques are able to interpolate for the missing data. If the system workedby simply having one traffic block per burst, then it would be unable to do this andtransmission quality would suffer.

It is interleaving that is largely responsible for the robustness of the GSM air interface,enabling it to withstand significant noise and interference and maintain the quality ofservice presented to the subscriber.

Table 3-19 Interleaving

TRAU Frame Type Number of GSM Bursts spread over

Speech 8

Control 4

Data 22

TRAU = Transcoder Rate Adaption Unit

NOTE




Diagonal interleaving – speech

Figure 3-48 illustrates, in a simplified form, the principle of the interleaving processapplied to a full-rate speech channel.

The diagram shows a sequence of ‘speech blocks’ after the encoding process previouslydescribed, all from the same subscriber conversation. Each block contains 456 bits,these blocks are then divided into eight blocks each containing 57 bits. Each block willonly contain bits from even bit positions or bits from odd bit positions.

The GSM burst will now be produced using these blocks of speech bits.

The first four blocks will be placed in the even bit positions of the first four bursts. Thelast four blocks will be placed in the odd bit positions of the next four bursts.

As each burst contains 114 traffic carrying bits, it is in fact shared by two speech blocks.Each block will share four bursts with the block preceding it, and four with the block thatsucceeds it, as shown. In the diagram block 5 shares the first four bursts with block 4and the second four bursts with block 6.

20 ms SPEECH SAMPLE 456 BITS

ÍÍÍÍ

ÍÍÍÍ

ÍÍÍÍ

ÍÍÍÍ

ÍÍÍÍ

ÍÍÍÍ

ÍÍÍÍ

MAPPED TO ODD BITSOF BURST

BITS 4, 12, 20, 28 ..... 452

ÍÍÍÍ

20 ms SPEECH SAMPLE 456 BITS 20 ms SPEECH SAMPLE 456 BITS

BITS 0, 8, 16, 24 ..... 448

MAPPED TO EVEN BITSOF BURST

BITS 0, 8, 16, 24 ..... 448

MAPPED TO EVEN BITSOF BURST

MAPPED TO ODD BITSOF BURST

BITS 4, 12, 20, 28 ..... 452

012345678 .... 113 012345678 .... 113

Figure 3-48 Diagonal interleafing – speech



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Transmission – speech

Each burst will be transmitted in the designated timeslot of eight consecutive TDMAframes, providing the interleaving depth of eight.

Table 3-20 shows how the 456 bits resulting from a 20 ms speech sample are distributedover eight normal bursts.

It is important to remember that each timeslot on this carrier may be occupied by adifferent channel combination: traffic, broadcast, dedicated or combined.

Note that FACCH, because it ‘steals’ speech bursts from a subscriber channel,experiences the same kind of interleaving as the speech data that it replaces(interleaving depth = 8).

NOTE

The FACCH will steal a 456 bit block and be interleaved with the speech. Each burstcontaining a FACCH block of information will have the appropriate stealing flag set.

Table 3-20 Distribution of 456 bits from one 20 ms speech sample

Distribution Burst

0 8 16 24 32 40 ..........................448 even bits of burst N

1 9 17 25 33 41 ..........................449 even bits of burst N + 1



4 12 20 28 36 44 ..........................452 odd bits of burst N + 4







Rectangular interleaving – control

Figure 3-49 illustrates, in a simplified form, the principle of rectangular interleaving. Thisis applied to most control channels.

The diagram shows a sequence of ‘control blocks’ after the encoding process previouslydescribed. Each block contains 456 bits, these blocks are then divided into four blockseach containing 114 bits. Each block will only contain bits for even or odd bit positions.

The GSM burst will be produced using these blocks of control.

Transmission – control

Each burst will be transmitted in the designated timeslot of four consecutive TDMAframes, providing the interleaving depth of four.

The control information is not diagonally interleaved as are speech and data. This isbecause only a limited amount of control information is sent every multiframe. If thecontrol information was diagonally interleaved, the receiver would not be capable ofdecoding a control message until at least two multiframes were received. This would betoo long a delay.

FRAME 1

54

654321

ÍÍÍ

ÍÍÍ

ÍÍÍ

ÍÍÍ

ÍÍÍ

ÍÍÍ

ÍÍÍ

ÍÍÍ

6

FRAME 2 FRAME 3

456 BITS

BURSTS

TDMA FRAMES

CONTROLBLOCKS

30 1 2 4 5 6 730 1 2 4 5 6 730 1 2 4 5 6 7

114BITS

114BITS

114BITS

114BITS

ODDEVENODDEVEN

Figure 3-49 Rectangular interleaving – control



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Diagonal interleaving – data

Figure 3-50 illustrates, in a simplified form, diagonal interleaving applied to a 9.6 kbit/sdata channel.

The diagram shows a sequence of ‘data blocks’ after the encoding process previouslydescribed, all from the same subscriber. Each block contains 456 bits, these blocks aredivided into four blocks each containing 114 bits. These blocks are then interleavedtogether.

The first 6 bits from the first block are placed in the first burst. The first 6 bits from thesecond block will be placed in the second burst and so on. Each 114 bit block is spreadacross 19 bursts and the total 456 block will be spread across 22 bursts.

Data channels are said to have an interleaving depth of 22, although this is sometimesalso referred to as an interleaving depth of 19.




Transmission – data

The data bits are spread over a large number of bursts, to ensure that the data isprotected. Therefore, if a burst is lost, only a very small amount of data from one datablock will actually be lost. Due to the error protection mechanisms used, the lost data hasa higher chance of being reproduced at the receiver.

This wide interleaving depth, although providing a high resilience to error, does introducea time delay in the transmission of the data. If data transmission is slightly delayed, it willnot effect the reception quality, whereas with speech, if a delay were introduced thiscould be detected by the subscriber. This is why speech uses a shorter interleavingdepth.

Í

5

654321

456 BITS

DATABLOCKS

ÍÍ ÍÍÍ ÍÍÍ

114

ÍÍÍÍ ÍÍÍÍ ÍÍ Í ÍÍÍ ÍÍ

114 114114

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

114BITS

114BITS

114BITS

114BITS

LAST6

BITS

LAST6

BITS

LAST6

BITS

LAST6

BITS

FIRST6

BITS

FIRST6

BITS

FIRST6

BITS

FIRST6

BITS

Figure 3-50 Diagonal interleaving – data



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Voice ActivityDetection – VAD

VAD is a mechanism whereby the source transmitter equipment identifies the presenceor absence of speech.

VAD implementation is effected in speech mode by encoding the speech patternsilences at a rate of 500 bit/s rather than the full 13 kbit/s. This results in a datatransmission rate for background noise, known as comfort noise, which is regenerated inthe receiver.

Without comfort noise the total silence between the speech would be considered to bedisturbing by the listener.

DiscontinuousTransmission –DTX

DTX increases the efficiency of the system through a decrease in the possible radiotransmission interference level. It does this by ensuring that the MS does not transmitunnecessary message data. DTX can be implemented, as necessary, on a call by callbasis. The effects will be most noticeable in communications between two MS.

DTX in its most extreme form, when implemented at the MS can also result inconsiderable power saving. If the MS does not transmit during silences there is areduction in the overall power output requirement.

The implementation of DTX is very much at the discretion of the network provider andthere are different specifications applied for different types of channel usage.

DTX is implemented over a SACCH multiframe (480 ms). During this time, of thepossible 104 frames, only the 4 SACCH frames and 8 Silence Descriptor (SID) framesare transmitted.

�

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0 103

4 x SACCH 26 FRAME MULTIFRAMES (120 ms)

8 x SILENCE DESCRIPTOR (SID)

26 FRAME MULTIFRAME 52–59

Figure 3-51 SACCH Multiframe (480 ms)




Receive diversity

In its simplest case, multipath fading arises from destructive interference between twotransmission paths. The deepest instantaneous fade occurring at the frequency for whichthe effective path length difference is an odd multiple of half wavelengths.

If two receive antennas are mounted a defined distance apart, then it follows that theprobability of them simultaneously experiencing maximum fade depth at a givenfrequency is very much less than for the single antenna situation.

There are three ways of utilizing this concept:

� The receiver can be switched between the two RF receive paths provided twoantennas.

� The RF signals from two receive paths can be phase aligned and summed.

� The phasing can be made so as to minimize the distortion arising from themultipath transmission.

Each of the methods has advantages and disadvantages.

In the case of the switched configuration, its simply chooses the better of the two RFsignals which is switched through to the receiver circuitry.

Phase alignment has the advantage of being a continuously optimized arrangement interms of signal level, but phase alignment diversity does not minimize distortion. TheMotorola DRCU/TCU uses this diversity concept.

The distortion minimizing approach, whilst being an attractive concept, has not yet beenimplemented in a form that works over the full fading range capabilities of the receiversand therefore has to switch back to phase alignment at low signal levels. This means arather complex control system is required.

It must be emphasized that diversity will not usually have any significant effect on themean depression component of fading, but the use of phase alignment diversity can helpincrease the mean signal level received.

Remember in microcellular applications that the M-Cellcity and M-Cellarenadoes not support spatial diversity.

NOTE

PATH LENGTHIN WAVE LENGTHS

MOBILE

ANTENNAS(approx 10 wave lengths)

SPACE BETWEEN

BTS

METHODS OF UTILIZATION:

a. SWITCHED.b. PHASE ALIGNED AND SUMMED.c. PHASE ALIGNED WITH MINIMUM DISTORTION.

Figure 3-52 Receive diversity



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Equalization

As mentioned in multipath fading, in most urban areas the only signals received aremultipath. If nothing was done to try and counter the effects of (Inter SymbolInterference) ISI caused by the time dispersed signals, the Bit Error Rate (BER) of thedemodulated signal would be far too high, giving a very poor quality signal, unacceptableto the subscriber. To counter this a circuit called an equalizer is built into the receiver.

The equalizer uses a known bit pattern inserted into every normal burst transmitted,called the training sequence code. This allows the equaliser to assess and modify theeffects of the multipath component, resulting in a far cleaner less distorted signal.Without this equalizer the quality of the circuit would be unacceptable for the majority oftime.

Training sequence code

The training sequence code, Figure 3-53, is used so that the demodulator can estimatethe most probable sequence of modulated data. As the training sequence is a knownpattern, this enables the receiver to estimate the distortion ISI on the signal due topropagation effects, especially multipath reception.

The receiver must be able to cope with two multipaths of equal power received at aninterval of up to 16 microseconds. If the two multipaths are 16 micro seconds delayedthen this would be approximately equivalent to 5–bit periods. There are 32 combinationspossible when two 5–bit binary signals are combined. As the transmitted trainingsequence is known at the receiver, it is possible to compare the actual multipath signalreceived with all 32 possible combinations reproduced in the receiver. From thiscomparison the most likely combination can be chosen and the filters set to remove themultipath element from the received signal.

The multipath element can be of benefit, once it has been identified, as it can then berecombined with the wanted signal in a constructive way to give a greater received signalstrength. Once the filters have been set, they can be used to filter the random speechdata as it is assumed they will have suffered from the same multipath interference as thetraining sequence code. The multipath delay is calculated on a burst by burst basis, as itis constantly changing.

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Signal from shortest path

Signal from delayed path

3 bits

Figure 3-53 Training sequence code

GSM-001-103Subscriber environment



Subscriber environment

Subscriberhardware

System quality, (for example; voice quality) system access and grade of service, asperceived by the customer, are the most significant factors in the success of a cellularnetwork. The everyday subscriber neither knows or really cares about the high level oftechnology incorporated into a cellular network. However, they do care about the qualityof their calls.

What the network designer must remember is that it is the subscriber who chooses thetype of equipment they wish to use on the network. It is up to the network provider tosatisfy the subscriber whatever they choose.

The output power of the mobile subscriber is limited in a GSM system to a maximum of8 W for a mobile and a minimum of 0.8 W for a hand portable. For a DCS1800 system,the mobile subscriber is restricted to a maximum of 1 W and a minimum of 250 mW handportable.

EnvironmentNot only does the network designer have to plan for the subscribers choice of phone, thedesigner has to plan for the subscribers choice as to where they wish to use that phone.

Initially when only the mobile unit was available, system coverage and hence subscriberuse was limited to on street, high density urban or low capacity rural coverage areas.During the early stages of cellular system implementation the major concern was tryingto provide system coverage inside tunnels.

However, with the advances in technology the hand portable subscriber unit is now firmlyestablished. With this introduction came new problems for the network designer. Theportable subscriber unit provides the user far more freedom of use but the subscriber stillexpected exactly the same service. The subscriber now wants quality service from thesystem at any location. This location can be on a street, or any floor of a building whetherit be the basement or the penthouse and even in lifts, refer to Figure 3-54. Thus greaterfreedom of use for the subscriber gives the network designer even greater problemswhen designing and implementing a cellular system.

URBAN/CITYENVIRONMENTS

BUILDINGS

LIFTS

RURAL AREAS

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TUNNELS

Figure 3-54 The subscriber environment

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Distribution

Not only do network designers have to identify the types of subscriber that use thecellular network now and in the future, but at what location these subscribers areattempting to use their phones.

Dense urban environments require an entirely different design approach, due toconsiderations mentioned earlier in this chapter, than the approach being used to designcoverage for a sparsely populated rural environment.

Road and rail networks have subscribers moving at high speed, so this must beaccounted for when planning the interaction between network entities whilst thesubscriber is using the network. Even in urban areas, the network designer must beaware that traffic is not necessarily evenly distributed. An urban area may containsub-areas of uneven distribution such as a business or industrial district, and may haveto plan for a seasonal increase of traffic due to, say, a convention centre. It is vitallyimportant that the traffic distribution is known and understood prior to network design, toensure that a successful quality network is implemented.

RURAL

URBAN

ROAD/RAILNETWORK

40%

20%

10%

EXHIBITIONS

BUSINESS AREAS

INDUSTRIAL

30%RESIDENTIAL

HIGH SPEED MOBILES(RAILWAYS)

SUBSCRIBERS DISTRIBUTION CHANGES ON A HOURLY BASIS

Figure 3-55 Subscriber distribution

GSM-001-103Subscriber environment



Most demanding

The network designer must ensure that the network is designed to ensure a qualityservice for the most demanding subscriber. This is the hand portable subscriber. Thehand portable now represents the vast majority of all new subscriber units introduced intocellular networks. So clearly the network operators, and hence the network designers,must recognise this.

Before commencing network design based around hand portable coverage, the networkdesigner must first understand the limitations of the hand portable unit and secondly,what the hand portable actually requires from the network.

The hand portable phone is a small lightweight unit which is easy to carry and has theability to be used from any location. The ability of the unit to be used at any locationmeans that the network must be designed with the provision of good in-building coverageas an essential element.

To further complicate the network designers job, these hand portable units have a lowoutput power:

� 0.8 W to 8 W for GSM900.

� 0.25 W to 1 W for DCS1800.

So the distance at which these units can be used from a cell is constrained by RFpropagation limitations.

For practical purposes, the actual transmit power of the hand portable should be kept aslow as possible during operation. This helps not only from an interference point of view,but this also helps to extend the available talk time of the subscriber unit, which is limitedby battery life.

GSM-001-103 Subscriber environment


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Future planning

Normal practice in network planning is to choose one point of a well know re-use modelas a starting point. Even at this early stage the model must be improved because anytrue traffic density does not follow the homogeneous pattern assumed in any theoreticalmodels.

Small–sized heavy traffic concentrations are characteristic of the real traffic distributions.Another well known traffic characteristic feature is the fast descent in the density of trafficwhen leaving city areas. It is uneconomical to build the whole network using a standardcell size, it becomes necessary to use cells of varying sizes.

Connecting areas with different cell sizes brings about new problems. In principle it ispossible to use cells of different size side by side, but without careful consideration thismay lead to a wasteful frequency plan. This is due to the fact that the re-use distance oflarger cells is greater than that of smaller cells. The situation is often that the borders areso close to the high density areas that the longer re-use distances mean decreasedcapacity. Another solution, offering better frequency efficiency, is to enlarge the cell sizegradually from small cells into larger cells.

In most cases the traffic concentrations are so close to each other that the expansioncannot be completed before it is time to start approaching the next concentration, bygradually decreasing the cell size. This is why the practical network is not a regularcluster composition, but a group of directional cells of varying size.

Besides this need for cells of different size, the unevenness of the traffic distribution alsocause problems in frequency planning. Theoretical frequency division methods applicableto homogenous clusters cannot be used. It is quite rare that two or more neighbouringcells need the same amount of channels. It must always be kept in mind that the valuescalculated for future traffic distribution are only crude estimates and that the real trafficdistribution always deviates from these estimates. In consequence, the network planshould be flexible enough to allow for rearrangement of the network to meet the realtraffic needs.

Conclusion

In conclusion there are no general rules for radio network planning. It is a work ofexperimenting and reiterating. By comparing different alternatives, the network designersshould find a plan that both fulfils the given requirements and keeps within practicallimitations. When making network plans, the designers should always remember thatevery location in a network has its own conditions, and all local problems must be tackledand solved on a individual basis.

GSM-001-103The microcellular solution



The microcellular solution

LayeredArchitecture

The basic term layered architecture is used in the microcellular context to explain howmacrocells overlay microcells. It is worth noting that when talking of the traffic capacity ofa microcell it is additional capacity to that of the macrocell in the areas of microcellularcoverage.

The traditional cell architecture design, Figure 3-56, ensures that, as far as possible, thecell gives almost total coverage for all the MSs within its area.

ÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈÈ

MICROCELL A MICROCELL B

TOP VIEW

MACROCELL

MICROCELL A MICROCELL B

SIDE VIEW MACROCELL

Figure 3-56 Layered architecture

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Combined cellarchitecture

A combined cell architecture system, Figure 3-57, is a multi-layer system of macrocellsand microcells. The simplest implementation contains two layers. The bulk of thecapacity in a combined cell architecture is provided by the microcells. Combined cellsystems can be implemented into other vendors networks.

Macrocells: Implemented specifically to cater for the fast-moving MSs and to provide afallback service in the case of coverage holes and pockets of interference in the microcelllayer. Macrocells form an umbrella over the smaller microcells.

Microcells: Microcells handle the traffic from slow-moving MSs. The microcells can givecontiguous coverage over the required areas of heavy subscriber traffic.

Picocells: Low cost installation by using in-building fibre optics or telephone wiring witha HDSL modem, easily expanded to meet capacity requirements. Efficient use of thefrequency spectrum due to low power radios causing low interference to externalnetworks. Higher quality speech compared with external illumination of the building dueto improved uplink quality.

UNDERLAYED MICROCELL(COULD BE A DIFFERENT VENDOR)

OVERLAYED MACROCELLS

CONTIGUOUS COVERAGE OVER AREAS OFHIGH SLOW MOVING TRAFFIC DENSITY

Figure 3-57 Combined cell architecture




Combined cellarchitecturestructure

A combined cell architecture employs cells of different sizes overlaid to providecontiguous coverage. This structure is shown in Figure 3-58.

Some points to note:

� Macrocell and microcell networks may be operated as individual systems.

� The macrocell network is more dominant as it handles the greater amount oftraffic.

� Microcells can be underlayed into existing networks.

� Picocells can be introduced as a third layer or as part of the second layer.

SYSTEM 1= OVERLAY SYSTEMSYSTEM 2= UNDERLAY SYSTEM

MACROCELL COVERAGE

MICROCELLCOVERAGE

BSC B

BTS 1

BSC A

MSC

PICOCELL

BTS 2

BTS 3 BTS 4

BTS 5SYSTEM 1MACROCELL

SYSTEM 2MICROCELL

LINK TO IMPLEMENT MICROCELLS AS A SEPARATE SYSTEM

ALTERNATIVE SYSTEM (MICROCELLS CONTROLLED BY THE SAME BSC AS MACROCELLS)

Figure 3-58 Combined cell architecture structure

GSM-001-103 The microcellular solution


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Expansionsolution

As the GSM network evolves and matures its traffic loading will increase as the numberof subscribers grow. Eventually a network will reach a point of traffic saturation. The useof microcells can provide high traffic capacity in localised areas.

The expansion of a BTS site past its original designed capacity can be a costly exerciseand the frequency re-use implications need to be planned carefully (co-channel andadjacent channel interference). The use of microcells can alleviate the increase incongestion, the microcells could be stand-alone cells to cover traffic hotpots or acontiguous cover of cells in a combined architecture. The increased coverage will givegreater customer satisfaction.





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i

Chapter 4

BTS planning steps and rules

GSM-001-103



GSM-001-103


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iii

Chapter 4BTS planning steps and rules i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


BTS planning overview 4–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Outline of planning steps 4–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Macrocell cabinets 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Horizonmicro 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-Cell6 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-Cell2 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Microcell enclosures 4–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Horizonmicro and Horizoncompact 4–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Receive configurations 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Receiver planning actions 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Transmit configurations 4–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transmit planning actions 4–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Antenna configurations 4–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Antenna planning actions 4–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Carrier equipment (CTU/TCU) 4–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CTU/TCU planning actions 4–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Micro base control unit (mBCU) 4–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . mBCU planning actions 4–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Network interface unit (NIU) and site connection 4–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NIU planning actions 4–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Main control unit, with dual FMUX (MCUF) 4–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MCUF planning actions 4–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Main control unit (MCU) 4–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MCU planning actions 4–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cabinet interconnection (FOX/FMUX) 4–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FOX/FMUX planning actions 4–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GSM-001-103



Power requirements 4–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Power planning actions 4–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Network expansion using Macro/Micro/Picocell BTS 4–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Expansion considerations 4–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mixed site utilization 4–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

PCC cabinet 4–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cabinet planning actions 4–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Line interface modules (HIM-75, HIM-120) 4–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 4–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 4–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HIM-75/HIM-120 planning actions 4–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .



68P02900W21-G


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Chapter overview

Introduction

This chapter provides the planning steps and rules for the BTS, including Macrocell,Microcell and Picocell. The planning steps and rules for the BSC are in Chapter 5, andremote transcoder (RXCDR) are in Chapter 6 of this manual. This chapter contains:

� BTS planning overview:

� Macrocell and Microcell planning overview:

– Planning rules for Macrocell cabinets.

– Planning rules for Microcell enclosures.

– Planning rules for receive configurations.

– Planning rules for transmit configurations.

– Planning rules for antenna configurations.

– Planning rules for the carrier equipment.

– Planning rules for the micro base control unit.

– Planning rules for the network interface unit and E1/T1 link interfaces.

– Planning rules for the main control unit, with dual FMUX (MCUF).

– Planning rules for the main control unit (MCU).

– Planning rules for cabinet interconnection.

– Planning rules for power requirements.

– Planning rules for network expansion using Macrocell and Microcell BTS.

� Picocell planning overview:

– Planning rules for PCC cabinets.

– Line interface modules (HIM-75, HIM-120)

GSM-001-103BTS planning overview



BTS planning overview

Introduction

To plan the equipage of a BTS site certain information must be known. The major itemsinclude:

� The number of cells controlled by the site.

� The number of carriers required.

� The number of standby carriers per cell.

� The output power per cell.

The required output power must be known to ensure that the selected combiningmethod and antenna configuration provides sufficient output power. Alternativesinclude changing combiner types or using more than one transmitting antenna.Duplexers may be used to reduce the amount of cabling and the number ofantennas.

� The antenna configuration for each cell.

� The cabinet/enclosure types to be used.

� Future growth potential.

It is useful to know about potential future growth of the site in order to makeintelligent trade offs between fewer cabinet/enclosures initially and ease of growthlater.

� Whether or not there are equipment shelters at the site.

Macro/Micro/Picocell6 outdoor equipments should be included in the BTS planningfor locations where there are no equipment shelters. Macro/Micro/Picocell2 shouldbe included where rooftop mounting or distributed RF coverage is required orwhere space and access are restricted.

To plan the equipage of a PCC cabinet (M-Cellaccess) certain information must beknown. The major items include:

� The traffic load to be handled.

� The number of PCU enclosures to be controlled.

� The physical interconnection of the PCU enclosures to the PCC cabinet.

� The use of optical or HDSL links.

� The use or otherwise of the collocated BSC option.

� The use or otherwise of the GDP/XCDR option.

� The use of E1 or T1 links.

� The use of balanced or unbalanced E1.

GSM-001-103 BTS planning overview


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Outline ofplanning steps

Macrocell and Microcell BTS sites

The information required for planning an Macro/Microcell BTS site is outlined in thefollowing list:

1. Determine if the site is indoor or outdoor.

2. Number of Macrocell cabinets required, refer to the section Macrocell cabinets inthis chapter.

3. Number of Microcell enclosures required, refer to the section Microcellenclosures in this chapter.

4. The receiver configuration, refer to the section Receiver configurations in thischapter.

5. The transmit configuration, refer to the section Transmit configurations in thischapter.

6. The antenna configuration, refer to the section Antenna configurations in thischapter.

7. The amount of carrier equipment required, refer to the section Carrier equipmentin this chapter.

8. The number of micro base control units required, refer to the section Micro basecontrol units in this chapter.

9. The number of network interface units required, refer to the section Networkinterface unit and site interconnection in this chapter.

10. The number of E1/T1 links required, refer to the section Network interface unitand site interconnection in this chapter.

11. The number of main control units required, refer to the section Main control unitin this chapter.

12. The number of FOX and FMUX boards required, refer to the section Cabinetinterconnection in this chapter.

13. The power supply requirements, refer to the section Power requirements in thischapter.

Picocell site

The information required for planning a Picocell (Macro/Micro/Picocellaccess) site isoutlined in this chapter.

GSM-001-103Macrocell cabinets



Macrocell cabinets

Horizon micro

An Horizonmicro cabinet can support six carriers (CTUs). Expansion beyond six carriersrequires additional cabinets.

An Horizonmicro HMS offers the following options:

� Fans that circulate ambient air through the cabinet, for both indoor and outdoorunits.

� An outdoor unit for ambient temperatures up to 50 �C, for outdoor cabinets only.

M-Cell 6

��

��

� ��

The M-Cell6 HMS offers the following options:


� A heat exchanger for ambient temperatures up to 45 �C, for outdoor cabinets only.

� An air conditioning unit for ambient temperatures up to 55 �C, for outdoor cabinetsonly.

M-Cell 2

An M-Cell2 cabinet can support two carriers (TCUs). Expansion beyond two carriersrequires additional cabinets.

The M-Cell2 outdoor cabinet accommodates all the elements in an indoor cabinet, inaddition, limited accommodation for LTUs and battery backup is provided. Cooling isprovided by a fan within the cabinet.

Unlike M-Cell6 outdoor cabinets where the antenna terminations are in a side cabinet,M-Cell2 terminations are on the main cabinet.

The M-Cell2 HMS offers the following options:


� A heat exchanger for ambient temperatures up to 45 �C, for outdoor cabinets only.

� An air conditioning unit for ambient temperatures up to 55 �C, for outdoor cabinetsonly.

GSM-001-103 Microcell enclosures


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Microcell enclosures

Horizon microandHorizon compact

The Horizonmicro is an integrated cell sites with a common design for indoor and outdooroperation. The single unit is offered as a two-carrier cell.

The Horizoncompact is an integrated cell sites with a common design for indoor andoutdoor operation and consists of:

� One unit, similar to M-Cellarena, is a two-carrier cell with combining.

� The other unit is an RF booster, with duplexing, delivering 10 W at each attenna.

Horizonmicro and Horizoncompact are specified for wall or pole mounting and thefollowing factors should be considered when planning the mounting for an Horizonmicroand Horizoncompact are:

� They may be fixed to walls of concrete, brickwork, stonework, dense aggregateblockwork, reconstituted stone with or without rendering, and to a suitable pole.

� The wall fixings should be: Fischer Nylon Wall Plugs – Type S with hex headedcoach screws, stainless A4 or Fischer Sleeve Anchor – Type FSA or equivalentfixings.

� The fixings should not penetrate more than 70 mm nor less than 50 mm.

� The uppermost wall fixings should have 600 mm of solid construction above them.

GSM-001-103Receive configurations



Receive configurations

Introduction

The receiver equipment provides the termination and distribution of the received signalsfrom the Rx antennas. Receiver equipment is required for each Rx signal in everycabinet or enclosure in which it is used. Each Rx antenna must terminate on a singlecabinet or enclosure. If the signal needs to go to multiple cabinets it will be distributedfrom the first cabinet.

Horizonmicro is two carrier only and are combined to a single antenna.Horizoncompact is two carrier only, with two antennas.

NOTE

Planningconsiderations

The factors affecting planning for GSM900 and DCS1800 M-Cell BTSs are provided inthis section.

GSM900

The following factors should be considered when planning the GSM900 receiveequipment:

� Horizonmicro BTSs require one SURF for each cabinet.

� Receive antennas can be extended across Horizonmicro cabinets by using theSURF expansion ports to feed a SURF in another cabinet.

� M-Cell2 and M-Cell6 BTSs require one DLNB for each sector.

� Receive antennas can be extended across M-Cell6 cabinets by using the IADUexpansion ports to feed an IADU in another cabinet.

GSM1800

The following factors should be considered when planning the DCS1800 receiveequipment:

� M-Cell2 and M-Cell6 BTSs require one LNA for each sector.

� Receive antennas can be extended across M-Cell6 cabinets by using the LNAexpansion ports to feed an LNA in another cabinet.

� Horizon BTS.

Receiverplanning actions

The following planning actions are required:

1. Determine the number of cells.

2. Determine number of cells which have CTU/TCUs in more than one cabinet.

3. Determine the number of Rx antennas per cell supported in each cabinet.

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4. Determine the type and quantity of receive equipment required.

GSM-001-103Transmit configurations



Transmit configurations

Introduction

The transmit equipment provides bandpass filtering and signal combining for the BTScabinets. A TxBPF is required for each antenna.

Horizonmicro is two carrier only and are combined to a single antenna.Horizoncompact is two carrier only, with two antennas.

NOTE


The factors affecting planning for GSM900 and DCS1800 M-Cell BTSs are provided inthis section.

GSM900

The transmit configuration listed in Table 4-1 are available for GSM900 equipment.

Table 4-1 Transmit configurations GSM900

Numberof

Carriers

Cabinet TransmitConfigurations

Wide Band Combining

Cabinet TransmitConfigurations

Cavity CombiningNotes

1 1 CBF Not available M-Cell2 and M-Cell6

2 1 CBF Not available M-Cell2 and M-Cell6

3

2 CBF plus 1 medium powerduplexer (an extra duplexer isrequired for 2 antennas)orone 3 input CBF

1 CCB output M-Cell6 only

4

2 CBF plus 1 medium powerduplexer (an extra duplexer isrequired for 2 antennas)orone 3 input CBF and oneHybrid combiningblock(HCOMB)

1 CCB output +1 CCB extension M-Cell6 only

5 One CBF and one 3 inputCBF


6 Two 3 input CBF and onenon-HCOMB (load block)


A CCB output includes a TxBPF, a CCB, extension does not.

NOTE

GSM-001-103 Transmit configurations


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DCS1800

The transmit configuration listed in Table 4-2 are available for DCS1800 equipment.

Table 4-2 Transmit configurations DCS1800

Numberof

Carriers

Cabinet Transmit Configurations

Wide BandCombining

Cabinet Transmit Configurations

Cavity CombiningNotes

1 1 DCF or TCF Not available Horizonmicro only

1 1 TxBPF Not available M-Cell2 and M-Cell6

2 1 DCF 1 CCB output Horizonmicro only

2 1 Hybrid combiner plus 1 TxBPF 1 CCB output M-Cell2 and M-Cell6

3 2 DCF or 1 DDF 1 CCB output Horizonmicro only

3 2 Hybrid combiner plus 1 TxBPF 1 CCB output M-Cell6 only

4 1 DDF and HCU 1 CCB output +1 CCB extension Horizonmicro only

4 2 Hybrid combiner plus 1 TxBPF


5 2 DDF and Air 1 CCB output +1 CCB extension Horizonmicro only


1 CCB output + 1 CCB extension M-Cell6 only

6 2 DDF and Air 1 CCB output +1 CCB extension Horizonmicro only



A CCB output includes a TxBPF, a CCB, extension does not.

NOTE

Transmitplanning actions

Determine the transmit equipment required.

GSM-001-103Antenna configurations



Antenna configurations


The following factors should be considered when planning the antenna configuration:

� Omni, one sector, two sector, three sector (either 120� or 60�), or six sector (twocabinets are needed).

� Share existing antenna(s) or new/separate antenna(s).

� Diversity considerations.

� Antenna type:

– Gain.

– Size.

– Bandwidth.

– Appearance.

– Mounting.

Antennaplanning actions

Determine the antenna configuration.

GSM-001-103 Carrier equipment (CTU/TCU)


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Carrier equipment (CTU/TCU)

Introduction

The carrier equipment kit, for Horizonmicro consists of a CTU.

The carrier equipment kit, for M-Cell2 and M-Cell6 consists of a TCU.


The following factors should be considered when planning carrier equipment:

� The number of carriers should be based on traffic considerations.

� Plan for future growth.

� Allowance must be made for BCCH and SDCCH control channels.

Information about how to determine the number of control channels required is inthe Control channel calculations section in Chapter 3, BSS cell planning in thismanual.

� Normally, one CTU/TCU is required to provide each RF carrier.

� Include redundancy requirements; redundancy can be achieved by installingexcess capacity in the form of additional carrier equipment kits.

CTU/TCUplanning actions

Determine the number of CTU/TCUs required.

GSM-001-103Micro base control unit (mBCU)



Micro base control unit ( �BCU)

Introduction

The �BCU is the Macro/Microcell implementation of a BTS site controller.


The following factors should be considered when planning the �BCU complement:

� Horizonmicro

Each Horizonmicro cabinet requires one �BCU cage.

The �BCU cage can be equipped for redundancy and/or additional E1/T1 linkcapacity.

� M-Cell6

Each M-Cell6 cabinet requires one �BCU cage.

Two �BCU cages can be equipped for redundancy and/or additional E1/T1 linkcapacity.

� M-Cell2

The first M-Cell2 cabinet requires one �BCU2 cage.

Two �BCU2 cages can be equipped for redundancy and/or additional E1/T1 li��

Additional cabinets do not require �BCU2 cages.

�BCU planningactions

Determine the number of �BCUs required.

GSM-001-103 Network interface unit (NIU) and site connection


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Network interface unit (NIU) and site connection

Introduction

The NIU provides the interface for the Macro/Microcell BTS to the terrestrial network.

Horizonmicro and Horizoncompact are fitted with a single NIU-m only.

NOTE


The following factors should be considered when planning the NIU��:

� The first NIU in a �BCU cage�can interface two E1/T1 links.

� The second NIU in a �BCU cage�in an M-Cell6 cabinet can interface one E1/T1link.

� Each E1/T1 link provides 31(E1) or 24 (T1) usable 64 kbit/s links.

� A minimum of one NIU is required for each BTS site.

� One NIU can support two MCUFs (Horizonmacro) or two MCUs (M-Cell6).

� The NIU feeds the active MCUF/MCU.

� To calculate the number of 64 kbit/s links required, view the site as consisting of itsown equipment, and that of other sites which are connected to it by the drop andinsert (daisy chain) method.

– Two 64 kbit/s links are required for each active CTU/TCU.

– A 64 kbit/s link is required for every RSL (LAPD signalling channel) to thesite. In the drop and insert (daisy chain) configuration, every site willrequire its own 64 kbit/s link for signalling.

� Redundancy for the NIU module depends on the number of redundant E1/T1 linksrunning to the site.

� Plan for a maximum of two NIUs per �BCU cage for Horizonmicro and M-Cell6cabinets (three E1 or T1 links).

� Plan for a maximum of one NIU per �BCU2 cage for M-Cell2 cabinets (two E1 orT1 links).

GSM-001-103Network interface unit (NIU) and site connection



The minimum number of NIUs and �BCU cages required for a given number of E1/T1links to a single M-Cell cabinet is shown in Table 4-3.

Table 4-3 Site connection requirements

Number ofE1/T1 links

Minimumnumber of NIU

required

Number of�BCU cages

required

Notes

1 1 1 Horizonmicro, M-Cell2 andM-Cell6

2 1 1 Horizonmicro, M-Cell2 andM-Cell6

3 2 1 Horizonmicro and M-Cell6

3 2 2 M-Cell2 and M-Cell6

4 2 2 M-Cell2 and M-Cell6

5 3 2 M-Cell6 only

6 4 2 M-Cell6 only

E1 link interfaces For driving a balanced 120 ohms 3 V (peak pulse) line use a BIB.

For driving a single ended 75 ohms 2.37 V (peak pulse) line use a T43.

T1 link interfaces

For driving a balanced 110 ohms 3 V (peak pulse) line use a BIB.

NIU planningactions

Determine the number of NI�s required.

GSM-001-103 Main control unit, with dual FMUX (MCUF)


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Main control unit, with dual FMUX (MCUF)

Introduction

The MCUF provides the main site control functions for a Horizonmicro BTS site.


The following factors should be considered when planning the MCUF��:

� Only the first cabinet requires an MCUF.

� An optional (PCMCIA) memory card may be installed for non-volatile code storage.

� For redundancy add a second MCUF in the first cabinet.

MCUF planningactions

Determine the number of MCUFs required.

GSM-001-103Main control unit (MCU)



Main control unit (MCU)

Introduction

The MCU provides the main site control functions for M-Cell6 and M-Cell2 BTS sites.


The following factors should be considered when planning the MCU��:

� Only the first cabinet requires an MCU.

� An optional (PCMCIA) memory card may be installed for non-volatile code storage.

� For redundancy add a second �BCU cage and MCU in the first cabinet.

MCU planningactions

Determine the number of MCUs required.

GSM-001-103 Cabinet interconnection (FOX/FMUX)


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Cabinet interconnection (FOX/FMUX)

Introduction

Horizon micro

The FMUX multiplexes and demultiplexes electrical connections between a MCUF andup to six CTUs.

M-Cell6 and M-Cell 2

The FOX provides the bidirectional electrical to optical interface between a MCU orFMUX and up to six TCUs.

The FMUX multiplexes and demultiplexes electrical connections for up to six TCUs ontoa single fibre optic connection operating at the rate of 16.384 Mbit/s.


Horizon macro

The following factors should be considered when planning the FMUX��

��:

Table 4-4 FMUX complement

Cabinet Master Extender 1 Extender 2 Extender 3

1 None

2 None 1

3 1 1 1

4 2 1 1 1

� An FMUX is not required in the Master cabinet, for two cabinet configurations.

� Each additional Horizonmicro cabinet requires one FMUX plus one FMUX in theMaster cabinet.

� Redundancy requires duplication of an FMUX and associated MCUFs.


The following factors should be considered when planning the FOX/FMUX�� :

� A FOX board is required for more than two TCUs.

� Each additional M-Cell6 cabinet requires a minimum of one FOX and FMUX plusone FMUX in the first cabinet.

� Redundancy requires duplication of all FOX and FMUX boards and associatedMCU and �BCU cages.

GSM-001-103Cabinet interconnection (FOX/FMUX)



FOX/FMUXplanning actions

Horizon micro

Determine the number of FMUXs required.


Determine the number of FOX/FMUXs required.

GSM-001-103 Power requirements


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Power requirements

Introduction

Macrocell cabinets and Microcell enclosures can operate from a variety of powersupplies.


The following factors should be considered when planning the power supplyrequirements:

� Horizonmicro

The Horizonmicro BTS cabinet can be configured to operate from either a +27 Vdc or –48 V/–60 V dc power source or 110 V/230 V ac, indoor and outdoor.

� M-Cell6

The M-Cell6 BTS cabinet can be configured to operate from either a +27 V dc or–48 V/–60 V dc power source (indoor) or 230 V/110 V ac.

� M-Cell2

The M-Cell2 BTS cabinet can be configured to operate from either a +27 V dc or230 V/110 V ac power source.

� M-Cellcity and M-Cellcity+

The M-Cellcity and M-Cellcity+ BTS enclosures operates from a 88 to 265 V acpower source.

� Horizonmicro and Horizoncompact

The Horizonmicro and Horizoncompact enclosures operates from a 88 to 265 Vac power source.

Power planningactions

Determine the power supply required.

GSM-001-103Network expansion using Macro/Micro/Picocell BTS



Network expansion using Macro/Micro/Picocell BTS

Introduction

An existing network with previous generations of Motorola equipment such as BTS4,BTS5, BTS6, TopCell, or ExCell may be expanded using Macro/Micro/Picocell. TheNetwork topology can be any of those specified in Chapter 2 of this manual. AnMacro/Micro/Picocell BTS may occupy any position in a network. Macro/Micro/PicocellBTSs may be collocated with previous generation equipment but cannot be operated asa single site with such equipment.

Expansionconsiderations

The following factors should be considered when expanding an existing network usingMacro/Micro/Picocell BTS cabinets:

� An Macro/Micro/Picocell BTS cannot share a cell with a BTS4, BTS5, BTS6,TopCell, or ExCell.

� The rules governing the number of NIUs required at the Macro/Micro/Picocell BTSare given in Table 4-3 of this chapter.

� The rules governing the number of MSIs required at the BSC are given in theMultiple serial interface (MSI, MSI-2) section of Chapter 5.

Mixed siteutilization

To upgrade sites utilizing previous generations of Motorola equipment such as BTS5,BTS4, BTS6, TopCell, or ExCell, proceed in the following manner:

1. Sites with previous generation equipment should be expanded with the appropriatemodules until the cabinets are full.

2. To further expand a previous generation site, the equipment in the previousgeneration cabinet must be re-configured so that it serves a complete set ofsectors in the target configuration.

3. An Macro/Micro/Picocell site should then be added to the site to serve theremaining sectors.

4. The Macro/Micro/Picocell site should then be connected into the network by daisychaining it to the existing site.

5. Customers who have not purchased the daisy chaining feature should order thefree of charge feature M-Cell – InCell Interworking, SWVN2460, to obtain asuitable licence for upgrading.

Example

To upgrade a BTS6 2/2/2 to a 3/3/3. Re-configure the BTS6 to a 3/3, order an M-CellOmni 3 and install it to serve the third sector.

GSM-001-103 PCC cabinet


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PCC cabinet

Introduction

Each PCC cabinet (M-Cellaccess) can support up to two sites (one cage = one site); andup to a maximum of six carriers (PCU enclosures) per site.

If a mix of 900 MHz and 1800 MHz equipments are required, then one shelf must beused for each frequency.

To assist in the planning of an M-Cellaccess site refer to Chapter 11, Picocell equipmentdescriptions.

Collocated BSC and XCDR/GDP options can be planned for the lower BSU shelf only,refer to Chapter 5, BSC planning steps and rules and Chapter 6, RXCDR planning stepsand rules.

Cabinet planningactions


� Determine the number of sites required.

� Determine the mix of frequencies.

� Determine the method of PCU/PCC interconnection.

GSM-001-103Line interface modules (HIM-75, HIM-120)



Line interface modules (HIM-75, HIM-120)

Introduction

The line interface modules, HDSL interface module, 75 ohm (HIM-75), and HDSLinterface module, 120 ohm (HIM-120), provide impedance matching for E1, T1 andHDSL links.


The following factors should be considered when planning the line interface complement:

� To match a balanced 120 ohm (E1 2.048 Mbit/s) or balanced 110 ohm (T11.544 Mbit/s) 3 V (peak pulse) line use a HIM-120.

� To match a single ended unbalanced 75 ohm (E1 2.048 Mbit/s) 2.37 V (peakpulse) line use a HIM-75.

� Each HIM-75/HIM-120 can interface four E1/T1 links to specific slots on one shelf.

� Up to three HIM-75s or HIM-120s per shelf can be mounted on a PCC cabinet.

– A maximum of four E1/T1 links can be connected to a BSU shelf.

– A maximum of six HDSL links can be connected to a BSU shelf.

– A PCC cabinet with two BSU shelves can interface eight E1/T1 and 12HDSL links.

HIM-75/HIM-120planning actions


� Determine the number to be deployed.

� Determine the number of HIM-75s or HIM-120s required.

Minimum number of HIM–75s or HIM–120s = Number of PCUs

2


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Chapter 5

BSC planning steps and rules

GSM-001-103



GSM-001-103


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Chapter 5BSC planning steps and rules i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .




BSC system capacity 5–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . System capacity summary 5–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scaleable BSC 5–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


BSS planning for GPRS 5–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview of introduction to BSS planning for GPRS 5–12. . . . . . . . . . . . . . . . . . . . . . . Introduction to BSS planning for GPRS 5–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Feature compatibility 5–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSS statistics 5–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PCU-to-SGSN interface planning 5–23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GPRS upgrade provisioning rules 5–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview of provisioning rules 5–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSS upgrade provisioning rules 5–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPRS PCU provisioning rules 5–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPRS link provisioning rules 5–33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Redundancy planning 5–34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Determining the RSLs required 5–38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 5–38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Standard traffic model 5–38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Non-standard traffic model 5–39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BTS-BSC E1 links (Abis) 5–39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC to BTS E1 interconnect planning actions 5–50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC to BTS T1 interconnect planning actions 5–51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculate the number of LCFs for RSL processing 5–52. . . . . . . . . . . . . . . . . . . . . . . . . LCF GPROC2 provisioning for GPRS signalling 5–53. . . . . . . . . . . . . . . . . . . . . . . . . . .


GSM-001-103



Generic processor (GPROC2) 5–61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC2 functions and types 5–61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC types 5–62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 5–62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC2 planning actions 5–64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cell broadcast link 5–64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OMF GPROC required 5–64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Code storage facility processor 5–65. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC redundancy 5–65. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Transcoding 5–66. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 5–66. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GDP/XCDR planning considerations 5–66. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T1 conversion 5–67. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning actions for transcoding at the BSC 5–68. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .










GSM-001-103


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GSM-001-103





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Chapter overview

Introduction

This chapter provides the planning steps and rules for the BSC. The planning steps andrules for the BTS are in Chapter 4 of this manual. This chapter contains:

� BSC planning overview.

� GPRS planning.

� Capacity calculations.

– Determining the required BSS signalling link capacities.

– Determine the number of RSLs required.

– Determine the number of MTLs required.

– BSC GPROC functions and types.

– Traffic models.

� BSC planning.

– Planning rules for BSC to BTS links (E1/T1).

– Planning rules for BSC to BTS links (RSL).

– Planning rules for BSC to MSC links (MTL).

– Planning rules for the digital modules.

– Planning rules for the digital shelf power supply.

GSM-001-103BSC planning overview



BSC planning overview

Introduction

To plan the equipage of a BSC certain information must be known. The major itemsinclude:

� The number of BTS sites to be controlled.

� The number of RF carriers (RTF) at each BTS site.

� The number of TCHs at each site.

� The total number of TCHs under the BSC.

� The number of cells controlled from each BTS site should not exceed themaximum per BSC detailed in Table 5-1.

� The physical interconnection of the BTS sites to the BSC.

� The location of the XCDR function.

� The path for the OML links to the OMC.



� The traffic load to be handled (also take future growth into consideration).

� The number of MSC to BSC trunks.

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Planning a BSC involves the following steps:

1. Plan the number of E1 or T1 links between the BSC and BTS site(s), refer to thesection Determine the required BSS signalling link capacities in this chapter.

2. Plan the number of RSL links between the BSC and BTS site(s), refer to thesection Determine the RSLs required in this chapter.

3. Plan the number of MTL links between the BSC and MSC, refer to the sectionDetermine the number of MTLs required in this chapter.

4. Plan the number of GPROCs required, refer to the section Generic processor(GPROC2) in this chapter.

5. Plan the number of XCDR/GDPs required, refer to the section Transcoding in thischapter.

6. Plan the number of MSI/MSI-2s required, refer to the section Multiple serialinterface (MSI, MSI-2) in this chapter.

7. Plan the number of KSWs and timeslots required, refer to the section Kiloportswitch (KSW) in this chapter.

8. Plan the number of BSU shelves, refer to the section BSU shelves in this chapter.

9. Plan the number of KSWXs required, refer to the section Kiloport switchextender (KSWX) in this chapter.

10. Plan the number of GCLKs required, refer to the section Generic clock (GCLK) inthis chapter.

11. Plan the number of CLKXs required, refer to the section Clock extender (CLKX)in this chapter.

12. Plan the number of LANXs required, refer to the section LAN extender (LANX) inthis chapter.

13. Plan the number of PIXs required, refer to the section Parallel interface extender(PIX) in this chapter.

14. Plan the number of BIB or T43s required, refer to the section Line interfaces(BIB, T43) in this chapter.

15. Plan the power requirements, refer to the section Digital shelf power supply inthis chapter.

16. Plan the number of BBBXs required, refer to the section Battery backup board(BBBX) in this chapter.

17. Verify the planning process, refer to the section Verify the number of BSUshelves and BSSC cabinets in this chapter.





Introduction

The throughput capacities of the BSC processing elements (for example, GPROC,GPROC2) and the throughput capacities of its data links, determines the number ofsupported traffic channels (TCHs). These capacities are limited by the ability of theprocessors, and links to handle the signalling information associated with these TCHs.

This section provides information on how to calculate processor requirements, signallinglink capacities and BSC processing capacities. This section describes:

� Traffic models.

� The required BSS signalling link capacities.

� BSC GPROC functions and types.

� The number of GPROCs required.

� A summary of BSC maximum capacities.

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BSC system capacity

System capacitysummary

Table 5-1 provides a summary of BSC maximum capacities.

Table 5-1

Capacity

Item 1.4.x.x GSR2 GSR3 GSR4 GSR4.1

BTS sites 40 40 40 100 100

BTSs (cells) 90 90 126 250 250

Active RF carriers 120 120 255 384 384

DRIs 210 381 634 634

RSLs 80 80 250 250

MMSs 72 102 128 128

PATHs 80 80 250 250

DHPs 161 296 232 232

Trunks (see note below) 960 960 1680 1920 1920

C7 links 16 16 16 16 16

T1 or E1 links 72 72 96 102 102

Maximum Busy Hour Callattempts

38,000 38,000 50,400 57,600 57,600

If two of the E1 links between the RXCDR and BSC are reserved forredundancy, the number of effective trunks (at GSR4) become 1680; whichcan support 1650 Erlangs of traffic at 1% blocking.

GPROC2 in GSR2 causes no change in capacity.At GSR3/GSR4, GPROC2 becomes mandatory for site controller.

NOTE

GSM-001-103BSC system capacity



Scaleable BSC

With the launch of the Scaleable BSC in GSR4, Motorola is moving to a position wherethe diverse requirements of network operators in terms of BSC size are addressed by asingle platform that can be efficiently configured in small, medium or large models.

For existing customers the move to a Scaleable BSC is enabled through the migration ofthe processing boards within the BSC to use the GPROC2 throughout. BSSs targeted atsmall, medium, or large networks are efficiently addressed by the Scaleable BSC whereminimal incremental hardware is required to be added as the networks grow.

Being able to expand capacity within a BSC is appealing from an operational viewpointbecause there is less time and effort involved than compared with having to move sitesfrom one BSC to another, or even from one OMC to another.

Put into context, the BSC capacity prior to GSR3 supports in the order of 40 sites ofthree sectors and one carrier per sector; or alternatively, 20 sites of three sectors andtwo carriers per sector. At GSR3, the capacity increased to allow the operator to moveto support in the order of 40 sites of three sectors and two carriers per sector. At GSR4,the capacity increased to allow the operator to move to support in the order of 64 sites ofthree sectors and two carriers per sector.

The Scaleable BSC also offers a substantial advantage for microcellular deploymentwhere a single BSC is able to support up to 100 microcellular BTSs, each equipped withtwo carriers per site.

The Scaleable BSC capacity is enabled because of the increased processingperformance and memory of the GPROC2. The maximum capacity is increased asshown in Table 5-1.

This increased capacity is achieved through the deployment of GPROC2s for eachfunction at the BSC, including base station processor (BSP) and link control function(LCF).

GSM-001-103 Determining the required BSS signalling link capacities


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Determining the required BSS signalling link capacities

BSC signallingtraffic model

For a GSM system the throughput of network entities, including sub-components,depends upon the assumed traffic model used in the network design or operation. Trafficmodels are fundamental to a number of planning actions.

The capacity of the BSC as a whole, or the capacity of a particular GPROC, depends onits ability to process information transported through signalling links connecting it to theother network elements. These elements include MSC, BTSs, and the OMC-R.Depending on its device type and BSC configuration, a GPROC may be controllingsignalling links to one or more other network elements. A capacity figure can be statedfor each GPROC device type in terms of a static capacity such as the number of physicalsignalling links supported, and a dynamic capacity such as processing throughput.

In general telephony environments, processing and link throughput capacities can bestated in terms of the offered call load. To apply this for the GSM BSC, all signallinginformation to be processed by the BSC, is related to the offered call load (the amount oftraffic offered/generated by subscribers). When calls are blocked due to all trunks or allTCHs busy, most of the signalling associated with call setup and clearing still takes place,even though few or no trunk resources are utilized. Therefore, the offered call load(which includes the blocked calls) should be used in planning the signalling resources (forexample; MTLs and RSLs).

In the case where the BSC has more than enough trunks to handle the offered traffic,adequate signalling resources should be planned to handle the potential carried traffic.The trunk count can be used as an approximate Erlang value for the potential carriedload.

As a result, the signalling links and processing requirements should be able tohandle the greater of the following:

� The offered load.

� The potential carried load.

To determine the link and processing requirements of the BSC, the number of trunks orthe offered call load in Erlangs (whichever is greater) should be used.

BSC capacity planning requires a model that associates the signalling generated from allthe pertinent GSM procedures: call setup and clearing, handover, location updating, andpaging, to the offered call load. To establish the relationship between all the procedures,the traffic model expresses processing requirements for these procedures as ratios to thenumber of call attempts processed. The rate at which call attempts are processed is afunction of the offered call load and the average call hold time.

Figure 5-1 graphically depicts various factors that should be taken into account whenplanning a BSS.

GSM-001-103Determining the required BSS signalling link capacities



MSC

A INTERFACE (TERRESTRIAL LINKS)–C7 SIGNALLING LINKS–X.25 CONTROL LINK*–REQUIRED TRUNKS

WITH SUBMULTIPLEXING TRANSCODING AT MSC1 x 64 kbit/s CIRCUIT/C7 SIGNALLING LINK1 x 64 kbit/s CIRCUIT/X.25 SIGNALLING LINK*1 x 64 kbit/s CIRCUIT/ XBL1 x 64 kbit/s CIRCUIT/4 TRUNKS

WITHOUT SUBMULTIPLEXING TRANSCODING AT BSC1 x 64 kbit/s CIRCUIT/C7 SIGNALLING LINK1 x 64 kbit/s CIRCUIT/X.25 SIGNALLING LINK*1 x 64 kbit/s CIRCUIT/TRUNK

1 x 64 kbit/s CIRCUIT/LAPD SIGNALLING LINK2 x 64 kbit/s CIRCUITS/DRCU/SCU

MOTOROLA BSC/BTS INTERFACENON-BLOCKING

AIR INTERFACE–TCHs AND SIGNALLING TSs–TYPICALLY 2% BLOCKING TRANSCODING MUST BE LOCATED AT THE

BSC, OR BETWEEN THE BSC AND MSC

TCH = TRAFFIC CHANNELTS = TIMESLOT* X.25 MAY BE PASSED TO RXCDR

OR MSC SITE

THE BSC TO MSC 64 kbit/s CIRCUITS ARE DETERMINED FROM THE # OFTRUNKS REQUIRED TO CARRY THE SUMMATION OF AIR INTERFACE TRAFFIC(IN ERLANGS, TYPICALLY USING 1% BLOCKING) FROM ALL BTSs

– PLUS –THE # OF C7 SIGNALLING LINKS

– PLUS – (IF APPLICABLE*)THE # OF X.25 LINKS (USUALLY ONE PER BSC)

– PLUS –THE # OF XBL LINKS

THE # OF TCHs REQUIRED (USING TYPICALLY 2% BLOCKING) TO CARRYSUBSCRIBER TRAFFIC THE TCHs PLUS THE REQUIRED SIGNALLING TSs DIVIDED BY EIGHTDETERMINES THE CARRIERS REQUIRED (ON A BTS/SECTOR BASIS)

TRANSCODER

BSC

BTS

AIR INTERFACE(TRAFFIC IN ERLANGS)

USING TRAFFIC, TO DETERMINE E1/T1 LINK INTERCONNECTHARDWARE FOR THE ‘A’ AND ‘BSC TO BTS’ INTERFACE.

Figure 5-1 BSS planning diagram



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Typicalparameter values

The parameters required to calculate BSC processing and signalling link capacities arelisted in Table 5-2 with their typical values.

Two methods for determining capacity are given. The first method is based on thetypical call parameters given in Table 5-2 and simplifies planning to lookup tables, orsimple formulae indicated in standard traffic model planning steps. When the callparameters being planned for differ significantly from the standard traffic model given inTable 5-2 in this case more complex formulae must be used as indicated innon-standard traffic model planning steps.

Table 5-2 Typical call parameters

Busy hour peak signalling traffic model Parameter reference




Ratio of location updates to calls l = 2

Ratio of IMSI detaches to calls I = 0

Location update factor L = 2

Paging rate in pages per second P = 3

Ratio of intra-BSC handovers to all handovers i = 0.6

Percent link utilization (MSC to BSS) for GPROC2 U (MSC – BSS) = 0.20

Percent link utilization (BSC to BTS) U (BSC – BTS) = 0.25

Blocking for TCHs PB–TCHs = 2%

Blocking for MSC–BSS Trunks PB–Trunks = 1%

The location update factor (L) is a function of the ratio of location updates to calls (l), theratio of IMSI detaches to calls (I ) and whether the short message sequence (type 1) orlong message sequence (type 2) is used for IMSI detach; typically I = 0 (that is IMSIdetach is disabled) as in the first formula given below. When IMSI detach is enabled, thesecond or third of the formulas given below should be used. The type of IMSI detachused is a function of the MSC.


L = I


L = I + 0.2 * �


L = I + 0.5 * �




Table 5-3 Other parameters used in determining GPROC and link requirements


Number of MSC – BSC trunks N

Number of BTSs per BSS B

Number of cells per BSS C

Pages per call PPC = P * (T/N)

Assumptionsused in capacitycalculations

To calculate link and processing capacity values, certain signalling message sequencepatterns and message sizes have been assumed for the various procedures included inthe signalling traffic model. New capacity values may have to be calculated if the actualmessage patterns and message sizes differ significantly from those assumed. Theassumptions used for the capacity calculations in this manual are summarized below.The number of uplink and downlink messages with the respective average messagesizes (not including link protocol overhead) for each procedure are provided in Table 5-4.

Table 5-4 Procedure capacities

Procedure MSC to BSC link

Call setup and clearing 5 downlink messages with average size of 30 bytes6 uplink messages with average size of 26 bytes

Handover, incoming andoutgoing

4 downlink messages with average size of 37 bytes5 uplink messages with average size of 38 bytes

Location update 5 downlink messages with average size of 30 bytes6 uplink messages with average size of 26 bytes

SMS-P to P (see note below)


IMSI detach (type 1) 1 downlink messages with average size of 30 bytes1 uplink messages with average size of 42 bytes


Paging 1 downlink message with average size of 30 bytes

The actual number and size of messages required by SMS depend on theimplementation of the SMS service centre. The numbers given are estimatesfor a typical implementation. These numbers may vary.

NOTE

An additional assumption, which is made in determining the values listed in Table 5-4, isthat the procedures not included in the traffic model are considered to have negligibleeffect.



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Link capacities

The level of link utilization is largely a matter of choice of the system designer. A designthat has more links running at a lower message rate can have the advantage of offeringbetter fault tolerance, since the failure of any one link affects less signalling traffic.Reconfiguration around the fault could be less disruptive. Such a design could offerreduced queueing delays for signalling messages. A design that utilizes fewer links at ahigher message rate, reduces the number of 64 kbit/s circuits required for signalling, andpotentially reduces the number of resources (processors, data ports) required in theMSC. It is recommended that the C7 links be designed to operate at no more than 20%link utilization when the MTL is running on a GPROC; and no more than 35% utilizationwhen the MTL is running on a GPROC2. However, before use of the 35% utilization forGPROC2, it is imperative that the operator verifies that the MSC vendor can also support35% utilization at the MSC end, if not, only 20% link utilization should be used forGPROC2.

If higher link utilizations are used, the controlling GPROCs (LCF–MTLs) may becomeoverloaded.

C7, the protocol used for the MSC to BSC links, allows for the signalling traffic from thefailed link to be redistributed among the remaining functioning links. A C7 link setofficially has at least two and at most 16 links. The failure of links, for any reason, causethe signalling to be shared across the remaining members of the link set. Therefore, thedesign must plan for reserve link and processing capacity to support a certain number offailed signalling links.

GSM-001-103BSS planning for GPRS



BSS planning for GPRS

Overview ofintroduction toBSS planning forGPRS

The BSS planning chapter has the following structure:

� Introduction to BSS planning .

� PCU-to-SGSN interface planning .

Introduction toBSS planning forGPRS

The BSS planning process for GPRS may involve adding additional BSS equipment andsoftware to the BSS, in addition to the Packet Control Unit (PCU) hardware and software.The extent of the additional BSS equipment depends on the amount of traffic expected tobe carried over the GPRS portion of the network.

Chapter 3 is intended to provide the network planner with the rules to determine thenumber of GPRS timeslots that are to be provisioned at the BTS, subsequentlyprovisioned in PCU hardware, and provisioned with communication links.

The BSS planning process in this document focuses on the provisioning of the PCUhardware within the BSS. A BSS planning example provided in a later chapter of thisguide. Its purpose is to unite the information presented in the entire document from aplanning perspective.

Featurecompatibility

Alarms consolidationNo additional BSS or GPRS network planning is required.

PCU device alarms impact only PCU functional unit severity, and not the cell functionalunit severities. Therefore, the impact is to the following PCU devices: DPROC and PCUSystem Processor (PSP).

BSC-BTS dynamic allocationNo additional BSS or GPRS network planning is required.

The Dynamic Allocation feature specifies how the BSC configures and shares theterrestrial backing between the GPRS data traffic and the Circuit Switched (CS) traffic.The terrestrial backing, between the BTS and BSC, must have enough capacity to carrythe radio timeslots assigned to both GPRS and circuit switched. If there is not enoughcapacity, either because there are not enough physical channels, the BSC allocates thebacking to CS first. The remaining capacity is assigned to GPRS (reserved GPRStimeslots first, and then to switchable GPRS timeslots).

Any terrestrial backing resources not used by circuit switched calls are allocated forswitchable use. However, circuit switched calls can take resources away from theswitchable pool when traffic demands require more terrestrial capacity. Terrestrialresources available in the switchable pool are available for GPRS traffic use.

The BSC may reassign GPRS switchable or reserved backing to CS if backing isrequired for emergency circuit switched calls. In this case, the backing is reassigned sothat the remaining GPRS radio timeslots within a carrier are contiguous.

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Circuit error rate monitor

No circuit error rate monitor support is provided by the GPRS feature.

Circuit switched (voice or data) calls

The addition of GPRS to a GSM network impacts the traffic and signalling handlingnetwork capability for GSM voice and circuit data traffic. Additional loading on the BSSelements, due to the GPRS traffic, may require additional BSS equipment and interfacecircuits to be added.

There are three classes of mobile devices, which permit non-simultaneous attachment tothe circuit switched and packet data channels. This means that the BSS does not needto be provisioned to simultaneously handle the call processing and signalling for bothcircuit switched traffic and GPRS packet data services on a per-subscriber basis. TheBSS treats class A mobiles like class B mobiles. Therefore, the BSS portion of thenetwork supports the simultaneous attachment, activation, and monitoring of circuitswitched and packet data services. Simultaneous GPRS and circuit switched traffic is notsupported. The mobile user can make and/or receive calls on either of the two servicessequentially, but not simultaneously. The selection of the appropriate service isperformed automatically.

Concentric cells

GPRS timeslots are available in the outer zone carriers.

Congestion relief

No additional BSS or GPRS network planning is required.

Congestion relief considers switchable GPRS timeslots as idle TCHs.

Cell resource manager dynamic reconfiguration


The Cell Resource Manager (CRM) dynamic reconfiguration feature can use theswitchable GPRS timeslots, but it cannot reconfigure the reserved GPRS timeslots underany circumstances.

Directed retry


The BSC uses directed retry to relieve cell congestion by redistributing traffic acrosscells. For the GPRS traffic portion of the BSS, the BSC treats switchable GPRS timeslotslike idle TCHs.




Emergency call pre-emption


The BSS will be able to configure any GPRS timeslot to carry out emegency calls.Should an emergency call be made within a cell with a GPRS carrier, the BSS will selectthe air timeslot that will carry it from the following:

� Idle TCH.

� Switchable GPRS timeslot (from lowest to highest).

If the Emergency Call Pre-emption feature is enabled, the BSS will select the air timeslotthat will carry the emergency call, from the following list in the following order:

A. Idle Tch.

B. Switchable GPRS timeslot (from lowest to highest).

C. In-use TCH.

D. Reserved GPRS timeslot (from lowest to highest)

Emergency TCH channels will never be pre-empted.

Extended range cells


The extended range cell feature extends the range of a GSM 900 MHz mobile to 35kilometres. This range extension is not supported for GPRS.

Frequency hopping and redefinition

The GSM radio uses slow frequency hopping to improve data reliability and to increasethe number of active users. The GPRS timeslots assigned to the uplink and downlinkchannels must have the same frequency parameters. GPRS may have a differenttimeslot activity factor to voice, and thereby causes the cell C/I performance to changefrom a GSM-only system.

The frequency redefinition feature extends the GSM 4.08 capabilities to GPRS.

Global reset


The global reset procedure initializes the BSS and MSC in the event of a failure. A globalreset does not affect any resources assigned to GPRS.

Integrated M-Cell HDSL interface

No additional BSS or GPRS network planning is required other than to plan for the GDSlink.

The PCU does not support a high bit-rate subscriber line (HDSL) between the PCU andthe BSC. However, the BSC can use an MSI board (with HDSL capabilities) to terminatea GDS link to the PCU if an E1 is used for the connection.

Multiband handovers


The BSC treats switchable GPRS timeslots like idle TCHs in the case of multibandhandovers.



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Over the air flow control for circuit switched


The BSC treats switchable GPRS timeslots like idle TCHs in the case of over-the-airFlow Control for the circuit switched mobiles feature.

RTF path fault containment

The BSC may use a switchable GPRS timeslot for a Cell Broadcast CHannel (CBCH) ora Slow Dedicated Command CHannel (SDCCH).

The Radio Transceiver Function (RTF) path fault feature converts TCHs to SDCCH whenan RTF path fault occurs. The RTF path feature may also convert switchable GPRStimeslots that are TCH barred, to SDCCH. The converted GPRS timeslots are returnedto GPRS after the original RTF path fault is cleared.

SMS cell broadcast

The CBCH can reside on a switchable GPRS timeslot. Therefore, switchable GPRStimeslots may be reconfigured as SDCCHs. However, GPRS reserved timeslots cannotbe reconfigured as SDCCHs.

SD Placement prioritization

A GPRS carrier cannot be configured so that the sum of the number of SDCCHs allowedand the number of GPRS timeslots, exceed the capacity of the carrier.

BSS statistics

The BSC and PCU collect the statistics listed in Table 5-5 to Table 5-11. The PCUforwards the statistics that it collects, via the BSC, to the OMC-R for collection andnetwork performance review. The following table lists all of the statistics collected, theirdefinition, and the recommended uses of these statistics for the purposes of evaluatingand adjusting the BSS portion of the network.

This version of the BSS Equipmemt Planning precedes commercialdeployment. After GPRS systems have been deployed and statisticsgenerated, the following table will be updated with recommended thresholdvalues to use in the system replanning process.

NOTE

The planning flowchart in the beginning of this planning guide has grouped the use ofinfrastructure statistics into the following categories for network planning purposes:

Stats_A: user profile Stats_C: configure GSN

Stats_B: BLER and protocol overhead impact Stats_D: configure BSS/PCU




Table 5-5 BSS statistics (part A)

PCU statistic Definition Recommended use

GBL_LINK_INS The PCU starts thisstatistic each time theGBL becomes INS andstops the statistic eachtime the GBL is no longerINS on a per GBL basis.The time available isreported in milliseconds.

Statistic used for GBLperformance.

GBL_UNAVAILABLE The PCU starts thisstatistic each time theGBL goes OOS andstops the statistic whenthe GBL comes INS on aper GBL basis. The timeunavailable is reported inmilliseconds.

Statistic used for GBLperformance.

GPRS_ACCESS_PER_AGCH The BSS increments thisstatistic when theAGCH/PCH/RACHchannel type is accessedfor GPRS usage on a percell basis.

Stats_D

Use to configure CCCHand carrier timeslots.This statistic is used inEquation 23 (seeChap 3) for the value ofλBURST_GPRS.



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Table 5-6 BSS statistics (part B)


GPRS_ACCESS_PER_PCH The BSS increments thisstatistic when theAGCH/PCH/RACHchannel type is accessedfor GPRS usage on aper-cell basis.

Stats_DUse to configure CCCHand carrier timeslots.This statistic is used inEquation 24 (seeChap 3) for the value ofNo_GPRS_Pages.

GPRS_ACCESS_PER_RACH The BSS increments thisstatistic when theAGCH/PCH/RACHchannel type is accessedfor GPRS usage on aper-cell basis.

Stats_D

Use to configure carriertimeslots.

CHANNEL_REQS_REC The BSS increments thisstatistic in order to countthe number of channel orresource requestmessages received on aper-cell basis.

Stats_D

Use to configure carriertimeslots.

CHANNEL_REQS_REJECT The BSS increments thisstatistic in order to countthe number of channel orresource requestmessages rejected on aper-cell basis.

Stats_D

GBL_UL_DATA_THRPUT The PCU measures thenumber of megabits ofdata informationtransmitted on the GBLuplink over a givenperiod of time. The PCUcalculates thisinstantaneous throughputby dividing the number ofmegabits transmitted bythe time interval. Thetime interval,gbl_ul_thrput_time_period, is programmable. ThePCU filters this statisticby computing a movingaverage of theinstantaneousthroughput. The numberof instantaneousthroughput samples,num_gbl_ul_thrput_samples, used to compute themoving average isprogrammable. Thisstatistic is measured on aper GBL basis.

Stats_A, Stats_D

Use to determinewhether adequatenumber of links andequipment aredeployed.




Table 5-7 BSS statistics (part C)


GBL_DL_DATA_THRPUT The PCU measures thenumber of megabits ofdata information receivedon the GBL downlinkover a given period oftime. The PCU calculatesthis instantaneousthroughput by dividingthe number of megabitsreceived by the timeinterval. The timeinterval,gbl_dl_thrput_time_period, is programmable. ThePCU filters this statisticby computing a movingaverage of theinstantaneousthroughput. The numberof instantaneousthroughput samples,num_gbl_dl_thrput_samples, used to compute themoving average isprogrammable. Thisstatistic is measured on aper GBL basis.

Stats_A, Stats_D


GBL_FLUSH_REQS This statistic counts thenumber of times arequest to flush the databuffers in the PCU. Thisstatistic is measured on aper BSS basis.

Stats_A, Stats_D


Threshold value to besupplied aftercommercialdeployment.

GBL_PAGING_REQS This statistics counts thenumber of pagingrequests received by thePCU. This statistic isreported on a per-BSSbasis.

Stats_D

Use to configureCCCH.

This static may be usedin Equation 17 (seeChap 5) if the locationarea equals therouteing area.



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Table 5-8 BSS statistics (part D)


GBL_FLOW_CNTL_SENT This statistic counts thenumber of flow controlmessages that are sentover the GBL within aprogrammable period oftime,bssgp_fc_period_c. Thisstatistic is measured ona per-cell basis.

Stats_A, Stats_D

Use to determine ifadequate number oflinks and equipment aredeployed and if there arelink outage problems.

Threshold value to besupplied aftercommercial deployment.

AIR_UL_DATA_BLKS This statistic counts thenumber of data blocksreceived by the PCU foreach QoS level andcoding schemecombination. Thisprovides eight statistics:QoS level 1 to 4 forcoding schemes CS-1and CS-2. The count isrounded to the nearest100 blocks. Thestatistics are providedon a per-cell basis.

Stats_A, Stats_B,Stats_D

Use to determinewhether adequatenumber of links andequipment are deployed.

Also use to see if cell C/Iperformance is asexpected. The C/Ieffects BLER, which inturn effects use of thehigher CS-2 rate.

AIR_DL_DATA_BLKS This statistic counts thenumber of data blockstransmitted by the PCUfor each QoS level andcoding schemecombination. Thisprovides eight (8)statistics: QoS level 1 to4 for coding schemesCS-1 and CS-2. Thecount is rounded to thenearest 100 blocks. Thestatistics are providedon a per-cell basis.

Stats_A, Stats_B,Stats_D

Use to determinewhether adequatenumber of links andequipment are deployed.

Also use to see if cell C/Iperformance is asexpected. The C/Ieffects BLER, which inturn effects use of thehigher CS-2 rate.

TOTAL_AIR_UL_AVAILABLE_BW This statistic counts thenumber of RLC datablocks available foruplink transfer at thePCU. This statistic is ona per-cell basis.

Stats_A, Stats_D

Use to determinewhether adequatenumber of links,equipment and carriertimeslots are deployed.

TOTAL_AIR_DL_AVAILABLE_BW This statistic counts thenumber of RLC datablocks available fordownlink transfer at thePCU. This statistic is ona per-cell basis.

Stats_A, Stats_D

Use to determinewhether adequatenumber of linksequipment, and carriertimeslots are deployed.




Table 5-9 BSS statistics (part E)


GBL_DL_DATA_THRPUT_HIST This provides ahistogram of the totaldownlink data throughputover the GBL interface.The histogram is createdon a per-GBL basis.

Stats_A, Stats_D

Use to determinewhether adequatenumber of links,equipment, and carriertimeslots are deployed.

This statistic may beused in Equation 1(see Chap 3) forMean_traffic_load.

GBL_UL_DATA_THRPUT_HIST This provides ahistogram of the totaluplink data throughputover the GBL interface.The histogram is createdon a per-GBL basis.

Stats_A, Stats_D

Use to determinewhether adequatenumber of links,equipment, and carriertimeslots are deployed.

This statistic may beused in Equation 1(see Chap 3) forMean_traffic_load.

MS_CLASS_1_10_REQ This statistic counts thenumber of requestsreceived for each mobileclass at the PCU. Thisstatistic has the samenumber of bins as thereare mobile classes, class1 through 10. Each bin isin units of 10 requests,and is measured on aper-cell basis.

Stats_A, Stats_D

Use to determinewhether adequatenumber of carriertimeslots andequipment aredeployed.


MS_CLASS_11_20_REQ This statistic counts thenumber of requestsreceived for each mobileclass at the PCU. Thisstatistic has the samenumber of bins as thereare mobile classes, class11 through 20. Each binis in units of 10 requests,and is measured on aper-cell basis.

Stats_A, Stats_D

Use to determinewhether adequatenumber of carriertimeslots andequipment aredeployed.




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Table 5-10 BSS statistics (part F)


MS_CLASS_21_29_REQ This statistic counts thenumber of requestsreceived for each mobileclass at the PCU. Thisstatistic has the samenumber of bins as thereare mobile classes, class21 through 29. Each binis in units of 10 requests,and is measured on aper-cell basis.

Stats_A, Stats_D

Use to determinewhether adequatenumber of links andequipment are deployed


UL_CH_ASGN_DURATION This statistic counts theamount of time, roundedto the nearestdeci-second (0.1 sec),that simultaneous uplinkdata channels areassigned to a mobile.This statistic has eightbins for 1 channel, 2channels, etc. up to 8channels simultaneouslyassigned. This statistic ison a per-cell basis.

Stats_A, Stats_D



DL_CH_ASGN_DURATION This statistic counts theamount of time, roundedto the nearestdeci-second (0.1 sec),that simultaneousdownlink data channelsare assigned to a mobile.This statistic has eightbins. Each bin representsa number of channels insimultaneous use. Thisstatistic is on a per-cellbasis.

Stats_A, Stats_D



GPRS_CHANNELS_SWITCHED This statistic counts thenumber of times that adata channel is switchedto a circuit switchedtraffic channel. Thisstatistic is on a per-cellbasis.

Stats_A, Stats_D

Use to determinewhether adequatenumber of links andequipment are deployed

This metric enables thenetwork planner to seeif GPRS performance isbeing effected due toover use of theswitchable timeslots bythe GSM circuitswitched part of thenetwork.




Table 5-11 BSS statistics (part G)


GPRS_DYNET_FAILURES This is a count of fourdifferent sources of aterrestrial backing failure.1) Terrestrial resource fora reserved GPRStimeslot is not providedwhen requested.

2) Terrestrial backing isstolen from switchabletimeslots.

3) Terrestrial backing istaken from reservedtimeslots.

4) When converting aswitchable GPRStimeslot from packet tocircuit mode, a terrestrialbacking is unavailable.

Stats_A, Stats_D

Use to determine whetheradequate number of linksand equipment aredeployed.

This metric enables thenetwork planner to see ifGPRS performance isbeing effected due to overuse of the switchabletimeslots by the GSMcircuit switched part of thenetwork.

Threshold value to besupplied after commercialdeployment.

GPRS_DYNET_SWI_REQS This statistic creates ahistogram of queue timeperiods measuringrequests for switchabletimeslot terrestrialbacking. Each bincorresponds to a rangeof queue lengths of time.The maximum, minimum,and average queue timelengths are also includedin this histogram. Thestatistic is pegged on aperiodic basis. Thishistogram is on aper-dynet-group basis.

Stats_A, Stats_D

Use to determine whetheradequate number of linksand equipment aredeployed.

This metric enables thenetwork planner to see ifGPRS performance isbeing effected due to overuse of the switchabletimeslots.


GPRS_DYNET_RES_REQS The statistic computes ahistogram of the timethat the number ofrequests for backing ofswitchable timeslots thatwere in the queue. Eachbin of the histogramcorresponds to a rangeof queue lengths. Whenthis statistic is pegged,the bin corresponding tothe length of the queue isincremented by one. Thestatistic is pegged on aperiodic basis. Themaximum and minimumqueue lengths and theaverage queue length isalso reported.

Stats_A, Stats_D

Use to determine whetheradequate number of linksand equipment aredeployed

This metric enables thenetwork planner to see ifGPRS performance isbeing effected due to overuse of the switchabletimeslots.




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PCU-to-SGSNinterfaceplanning

The PCU-to-SGSN interface is referred to as the Gb Interface. The Gb Interfaceconnects the BSS PCU to the GPRS SGSN. Motorola supports three Gb Interfaceoptions (options A, B, and C), as shown in Figure 5-2.

The Remote TransCoDeR (RXCDR) can be used as a E1 switching interface betweenthe PCU and SGSN, as shown in option A.

Alternatively, the BSC can be used as an E1 switching interface, as shown in option B.

Option C is the case where there is no BSS E1 switching element between the PCU andSGSN.

When an RXCDR or BSC is used as a E1 switching element, as shown in option A andoption B, respectively, additional equipment provisioning of these network elements maybe required in order to support the PCU E1 interfaces, in accordance with theprovisioning rules for adding E1 interfaces to the RXCDR and BSC network elements.

The BSS Gb interface alternatives are illustrated in Figure 5-2.

MSC

RXCDR

OMC-R

PCU

BSC

BTS1 BTSn

Gb OPTION A

Gb OPTION B

Gb OPTION C

A INTERFACE

FOR OPTION Aand B

Figure 5-2 Gb interface alternatives

GSM-001-103GPRS upgrade provisioning rules



GPRS upgrade provisioning rules

Overview ofprovisioningrules

The Provisioning rules have the following structure:

� BSS upgrade provisioning rules .

� PCU provisioning rules .

� Link provisioning rules .

� BTS-BSC E1 links (Abis) .

BSS upgradeprovisioningrules

Table 5-12 identifies the BSS network elements that may require upgrading. Consult therelevant planning information for the chassis-level planning rules covering the BSC, BTS,OMC-R, and RXCDR. The PCU expansion rules are provided in the next section.

Table 5-12 BSS upgrade in support of GPRS

Equipment Additionalelement

BSS upgrade

BSC Chassis(optional)

Add KSWs, LCF GPROC2s, MSIs per BSC as neededin support of the Gb, GDS TRAU, GDS LAPD (GSL),RSL, BSC-BTS traffic carrying E1 links.

BTS (BTS4,BTS5, BTS6,ExCell,TopCell)

ReplaceDRCU withDRCU2/3

Provision with DRCU2/3 or later version radios. FollowBTS provisioning rules for the number of radiosrequired at the BTS and other supporting boards,including DHP processor boards, as necessary. Thesame carrier dimensioning rules can be used for aGPRS carrier as for a circuit switched carrier. (TheTSW must be replaced with the KSW when GPRSsupport of the BSC-BTS dynamic allocation feature isenabled.)

OMC-R Softwareupgrade forGPRSsupport

One per 64 BSS network elements, with any mix ofcircuit or packet (GPRS) channels supported; softwarein support of the PCU.

RXCDR Chassis(optional)

Add KSWs, GPROC2s, MSIs per RXCDR as neededto support the Gb interface shown as option A inFigure 5-2.

GSM-001-103 GPRS upgrade provisioning rules


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GPRS PCUprovisioningrules

There is one PCU per BSS. The PCU planning process determines the type and numberof DPROC boards to populate in the PCU. The PCU provisioning rules provided in thefollowing Table 5-13 to Table 5-15 use the number of GPRS timeslots as the planningrule input. The estimation process for determining the number of GPRS timeslots isprovided in a previous chapter of the document.

The BSC-to-PCU E1 links should not go through any network elements. The E1 linksshould meet the ITU-T Recommendation G.703. This recommendation includes an E1length specification. Refer to Recommendation G.703, Physical/ElectricalCharacteristics of Hierarchical Digital Networks , Sept. 1991, for further detail.

E1 Interface provisioning

The PCU is configured for E1 loop timing recovery on all of the PCU E1 interfaces. ThePCU is connected directly to the BSC E1 interfaces and the BSC is configured to providethe E1 master clock. If the PCU attaches to a GSN that does not have a master clocksource, an interface piece of equipment, such as a Digital Cross Connect switch (DACs)that does have a master clock source, should be used. The Motorola BSC and RXCDRequipment can be used in place of a DACs for this purpose.




Table 5-13 PCU planning rules (part A)

Rulenumber

Element Planning rule

1 Air filter 1 per fan/power supply. Maximum of 3 per PCU.

2 Alarm board 1 per PCU.

3 Bridge board An MPROC board requires one bridge board.

4 Circuit breakers 1 main circuit breaker per PCU.

5 cPCI enclosure(16 slot)

1 per BSS.

6 Fan/powersupply unit

3 per cPCI shelf, providing N+1 hot-swap redundancy.

Minimum of 2 units required.

7 GDS TRAU E1 Up to 124 active timeslots is permitted on oneTRAU_Type_GDS E1.

8 GDS TRAU E1 One TRAU_Type_GDS E1 can carry up to 124 Activetimeslots or 124 standby timeslots or any combinationof active and standby timeslots.

9 GDS TRAU E1 A TRAU_Type_GDS E1 carrying 124 standby timeslotsrequires more than one PRP for standby timeslotprocessing. The load balancing software distributes theload evenly between PRPs. For example, if there aretwo PRPs in the system, each PRP processes 62standby timeslots.

10 GPROC2 LCF The BSC GPROC2 LCF needs to terminate 12 LAPDchannels in the case when a maximum number ofLAPD-Type links are provisioned at the PCU.

11 GSL LAPD(GSL) E1

The GSL traffic is load balanced over all GSLs. Thefirst E1 carries up to six LAPD links and the second E1up to another six LAPD links. For LAPD-Type GDSresiliency, two E1s are recommended to be usedregardless of the number of LAPD channels required.For example, if only one channel is required to carrythe expected signalling load, two E1s with one LAPDchannel per E1 should be used. The MPROC loadbalancing software distributes the load evenly betweenthe two LAPD channels.

The PCU provisioning rules are provided in the following Table 5-13 to Table 5-15.



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Table 5-14 PCU planning rules (part B)

Rulenumber


12 MPROC board The PCU cPCI shelf requires one MPROC.

13 PCU cabinet Up to three PCU cPCI shelves per cabinet may beprovisioned. Each PCU shelf is dedicated to one BSC.There are no PCU-to-PCU inter-connects within thecabinet.

14 PCU cPCI shelf The maximum number of active timeslots per PCU is240 in the fully redundant configuration, as shown inFigure 5-3.

15 PCU cPCI shelf The maximum number of standby timeslots per PCU is720 in the fully redundant configuration, as shown inFigure 5-3.

16 PCU Gb E1 There may be up to four Gb E1s per PCU.

17 PCU GDS E1 There may be up to nine GDS TRAU-Type GDS E1links per PCU.

18 PICP board The PICP boards can terminate the following links:GDS TRAU-Type GDS links, GDS LAPD-Type GDSlinks, and Gb links.

19 PICP board One PICP board is required per four TRAU-Type GDSE1s. This is a per E1 specification independent of thenumber of timeslots being carried on the individualE1s. Four TRAU-Type GDS E1s can carry a maximumof (4 x 124) 496 active timeslots, standby timeslots, orany combination of the two. However, the PCU limitsthe number of PRP boards that can be used on thecPCI shelf to 10; so this restriction limits the number ofactive timeslots that can be processed to 300.

20 PICP board The PCU can support up to three PICP boards.

21 PICP board A PICP board has two PMC modules.

22 PICP board N+1 board redundancy is supported.

23 PMC module TRAU-Type GDS, LAPD-Type GDS (GSL), Gb E1links cannot share a PMC module.

24 PMC module Only one TRAU-Type GDS per PMC module on a PRPboard is allowed. The other E1 termination on the PMCmodule cannot be used.

25 PMC module Up to two Gb E1 links per PMC module is allowed.

26 PRP board PRP boards with PMCs can terminate one GDS TRAUE1 per PMC module, but cannot terminate GDS LAPDE1s or Gb E1 links.

27 PRP board Up to 30 active and 90 standby timeslots can beterminated on one PRP.

The PCU provisioning rules are provided in the following Table 5-13 to Table 5-15.




Table 5-15 PCU planning rules (part C)

Rulenumber


28 PRP board The active timeslots and standby timeslots aremanaged by load balancing software which limits thenumber of active timeslots to 30 for each PRP.Therefore, one E1 carrying 124 active timeslots cansupply up to five PRPs with active timeslots. Thesoftware load balances, in this case, such that four ofthe PRPs receives 25 active timeslots and the fifthreceives 24.

Note that the actual distribution of timeslots may beslightly different from that shown in this exampledepending on cell configurations. That is, all timeslotsfor a single cell must terminate on a single PRP, whichcan lead to slight imbalances when multiple timeslotsare configured per cell.

29 PRP board The PCU can support up to 10 PRP boards. When 10PRP boards are populated, there are only two slotsavailable for PICP boards, thereby limiting PICPredundancy, Gb link redundancy, LAPD-Type GDSredundancy, and TRAU-Type GDS link redundancy.

30 PRP board A PRP board has one PMC module.

31 PRP board N+1 board redundancy is supported.

32 Transitionmodule

A transition module is required per PRP and PICPboard.



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Figure 5-3 shows the PCU layout.

PSU/FAN PSU/FANPSU/FAN

DPROC

DPROC

DPROC

DPROC

DPROC

DPROC

DPROC

DPROC

DPROC

DPROC

DPROC

DPROC

MPROC

CARDSLOT 1

ALARMMODULE

CARDSLOT 11

IO

CARDSLOT 1

CARDSLOT 11

TRANSITIONMODULE

TM

TM

TM

TM

TM

TM

TM

TM

TM

TM

TM

HSC

POWERDISTRIBUTION

MODULE

Figure 5-3 PCU physical layout




DPROC (PICP or PRP use)DPROC board slots can be used for either PICP or PRP purposes. Each DPROC has anE1 transition module mounted in the rear of the shelf directly behind it.

A DPROC may be configured as a PICP with zero, one, or two E1 PMC modules, andwith PICP software. The DPROC may be configured as a PRP with zero or one E1 PMCmodules, and with PRP software.

The PICP provisioned boards should be populated from left to right. For systemavailability reasons, PICPs should be evenly distributed between the two backplaneswithin the PCU shelf. The left and right backplanes are connected together through thebridge board located behind the MPROC processor board. Therefore, the first PICPwould occupy board slot 1, PICP two would occupy board slot 11, PICP three would be inslot 2, and PICP four in slot 12. PRP provisioning should also be performed in a similarfashion, alternating provisioned boards between the left and right backplanes.

MPROCThe MPROC board takes the equivalent of two board slots of space. An MPROC has abridge board in the rear of the shelf directly behind it. The redundant MPROC is identifiedwith an R. The bridge board associated with the MPROC is also a redundant board.

AUXThere are four bays on the right side of the shelf that may be used for auxiliaryequipment such as tape drives, CD-ROM drives, and hard disks. The PCU is configuredwithout any auxiliary equipment and this area of the shelf is covered with blank panels.

Alarm panelThis panel is located above the DPROCs and MPROC, and has front access.

Fan/power suppliesThere are three separate fan/power supplies modules. They are located in the bottom ofthe shelf. Replacement is from the front.

Air filterThere is an air filter that is mounted in front of each fan/power supply unit, and isreplaceable from the front. Replace each air filter every 12 months.

PCU cabinetThe PCU shelf mounts in a cabinet that can hold up to three PCU shelves. Each PCU isconnected to only one BSC; so one PCU cabinet can serve up to three BSCs. Eachcabinet is pre-wired with a panel in the rear of the cabinet for the desired E1 terminationtype, balanced 120-ohm, or unbalanced 75-ohm terminations with 1500-volt lightningprotection per E1.

N+1 equipment redundancy supportedThe following N+1 equipment redundancy is supported:

� N+1 PICP and PRP board redundancy.

� 2 PS/FAN units non-redundant, 3 PS/FAN unit redundant.

� 1 MPROC/bridge board pair non-redundant, 2 MPROC/bridge board pairsredundant (requires future software release, redundant configuration not availablein GSR 4.1).

� E1 redundancy requires the provisioning of the redundant hardware with active E1links. The E1 redundancy is available for GSL, GDS, and GBL links. Loadbalancing is performed across the GDS, GSL, and GBL E1 links so that if a linkshould fail, the existing load is redistributed to the other links.



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System increments

The PCU may be upgraded for additional capacity, by one PRP board and by one PICPboard at a time. This upgrade must adhere to the PCIP to GDS TRAU E1 ratio rule, ofone PICP board per four GDS TRAU E1 links.

Maximum configuration

Table 5-16 provides the maximum BSS network parameter values in support of GPRSper BSS network element.

Table 5-16 Maximum BSS network parameter values in support of GPRS (part A)

Network element Network parameter Maximum value

BSS(BTS) GPRS carriers per cell 1

BSS (BTS) Timeslots per carrier 8

BSS (BTS) Users per timeslot 1

BSS (BTS) Users per carrier 8

BSS (BTS) Timeslots per active userDL

6

BSS (BTS) Timeslots per active userUL

4

BSS (BTS) Switchable GPRStimeslots per carrier

8

BSS (BTS) Reserved GPRS timeslotsper carrier

8

BSS (PCU) Active air interfacetimeslots

240 redundant, perFigure 5-4.

Table 5-17 and Table 5-18 provide the maximum BSS network parameter values insupport of GPRS per BSS network element.

Table 5-17 Maximum BSS network parameter values in support of GPRS (part B)

Network element Network parameter Maximum value

BSS (BTS) GPRS carriers per cell 1

BSS (BTS) Time slots per carrier 8

BSS (BTS) Users per time slot 1

BSS (BTS) Users per carrier 8

BSS (BTS) Time slots per active userDL

6

BSS (BTS) Time slots per active userUL

4

BSS (BTS) Switchable GPRS timeslots per carrier

8

BSS (BTS) Reserved GPRS timeslots per carrier

8

BSS (PCU) Active air interface timeslots

240 redundant, seeFigure 5-4

BSS (PCU) Monitored air interfacetimeslots

720 redundant, seeFigure 5-4.




Network element Maximum valueNetwork parameter

BSS (PCU) Active air interfacetimeslots

300 non-redundant, seeFigure 5-5.

BSS (PCU) Monitored air interfacetimeslots

810 non-redundant, seeFigure 5-5.

PCU (PRP DPROC) GDS link processing 30 active users, 90 standbytimeslots.

This is equivalent to 30 activeTimeSlots (TSs) with one TS/user. For multislot operation,fewer users are supported.For example, if each user isallocated 2 TSs, only 15active users are supportedper PRP. The standbytimeslots are monitored forservice request, but notcarrying traffic.

PCU (PICP DPROC) BSC-PCU E1 interface Up to 4 E1s per PICPDPROC.

PCU (PICP DPROC) PCU-SGSN (Gb) interface 1 Gb E1 to carry frame relaychannellized ornon-channellized GPRStraffic per 150 active CS-1 orCS-2 timeslots deployed overthe BSC-to-PCU interface.The Gb E1 carries both dataand signalling traffic betweenthe PCU and SGSN.

PCU Max PICP DPROCs 3

PCU Max PRP DPROCs 10

PCU Number of cells supported 250

PCU Number of BTS sitessupported

100

GSL E1 links Max physical E1s betweenBSC & PCU (one primaryE1 and one redundant)

2

LAPD-Type GDS (GSL)links

Max per E1 link

(corresponds to a quantityof six 64 kbit/s LAPDchannels)

6

TRAU-Type GDS links(E1s)

Max per PCU 9

GBL links (E1s) Max per PCU 4

Gb PVCs Max on one bearer Link 318

Gb Frame Relay frameoctet size

Max 1600 bytes



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GPRS linkprovisioningrules

The following text provides the rules for provisioning the PCU and BSC links in support ofGPRS. The typical call parameters used in the link defining equations are detailed inTable 5-18.


Parameter Value

PgMsgSize 400 bits.

Mean_TBF_Rate 1 TBF per sec based on transmission timefor 2 435byte LLC PDUs at the CS-1 rate.

ImmAssignMsgSize 400 bits.

No_GPRS_TS_Site 24 GPRS timeslots (3-sector site, 1 GPRScarrier per sector).

Mean_LLC_PDU_size 3.48 kbits.

GPRS_Page_Rate_Max 12 pages per second per site.

LAPD_Utilization 0.25.

RSL_Rate 16 kbit/s for 16 kbit/s RSLs and

64 kbit/s for 64 kbit/s RSLs.

Code_load rate 0 kbit/s.

Cell_update rate 0 kbit/s, approximately.

Msg_sw_ts_chg rate 0 kbit/s, approximately.

Status_queries rate 0 kbit/s, approximately.

No_Active_ts 0 to 300 per PCU.

Mslot_Util_factor 0.5, ratio of mean number active timeslotson a GPRS carrier to total number ofprovisioned GPRS timeslots on a carrier.

Mean_TBF_duration 1 second.

%TBF_pg 0.1, use decimal form.

Stat_Msg_size 720 kbits maximum message size basedon maximally configured PCU.

Stat_meas_interval 360 seconds, minimum measurementinterval.

CS_rate CS-1 = 9.05 kbit/s,

CS-2= 13.4 kbit/s.

%GBL_protocol_ovhd 0.16, decimal form.

%RLC/MAC_ovhd 0.1, decimal form.

GBL_E1_BW 1.984 Mbit/s.




Redundancyplanning

For redundant PCU operation, the PCU should be planned such that there are N+1boards provisioned as shown in Figure 5-4. That is, only eight PRP boards and two PICPboards are required to handle the expected maximum GPRS traffic load. The ninth PRPboard and third PICP board offer the N+1 hardware redundancy. The third PICP boardprovides redundancy for the software processes that run on the first two PICP boards.For a fully configured PCU with eight GDS TRAU E1s, at least two PICP boards arerequired in order to provide enough processing capability.

The GDS TRAU E1 link redundancy is obtained with the N+1 PRP board. The GSL E1link redundancy is obtained by provisioning a second GSL E1 on the second PICP. OnePICP is required per four GDS TRAU E1 links. The PCU load-balances across the GDSTRAU and LAPD GSL links. If a PRP or PICP board fails, the PCU automaticallyre-distributes the load to the other boards in-service.

Two Gb E1s are required to handle the traffic for a fully configured PCU. Gb E1 linkresiliency is obtained by adding an additional two Gb E1s and load balancing across all ofthe Gb E1s.

The PRP and PICP (DPROC) boards are hot swappable, so that when a board failure isdetected, a replacement board may be inserted without disrupting ongoing GPRS trafficon the other boards. The DPROC must be locked before removal, and unlocked followingboard insertion. The PRP and PICP boards have associated transition module boards notshown in the figures below. There is an associated redundant transition module boardwith each redundant PRP and PICP board.

The PCU shelf hardware allows for N+1 MPROC board redundancy. This N+1redundancy capability is subject to MPROC redundancy software availability. TheMPROC board(s) and the MPROC bridge boards are not shown in the figure below, butthe redundant MPROC has an associated redundant bridge board.

The PCU shelf comes with N+1 power supply/fan redundancy. The power supplies arehot swappable. The power supply/fan units are not shown in figures below.

The PCU architecture offers the network planner a considerable degree of provisioningflexibility. Figure 5-4 and Figure 5-5 demonstrate this flexibility where the provisioninggoals may range from full redundancy (Figure 5-4) to maximum coverage (Figure 5-5).

Table 5-19 summarizes the provisioning goals demonstrated with Figure 5-4 andFigure 5-5.



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PMC

PCU HARDWARE

PMC

PMC

PMC

PMC

PMC

PMC

PMC

PMC

PMC

PRP1

PRP2

PRP8

PRP9REDUN-

DANT

PICP1

PICP2

PICP3REDUN-

DANT

GDS

GDS

GDS

REDUNDANTGDS

GSL

REDUNDANTGSL

GBL

GBL

REDUNDANTGBLs

6 LAPD TS

6 LAPD TS

BSC SGSN

30 TS ACTIVE90 TS STANDBY




GBL

GBL

TO

Figure 5-4 Goal: maximum throughput and coverage with a fully redundant configuration




PMC

PCU HARDWARE

PMC

PMC

PMC

PMC

PMC

PMC

PMC

PRP1

PRP2

PRP8

PRP9

PICP1

PICP2

PICP3

GDS

GDS

GDS

GSL

REDUNDANTGSL

GBL

GBL

REDUNDANTGBLs

6 LAPD TS

6 LAPD TS

BSC SGSN





GBL

GBL

GDS

TO

PMC

PMC

Figure 5-5 Goal: maximum throughput and coverage, full redundant not required

Refer to Table 5-11 for a matrix of provisioning goals achieved with this instance of PCUprovisioning.



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Table 5-19 PCU provisioning goals

Metric

Goal Maximum coverage withredundant configuration;see Figure 5-4.

Maximum coverage,redundancy not required;see Figure 5-5.

No. active timeslots 240 270

No. standby timeslots 720 810

Total number of provisionedtimeslots at a BSS is the sumof the number of activetimeslots with the number ofstandby timeslots.

960 1080

No. PRPs 9 9

No. PICPs 3 3

No. TRAU-Type GDS E1s 9 9

No. LAPD-Type GDS (GSL)E1s

2 2

No. Gb E1s 4 4

PRP board redundancy Yes No

PICP board redundancy Yes No

GDS TRAU timed E1redundancy

Yes No

GSL E1 redundancy Yes Yes

Gb E1 redundancy Yes Yes

GSM-001-103Determining the RSLs required



Determining the RSLs required

Introduction

Each BTS site which is connected directly to the BSC, including the first site in a daisychain, must be considered individually. Once individual RSL requirements are calculatedthe total number of LCFs can be determined for the BSC.


The following factors should be considered when planning the provision of RSL (LAPDsignalling) links from the BSC to BTS sites:

� With the Motorola BSC/BTS interface there is a need for an RSL link to every BTSsite. One link can support multiple collocated cells. As the system grows,additional signalling links may be required. Refer to the section Determining therequired BSS signalling link capacities in this chapter to determine the numberof RSL links required.

� If closed loop daisy chains are used, each site requires an RSL in both directions.

� The provision of additional RSL links for redundancy.

Standard trafficmodel

The number of BSC to BTS signalling links (RSL) must be determined for each BTS.This number depends on the number of TCHs at the BTS. Table 5-20 gives the numberof RSLs required for a BTS to support the given number of TCHs. These numbers arebased on the typical call parameters given in the standard traffic model column ofTable 5-2. If the call parameters differ significantly from the standard traffic model, usethe formulae for the non-standard traffic model .

Table 5-20 Number of BSC to BTS signalling links

n = number of TCHs at the BTS Number of 64 kbit/sRSLs

Number of 16 kbit/sRSLs

n <= 30 1 1

30 < n <= 60 1 2

60 < n <= 90 1 3

90 < n <= 120 1 4

120 < n <= 150 2 5

150 < n <= 180 2 6

180 < n <= 210 2 7

210 < n <= 240 2 8

A BTS shall support either 64 kbit/s RSLs or 16 kbit/s RSLs, but not both.

NOTE

GSM-001-103 Determining the RSLs required


68P02900W21-G


5–39

Non-standardtraffic model

If the call parameters differ significantly from those given in Table 5-2, use the followingformula to determine the required number of 64 kbit/s RSLs (rounded up to the nextnearest integer).

NBSC�BTS �

(n * (95 � 67 * S � 35 * H � 25 * L))(1000 * U * T)

�6 * P

(1000 * U)


NBSC�BTS � �(n * (95 � 67 * S � 35 * H � 25 * L))

(1000 * U * T)�

6 * P(1000 * U)

� * 4

Where: NBSC to BTS is: the number of MSC to BSC signalling links.

n the number of TCHs at the BTS site.


H the number of handovers per call.

L the location update factor.

U the percent link utilization (for example 0.20).

T the average call duration.

P the paging rate in pages per second.

BTS-BSC E1links (Abis)

Traffic (GPRS timeslots)

E1 line capacity should be added from the BTS to the BSC in direct proportion to thenumber of timeslots that are added for GPRS timeslot provisioning. Each GPRS timeslotcorresponds to 16 Kbit/s of E1 bandwidth, or one quarter of one 64 timeslot on an E1.The additional GPRS traffic may be accommodated with the existing E1 lines carryingcircuit switched traffic. This provisioning step requires the network planner to look at thecurrent E1 provisioning at each BTS site in order to determine whether additional E1 linecapacity should be added.

Signalling (RSL)

The RSL signalling link provisioning has a contribution from the GSM circuit switchedportion of the network and from the GPRS portion. The equation for determining thenumber of RSL links for the combined signalling load is as follows.

Equation 5

RSLGPRS�GSM � RSLGPRS � RSLGSM

Equation 5 is evaluated for 16 kbit/s RSLs or for 64 kbps RSLs. The interface betweenthe BTS and BSC does not permit mixing the two RSL rates.




Where: RSLGPRS+GSM is: The combined number ofRSL signalling links on aper BTS site basisoperating at a 16 kbit/sRSL rate or at a 64 kbit/sRSL rate.

RSLGPRS This is the number of RSLsignalling links required toserve the GPRS portion ofthe network at 16 kbit/s orat 64 kbit/s.

RSLGSM This is the number of RSLsignalling links required toserve the GPRS portion ofthe network at 16 kbit/s orat 64 kbit/s.

Equation 8

IMM_ASSIGNGPRS � No_GPRS_TS_Site * Mean_TBF_Rate * ImmAssignMsgSize

Where: IMM_ASSIGNGPRS is: The Immediateassignment message bitrate, in Kbps per BTS site.

No_GPRS_TS_Site This is the number ofactive GPRS timeslots forthe BTS site.

Mean_TBF_Rate This is the mean rate ofTBFs per second for theBTS site.

ImmAssignMsgSize This is the size of theimmediate assignmentmessages measured inbits.



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5–41

Equation 6

RSLGPRS �PGPRS � IMM_ASSIGNGPRS

RSL_Rate * LAPD_Utilization

Where: RSLGPRS is: This is the number of RSLsignalling links required toserve the GPRS portion ofthe network.

PGPRS This is the number ofGPRS page bitsgenerated per BTS siteper second.

IMM_ASSIGNGPRS The immediateassignment message bitrate, in kbps per BTS site

RSL_Rate This is the RSL channelrate that is to be used. Itshould match the rateused for the GSM RSLmessages, either16 kbit/sor 64 kbit/s.

LAPD_Utilization This is the utilization factorfor the RSL LAPDmessaging, typically avalue of 0.25 is used.

Equation 7

PGPRS � PgMsgSize * GPRS_Page_Rate_Max

Where: PGPRS is: This is the number ofGPRS page bitsgenerated per BTS siteper second.

PgMsgSize This is the size of thepaging messagemeasured in bits per pagemessage.

GPRS_Page_Rate_Max This is the GPRS pagingrate on a per BTS sitebasis measured in pagemessages per second.

Determine the contribution from the existing or planned GSM circuit switched RSLs.RSLs are deployed as 16 kbit/s signalling links or as 64 kbit/s signalling links. Thenumber of RSLs to deploy for a given GSM circuit switched traffic load is defined earlierin the text. The following equations are provided in order to calculate the correct level ofRSL provisioning for the 16 kbit/s and 64 kbit/s RSL signalling channel rates.

For the GSM circuit switched call model, evaluate the following Equation 9 when 64kbit/s RSL signalling links are used.




Equation 9

RSLGSM � RSLGSM_64Kbps �n * (95 � 67 * S � 35 * H � 25 * L)

1000 * U * T�

6 * P1000 * U

Evaluate the following Equation 10 when 16 Kbps RSL signalling links are used.

Equation 10

RSLGSM � RSLGSM_16Kbps � �n * (95 � 67 * S � 35 * H � 25 * L)

1000 * U * T�

6 * P1000 * U

� * 4

The variables in Equation 9 and Equation 10 above are defined as follows:

Where: n is: The number of TCHs forthe BTS site.

S The ratio of SMSs to calls.

H The number of handoversper call.

L The location update factor.

U The percent link utilization(for example 0.25).

T The average call durationin seconds.

P The paging rate in pagesper second.

BSC-PCU

E1 links connect the BSC to the PCU. The E1 length (or BSC to PCU distance) complieswith G.703 recommendations and does not support any equipment, including a ’repeater’in between.

BSC-PCU: traffic (GDS TRAU)

Typically, one E1 is provisioned per PCU PRP circuit board to carry GDS TRAU. EachE1 can support up to 124 timeslots that can be a mix of active and standby timeslots.The E1 can carry traffic originating from several different cells. The allocation of timeslotson the E1 is managed by the infrastructure. Each cell can contribute GPRS traffic for upto 8 timeslots.

BSC-PCU: signalling (GDS LAPD GSL)

The PCU requires one E1 in order to carry GSL signalling, and a second E1 forredundancy. The PCU can support up to six primary GSL 64 kbit/s timeslots and sixredundant. Each 64 kbit/s timeslot is one LAPD channel. Provisioned GSL timeslots areload balanced over two E1 links, as the mechanism for providing resiliency against linkfailures. It is recommended that two GSL E1 links are provisioned for resiliencypurposes, even when the GSL is lightly loaded.

Each GSL message consists of three parts: LAPD protocol, BSS executive headerprotocol, and the application message carrying actual signalling information. The LAPDand BSS protocol portion can be considered messaging overhead. Therefore, the actualusable bandwidth per E1 timeslot for GSL signalling is 60 kbit/s. The calculation for therequired number of GSL links is as per Equation 11 .



68P02900W21-G


5–43

Equation 11

No_GSL_TS �Num_1

60Kbps * LAPD_Utilization

Where: No_GSL_TS is: This is the number of64 kbit/s LAPD GSLtimeslots to provision.

Num_1 The numerator forEquation 11 . SeeEquation 12 .

LAPD_Utilization This is the LAPDutilization factor, typicallyon the order of 0.25.

Equation 12

Num_1 � Code_load � Cell_update � Msg_sw_ts_chg � Status_Queries � No_Imm_Assign � GPRS_Page � Stat_msg

Where: Num_1 is: The numerator forEquation 11 .

Code_load The PCU code load ratefrom the BSC to the PCU.Typically this value isequal to zero because thecode load occurs onlywhen the PCU is out ofservice.

Cell_update Periodic cell list updaterate to the BSC from thePCU. This traffic isnegligible, and can beconsidered equal to zero.

Msg_sw_ts_chg PCU message rategenerated due toswitchable timeslotchanges. This traffic isnegligible, and can beconsidered equal to zero.

Status_queries PCU status query ratefrom the BSC and OMC.This traffic is negligible,and can be consideredequal to zero.




Equation 13

n

No_Imm_Assign � �IMM_ASSIGNGPRSii�1

Where: No_Imm_Assign is: This is the rate ofimmediate assignmentmessage Kbps per-BSSsite (see equation 8)

N This is the number ofBTSs per BSS.

Equation 14

n

GPRS_Page �1

PgMsgSize0.0001 * PgMsgSize * �PGPRSi

i�1

Where: GPRS_Page is: The GPRS page trafficmeasured in kbit/s perBSS basis.

PGPRS This is the number ofGPRS page bitsgenerated per BTS siteper second. (SeeEquation 7 )

PgMsgSize This is the size of a pagemessage measured in bitsper page message.

n number of BTS per BSS



68P02900W21-G


5–45

Equation 15

Stat_msg � Stat_msg_size�Stat_meas_interval

Where: Stat_msg is: This is the PCU generatedstatistics message ratemeasured in bits persecond.

Stat_msg_size The size of a PCUstatistics messagemeasured in bits.

Stat_meas_interval This is the interval of timebetween PCU statisticsmessage transfers to theBSC. This value ismeasured in seconds.

The average bandwidth use of a GSL 64 kbit/s LAPD in support of Stat_msg transfers ismuch lower than 64 kbit/s. However, when a transfer occurs, it is possible to occupy thetimeslot for the duration of the Stat_msg transfer which, for a maximally-configured PCU,could be of the order of 12 seconds. Therefore, it is recommended that an extra GSLtimeslot is allocated in support of this periodic burst transfer condition when Equation 15evaluates to one. This prevents the potential blocking of paging messages during theinterval of time the Stat_msg transfers occur. When GSL N+1 redundancy is provisioned,there is no need for an extra timeslot.

PCU-SGSN: traffic and signalling (Gb)

The traffic and signalling is carried over the same E1 on the Gb Link (GBL). The numberof required 64 kbit/s Gb link timeslots can be calculated using Equation 16 . Each E1 cancarry up to 31 timeslots. When fewer than 31 timeslots are needed on an E1, specifyinga fractional E1 may be more cost effective. Table 5-21 may be used to look up thenumber of E1 links to use for a given number of timeslots.

Table 5-21 Timeslots-E1s

Number of timeslots(No_GBL_TS)

Number of E1s

1-31 1

32-62 2

63-93 3

94-124 4




Equation 16

Im No_GBL_TS �Reqd_GBL_BW

64, 000

Where: No_GBL_TS is: This is the number oftimeslots to provision onthe GBL E1 between thePCU and SGSN. Thisvalue can be used tospecify a fractional E1.

Reqd_zsGBL_BW This parameter is definedby Equation 17 , andrepresents the requiredbandwidth (bps) for GPRSdata transmission over aGBL interface between thePCU and SGSN after all ofthe protocol and signallingoverhead is accounted for.

Equation 17

Reqd_GBL_BW � [No_Active_ts * CS_rate * (1 � %GBL_protocol_ovhd) * (1 � %RLC�MAC_ovhd)] � [PgMsgSize * GPRS_Page_Rate_Max * No_BTS_sites]

Where: Reqd_GBL_BW is: This parameter is thenumerator for Equation16. It represents therequired bandwidth (bps)for GPRS datatransmission over the GBLinterface between thePCU and SGSN after all ofthe protocol and signallingoverhead is accounted for.

No_Active_ts This is the number ofactive timeslots on aper-BSS basis.

CS_rate CS_rate is the CS ratemeasured in bits persecond. This should be aweighted value over theCS-1 and CS-2 rates. Theweighting factor isdetermined by thepercentage of time theCS-1 rate is used and theCS-2 rate is used.Typically, the networkchooses the CS-2 rateapproximately 90% of thetime, and CS-1 rate 10%of the time, thereby givinga weighted value ofapproximately 13 kbit/s.



68P02900W21-G


5–47

Where: This parameter is thenumerator for Equation16. It represents therequired bandwidth (bps)for GPRS datatransmission over the GBLinterface between thePCU and SGSN after all ofthe protocol and signallingoverhead is accounted for.

is:Reqd_GBL_BW

%GBL_Protocol_ovhd This is the percentageprotocol overhead on theGBL link expressed as adecimal number.

%RLC/MAC_ovhd The is the percentageprotocol overhead of theRLC/MAC protocol layerremoved at the PCU priorto relaying the PDU overthe Gb link.

PgMsgSize This is the size of thepage messages sent fromthe SGSN to the PCUover the Gb link. Thismessage size isexpressed in bits.

GPRS_Page_Rate_Max This is the maximum pagerate expected over the Gblink from the SGSN to thePCU. This value isexpressed in pages persecond per BTS site.

No_BTS_sites This is the number of BTSsites served by the SGSNmodule for the attachedPCU. Note that an SGSNmodule can serve morethan one PCU.

Frame relay parameter values

The network planner needs to specify the values for the following three frame relayinterface parameters:

� Committed Information Rate (CIR).

� Committed Burst Rate (Bc).

� Burst Excess Rate (Be).

These frame relay parameter values are determined as detailed in the following text.




Committed information rate

The recommended Committed Information Rate (CIR) value per each NS-VC should begreater than, or equal to, 50 percent of the cumulative information rate of the activetimeslots routed to a single NS-VC by the PCU. The Motorola PCU distributes the use ofall the NS-VCs by the subscribers evenly in a round-robin manner. The round-robinalgorithm continuously assigns subscribers to the next NS-VC in a sequential mannerwhen a subscriber PDP context is established. If an NS-VC becomes unavailable, it isskipped over, and the next available NS-VC in the round-robin is used. This is theBSSGP feature that inherently provides load sharing over all available NS-VCs. The loadsharing capability over multiple Gb links is provided by the BSSGP high-level protocollayer, which results in link resiliency.

The recommended CIR value per each PVC should be greater than, or equal to, half thecumulative information rate of the active timeslots routed to a single NS-VC. Thismapping is actually determined as a mean load, evenly distributed over all of theavailable NS-VCs as next described.

The mean busy hour load of each cell may require one to four active timeslots, based onthe recommended BSS provisioning rules. The BSS planning rules recommend that themean traffic load of a cell should not exceed four active timeslots per cell. The number ofstandby timeslots planned at each cell should equal the number of planned activetimeslots. The standby timeslots, when used as active timeslots, enable a cell to handlethe peak or burst characteristic of packet data traffic. Over many cells, it is expected thatthe PCU will handle the traffic throughput equal to the number of active timeslots plannedfor the busy hour traffic load.

The recommended frame relay network CIR value is calculated by dividing the bandwidthrequired to serve half the number of active timeslots for all the cells served by the PCUby the number of NS-VCs provisioned between the PCU and SGSN over the Gbinterface.



68P02900W21-G


5–49

Equation 18n

CIR_Value �F

Num_NSVC* �[(Num_Act) * (%CS1) * 9.05 � (Num � Act) * (%CS2) * 13.4] i

i � 1

Where: CIR Value is: Committed Information rate per NS VC (PVC)

n The number of sites served by the PCU

Num_Active TS The number of Active Timeslots per site

Num_NSVC The number of provisioned NS–VC per PCU.The recommended number is between 2 and 31per each provisioned E1 GBL

F CIR provisioning factor equal to 0.5

%CS1 100–%CS2

%CS2 100–%CS1

Note: Always, (CS–1%) + (CS–2%) = 100%

By using half the number of active timeslots in the CIR calculation, the load of all theactive timeslots is served by the combination of the CIR and Bc frame relay networkrated capacity. It should be noted that this strategy makes use of the overload carryingcapacity of the frame relay network when more than half of the planned active timeslotsare in use.

When a cell uses some of its standby timeslots as active timeslots, other cells must usefewer of their active timeslots in order for the overall PCU Gb interface bandwidthallocation to be within configured frame relay network interface parameter (CIR, Bc, Be)values. The BSS attempts to utilize as many active timeslots as are supported in PCUhardware and in communication links.

Committed burst rate (Bc)

The Bc is the maximum amount of data (in bits) that the network agrees to transfer,under normal conditions, during a time interval Tc.

The Bc value should be configured such that if one of the provisioned E1 links fails, theremaining E1 links can carry the load of the failed link, by operating in the Bc region. Forexample, with three E1 links are provisioned, if any one of the three should fail, the othertwo should have the capacity to carry the load of the failed link on the remaining twolinks, by operating in the Bc region.

Burst excess rate (Be)

The Be is the maximum amount of uncommitted data (in bits) in excess of Bc that aframe relay network can attempt to deliver, during a time interval Tc. The network treatsBe data as dicard eligible.




BSC to BTS E1interconnectplanning actions

Determine the number of E1 links required to connect to a BTS. Redundant links may beadded, if required.

N �

[(nTCH + L16) / 4] + L6431

Where: N is: the minimum number of E1 links required (rounded upto an integer).

nTCH the number of traffic channels at the BTS.

L16 the number of 16 kbit/s RSLs (LAPD links).


Refer to Chapter 2, in this manual, for a discussion on TCH planning for theBTS Concentration feature.

This formula includes both L16 and L64 to provide necessary number of RSLs.As above, either L16 or L64 RSL can be used, but not both, to a single BTS.

NOTE

BSC-PCU: traffic (GDS TRAU)

Typically, one E1 is provisioned per PCU PRP circuit board to carry GDS TRAU. EachE1 can support up to 124 timeslots that can be a mix of active and standby timeslots.The E1 can carry traffic originating from several different cells. The allocation of timeslotson the E1 is managed by the infrastructure. Each cell can contribute GPRS traffic for upto 8 timeslots.



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BSC to BTS T1interconnectplanning actions

Determine the number of T1 links required to connect to a BTS. Redundant links may beadded, if required.

N �

[(nTCH + L16) / 4] + L6424

Where: N is: the minimum number of T1 links required (rounded upto an integer).




Refer to Chapter 2, in this manual, for a discussion on TCH planning for theBTS Concentration feature.


NOTE




Calculate thenumber of LCFsfor RSLprocessing

LCFs for BSC to BTS links and Layer 3 call processing

There are three steps needed to determine the number of LCF GPROCs required tosupport the BSC to BTS signalling links (RSL) and layer 3 call processing.

1. Calculate the number of LCFs required to support the RSLs.

2. Calculate the number of LCFs required to support the layer 3 call processing.

3. The larger of the numbers calculated in steps 1 and 2 is the number of LCFsrequired to support the RSLs signalling links and layer 3 call processing.

Step 1

Determine the number of LCFs required to support RSLs.

GRSL �(R � 2 * B)

120

Where: GRSL is: the number of LCFs required to support the BSC toBTS signalling links (RSL).

R the number RTFs (radio carriers).

B the number of BTS sites.

Step 2

Determine the number of GPROCs required to support the layer 3 call processing. Thereare two methods for calculating this number. The first is used when the call parametersare similar to those listed in Table 5-2. The second method is to be used when callparameters differ significantly from those listed in Table 5-2.

Standard traffic model

GL3 � �n

440�

B15

�C35� * � 1

2.5�

Where: GL3 is: the number of LCF GPROC2s required to support thelayer 3 call processing.

n the number of TCH at the BSC.


C the number of cells.



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5–53

Non-standard traffic model

If the call parameters differ significantly from those given in Table 5-2, the alternativeformula given below should be used to determine the recommended number of LCFs.

GL3 � �n * (1 � 0.7 * S � 0.5 * H * (1 � 0.3 * i) � 0.5 * L)

(11.3 * T)� (0.006 � 0.02 * P) * B �

C35� * � 1

2.5�

Where: GL3 is: the number of LCF GPROC2s required to support thelayer 3 call processing.

n the number of TCHs under the BSC.



i the ratio of intra-BSC handovers to all handovers.






Formula 2 has been calculated using 70% mean utilization of GPROC2.

NOTE

Step 3

The number of LCFs required is the greater of GRSL and GL3.

LCF GPROC2provisioning forGPRS signalling

The BSC supports the RSL and layer 3 signalling on the LCF GPROC2 for the GSMcircuit switched traffic. The LCF GPROC2 also supports RSL signalling in support of theGPRS signalling traffic. The RSL signalling traffic is carried on 16 kbit/s or on 64 kbit/stimeslot increments over E1 links from the BSC to the BTSs. The provisioning rules forthe GSM circuit switched traffic signalling are available in the planning information. ThisGPRS planning guide provides the LCF GPROC2 provisioning rules for the GPRSportion of RSL signalling that is presented to the BSC from the PCU on the GDS LAPDGSL link(s). The LCF GPROC2 can simultaneously handle signalling traffic from both theGSM and GPRS portions of the network. It is possible to calculate the GPRS portion ofthe signalling load for the LCF GPROC2 in fractional increments. The GPRS LCFGPROC2 requirements can be directly added to the GSM requirements in order todetermine the total number of LCF GPROC2s to equip at a BSC.

The MSC can send GSM alerting pages to a GPRS mobile that operates in class A orclass B modes. The significance of this is that GPRS mobile stations capable of class Aand B operation create a larger population of GSM capable mobile stations that shouldbe considered when provisioning the LCF GPROC2. The planning information should beused for this provisioning.

The number of LCF GPROC2s to equip in support of the GPRS signalling load iscalculated by using the GL3 formula, previously outlined in step 2, with the appropriateterms set equal to zero. The resulting equation is shown in the following Equation 26 .




Equation 26

GL3_GPRS �

NGPRSGGPRS_PF*TGPRS

� (0.006 � 0.02 * PGPRS) * (BRA_GPRS) �CGRPS

35

2.5

Where: GL3_GPRS is: Number of LCF GPROC2sto handle GPRS relatedRSL signalling traffic.

NGPRS Number of active GPRStimeslots served at theBSC.

GGPRS_PF GPROC2 GPRSperformance factor forRSL processing.

TGPRS Mean duration of a TBF inseconds.

PGPRS Paging rate in pages persecond.

BRA_GPRS Number of BTS sitesunder a BSC.

CGPRS Number of cells under aBSC.

The value for NGPRS is determined using the following MIN function.

Equation 27

NGPRS � MIN[No_PRP_boards * 30, No_GPRS_ts * Mslot_Util_factor]

Where: NGPRS is: Number of active GPRStimeslots served at theBSC.

No_PRP_boards Number of PRP boards inthe PCU.

No_GPRS_ts Number of GPRStimeslots in all of the BTScells served by the BSC.

Mslot_Util_factor This is the ratio of themean number of activetimeslots on a GPRScarrier to the total numberof provisioned GPRStimeslots on a carrier.

Using the figures in the following table, it can be determined that six LCF GPROC2s maybe required for a maximally configured PCU.



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Table 5-22 Typical values for GPRS LCF GPROC2 provisioning

Parameter Value

NGPRS 30 to 300 is the range for the number ofactive timeslots provisioned at one PCU.

GGPRS_PF 100.

TGPRS 1 second, corresponds to the duration oftime to transmit two mean length LLCPDUs at the CS-2 rate.

PGPRS 12, for a fully configured redundant PCUwith a 10% paging load based on a meannumber of active timeslots equal to 120.

BRA_GPRS 1 to 100 for the number of BTS sites undera BSC.

CGPRS 1 to 250 for the number of cells in a BSCrouteing area.

Mslot_Util_factor 0.5.

No_PRP_boards This number can range from 1 to 10.

No_GPRS_ts This number can range from 1 to 300.

GSM-001-103Determining the number of MTLs required



Determining the number of MTLs required

Introduction

MTLs carry signalling traffic between the MSC and BSC. The number of required MTLsdepends upon the BSS configuration size and traffic model. MTLs are carried on E1 orT1 links between the MSC and BSC, which are also used for traffic.


The following factors should be considered when planning the links from the BSC toMSC:

� Determine traffic requirements for the BSC. Traffic may be determined usingeither of the following methods:

– Multiply the number of subscribers expected to use the BSC by the averagetraffic per subscriber.

or

– Total the traffic potential of each BTS under the BSC; determined by thenumber of TCHs available, the number of TCHs required or the subscriberpotential.

� Determine the number of trunks to support the traffic requirements of the BSCusing Erlang B tables at the required blocking rate.

GSM-001-103 Determining the number of MTLs required


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The number of MSC to BSC signalling links (MTL) required depends on the desired linkutilization, the type and capacity of the GPROCs controlling the MTLs. C7 uses a 4 bitnumber, the Signalling Link Selection (SLS), generated by the upper layer to load sharemessage traffic among the in-service links of a link set. When the number of in-servicelinks is not a power of 2, some links may experience a higher load than others.

The number of MTLs is a function of the number of MSC to BSC trunks or the offeredcall load. Table 5-23 give the recommended minimum number of MSC to BSC signallinglinks based on the typical call parameters given in Table 5-2. The value for N is thegreater of the following:

� The offered call load (in Erlangs) from all the BTSs controlled by the BSC.

� The potential carried load (approximately equal to the number of MSC to BSCtrunks).

The offered call load for a BSS is the sum of the offered call load from all of the cells ofthe BSS. The offered call load at a cell is a function of the number TCHs and blocking.As blocking increases the offered call load increase. For example, for a cell with15 TCHs and 2% blocking, the offered call load is 9.01 Erlangs.

Table 5-23 Number of MSC to BSC signalling links

N = the number of MSC to BSC Trunksor the offered load from the BTSs

( hi h i t )

Minimum numberof MTLs

Recommendednumber of MTLs

(whichever is greater) (each MTL at <= 20% link utilization)

N <= 145 1 2

145< N <=290 2 3

290 < N <= 385 3 4

385 < N <= 580 4 5

580 < N <= 775 6 7

775 < N <= 1160 8 9

1160 < N <= 1892 16 16

The capacities shown are based on the standard traffic model shown inTable 5-2.

It is recommended that the C7 links be designed to operate at no more than20% link utilization when the MTL is running on a GPROC, and no more than35% utilization when the MTL is running on a GPROC2. However, before useof the 35% utilization of GPROC2, it is imperative that the operator verifies thatthe MSC vendor can also support 35% utilization at the MSC end, if not, thenonly 20% link utilization should be used for GPROC2.

NOTE





If the call parameters differ significantly from those given in Table 5-2, the followingprocedure is used to determine the required number of MSC to BSC signalling links:

1. Use the formula given below to determine the maximum number of Erlangssupported by a C7 signalling link (nl link ).

nl link �

(1000 * U * T)((67 � 47 * S � 31 * H * (1 � 0.8 * i) � 25 * L) � 14 * PPC)

2. Use the formula given below to determine the maximum number of Erlangssupported by a GPROC2 (LCF–MTL) supporting a C7 signalling link (nl LCF–MTL).

nl LCF�MTL �2.5 * (3.6 * T)

((1 � 0.7 * S � 0.5 * H * (1 � 0.6 * i) � 0.5 * L) � PPC * (0.01 * B � 0.05))

3. The maximum amount of traffic a MTL (a physical link) can handle (nl min ) is thesmaller of the two numbers from Steps 1 and 2.

4. Since the signalling traffic is uniformly distributed over 16 logical links, and theselogical links will be assigned to the MTLs (physical links). We need to firstdetermine the amount of traffic each logical link holds (nl logical ):

nl logical �N16

5. Next we need to determine the number of logical links each MTL (physical link)can handle (nlog-per-MTL ):

n log�per�MTL � ROUND DOWN � nl min

nl logical�

6. Finally, the number of required MTLs (mtls ) is:

mtls � ROUND UP � 16n log�per�MTL

�� R � 16

mtls should not exceed 16. Formula 2 has been calculated using 70% meanutilization of GPROC2.

NOTE



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Where: U is: the percent link utilization (for example 0.20).




i the ratio of intra-BSC handovers to allhandovers.


PPC the number of pages per call.

B the number of BTSs supported by the BSC.

mtls the number of MSC to BSC signalling links(MTL).

ROUND UP rounding up to the next integer.

ROUND DOWN rounding down to the next integer.

N the greater of either the offered traffic load orpotential carried traffic load (approximatelyequal to the number of MSC to BSC trunks).

R the number of MTLs for redundancy.




Calculate thenumber of LCFsfor MTLprocessing

The purpose of the LCF GPROC2 is to support the functions of MSC link protocol,layer 3 call processing, and the BTS link protocol. It is recommended that an LCFsupports either 2 MTLs or 1 to 30 BTSs, with up to 31 RSLs and layer 3 call processing.

It is not recommended that an LCF support both an MTL and BSC to BTSsignalling links.

NOTE

LCFs for MSC to BSC links

Since one LCF GPROC2 can support two MTLs, the number of required LCF is:

NLCF � ROUND UP �MTLs2�

However, if the traffic model does not conform to the standard model:

NLCF � mtls, if 2 � nl link � nl LCF�MTL

otherwise:

NLCF � ROUND UP �mtls2�

Where: NLCF is: the number of LCF GPROC2s required.


mtls calculated in the previous section.

nllink calculated in the previous section.

nlLCF-MTL calculated in the previous section.

MSC to BSCsignalling over asatellite link

The BSC supports preventative cyclic retransmission (PCR) to interface to the MSC overa satellite link. PCR retransmits unacknowledged messages when there are no newmessages to be sent. This puts an additional processing load on the GPROC2(LCF–MTLs) controlling the C7 signalling links. It is recommended that when PCR isused, that the number of MTLs (and thus the number of LCF–MTLs) be doubled from thenumber normally required.

GSM-001-103 Generic processor (GPROC2)


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Generic processor (GPROC2)

Introduction

The generic processor (GPROC2) is used throughout the Motorola BSS as a genericcontrol processor board. GPROC2s are assigned functions and are then known by theirfunction names.

This section describes the BSC GPROC types and their functions. The BSCconfiguration type and GPROC device type, are essential factors for BSC planning.

GPROC2functions andtypes

The GPROC2 is the basic building block of a distributed architecture. The GPROC2provides the processing platform for the BSC. By using multiple GPROC2s softwaretasks can be distributed across GPROC2s to provide greater capacity. The set of tasksthat a GPROC2 is assigned, depends upon the configuration and capacity requirementsof the BSC. Although every GPROC2 is similar from a hardware standpoint, when agroup of tasks are assigned to a GPROC2, it is considered to be a unique GPROC2device type or function in the BSC configuration management scheme.

There are a limited number of defined task groupings in the BSC, which result in thenaming of four unique GPROC2 device types for the BSC. The processing requirementof a particular BSC determines the selection and quantity of each GPROC2 device type.

The possible general task groupings or functions for assignment to GPROC2s are:

� BSC common control functions.

� OMC communications – OML (X.25) including statistic gathering.

� MSC link protocol (C7).

� BSS Layer 3 call processing (BSSAP) and BTS link protocol, RSL (LAPD).

� Cell broadcast centre link (CBL).

The defined GPROC2 devices and functions for the BSC are:

� Base Site Control Processor (BSP).

� Link Control Function (LCF).

� Operations and Maintenance Function (OMF).

� Code Storage Facility Processor (CSFP).

At a combined BSC BTS site the BTF and DHP are additional GPROC2 function andtype in the network element.

GSM-001-103Generic processor (GPROC2)



BSC types

The BSC is configured as one of two types; the type is determined by the GPROCspresent.

� BSC type 1

– Master GPROC2.

Running the base site control processor (BSP) and carrying out operationsand maintenance functionalities.

– Link control processor (LCF).

Running the radio signalling link (RSL) and layer 3 processing or MTL (C7signalling link) communications links.

� BSC type 2

– Master GPROC.

Running the BSP.

– LCF.

– OMF.

Running the O&M, including statistics collection, and OML link (X.25 controllinks to the OMC-R).


The following factors should be considered when planning the GPROC complement:

� Each BSC requires:

– One master GPROC2 (BSP).

– One OMF (if it is a type 2 BSC).

– A number of LCFs for MTLs, see Link control processor below.

– LCFs to support the RSL and control of the BTSs.

� Optional GPROCs Include:

– One redundant master GPROC2 (BSP).

– At least one redundant pool GPROC (covers LCFs).

– An optional dedicated CSFP.

� A maximum of eight GPROCs can be supported in a BSU shelf.

� The master GPROC slot (20) in the first shelf should always be populated toenable communication with the OMC-R.

� For redundancy each BSC should be equipped with a redundant BSP controllerand an additional GPROC to provide redundancy for the signalling LCFs. Wheremultiple shelves exist, each shelf should have a minimum of two GPROCs toprovide redundancy within that shelf.



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Link control function

The following factors should be considered when planning the number of LCFs:

� MTLs are handled by dedicated LCFs.

� GPROC2s can handle up to two MTLs.

� For RSL handling the maximum number of carriers that can be supported by anLCF depends on the number of BTSs controlled by that LCF. The sum of 2 x (thenumber of BTSs) and the number of carriers cannot exceed 120 for a GPROC2LCF.

The planning rules for LCFs exclusively using GPROC2 are:

� A single GPROC2 will support two MTLs each working at 20% link utilization.

� A single GPROC2 will support up to 31 BTS sites and 31 RSLs, limited to thefollowing calculation:

2 * rsls � carriers � 120

Where carriers = the total number of radios for the BTS site(s).

Combining MTL and RSL processing on a single GPROC2 is notrecommended.

There is a limit of 30 carriers in a single site (M-Cell6 has a limit of 24 carriers).

NOTE

� The link utilization of an RSL should not exceed 25%.

� Up to 17 LCFs can be equipped.

In some cases the software will allow maximums greater than the planningguide, to allow ease of capacity expansion in future releases, but it is notsupported with this software release.

NOTE

� A maximum of 31 BTS sites can be controlled by a single LCF. All RSLs (LAPDlinks) for the BTSs will terminate on the same GPROC2, so if return loops areused the maximum number of BTS sites will be 15 (if GPROC_slots = 31). If theGPROC_slots is set to 16 then at most 15 RSLs may exist which would supportup to seven BTS sites.

The number of serial links per GPROC2 must be determined for each site.The current values are 16 or 32 with 16 being the default value. One link isreserved for each board (GPROC test purposes) so the number of availableserial links is either 15 or 31.

NOTE

GSM-001-103Generic processor (GPROC2)



GPROC2planning actions

Determine the number of GPROC2s required.

NGPROC2 � 2B � L � C � R

Where: NGPROC2 is: the total number of GPROC2s required.

B the number of BSP GPROCs (2B for redundancy).

L the number of LCF GPROC2s.

C the number of CSFP GPROCs.

R the number of pool GPROC2s (for redundancy).

If dedicated GPROC2s are required for either the CSFP or OMF functionsthen they should be provisioned separately.

NOTE

Cell broadcastlink

The cell broadcast link (CBL) connects the BSC to the cell broadcast centre. For typicalapplications (less than ten messages per second), this link can exist on the same LCF asthat used to control BTSs. The CBL should not be controlled by a LCF–MTL (a GPROCcontrolling an MTL).

OMF GPROCrequired

The BSC type 2 configuration offloads many of the O&M functions and control of theinterface to the OMC-R from the BSP. One of the major functions off loaded from theBSP is the central statistics process. When determining the total number of statistics,consider the number of instances of that statistic.

NST � (ECS � C) � (TCS � n) � SX25LAPD (L � X � B)

Where: NST is: the total number of statistics.

ECS the number of enabled cell statistics


Tcs the number of traffic enabled channel statistics.

n the number of traffic channels.

SX25LAPD the number of X.25/LAPD statistics.

L the number of RSLs.

X the number of OMLs.

B the number of XBLs

The formula assumes that the same cell and channel statistics are enabledacross all cells.

NOTE



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The BSS supports a GPROC acting as the code storage facility processor (CSFP). TheCSFP allows pre-loading of a new software release while the BSS is operational.

If a dedicated GPROC is to exist for the CSFP, an additional GPROC will be required.

When M-Cell BTSs are connected to the BSC, a dedicated CSFP is required at the BSCand a second dedicated CSFP should be equipped for redundancy.

The BSS supports a method whereby a dedicated CSFP GPROC is not required. Thismethod is called configure CSFP and works as follows:

The system can borrow certain devices and temporarily convert them into a CSFP, andwhen the CSFP functionality is no longer needed the device can be converted back intoits previous device. The devices the system can borrow are a redundant BSP/BTP or apooled GPROC2.

This functionality allows an operator who already has either a redundant BSP/BTP or apooled GPROC2 in service to execute a command from the OMC-R to borrow the deviceand convert it into a CSFP. The operator can then download the new software load ordatabase and execute a CSFP swap. Once the swap has been completed and verifiedas successful, the operator can return the CSFP back to the previous redundant orpooled device type via a separate command from the OMC-R.

See the Technical Description: BSS/RXCDR (GSM-100-323A) or Service Manual:BSC/RXCDR (GSM-100-030) for more details.

GPROCredundancy

BSP redundancy

The failure of the BSP GPROC2 will cause a system outage. If the BSC is equipped witha redundant BSP GPROC2, the system will restart under the control of the redundantBSP GPROC2s. If the BSC is not equipped with a redundant BSP and the BSPGPROC2 were to fail, the BSC would be inoperable.

Pooled GPROC2s for LCF and OMF redundancy

The BSS supports pooled GPROC2s for LCF and OMF redundancy. By equippingadditional GPROC2s for spares, if an LCF or the OMF GPROC2 were to fail, the systemsoftware will automatically activate a spare GPROC2 from the GPROC2 pool to replacethe failed GPROC2.

GSM-001-103Transcoding



Transcoding

Introduction

Transcoding reduces the number of cellular subscriber voice/data trunks required by afactor of four. If transcoding takes place at the switch using a RXCDR, the number oflinks between the RXCDR and the BSC is reduced to approximately one quarter of thenumber of links between the RXCDR and the MSC.

The capacity of one BSU shelf is 12 MSI slots, six of which may contain a transcoder(XCDR) or generic DSP processor (GDP); this limitation is due to power constraints. AnRXU shelf can support up to 16 GDP/XCDRs or GDPs and typically provides a bettersolution of the transcoding function for larger commercial systems. Refer to the sectionRemote transcoder planning overview in Chapter 6.

GDP/XCDRplanningconsiderations

The following factors should be considered when planning the GDP/XCDR complement:

� A GDP/XCDR can process 30 voice channels (GDP-E1/XCDR) or 24 voicechannels (GDP-T1), will support enhanced full rate speech, uplink/downlink volumecontrol and is capable of terminating one E1 or T1 link from the MSC.

� The master MSI slot(s) should always be populated to enable communication withOMC-R. The master MSI slot may contain a GDP/XCDR, if the OML goes throughthe MSC.

� The A interface must terminate on the GDP/XCDR. A GDP can terminate T1 orE1 links; whereas an XCDR can only terminate E1 links (refer to T1 conversionsbelow).

The fitting of a GDP in place of an XCDR does not effect the planningcalculations for E1 links. For T1 links an MSI-2 is not required.

NOTE

GSM-001-103 Transcoding


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T1 conversion

T1 to E1 conversion is needed for XCDR, but not for GDP.

When required, MSI-2s can be used to provide T1 to E1 conversion. This can be done inone of two ways. In either case the conversion may be part of an existing networkelement or a standalone network element which would appear as a RXCDR.

Without KSW switching

A single MSI-2 can be programmed to be E1 on one port and T1 on the other. This is thesimplest method, but uses at most 23 of the transcoding circuits on the XCDR. Thismethod has no impact on the TDM bus ports, but does require MSI slots. This methodrequires the number of GDP/XCDRs and additional MSI-2s to be equal to the number ofT1 links.

With KSW switching

For better utilization of the GDP/XCDRs, a mapping of five T1 circuits onto four E1circuits may be done. This uses the ability of the KSW to switch between groups usingnailed connections. Although more efficient in XCDR utilization, this method may causeadditional KSWs to be used. Each MSI-2 requires an MSI slot. The number of MSI-2sneeded for T1 to E1 conversion is:

m = T + E

2

Where: m is: the number of MSI-2s required for T1 to E1 conversion.

T the number of T1 circuits required.

E the number of E1 circuits required.




Planning actionsfor transcodingat the BSC

Planning transcoding at the BSC must always be performed as it determines the numberof E1 or T1 links for the A interface. This text should be read in conjunction with the BSSplanning diagram Figure 5-1.

Using E1 links

The minimum number of E1 links required is the greater of two calculations that follow(fractional values should be rounded up to the next integer value).

N = T30

N = C + X + T

31

Where: N is: the minimum number of E1 links required.

C the number of MTL links (C7 signalling links) tothe MSC.

X the number of OML links (X.25 control links tothe OMC-R) through the MSC.

T the number of trunks between the MSC and theBSC.

Using T1 links

The minimum number of T1 links required is the greater of two calculations that follow(fractional values should be rounded up to the next integer value).

N = T23

N = C + X + T

24

Where: N is: the minimum number of T1 links required.


X the number of OML links (X.25 control links tothe OMC-R) through the MSC.


GSM-001-103 Multiple serial interface (MSI, MSI-2)


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Multiple serial interface (MSI, MSI-2)

Introduction

A multiple serial interface provides the interface for the links between a BSSC cabinetand other network entities in the BSS, BSC to BTS and BSC to RXCDR. An MSI caninterface only E1 links, an MSI-2 can interface both E1 and T1 links, but notsimultaneously.


The following factors should be considered when planning the transcoder complement:

� Each MSI can interface two E1 links.

� Each MSI-2 can interface two T1 links.

Although the MSI-2 is configurable to support either E1 or T1 on each of its twoports, it is not recommended for E1 systems.

NOTE

� Each E1 link provides 31 usable 64 kbit/s channels.

� Each T1 link provides 24 usable 64 kbit/s channels, T1 links use MSI-2.

� Redundancy for the MSI/MSI-2 depends on the provisioning of redundant E1/T1links connected to the site.

� The master MSI slot(s) should always be populated to enable communication withOMC-R.

If the OML links go directly to the MSC the master slot should be filled with anGDP/XCDR, otherwise the slot should be filled with an MSI/MSI-2 whichterminates the E1/T1 link carrying the OML link to the OMC-R. These E1/T1 linksdo not need to go directly to the OMC-R, they may go to another network elementfor concentration.

GSM-001-103Multiple serial interface (MSI, MSI-2)



MSI/MSI-2planning actions

The following formulae assume local transcoding. Refer to Chapter RXCDR planningsteps and rules for MSI planning formulae for remote transcoding.

With E1 links

Determine the number of MSIs required.

M = B2

Where: M is: the number of MSIs required.

B the number of BSC to BTS links.

With T1 links

Determine the number of MSI-2s required.

M = B2� m

Where: M is: the number of MSI/MSI-2s required.


m the number of MSI/MSI-2s used for T1 to E1conversion.

GSM-001-103 Kiloport switch (KSW)


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Kiloport switch (KSW)

Introduction

The kiloport switch (KSW) card provides digital switching for the TDM highway of theBSC.


The following factors should be considered when planning the KSW complement:

� A minimum of one KSW is required for each BSC site.

� The KSW capacity of one thousand and twenty four 64 kbit/s ports can beexpanded by adding up to three additional KSWs, giving a total switching capacityof four thousand and ninety six 64 kbit/s ports of which, eight timeslots arereserved by the system for test purposes and are not available for use.

� For planning purposes assume fourteen MSI maximum per KSW. Each MSI maybe replace with four GDP/XCDRs.

� Using twelve MSIs per KSW may reduce the number of shelves required at a costof additional KSWs. For example, a BSC with 28 MSIs could be housed in threeshelves with three KSW modules or four shelves with two KSW modules.

� Verify that each KSW uses fewer than 1016 ports. There are three devices in aBSC that require TDM timeslots. They are:

– GPROC = 16 Timeslots.

– GPROC2 = 32 (or 16) Timeslots.

– GDP or XCDR = 16 Timeslots.

– MSI/MSI-2 = 64 Timeslots.

– The number of TDM timeslots is given by.

N = (G * n) + (R * 16) + (M * 64)

Where: N is: the number of timeslots required.

G the number of GPROC2s.

n 16 or 32 (depending on the value of thegproc_slots database parameter).

R the number of GDP/XCDRs.

M the number of MSI/MSI-2s (do not count MSI-2swhich are doing on board E1 to T1 conversion,when determining TDM bandwidth).

� For redundancy, duplicate all KSWs.

Any BSC site which contains a DRIM has 352 timeslots allocated to DRIMsirrespective of the number of DRIMs equipped.

NOTE

GSM-001-103Kiloport switch (KSW)



KSW planningactions

Determine the number of KSWs required:

N = (G * n) + (R * 16) + (M * 64)

(1016)

Where: N is: the number of KSWs required.

G the number of GPROC2s.

n 16 or 32 (depending on the value of thegproc_slots database parameter).


M the number of MSI/MSI-2s (do not count MSI-2swhich are doing on board E1 to T1 conversion).

GSM-001-103 BSU shelves


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BSU shelves

Introduction

The number of BSU shelves is normally a function of the number of GPROC/GPROC2,MSI/MSI-2s and GDP/XCDRs required.


The following factors should be considered when planning the number of BSU shelves:

� Each BSU shelf supports up to eight GPROCs or GPROC2s, if the number ofthese exceed the number of slots available an additional BSU shelf is required.

� Each shelf is allocated to a single KSW and extension shelves are differentiated bythe presence of the KSW; extension shelves are those which do not contain aprimary KSW.

� A BSU shelf can support up to 12 MSI/MSI-2 boards.

� A BSU shelf can support up to six GDP/XCDRs boards.(reducing appropriately, the number of MSI/MSI-2 boards).

BSU shelfplanning actions

Determine the number of BSU shelves required.

The number of BSU shelves required is the greater of three calculations that follow(fractional values should be rounded up to the next integer value).

Bs = G8

Bs = M + R

12

Bs = R6

Where: Bs is: the minimum number of BSU shelves required.

G the number of GPROC/GPROC2s.

M the number of MSI/MSI-2s.


The number of shelves may be larger if an attempt to reduce the number ofKSWs is made.The number of shelves (cages) = 134The number of cabinets = 170There is a database limitation of 50 cabinets/shelves.M-Cell sites do not require a cage to be equipped, only a cabinet.

NOTE

GSM-001-103Kiloport switch extender (KSWX)



Kiloport switch extender (KSWX)

Introduction

The kiloport switch extender (KSWX) extends the TDM highway of a BSU to other BSUsand supplies clock signals to all shelves in multi-shelf configurations. The KSWX isrequired whenever a network element grows beyond a single shelf.


The following factors should be considered when planning the KSWX complement:

� For redundancy, duplicate all KSWX boards (requires redundant KSW).

� KSWXs are used in three modes:

– KSWXE (Expansion) are required to interconnect the KSWs for sites withmultiple KSWs.

– KSWXR (Remote) are required in shelves with KSWs to drive the TDMhighway in shelves that do not have KSWs.

– KSWXL (Local) are used in shelves that have KSWs to drive the clock bus inthat shelf and in shelves that do not not KSWs to drive both the local TDMhighway and the clock bus in that shelf.

� Five of the redundant KSWX slots are also CLKX slots.

� The maximum number of KSWX slots per shelf is 18, nine per KSW.

KSWX planningactions

The number of KSWXs required is the sum of the KSWXE, KSWXL and KSWXR.

NKX � NKXE � NKXR � NKXL

NKXE � K � (K � 1)

NKXR � SE

NKXL � K � SE

Where: NKX is: the number of KSWX required.

NKXE the number of KSWXE.

NKXR the number of KSWXR.

NKXL the number of KSWXL.

K the number of non-redundant KSWs.

SE the number of extension/expansion shelves.

Ensure that SE = 0 for extension shelves and 1 for expansion shelves.

NOTE

GSM-001-103 Kiloport switch extender (KSWX)


68P02900W21-G


5–75

For example:

Table 5-24 KSWX (non-redundant)

Extensionshelves

KSW (non redundant)shelves

1 2 3 4

0 1 4 9 16

1 3 6 11 18

2 5 8 13 20

3 7 10 15 22

4 9 12 17 24

Table 5-25 KSWX (redundant)

Extensionshelves

KSW (redundant)shelves

1 2 3 4

0 2 8 18 32

1 6 12 22 36

2 10 16 26 40

3 14 20 30 44

4 18 24 34 48

GSM-001-103Generic clock (GCLK)



Generic clock (GCLK)

Introduction

The generic clock (GCLK) generates all the timing reference signals required by a BSU.


The following factors should be considered when planning the GCLK complement:

� One GCLK is required at each BSC.

� The maximum number of GCLK slots per shelf is two.

� For redundancy add a second GCLK at each BSC in the same shelf as the firstGCLK.

GCLK planningactions

Determine the number of GCLKs required.

GCLKs = 1 + 1 redundant .

GSM-001-103 Clock extender (CLKX)


68P02900W21-G


5–77

Clock extender (CLKX)

Introduction

A clock extender (CLKX) board provides expansion of GCLK timing to more than oneBSU.


The following factors should be considered when planning the CLKX complement:

� One CLKX is required in the first BSU shelf, which contains the GCLK, whenexpansion beyond the shelf occurs.

� Each CLKX can supply the GCLK signals to six shelves.

� There are three CLKX slots for each GCLK, allowing each GCLK to support up to18 shelves (LAN extension only allows fourteen shelves in a single networkelement).

� The maximum number of CLKX slots per shelf is six.

The CLKX uses six of the redundant KSWX slots.

NOTE

� With a CLKX, a KSWXL is required to distribute the clocks in the master and eachof the expansion/extension cages.

� For redundancy, duplicate each CLKX (requires a redundant GCLK).

CLKX planningactions

Determine the number of CLKXs required.

NCLKX � ROUND UP �E6� * (1 � RF)

Where: NCLKX is: the number of CLKX required.


E the number of expansion/expension shelves.

RF Redundancy factor(1 if redundancy required (recommended).0 for no redundancy).

GSM-001-103LAN extender (LANX)



LAN extender (LANX)

Introduction

The local area network extender (LANX) provides a LAN interconnection forcommunications between all GPROCs at a site.


The following factors should be considered when planning the LANX complement:

� One LANX is supplied in each shelf.

� For full redundancy add one LANX for each shelf.

� The LANX can support a maximum network size of 14 shelves.

LANX planningactions

Determine the number of LANXs required.

NLANX � NBSU * (1 � RF)

Where: NLANX is: the number of LANX required.

NBSU the number of BSU shelves.


BSU � 14

GSM-001-103 Parallel interface extender (PIX)


68P02900W21-G


5–79

Parallel interface extender (PIX)

Introduction

The parallel interface extender (PIX) provides eight inputs and four outputs for sitealarms.


The following factors should be considered when planning the PIX complement:

� The maximum number of PIX board slots per shelf is two.

� The maximum number of PIX board slots per site is eight.

PIX planningactions

Choose the number of PIXs required.

PIX � 2 * number of BSUs.

or

PIX � 8.

GSM-001-103Line interfaces (BIB, T43)



Line interfaces (BIB, T43)

Introduction

The line interfaces, balanced-line interface board (BIB) and T43 board (T43), provideimpedance matching for E1 and T1 links.



� To match a balanced 120 ohm (E1 2.048 Mbit/s) or balanced 110 ohm (T11.544 Mbit/s) 3 V (peak pulse) line use a BIB.

� To match a single ended unbalanced 75 ohm (E1 2.048 Mbit/s) 2.37 V (peakpulse) line use a T43 Board (T43).

� Each BIB/T43 can interface six E1/T1 links to specific slots on one shelf.

� Up to four BIBs or T43s per shelf can be mounted on a BSSC2 cabinet

– A maximum of 24 E1/T1 links can be connected to a BSU shelf.

– A BSSC2 cabinet with two BSU shelves can interface 48 E1/T1 links.

BIB/T43 planningactions


� Determine the number and type of link (E1 or T1) to be driven.

� Determine the number of BIBs or T43s required.

Minimum number of BIBs or T43s = Number of MSIs

3 =

Number of E1/T1 links6

GSM-001-103 Digital shelf power supply


68P02900W21-G


5–81

Digital shelf power supply

Introduction

A BSSC cabinet can be supplied to operate from either a +27 V dc or –48/–60 V dcpower source.


The following factors should be considered when planning the PSU complement:

� Two DPSMs are required for each shelf in the BSSC.

� Two IPSMs are required for each shelf in the BSSC2 (–48/–60 V dc).

� Two EPSMs are required for each shelf in the BSSC2 (+27 V dc).

� For redundancy, add one DPSM, IPSM, or EPSM for each shelf.

Power supplyplanning actions

Determine the number of PSUs required.

PSUs = 2 * Number of BSUs + R F * Number of BSUs

Where: RF is: Redundancy factor(1 if redundancy required (recommended).0 for no redundancy).

GSM-001-103Battery backup board (BBBX)



Battery backup board (BBBX)

Introduction

The battery backup board (BBBX) provides a backup supply of +5 V dc at 8 A from anexternal battery to maintain power to the GPROC2 DRAM and the optical circuitry on theLANX in the event of a mains power failure.


The following factors should be considered when planning the BBBX complement:

� One BBBX is required per shelf; if the battery backup option is to be used.

BBBX planningactions

Determine the number of BBBXs required.

BBBX = number of BSUs for battery backup (recommended).

BBBX = 0 if no battery backup required.

GSM-001-103 Verify the number of BSU shelves and BSSC2 cabinets


68P02900W21-G


5–83

Verify the number of BSU shelves and BSSC2 cabinets

Verification

After planning is complete, verify that:

� The number of shelves is greater than one eighth the number of GPROC2modules.

� Each non-redundant KSW has its own shelf.

� Each extension shelf supports extension of a single KSW.

� The number of KSWX, LANX, CLKX, and GPROC2s is correct.

� The number of MSI/MSI-2 and GDP/XCDR

� 12 * number of shelves.

� The number of GDP/XCDR


� The number of BTS sites

� 100

� The number of BTS cells

� 250

� RSLs.

� 250

� Carriers.

� 384

� Erlangs.

� 1892

If necessary, add extra BSU shelves. Each BSSC2 cabinet supports two BSU shelves.

GSM-001-103Verify the number of BSU shelves and BSSC2 cabinets




68P02900W21-G


i

Chapter 6

RXCDR planning steps and rules

GSM-001-103



GSM-001-103


68P02900W21-G


iii

Chapter 6RXCDR planning steps and rules i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter overview 6–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction 6–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Remote transcoder planning overview 6–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 6–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Outline of planning steps 6–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

RXCDR to BSC links 6–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 6–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E1 interconnect planning actions 6–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T1 interconnect planning actions 6–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

RXCDR to MSC links 6–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 6–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E1 interconnect planning actions 6–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T1 interconnect planning actions 6–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Generic processor (GPROC, GPROC2) 6–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 6–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 6–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC planning actions 6–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Transcoding 6–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 6–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GDP/XCDR planning considerations 6–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T1 conversion 6–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Multiple serial interface (MSI, MSI-2) 6–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 6–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 6–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MSI planning actions 6–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


RXU shelves 6–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 6–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 6–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RXU shelf planning actions 6–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .





GSM-001-103







Verify the number of RXU shelves and BSSC cabinets 6–22. . . . . . . . . . . . . . . . . . . . . . . . . . . Verification 6–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .



68P02900W21-G


6–1

Chapter overview

Introduction

This chapter provides the planning steps and rules for the RXCDR. This chaptercontains:

� RXCDR planning overview.

� RXCDR planning.

– Planning rules for RXCDR to BSC links.

– Planning rules for RXCDR to MSC links.



GSM-001-103Remote transcoder planning overview



Remote transcoder planning overview

Introduction

To plan the equipage of an RXCDR, certain information must be known. The major itemsinclude:

� The BSC traffic requirements.

� The number of trunks (including redundancy) from the MSC.

� Each RXCDR may support multiple BSCs.

� The sum of the MSI/MSI-2s and the XCDR/GDPs for each BSC define the numberof slots required at the RXCDR.



GSM-001-103 Remote transcoder planning overview


68P02900W21-G


6–3


Planning a RXCDR involves the following steps:

1. Plan the number of links between the XCDR and BSC site(s), refer to the sectionRXCDR to BSC links in this chapter.

2. Plan the number of E1 or T1 links between the RXCDR and MSC site(s), refer tothe section RXCDR to MSC links in this chapter.

3. Plan the number of GPROCs required, refer to the section Generic processor(GPROC, GPROC2) in this chapter.

4. Plan the number of GDP/XCDRs required, refer to the section Transcodingin this chapter.



7. Plan the number of RXU shelves, refer to the section RXU shelves in this chapter.









16. Verify the planning process, refer to the section Verify the number of RXUshelves and BSSC cabinets in this chapter.

GSM-001-103RXCDR to BSC links



RXCDR to BSC links

Introduction

The number of E1 or T1 links between the RXCDR and the BSCs is the number requiredto support the A interface from the RXCDR to the BSC.

This text should be read in conjunction with the BSS planning diagram, Figure 6-1.

MSC









OR MSC SITE






TRANSCODER

BSC

BTS




GSM-001-103 RXCDR to BSC links


68P02900W21-G


6–5

E1 interconnectplanning actions

Determine the number of E1 links required.

N = C + X + B64 + (T + B16) / 4

31


C the number of C7 signalling links to the MSC.

X the number of OML links (X.25 control links to theOMC) through the RXCDR.

B64 the number of 64 kbit/s XBL links.

T the number of trunks between the MSC and the BSC.


Each E1 link carries up to 120 trunks with a signalling link or 124 trunkswithout a signalling link. Redundant E1 links carrying extra trunks may beadded.

NOTE

T1 interconnectplanning actions

Determine the number of T1 links required.

N = C + X + B64 + (T + B16) / 4

24


C the number of C7 signalling links to the MSC.

X the number of OML links (X.25 control links to theOMC) through the RXCDR.




Each T1 link carries up to 92 trunks with a signalling link or 96 trunks without asignalling link. Redundant E1 links carrying extra trunks may be added.

NOTE

GSM-001-103RXCDR to MSC links



RXCDR to MSC links

Introduction

The number of E1 or T1 links between the RXCDR and the MSC is the number requiredto support the A interface from the RXCDR to the MSC.

E1 interconnectplanning actions

Determine the number of E1 links required.


N = C + X + T

31


C the number of MTL links (C7 signalling links) to theMSC.

X the number of OML links (X.25 control links to theOMC) through the MSC.


T1 interconnectplanning actions

Determine the number of T1 links required.

N = C + X + T

24


C the number of MTL links (C7 signalling links) to theMSC.

X the number of OML links (X.25 control links to theOMC) through the MSC.


GSM-001-103 Generic processor (GPROC, GPROC2)


68P02900W21-G


6–7

Generic processor (GPROC, GPROC2)

Introduction

Generic processors (GPROC, GPROC2) are used throughout the Motorola BSS as ageneric control processor.


The following factors, for GPROCs at the RXCDR, should be considered when planningthe GPROC, GPROC2 complement:

� Each shelf requires at least one GPROC, GPROC2; plus one for redundancy.

� A maximum of two GPROC, GPROC2s per shelf are supported.

GPROC planningactions

An RXCDR should have:

� One BSP GPROC or GPROC2 per shelf.

� One BSP GPROC or GPROC2 for redundancy.

� One optional CSFP.

The factors described in the planning considerations section should be taken intoaccount in this planning.

In a transcoder either GPROC or GPROC2 can be used.

NOTE




Transcoding

IntroductionTranscoders (XCDR) provide the interface for the E1 (or converted T1) links between theMSC and the BSC. The XCDR performs the transcoding/rate adaption function whichconverts the information on the trunks to 16 kbit/s.

Figure 6-2 shows sub-multiplexing and speech transcoding at the RXCDR.

� Each Trunk requires a quarter (1/4th) of a 64 kbit/s circuit between the RXCDRand BSC.

� Each control link (RSL, OML,XBL,C7) requires one 64 kbit/s circuit.

(RSL and XBL have the option of using 16 kbit/s circuits)

ONE RFCARRIER

KSW

MSI/MSI2

MCU

MSI/MSI2

KSW

XCDR

MSC

8 x 22.8 kbit/sTIMESLOTS

THE TCU ENCODES/DECODES 13kbit/s TO/FROM 22.8 kbit/s FOR 8TIMESLOTS, AND SUBMULTIPLEXES4 (13 kbit/s MAPPED ON 16 kbit/s)TIMESLOTS ONTO 1 x 64 kbit/sCIRCUIT, OR THE OTHER WAYAROUND. .

64 kbit/s 4 TCHs

THE KSW SUBRATESWITCHES 16 kbit/sTIMESLOTS.THE XCDR TRANSCODES 64

kbit/s A–LAW PCM TO/FROM 13kbit/s MAPPED ONTO 16 kbit/s,AND SUBMULTIPLEXES 4TRUNKS TO/FROM 1 X 64 kbit/sCIRCUIT.

64 kbit/sA–LAWTRUNKS

MSI/MSI2

TCU

NIU

4 TRUNKS PER64 kbit/s CIRCUIT

RXCDR BSC M-CELL BTS

Figure 6-2 Sub-multiplexing and speech transcoding at the RXCDR







NOTE



68P02900W21-G


6–9

T1 conversion


When required MSI-2s can be used to provide T1 to E1 conversion. This can be done inone of two ways. In either case the conversion may be part of an existing networkelement or a standalone network element which would appear as a RXCDR.


A single MSI-2 can be programmed to be E1 on one port and T1 on the other. This is thesimplest method but uses at most 23 of the transcoding circuits on the XCDR. Thismethod has no impact on the TDM bus ports, but does require MSI slots. This methodrequires the number of GDP/XCDRs and additional MSI-2s to be equal to the number ofT1 links.

With KSW switching

For better utilization of the GDP/XCDRs a mapping of five T1 circuits onto four E1circuits may be done. This uses the ability of the KSW to switch between groups usingnailed connections. Although more efficient in XCDR utilization, this method may causeadditional KSWs to be used. Each MSI-2 requires an MSI slot. The number of MSI-2sneeded for T1 to E1 conversion is:

m = T + E

2








Introduction

A multiple serial interface provides the interface for the links between a RXCDR site andother network entities, RXCDR to OMC-R and RXCDR to BSC. An MSI can interfaceonly E1 links, an MSI-2 can interface both E1 and T1 links.




� Each MSI-2 can interface two E1/T1 links.

Although the MSI-2 is configurable to support either E1 or T1 on each of its twoports, it is not required for E1 systems.

NOTE




� When one remote transcoder site is supporting multiple BSCs, each BSC requiresits own E1 interface(s) as follows:

– The number of MSI/MSI-2s should be equal to half the number of RXCDR toBSC E1 or T1 links. Redundancy requires additional links and MSI/MSI-2s.

– If the OMLs (X.25 links) do not go through the MSC, a dedicated E1 or T1link (half an MSI/MSI-2) is required for the X.25 links to the OMC.

– At least one MSI/MSI-2 is required for every eight GDP/XCDR modules.Additional MSI/MSI-2s will be used if the links are not fully occupied.

If the XCDR is using all 30 ports in a T1 network, use one MSI-2 forapproximately every ten GDPs.

– Additional E1 or T1 links may be required to concentrate X.25 links fromother network entities.

– Each BSC may use one to four 64 kbit/s or 16 kbit/s channels for XBL faultmanagement communications. Reference should be made to TechnicalDescription: BSS/RXCDR (GSM-100-323A) or Service Manual:BSC/RXCDR (GSM-100-030) for more details.


If the OML links go directly to the MSC, the master slot should be filled with anXCDR, otherwise the slot should be filled with an MSI/MSI-2 which terminates theE1/T1 link caring the OML link to the OMC-R. These E1/T1 links do not need togo directly to the OMC-R, they may go to another network element forconcentration.



68P02900W21-G


6–11

MSI planningactions

With E1 links

Determine the number of MSI or MSI-2s required.

NMSI �NBSC

2

Where: NMSI is: the number of MSIs required.

NBSC the number of E1 links required.(as N calculated in RXCDR to BSC links in thischapter)

With T1 links

If MSI-2s are used, T1 to E1 conversion is not needed. Therefore the number of MSI-2srequired is:

NMSI �NBSC

2



If MSIs are used, conversion becomes necessary. Therefore the number of MSIsrequired is:

NMSI �NBSC

2� m



m the number of MSI-2s used for T1 to E1conversion.





Introduction

The kiloport switch (KSW) provides digital switching for the TDM highway of the RXU.


The following factors should be considered when planning the kiloport switchcomplement:

� A minimum of one KSW is required for each RXU site.

� The KSW capacity of one thousand and twenty four 64 kbit/s ports or fourthousand and ninety six 16 kbit/s ports can be expanded by adding up to threeadditional KSWs, giving a total switching capacity of four thousand and ninety six64 kbit/s ports or sixteen thousand three hundred and eighty four 16 kbit/s ports.

� One KSW can provide switching for two fully occupied shelves with 16GDP/XCDRs and up to three MSI/MSI-2s each. If more than one XCDR isexchanged for an MSI/MSI-2s, each shelf will require its own KSW.


� Verify that each KSW uses fewer than 1016 ports. There are three devices in aRXCDR that require TDM timeslots. They are:





KSW planningactions


� Determine the number of KSWs required.

N = (G * n) + (R * 16) + (M * 64)

(1016)



n 16 or 32 (depending on the value of theGPROC_slot database parameter).



GSM-001-103 RXU shelves


68P02900W21-G


6–13

RXU shelves

Introduction

The number of RXU shelves is normally a function of the number of MSI/MSI-2s andGDP/XCDRs required.


The following factors should be considered when planning the number of RXU shelves:

� Each shelf is allocated to a single KSW and shelves are differentiated by thepresence of the KSW; extension shelves are those which do not contain a primaryKSW.

� Two shelves each equipped with three MSI/MSI-2s and 16 GDP/XCDRs can beserved by a single KSW.

If each shelf has five MSI/MSI-2s with 14 GDP/XCDRs the KSW can serve only oneshelf, and two KSWs will be required.

RXU shelfplanning actions

Determine the number of RXU shelves required.

RX � max�M5

, R16�

Where: Rx is: the minimum number of RXU shelves required.







Introduction

The kiloport switch extender (KSWX) extends the TDM highway of a RXU to other RXUsand supplies clock signals to all shelves in multi-shelf configurations. The KSWX isrequired whenever a network element grows beyond a single shelf.









� The maximum number of KSWX slots per shelf is 18, 9 per KSW.


The number of KSWXs required is the sum of the KSWXE, KSWXL, and KSWXR.


NKXE � K � (K � 1)

NKXR � SE

NKXL � K � SE








NOTE

GSM-001-103 Generic clock (GCLK)


68P02900W21-G


6–15


Introduction

The generic clock (GCLK) generates all the timing reference signals required by a RXU.



� One GCLK is required at each RXCDR.

� A second GCLK is optionally requested for redundancy.

� Both GCLKs must reside in the same shelf of the RXCDR.




GSM-001-103Clock extender (CLKX)




Introduction

A clock extender (CLKX) board provides expansion of GCLK timing to more than oneRXU.



� One CLKX is required in the first RXU shelf, which contains the GCLK, whenexpansion beyond the shelf occurs.


� There are three CLKX slots for each GCLK, allowing each GCLK to support up to18 shelves (LAN extension only allows fourteen shelves in a single networkelement).



NOTE





NCLKX � ROUND UP �E6� * (1 � RF)



E the number of shelves.


GSM-001-103 LAN extender (LANX)


68P02900W21-G


6–17

LAN extender (LANX)

Introduction









NLANX � NRXU * (1 � RF)


NRXU the number of RXU shelves.


RXU � 14

GSM-001-103Parallel interface extender (PIX)




Introduction






PIX planningactions

Determine the number of PIXs required.

PIX � 2 * number of RXUs.

or

PIX � 8.

GSM-001-103 Line interfaces (BIB, T43)


68P02900W21-G


6–19


Introduction




� To match a balanced 120 ohm (E1 2.048 Mbit/s) or balanced 110 ohm (T1 1.544Mbit/s) 3 V (peak pulse) line use a BIB.

� To match a single ended 75 ohm 2.37 V (peak pulse) line use a T43 Board (T43).


� All E1/T1 links must be terminated, including the links which are fully contained inthe cabinet, for example, between RXU and BSU or links used for T1 to E1conversion.

� Up to four BIBs or T43s per shelf can be mounted on a BSSC cabinet

– A maximum of 24 E1/T1 links can be connected to a RXU shelf.

– A BSSC cabinet with two RXU shelves can interface 48 E1/T1 links.





Minimum number of BIBs or T43s = Number of E1/T1 links

6

GSM-001-103Digital shelf power supply




Introduction



The following factors should be considered when planning the PSM complement:

� Two DPSMs are required for each shelf in the BSSC/RXCDR.

� Two IPSMs are required for each shelf in the BSSC2/RXCDR (–48/–60 V dc).

� Two EPSMs are required for each shelf in the BSSC2/RXCDR (+27 V dc).

� For redundancy, add one DPSM, IPSM or EPSM for each shelf.


Determine the number of PSMs required.



GSM-001-103 Battery backup board (BBBX)


68P02900W21-G


6–21


Introduction

The battery backup board (BBBX) provides a backup supply of +5 V dc at 8 A from anexternal battery to maintain power to the GPROC DRAM and the optical circuitry on theLANX in the event of a mains power failure.



� One BBBX is required per shelf.





GSM-001-103Verify the number of RXU shelves and BSSC cabinets



Verify the number of RXU shelves and BSSC cabinets

Verification




� The number of KSWX, LANX, CLKX, and GPROCs is correct.

If necessary, add extra RXU shelves. Each BSSC cabinet supports two RXU shelves.


68P02900W21-G


i

Chapter 7

OMC-R planning steps and rules

GSM-001-103



GSM-001-103


68P02900W21-G


iii

Chapter 7OMC-R planning steps and rules i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Authorized OMC-R configurations 7–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 7–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Terminology 7–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Capacity 7–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Outline of planning steps 7–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6560 planning rules 7–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scaleable OMC-R server and workstation composition 7–6. . . . . . . . . . . . . . . . . . . . .

GSM-001-103



GSM-001-103 Authorized OMC-R configurations


68P02900W21-G


7–1

Authorized OMC-R configurations

Introduction

The purpose of this chapter is to enable the customer to correctly select the items thatconstitutes an OMC-R Scaleable system, depending on their current configuration.

Terminology

In order to avoid confusion, certain terms used are described. These are not mutuallyexclusive and may be combined.

Expansion

This is where the system size is increased, usually to improve capacity (for example,from low-end to high-end).

Upgrade

This is where the software is upgraded (for example, GSR3 to GSR4). There may be anassociated hardware upgrade at the same time.

Capacity

The OMC-R is capable of supporting the following:

Table 7-1 Capacities

OMC-R TCH NE

Low-end < 5,000 16

High-end > 5,000 120

In calculating the capacity of the OMC-R; whichever limit is reached first (traffic channel(TCH) or network element (NE)) will determine the size of the OMC-R.

GSM-001-103Authorized OMC-R configurations




Planning an OMC-R configuration involves the following steps:

1. Select the appropriate server.

2. Select the appropriate level of initial program load (IPL) software.

3. Select the ancillaries according to the country of use.

4. Choose the appropriate data communications interface.

5. Select the quantities of optional items required.

6. Ensure that the order quantities are correct according to the product structure.

7. Expand software maintenance program, as required.

Assumptions

Certain assumptions have been made which may not reflect the actual circumstances foreach configuration. the assumptions made are as follows:

� A Low-end to High-end hardware expansion configuration will require the IPLs tobe at Low-end, as a minimum.

1. The server at GSR4 will include the MIB functionality.2. The Codex 6560 is now known as 6560 Multi Protocol Router (MPR).3. The 6560 MPR is software configurable for either 75 ohms or 120 ohms.

NOTE



68P02900W21-G


7–3

Example

Table 7-2 is an example of an order for a Low-end system, with two MMIs as an option,using UK server country kit, a new 6560 MPR, an OMC-R Map 1 and an IPL of 2,500TCH.

Table 7-2 Example order

Order number Equipment Quantity

SWDN5025 Server hardware, Low-end 1

SWDN5027 OMC-R Scaleable IPL 0 – 499 TCH 1

SWDN5028 OMC-R Scaleable IPL 500 –1000 TCH 1

SWDN5029 OMC-R Scaleable IPL 1000 – 2500 TCH 1

SWLN3602 MMI workstation hardware 2

SWDN5039 Thinnet ethernet adapter kit 1

SWDN4894 Sunlink HSI interface 1

SWLN3567 6560 MPR (30 timeslots) 1

SWDN5051 Server country kit(modem, keyboard, power cord)

1

SWDN4740 OMC-R Map 1 1

EUR8880 OMC-R 1

6560 planningrules

Consult your Product Manager or Motorola local office regarding the availableoptions.

NOTE

The 6560 configuration has been standardized as much as possible so that it forms thebasic building block for datacomms. In order to expand the datacomms capability;multiply 6560s are connected in a ring. In addition a couple of simple optional items havebeen added. Each 6560 can support only 30 timeslots.

Figure 7-1 and Figure 7-2 shows the various standard configurations and interconnectionof multiple 6560s. The connections between the HSIs and the 6560s vary according toquantity. The 6560s are connected in a ring using ports 1 and 3. Any of the E1 timeslotscan be patched to any connected 256 kbit/s HSI port.

Each 6560 can only support 30 timeslots across its two E1 ports.

NOTE




High-endOMC-R

SINGLE 6560

HSI 1

HSI 2

6560

DUAL 6560

3 x 6560

High-endOMC-R

HSI 1

HSI 2

6560

6560

Port 1

Port 3

30 T/S2 x E1

60 T/S4 x E1

High-endOMC-R

HSI 1

HSI 2

6560

656090 T/S6 x E1

6560

Figure 7-1 6560 MPR configurations (Part 1)



68P02900W21-G


7–5

4 x 6560

5 x 6560

High-endOMC-R

HSI 1

HSI 2

6560

6560

120 T/S8 x E1

6560

6560

High-endOMC-R

HSI 1

HSI 2

6560

6560

150 T/S10 x E16560

6560

6560

Figure 7-2 6560 MPR configurations (Part 2)




Scaleable OMC-Rserver andworkstationcomposition

Table 7-3 lists the various elements and quantities of the Low-end and High-endScaleable OMC-R configurations.

Table 7-3 Scaleable OMC-R server composition

Standard (mandatory) Low-end(Qty)

High-end(Qty)

Server hardware Low-end 1 1

OMC-R (must be ordered) 1 1

Sun scaleable IPLs(either additive to the required capacity or full capacity)

1 + 1 +

Sunlink HSI interface and cables (varies according topacket switch)

1 2

Server country kit (as appropriate for country of use) 1 1

Table 7-4 lists the various optional elements and quantities of the Low-end and High-endScaleable OMC-R configurations.

Table 7-4 Scaleable OMC-R options

Options Low-end(Qty)

High-end(Qty)

Expansion kit

Low-end to High-end TCH expansion kit (Hardwareonly)

1 N/A

MMI workstations Up to 4 Up to 10

MMI workstation hardware 1 per 1 per

MMI workstation software (as above) 1 per 1 per

MMI workstation country kit(as appropriate for country of use)

1 per 1 per

MMI workstation remote operation kit 1 per 1 per

Map

OMC-R Map (Details required from customer) 1 1


68P02900W21-G


i

Chapter 8

Planning exercise

GSM-001-103



GSM-001-103


68P02900W21-G


iii

Chapter 8Planning exercise i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Order creation 8–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 8–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Initial requirements 8–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Requirements 8–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The exercise 8–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 8–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Determine the hardware requirements for BTS 2 8–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 8–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cabinet 8–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Summary 8–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Determine the hardware requirements for BTS 10 8–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 8–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cabinet 8–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Receiver requirements 8–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transmitter combining requirements 8–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Summary 8–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Determine the hardware requirements for the BSC 8–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 8–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Summary 8–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Determine the hardware requirements for the RXCDR 8–15. . . . . . . . . . . . . . . . . . . . . . . . . . . MSI requirements 8–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transcoder requirement 8–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Link interface 8–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC2 requirement 8–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . KSW requirement 8–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . KSWX requirement 8–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GCLK requirement 8–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CLKX requirement 8–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PIX requirement 8–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BBBX requirement 8–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LANX requirement 8–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Power supply 8–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Summary 8–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Determine the hardware requirements for the OMC-R 8–18. . . . . . . . . . . . . . . . . . . . . . . . . . . OMC-R example 8–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Determine the hardware requirements for the GPRS PCU 8–20. . . . . . . . . . . . . . . . . . . . . . . .

Calculations using alternative call models 8–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 8–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Parameters used in calculations 8–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Determine the number of CCCHs per cell 8–27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Determine the number of SDCCHs per cell 8–28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Determine the number of GPROC2s 8–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GSM-001-103





68P02900W21-G


8–1

Chapter overview

Introduction

This chapter is a planning exercise designed to illustrate the use of the rules andformulae provided in Chapter 3, BSS cell planning; Chapter 4, BTS planning steps andrules; Chapter 5, BSC planning steps and rules; Chapter 6, RXCDR planning steps andrules and Chapter 7, OMC-R planning steps and rules.

The tables of required equipment in this chapter list only the major Motorola supplieditems. Equipment not covered in these examples includes: cable, external powersupplies and air conditioning equipment. Consult the appropriate Motorola local office forassistance in ensuring that all necessary items are purchased.


� Order creation.

� The initial requirements for the planning exercise using the standard call model.

� A planning exercise using the standard call model.

� A planning exercise using alternative call models.

� Determining the hardware requirements for the GPRS PCU.

GSM-001-103Order creation



Order creation

Introduction

The following BTS and OMC-R examples are compiled using Tables referenced in theGSM Ordering Manual (68P02900W20).

Determine if the site is to operate in an EGSM900 network or a DCS1800 network.Answer the following four questions and refer to the appropriate group of reference tables

Question Options Frequency Table reference

What type of environmentis required?

Indoor

Outdoor

Is a Macrocell productrequired?

Horizonmacro

M-Cell6 (indoor)

M-Cell6 (indoor)

M-Cell6 (indoor)

M-Cell6 (outdoor)

M-Cell6 (outdoor)

M-Cell6 (outdoor)

Horizonmicro

M-Cell2 (indoor)

M-Cell2 (indoor)

M-Cell2 (outdoor)

M-Cell2 (outdoor)

1800

900

1800

Dual

900

1800

Dual

900

900

1800

900

1800

Information available innext issue

Table 1 to Table 28

Table 101 to Table 124










Is a Microcell productrequired?

Horizonmicro 900/1800 Table 263 to Table 267

Is a Wireless enterpriseproduct required?

M-Cellaccess 900/1800 Table 274 to Table 281

GSM-001-103 Initial requirements


68P02900W21-G


8–3

Initial requirements

Requirements

In the area of interest, a demand analysis has identified the requirement for 11 BTSs withthe busy hour Erlang requirement shown in column two of Table 8-1.

Column three of Table 3-3 or Table 3-4 (depending on position in location area) in theCapacity calculations section of Chapter 3 provides the maximum Erlang capacity for agiven number of carriers at 2% blocking. Column one of the same tables lists thenumber of carriers (RTF) required; column three of Table 8-1 lists this information.

If other blocking factors at the air interface are required, the number of Erlangs forcolumn three of Table 3-3 or Table 3-4 in the Capacity calculations section of Chapter 3can be found by reference to standard Erlang B tables for the number of traffic channelsin column two of Table 3-3 or Table 3-4 in the Capacity calculations section of Chapter3 at the required blocking factor.

Table 8-1 Busy hour demand and number of carriers

BTS No Erlangs Antenna configuration

1 6 Omni 2

2 5 Omni 2

3 2 Omni 1

4 5 Omni 2

5 14 Omni 3

6 10 Omni 3

7 5 Omni 2

8 2 Omni 1

9 5 Omni 2

10 20/20/20 Sector 4/4/4

11 5 Omni 2

Total 119 32 carriers

GSM-001-103Initial requirements



By reference to a frequency planning tool it is possible to assign adequate frequencies tosupport the BTS antenna configurations of Table 8-1. Based on this, initial planning ofthe network gives the topology shown in Figure 8-1.

BSC

BTS 2

BTS 3

BTS 4

BTS 10

BTS 11

BTS 5

BTS 6

BTS 7 BTS 9

BTS 8

BTS 1

RXCDR MSC

OMC-R

Figure 8-1 Network topology

GSM-001-103 The exercise


68P02900W21-G


8–5

The exercise

Introduction

In order to illustrate the planning steps, the hardware requirement for BTS 2 and BTS 10will be calculated, followed by the calculation to produce the hardware requirement forthe BSC, RXCDR, and the OMC-R. Where parameters are required for the databasegeneration they are noted.

The calculations for the hardware capacity use the standard call model given in:

� Chapter 3: BSS cell planning.

� Chapter 4: BTS planning steps and rules.

� Chapter 5: BSC planning steps and rules.

� Chapter 6: RXCDR planning steps and rules.

� Chapter 7: OMC-R planning steps and rules.

GSM-001-103Determine the hardware requirements for BTS 2



Determine the hardware requirements for BTS 2

Introduction

From Figure 8-1 and Table 8-1 it can be seen that BTS 2 is required to have two RFcarriers in an omni configuration to carry a peak demand of five Erlangs.

Cabinet

From the site requirements and the potential future expansion it can be determined thatthis site should be built using an M-Cell6 indoor cabinet. Reference should be made tothe Motorola local office.

Main site number

Reference to Table 8-2 indicates that the appropriate order number for an M-Cell6Omni 2 GSM900 is SWUF2941.

Interface option

Reference to Table 8-2 indicates that, for an E1 120 ohm interface, order numberSWLN2923 is required.

Power redundancy

Reference to Table 8-3 indicates that, for a one cabinet site, order number SWLN2910 isrequired.

Duplexing

Only two antennas will be used on this site, so we need to specify duplexing. Referenceto Table 8-3 indicates that, for a one cabinet site, order number SWLF2650 is required.This duplexer will be fitted on the top panel of the site cabinet.

Digital redundancy

It is not considered that the purpose of this site justifies the expense of digitalredundancy.

Alarm inputs

More that eight alarm inputs are not required, so nothing is needed here.

Memory

Requirement is to have non-volatile code storage and the ability to download code inbackground mode. Reference to Table 8-3 indicates that, for a one cabinet site, ordernumber SWLN4839 is required.

Database option

Reference to Table 8-3 indicates that, for a database, order number EUR8888 isrequired.

GSM-001-103 Determine the hardware requirements for BTS 2


68P02900W21-G


8–7

Summary

The equipment required, and an example of customer order creation for an M-Cell6outdoor (900 MHz) configuration, to implement BTS 2 is listed in Table 8-2 and Table 8-3.

Table 8-2 Customer ordering guide 900 MHz (M-Cell6 indoor)

Question Compulsory � Table reference Selection

Voltage used +27 V dc

–48/60 V dc

110/240 V ac

�

How many cells arerequired?

1

2

3

�

How many carriers arerequired per cell?(RF configuration)

1

2

3

4

5

6

7

8

�

4 to 11 SWUF2941

How many cabinets arerequired for the RFconfiguration?

1

2

3

4

�

What type of combiningis required?

CBF (Hybrid)

CCB (Cavity)

3 I/P CBF

Air

�

What line interface isrequired?

T43 (E1)(75 ohm)

BIB (E1)(120 ohm)

BIB (T1)(120 ohm)

� 12 SWLN2923




Table 8-3 Customer ordering guide 900 MHz (M-Cell6 indoor)

Question Options � Table reference Selection

Is link redundancyrequired?

Yes

No �

13

Is digital redundancyrequired?

Yes

No �

14

Is power redundancyrequired?

Yes

No

� 15 SWPN2910

Is duplexing required? Yes

No

� 16 to 20 SWLF2650

Is a high powerduplexer shelf and/orexternal rack required?

Yes

No �

21

Are 16 way alarm inputsrequired?

Yes

No �

22

Is a memory cardrequired?

Yes

No

� 23 SWLN4839

Is database required?(Provided by localoffice)

Yes

No

� 24 EUR8888

Is ac battery backuprequired?

Yes

No �

25

Select ac battery boxoptions?

Yes

No �

26

Is –48 V power supplymodule (APSM)required?

Yes

No �

27

Is Comms power supplymodule (CPSM)required?

Yes

No �

28



68P02900W21-G


8–9

Determine the hardware requirements for BTS 10

Introduction

From Figure 8-1 and Table 8-1 it can be seen that BTS 10 is required to have 12 RFcarriers in a sector 4/4/4 configuration to carry a peak demand of 20 Erlangs per sector.

Cabinet

From the site requirements and the potential future expansion it can be determined thatthis site will be contained in two or three Horizonmacro cabinets.

Receiverrequirements

A two cabinet solution and a three cabinet solution are provided below.

Two cabinet solution

Each cabinet will have four carriers of a sector plus two carriers of a shared sector. TwoSURF modules will support the four carriers in each sector. The shared sector will besupported by inter-connecting the SURF in the Master cabinet to the SURF in theExtender cabinet.

Three cabinet solution

Each cabinet will be dedicated to a sector, allowing for easy expansion.

Transmittercombiningrequirements

A two cabinet solution and a three cabinet solution are provided below.

Two cabinet solution

Each sector requires two DCF modules. The shared sector will have one DCF modulesin the Master cabinet and the other DCF in the Extender cabinet.

Three cabinet solution

Each cabinet will be dedicated to a sector which requires one DDF and HCU modules.




Summary

The equipment required, and an example of customer order creation for a two cabinetHorizonmicro indoor (1800 MHz) configuration, to implement BTS 10 is listed in Table 8-4and Table 8-5.

Table 8-4 Customer ordering guide 1800 MHz (Horizonmicro indoor)


Voltage used +27 V dc

–48/60 V dc

240 V ac �

How many cells arerequired?

1

2

3 �

How many carriers arerequired per cell?(RF configuration)

1

2

3

4

5

6

7

8

�

How many cabinets arerequired for the RFconfiguration?

1

2

3

4

�

What type of combiningis required?

DCF (Hybrid)

DCF & Air

TDF

DDF

DDF & HCU

DDF, HCU &Air

DDF & Air

�

What line interface isrequired?

T43 (E1)(75 ohm)

BIB (E1)(120 ohm)

�

The Horizonmicro product ordering information will become available in thenext issue of this manual.

NOTE



68P02900W21-G


8–11

Table 8-5 Customer ordering guide 1800 MHz (Horizonmicro indoor)


Is digital redundancyrequired?

Yes

No

�

Is power redundancyrequired?

Yes

No �

Is an extra line interfacerequired?

Yes

No �

Are 16–way alarminputs required?

Yes

No �

Is a memory cardrequired?

Yes

No

�

Is a stacking bracketrequired?

Yes

No

�

Is battery backuprequired?

Yes

No

�

Is database required?(Provided by localoffice)

Yes

No

�

The Horizonmicro product ordering information will become available in thenext issue of this manual.

NOTE

GSM-001-103Determine the hardware requirements for the BSC



Determine the hardware requirements for the BSC

Introduction

From Figure 8-1 and Table 8-1 it can be seen that this BSC controls 11 BTSs with 32carriers in 13 cells to carry a peak demand of 119 Erlangs.

BSC to BTS Links

Reference to Figure 8-1 shows that the number of links connected from the BTS to theBSC is four.

BSC to MSC Links

Reference to standard Erlang B tables shows that 119 Erlangs at 1% blocking requires138 traffic channels.

One OML link, one XBL link and one C7 signalling link are required. The number oftrunks required is given by:

((1 � 1) � (1 � 1) � (1 � 1) � (138�4))�31 � 1.3

This value should be rounded up to 2.

Transcoder requirement

None required, remote transcoding.

MSI requirement

Minimum number of MSIs required is given by:

(4 � 2)�2 � 3

Line interface

Depending on the interface standard (balanced or unbalanced) used, one BIB or one T43is adequate for three MSIs.

GPROC2 requirement

GPROC function requirements are listed in Table 8-6.

Table 8-6 GPROC2s required at the BSC

Function Number required

BSP 1

LCFs for MTLs 1

LCFs for RSLs 1

Optional GPROC requirements

Redundant BSP, CSFP 1

Redundant LCP 1

Total GPROC2s 3+2

The notation n + m means that n items are required plus m for redundancy.

NOTE

GSM-001-103 Determine the hardware requirements for the BSC


68P02900W21-G


8–13

KSW requirement

Device timeslot requirements are listed in Table 8-7.

Table 8-7 BSC timeslot requirements

Device Number required

GPROC2s 5*32 = 160

XCDR None

MSI 3*64 = 192

Total timeslots 352

Therefore the BSC can be accommodated in one BSU shelf and one KSW is required.

KSWX requirement

The BSC is contained in one shelf so there is no requirement for a KSWX.

GCLK requirement

One GCLK per BSC is required plus one for redundancy.

CLKX requirement

The BSC is contained in one shelf so there is no requirement for a CLKX.

PIX requirement

The number of PIX boards required depends on the number of external alarms that arerequired. Use one for this example.

BBBX requirement

One BBBX is required in each shelf.

LANX requirement

An adequate number of LANXs are provided for non redundant operation. A redundantLAN requires one additional LANX per cabinet.

Power supply

Depending on the power supply voltage two EPSM plus one for redundancy or two IPSMplus one for redundancy will be required.

GSM-001-103Determine the hardware requirements for the BSC



Summary

The equipment required to implement the BSC is listed in Table 8-8.

Table 8-8 Equipment required for the BSC

Equipment Order Number Number required

BSSC2 cabinet SW1037 1

BSU shelf SWLN4653 1

MSI SLN7134 3

BIB or T43 SWLN4024/SWLN4025 1

GPROC2 SGLN4293 3+2

KSW SLN7131 1+1

GCLK SLN7130 1+1

PIX (provides up to 8 externalalarms)

SLN7135 1

BBBX SWLN4101 1

LANX SLN7138 1

EPSM/IPSM (+27 V)

(–48 V)

SWLN4100/SWPN1021

SWLN4098/SWPN1020

2+1


NOTE

GSM-001-103 Determine the hardware requirements for the RXCDR


68P02900W21-G


8–15

Determine the hardware requirements for the RXCDR

MSI requirementsIt is necessary to provide enough MSIs to communicate on the links to the BSC, for E1links the traffic connection comes directly from the transcoder card.

Links to the BSC

From the calculation in the Section BSC to MSC links above it can be seen that there aretwo links to the BSC.

Links to the OMC-R

From the topology, see Figure 8-1, it can be seen that a link to the OMC-R from theRXCDR must be provided.

Number of MSIs required

From the foregoing it can be seen that three E1 links are required.

The number of MSI cards is given by:

3�2 � 1.5


Transcoderrequirement

From the calculation in the Section BSC to MSC links above it can be seen that 138traffic channels and two C7 links are required.

The number of transcoder cards is given by:

138�30 � 5

This applies to either XCDR or GDP cards.

Link interfaceFrom the MSI requirements it can be seen that two E1 links to the BSC and one to theOMC-R are required. From the Transcoder requirements it can be seen that a furtherfive E1 links are required. A total of eight E1 links are required.

The number of BIB/T43s is given by:

8�6 � 1.3


GPROC2requirement

One GPROC2 is required, plus one for redundancy.

KSW requirementFrom the number of MSIs, transcoders and E1 links it can be seen that the total numberof timeslots is given by:

2 * 16 � 5 * 16 � 2 * 64 � 240

One KSW is required, plus one for redundancy.

GSM-001-103Determine the hardware requirements for the RXCDR



KSWXrequirement

The RXU is contained in one shelf so there is no requirement for a KSWX.

GCLKrequirement

One GCLK is required plus one for redundancy.

CLKXrequirement

The RXU is contained in one shelf so there is no requirement for a CLKX.

PIX requirement

The number of PIX boards required depends on the number of external alarms that arerequired. Use one for this example.

BBBXrequirement

One BBBX is required in each shelf.

LANXrequirement

An adequate number of LANXs are provided for non redundant operation. A redundantLAN requires one additional LANX per cabinet.

Power supply

Depending on the power supply voltage two EPSM plus one for redundancy or two IPSMplus one for redundancy will be required.

GSM-001-103 Determine the hardware requirements for the RXCDR


68P02900W21-G


8–17

Summary

The equipment required to implement the RXCDR is listed in Table 8-9.

Table 8-9 Equipment required for the RXCDR

Equipment Order Number Number required

BSSC2 cabinet SW1037 1

RXU shelf SWLN2195 1

MSI SLN7134 2

XCDR/GDP-E1 SLN7803/SWLN4485 5

BIB or T43 SWLN4024/SWLN4025 2

GPROC2 SGLN4293 1+1

KSW SLN7131 1+1

GCLK SLN7130 1+1

PIX (provides up to 8 externalalarms)

SLN7135 1

BBBX SWLN4101 1

LANX SLN7138 1

EPSM/IPSM (+27 V)

(–48 V)

SWLN4100/SWPN1021

SWLN4098/SWPN1020

2+1


NOTE

GSM-001-103Determine the hardware requirements for the OMC-R



Determine the hardware requirements for the OMC-R

OMC-R example

The following is an example of customer order creation for an OMC-R systemconfiguration.

� Basic configuration items:

Low-end.

Low-end server hardware.

Sunlink HSI interface to 6560.

OMC-R.

OMC-R server country kit (UK)

� Optional items:

Map 1.

Local MMI workstation.

MMI workstation country kit (UK).

6560 MPR (30).

Table 8-10 Customer ordering guide for the OMC-R


How many trafficchannels (TCH) arerequired?

Software

Hardware

Low-end

High-end

�

�

301/302

303

304

SWDN5035

SWDN5025

SWDN4894

Select keyboard,power cord andmodem as required?

Countryspecific kit

� 305

306

307

GPDOMCX3507

GPDOMCX317

SWDN5051

GSM-001-103 Determine the hardware requirements for the OMC-R


68P02900W21-G


8–19

Table 8-11 Customer ordering guide for the OMC-R


Are Local workstationsrequired?

Yes

No

� 308 SWLN3602

Are Remoteworkstations required?

Yes

No �

309

Select MMI keyboardand power cord.

Countryspecific kit

� 310

311

GPDOMCX3507

GPDOMCX317

Is a Multi ProtocolRouter (MPR) required?

Yes

No

� 312 SWDN5050

Select MPR powercord.

Yes

No

� 313 GPDOMCX317

Are optional items forMPR required?

Yes

No �

314

Are Maps required? 1

3

6

� 315 SWDN4740

Is third partydocumentationrequired?

Yes

No �

316

Are any optionalsoftware featuresrequired?

Yes

No �

317

GSM-001-103Determine the hardware requirements for the GPRS PCU



Determine the hardware requirements for the GPRS PCUThis section provides an example of the PCU hardware provisioning process and the linkprovisioning process associated with adding a PCU to the BSC as shown in Figure 8-2.For the provisioning of the BSC hardware, the network planner should follow the releventplanning rules for adding additional E1 interface hardware in support of the GDS andGSL links. The provisioning of the SGSN hardware is described by the example in thenext section.

BSC PCU SGSN

BTS

GDS

GBLGSL

GSM + GPRS E1s

1 to 4 E1s1 or 2 E1s

1 to 9 E1s

Figure 8-2 PCU equipment and link planning

The network planner would use the following process in order to provision a BSS with 10sites consisting of 20 cells with one GPRS carrier per cell.

Step 1: choose a cell RF plan

Use the 1 x 3 2/6 and 1 x 1 2/18 hopping tables, in Chapter 3, to determine whatthe values to use for CS rate and BLER for the chosen cell RF plan. For thisexample, use for the 1x3 2/6 hopping RF plan.

Step 2: determine number of GPRS carrier timeslots

Use Equation 1 (see Chap 3) to determine the number of GPRS timeslots thatare required on a per cell basis. In order to use Equation 1 , the network plannershould have the expected cell load in kbit/s. For this example, assume each cell isbeing planned to handle 30 kbit/s. Equation 1 evaluates to 5.8 timeslots; soprovision 6 timeslots. Therefore, the mean load is handled by 3 active timeslots,and 3 timeslots are considered standby timeslots.

GSM-001-103 Determine the hardware requirements for the GPRS PCU


68P02900W21-G


8–21

Step 3: calculate the number of GDS E1 links

For this calculation, a conservative provisioning approach would be to provisionone GDS TRAU E1 per PRP board. Each PRP board can process 30 activetimeslots and 90 monitored timeslots. Using the number of mean PDCHs =3 fromstep 2, the number of PRPs required to serve 20 cells is:

(3 active timeslots per Cell) * (20 cells per BSC) / (30 active timeslots per PRP) =2 PRPs.

These 2 PRPs have more than enough capacity to handle the additional 3 standbytimeslots per cell. Using the conservative provisioning rule of one GDS TRAU E1per PRP, we would provision 2 GDS TRAU E1s.

Refer to Chapter 3 for the PCU provisioning rules. A more aggressive GDS TRAUE1 provisioning approach can be taken where 60 Active and 64 Standby timeslotsare provisioned on only one GDS TRAU E1. The PCU load balancing softwarewould distribute the load over the two PRP boards.

The advantage of the more aggressive provisioning approach is that one less E1would need to be provisioned at the BSC. The disadvantage is that if the one GDSTRAU E1 were to fail, 100% of the PCU service would be lost.

Step 4: calculate the PCU hardware to support the PCU traffic of 60 activetimeslots and 2 GDS E1s

For the calculation bear the following in mind:

– Qty 2 PRP boards, 1 PRP board per GDS E1 link.

– Qty 1 PICP board, 1 PICP board per 4 GDS TRAU links (2 linksprovisioned).

– Qty 1 MPROC board, 1 MPROC board per PCU shelf.

– Qty 1 PCU shelf with alarm board and 3 power supply/Fan assemblies, 1PCU shelf per 9 PRP boards.

– Qty 1 PCU cabinet, 1 PCU cabinet per 3 PCU shelves.

Step 5: calculate the number of GBL links

The number of GBL E1 links is directly related to the number of active timeslots,being provisioned between the BSC and the PCU. In this example 60 activetimeslots are required. One GBL E1 can carry the equivalent of 150 activetimeslots. This figure includes the GBL signalling traffic and the GPRS packet datatraffic including protocol overhead. Therefore, the number of GBL E1 links requiredis:

(60 active BSC-PCU timeslots)/ (150 active timeslots per GBL E1) = 0.4 E1s.

This answer would be rounded up to 1 E1 without redundancy unless a fractionalE1 is available for use. If a fractional E1 is available, it is not necessary to roundup to the nearest integer value for the number of E1s to specify.

Step 6: calculate the number of GSL links:

Use Equation 11 (see Chap 5) to calculate how many 64kbits/sGSL links arerequired. For this example, the number of active timeslots is 60. EvaluatingEquation 11 and the supporting expressions results in two 64 kbit/s GSL linksbeing required, after rounding up to the nearest integer value.

The significant intermediate values that are used to evaluate Equation 11 areshown in Table 8-12.




Table 8-12 Significant intermediate values to evaluate Equation 11

Equation Parameter Location

Equation 11 No_GSL_TS= 15,200/15000 Chapter 5

Equation 13 No_Imm_Assign= 12,000 Chapter 5

Equation 14 GPRS_Page= 1,200 Chapter 5

Equation 15 Stat_msg= 2,000 Chapter 5

Step 7: recalculate the number of PICP boards required

Now that the number of GDS, GBL, and GSL E1 links have been calculated, makesure that there are a sufficient number of PICP boards to cover the GBL and GSLE1 links, and to satisfy the 1-to-4 ratio of GDS TRAU E1s to PICP boards. ThePCU hardware calculation in step 4 calculated the number of PICP boards basedonly on the ratio of PICP boards to PRP boards. This step takes into account thenumber of E1 links terminated on the PICP boards for the GBL and GSL E1 links.A PICP board can terminate both GBL and GSL links on the board, but not on thesame PMC module. Each PICP has two PMC modules.

In step 5 it was determined that 1 E1 link is required for the GBL. Each PICP canterminate up to 4 GBL links. Therefore, 1/4 of a PICP is required for the GBL E1links.

In step 6 it was determined that 1 E1 link is required for the GSL. Each PICP canterminate up to 2 E1 GSL links and up to 12 GSL 64 kbit/s timeslots distributedover two E1s. Note that there is a limit of 2 GSL E1s per PCU. Therefore, 1/4 of aPICP is required for the GSL E1 link.

Reviewing the GBL and GSL E1 link requirements, we can see that one PICP issufficient to handle the link provisioning requirements.

Step 8: calculate the increased data traffic load on the E1s between theBSC and BTSs

It is assumed that the GPRS traffic is in addition to the existing circuit switchedtraffic. In step 2 it was determined that 6 timeslots would be required for thecombined active plus standby GPRS timeslot traffic on a per cell basis. The activeplus standby timeslots should be allocated as reserved. Therefore, 12 more16kbits/stimeslots are required on a per-BTS-site basis, 2 cells per site, in order tocarry the GPRS traffic. A decision can be made at this stage of the provisioningprocess on how to allocate the GPRS carrier timeslots. That is, they are reservedor switchable . If GSM circuit switched statistics are available, they could bereviewed to aid in this decision. Refer to the section in the planning guide thatdiscusses the tradeoffs of using reserved and switchable timeslots.

Since a whole carrier of 8 timeslots was added to each BTS cell in support ofGPRS, it might be advantageous to configure the E1 to carry the traffic for theadditional 2 timeslots. If these two timeslots are provisioned as switchable , bothGPRS and GSM circuit switched traffic could benefit from this additional capacity.

GSM-001-103 Determine the hardware requirements for the GPRS PCU


68P02900W21-G


8–23

Step 9: calculate the increased signalling traffic load (RSL load) on the E1sbetween the BSC and BTSs:

The BTS combines the additional signalling load for the GPRS data traffic with theexisting circuit switched traffic load. This results in an additional load on theexisting RSL links between each BTS and the BSC.

The additional load on the RSL for GPRS is based on the evaluation of Equation6 (see Chap 5) and supporting equations. For 60 active timeslots, two 64 kbit/sRSL channels would be required, after rounding up to the nearest integer value tosupport the GPRS portion of the network.

The network planner should calculate the RSL load for the GSM circuit switchedportion of the network, and then add the the GSM number of RSLs to the GPRSrequirements in order to determine the total number of RSL links to provision perEquation 6 . The GSM RSL calculation should be performed with 64 kbit/s RSL inorder to be consistent with the GPRS calculation.

Step 10: calculate the increased load due to GPRS traffic on the commoncontrol channel at each BTS cell

Equations 19 to 25 will be found in Chapter 3.

NOTE

Use Equation 19 (see Chap 3) for this calculation. The BTS combines theadditional control channel load for the GPRS data traffic with the existing circuitswitched traffic load onto the Common Control CHannel (CCCH). The networkplanner needs the expected paging rate and the access grant rate in order tocalculate the number CCCH blocks needed to support the additional GPRS trafficload. This calculation should be performed using the guidelines given in the GPRScontrol channel provisioning section of the planning guide. Use Equation 21(see Chap 3) to determine the paging load, and use Equation 24 (see Chap 3) todetermine the access grant load. Substituting the value 1.5 (No_GPRS_Pages) forthe number of pages per second per cell and the value 3 (λburst_GPRS) for thenumber of bursts per second per cell, evaluates to 2.9 CCCH blocks required insupport of GPRS. This most likely means that the network planner cannot use acombined BCCH. The GSM circuit switched signalling load is in addition to the 2.9CCCH blocks required for GPRS.

Step 11: BSC provisioning impact

The BSC may require additional hardware in order to support the addition of theGPRS network traffic. For BSC provisioning rules, the relevant planning rulesshould be consulted.

The BSC may require more E1 terminations in support of the additional E1 links tothe PCU and in support of the additional GPRS traffic over the BTS-to-BSCinterface. In this example, two E1s were added for the GDS links and one E1added for the GSL link.

The BSC LCF GPROC2 processor load is increased by the volume of GPRSsignalling traffic. The BSS planning rule for LCF provisioning in Equation 26 (seeChap 5) should be used. Scaling the paging load of a maximally-configured PCUby 25 % would give 3 pages/second to use as the PGPRS value. Substituting theother values into Equation 26 the answer is 0.7 LCF GPROC2.

The network planner may choose to add an additional LCF GPROC2, or toexamine the GSM circuit switched provisioning to see whether an existing LCFGPROC2 could handle this additional load.




Step 12: BTS provisioning impact

The BTS requires one carrier per cell to be provisioned as a GPRS carrier. Addinga GPRS carrier to a cell may require that another DHP processor board is addedto the BTS.

The relevant planning rules should be consulted in order to provision the BTShardware, including the addition of DHP processor board to the BTS.

Step 13: OMC-R provisioning impact

The OMC-R is impacted primarily through the additional statistics generated by thePCU. The BSC merges the PCU statistics with the rest of the BSS statistics foruploading to the OMC-R over the 64kbits/s X.25 link. No change in this linkprovisioning is required.

GSM-001-103 Calculations using alternative call models


68P02900W21-G


8–25

Calculations using alternative call models

Introduction

This section is provided to assist users for whom the planning models given in Chapter 4,Chapter 5 and Chapter 6 are inappropriate. Where this is the case, the various planningtables that are used in the example above will not be correct and the actual values willneed to be derived using the formulae given in Chapters 4, 5, and 6. These necessarycalculations are demonstrated below.

Parameters usedin calculations

It is assumed that the BSS consists of a BSC supporting 360 MSC to BSC trunks, with420 TCHs (minus the channels required for control channels) distributed among 31remote BTSs. Each BTS is an omni cell with four CTU/TCUs each containing 32 TCHs(minus the channels required for control channels). The signalling traffic from each BTSis assumed to be identical. Calculations will be made for the number of:

� CCCHs required per BTS cell.

� SDCCHs required per BTS cell.

� MSC to BSC links required.

� BSC to BTS links required.

� GPROCs required in the BSC.

Redundancy is not considered in the calculations. The sample signalling traffic modelparameters that will be used for the example are given in Table 8-13.

GSM-001-103Calculations using alternative call models



Table 8-13 Parameters for planning example




Ratio of handovers per call H = 2.5



Location update factor: non-border location area L = 2

Paging rate per second P = 3


Number of BTSs B = 10

Number of cells (sectors) C = 30

Number of TCHs n = 480

Percent link utilization U = 20%

Number of radio carriers R = 60

Number of MSC to BSC trunks N = 360

Number of traffic channels per cell n/C = 16

Time duration for location updates TL = 4 seconds

Time duration for SMSs TS = 6 seconds

Time duration for call set ups TC = 5 seconds


Probability of blocking for TCHs PB–TCH < 2%

Probability of blocking for SDCCHs PB–SDCCH < 1%

CCCH utilization UCCCH = 0.33



68P02900W21-G


8–27

Determine thenumber ofCCCHs per cell

The text that follows should be read in conjunction with the material in the Controlchannel calculations section of Chapter 3. To determine the number of CCCHs per cellproceed as follows.

Using the formulae provided in the Control channel calculations section of Chapter 3the following values can be calculated.

From the Erlang B tables the number of Erlangs, e, supported by 16 TCHs with a gradeof service (GOS) of 2% is 9.83.

From Table 8-13, the average call hold time, T, is 120 s, so the call arrival rate is givenby:

�call � e�T � 9.83�120 � 0.082

From Table 8-13, the ratio of location updates to calls, L is 2 so the location update rateis given by:

�LU � L � e�T � 2 � 0.082 � 0.164

From Table 8-13, the ratio of SMSs to calls, S is 0.1 so the SMS rate is given by:

�S � S � e�T � 0.1 � 0.082 � 0.0082

Then the access grant rate is given by:

�AGCH � �call � �LU � �SMS � 0.082 � 0.164 � 0.0082 � 0.254

From Table 8-13, the paging rate, P, is 3 so the average number of CCCH blocksrequired to support paging only is given by:

NPCH �P

(4 � 4.25) �3

(4 � 4.25) � 0.0299

The average number of CCCH blocks required to support AGCH only is given by:

NAGCH ��AGCH

(2 � 4.25)�

0.254(2 � 4.25)

� 0.049

Using a CCCH utilization figure, UCCCH, of 0.33, the average number of CCCH blocksrequired to support both PCH and AGCH is given by:

NPAGCH �

�NAGCH � NPCH�

UCCCH�

(0.0299 � 0.049)0.33

� 0.239

Assuming a 1% blocking, the Erlang B tables show that three CCCHs are required.

This can be supported by a combined BCCH with three CCCHs. No CCCH should bereserved for AGCH only, since the probability of PCH overload would be significantlyincreased; NPCH = 0.0299 so:

0.0299�0.33 � 0.091.




Determine thenumber ofSDCCHs per cell

The text that follows should be read in conjunction with the material in the Controlchannel calculations section of Chapter 3. To determine the number of SDCCHs percell proceed as follows.

Using the values calculated in the last section and from Table 8-13, The average numberof SDCCH, NSDCCH, is given by:

NSDCCH = �call � Tc � �LU � �TL � Tg� � �S ��TS � Tg�

� 0.082 � 5 � 0.164 � (4 � 4) � 0.0082 � (6 � 4) � 1.77

The number of SDCCHs to support an average number of busy SDCCHs of 1.77 withless than 1% blocking as determined by the use of Erlang B tables. When PB < 1% therequired number of SDCCHs is six. The nearest number of SDCCH blocks available iseight.

This configuration can be realized with two control channel timeslots per cell, onecombined BCCH with three CCCHs and a timeslot of eight SDCCHs.



68P02900W21-G


8–29

Determine thenumber ofGPROC2s

The following text should be read in conjunction with the material in the Capacitycalculation section of Chapter 5.

To determine the number of SDCCHs per cell, proceed as follows:

GPROC2s for MSC to BSC signalling

One MTL is required, and this can be handled by a single GPROC2.

GPROCs for layer 3 call processing and BSC to BTS signalling links

There are three steps needed to determine the number of LCP GPROC2s required tosupport the BSC to BTS signalling links (RSL) and layer 3 call processing:

1. Calculate the number of LCPs required to support the RSLs.

2. Calculate the number of GPROC2s required to support the layer 3 call processing.

3. The larger of the numbers calculated in steps 1 and 2 is the number of LCPsrequired to support the RTLs signalling links and layer 3 call processing.

Step 1

Determine the number of LCPs required to support RSLs. The GPROC2 formula will beused.

GRSL �(R � 2 * B)

120�

(60 � 2 * 10)120

� 0.66

Step 2

Determine the number of GPROC2s required to support the layer 3 call processing.

NL3 � �n

440�

B15

�C35� * � 1

2.5� � �480

440�

1015

�3035� * � 1

2.5� � 2.6

2.5� 1.04

Step 3

Take the greater of these two numbers (1.04) and round it up to 2.

Additional LCP GPROC2s for redundancy

It is recommended that an additional GPROC2 exists to act as a redundant LCP.Therefore the total number of GPROC2s required as LCPs is given by:

1 (for the MSC to BCS signalling links) + 2 (for the BTSs) + 1 (for redundancy) = 4

Total number of GPROC2s at the BSC

A GPROC2 is required for the BSP and it is recommended that an additional GPROC2exists as the redundant BSP. So the total number of GPROC2s required at the BSC isgiven by:

2 (for BSP and redundant BSP) + 4 (for the LCPs) = 6

Redundancy and CSFP requirements are additional to this.





68P02900W21-G


i

Chapter 9

Standard configuration

descriptions

GSM-001-103



GSM-001-103


68P02900W21-G


iii

Chapter 9Standard configuration descriptions i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Standard configurations 9–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 9–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Typical BSS configurations 9–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC with 24 BTS 9–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC with full redundancy 9–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transcoder 9–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Picocell configurations (M-Cellaccess) 9–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Single site 9–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Two site cabinet 9–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

One cabinet configurations 9–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with one Horizonmacro cabinet 9–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with one M-Cell6 cabinet 9–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with one M-Cell2 cabinet 9–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Two cabinet configuration 9–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with two Horizonmacro cabinets 9–13. . . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with two M-Cell6 cabinets 9–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Three cabinet configuration 9–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with three Horizonmacro cabinets 9–15. . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with three M-Cell2 cabinets 9–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Four cabinet configuration 9–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with four Horizonmacro cabinets 9–17. . . . . . . . . . . . . . . . . . . . . . . . . . . Macrocell BTS with four M-Cell6 cabinets 9–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Macrocell RF configurations 9–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview of configuration diagrams 9–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Horizonmacro cabinets 9–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-Cell6 cabinets 9–35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-Cell2 cabinets 9–98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-Cellarenamacro enclosure 9–107. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Microcell RF configuration 9–108. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-Cellarena enclosure 9–108. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GSM-001-103





68P02900W21-G


9–1

Chapter overview

Introduction

This chapter provides diagrams of the logical interconnections of the components invarious standard BSS and BTS site configurations, Picocell, Horizonmacro, and M-Cell.


� Typical BSS configurations.

� Picocell configurations (M-Cellaccess).

� One cabinet configurations.

– Horizonmacro

– M-Cell6.

– M-Cell2.

� Two cabinet configurations.

– Horizonmacro

– M-Cell6.

� Three cabinet configurations.

– Horizonmacro

– M-Cell6.

� Four cabinet configurations.

– Horizonmacro

– M-Cell6.

� Macrocell RF configurations.

– Horizonmacro

– M-Cell6.

– M-Cell2.

– Horizoncompact

� Microcell RF configuration.

– Horizonmicro.

GSM-001-103Standard configurations



Standard configurations

Introduction

The examples in this section are shown with individual antennas for transmit and receivesignals. If individual antennas are not used, duplexers will be required. However,duplexers can result in performance degradation.

For carrier redundancy the RF carrier equipment should be duplicated for each BTS.

The diagrams that follow are not intended to imply the maximum capacity nor a typicalconfiguration using that specific equipment. Rather, they are meant to highlight theconfigurations that, within the constraints of the BSS architecture, are feasible when theMacrocell hardware is deployed in a �BCU controlled BTS. The diagrams also showpossible cabinet boundaries. Cabinet designs, however, allow for a number of differentarrangements of the same configuration.

Rather than showing redundancy for all M-Cell BTS configurations, the controlredundancy is depicted only for one Horizonmacro, one M-Cell6, and one M-Cell2cabinet diagram, see Figure 9-8, Figure 9-9, and Figure 9-10.

GSM-001-103 Typical BSS configurations


68P02900W21-G


9–3

Typical BSS configurations

BSC with 24 BTS

The digital module configuration for a BSC controlling 24 BTSs is shown in Figure 9-1.

2 Mbit/s LINKS

2 Mbit/s LINKS

DUAL SERIAL BUSDUAL MCAP BUS

DUAL MCAP BUS

DUAL SERIAL BUS

BSU SHELF 1

GPROC0

DUAL IEEE LAN

DUAL TDM HIGHWAY BUS

MSI0

BTS 1

MSI1

BTS 2

MSI2

BTS 3

MSI7

BTS 12

RMTKSWX

A

GPROC3

GPROC1

GCLK

CLKX

BSSC CABINET

LCLKSWX

B

LCLKSWX

B

BTC

BTC

BTC

BSU SHELF 2

GPROC2

MSI2

MSI1

MSI0

MSI6

LCLKSWX

A

KSWB

REDUNDANT

GCLK

REDUNDANT

FIBRE OPTIC LINKS

KSWA

CLKXLCL

KSWXA

BTC

A

B

PIX

A

B

RMTKSWX

B

MSC/RXCDR

BTS15,16BTS 14BTS 13

DUAL IEEE LAN


LANXA

LANXB

LANX A

GPROC2

BTS 23, 24

GPROC 1

GPROC 0

LANX B

2.048 Mbit/s LINK INTERFACESFROM/TO MSC AND TO/FROM BTS

SITES

Figure 9-1 BSC controlling 24 BTS

GSM-001-103Typical BSS configurations



BSC with fullredundancy

The digital module configuration for a fully redundant BSC controlling 34 BTS is shown inFigure 9-2.

DUAL MCAP BUS

BSU SHELF 1

BSSC CABINET

BSU SHELF 2DUAL IEEE LAN


MSI 0

MSI1

MSI2

MSI9

BTS 16,17

EXPKSWX

A

GCLK A

CLKXLCL

KSWXB

BTC

MSC

BTS 33,34

KSWA

KSWB

REDUNDANT

CLKX LCLKSWX

A

A

B

PIX

A

B

KSWA

KSWB

REDUNDANT

BTS 2 BTS 3BTS 1

BTS 18 BTS 20BTS 19


GPROC0

BTC

LANX B

LANX A

GPROC3BTC

LANX A

LANX B

DUAL SERIAL BUS

DUAL SERIAL BUS

GPROC1

GPROC 2

GPROC 3

GCLK B

EXPKSWX

B

EXPKSWX A

EXPKSWX

B

LCLKSWX

A

LCLKSWX

BBTC MSI

0MSI

1MSI

2MSI

9

GPROC2

GPROC1

GPROC0

2.048 Mbit/s LINK INTERFACESFROM/TO MSC AND TO/FROM BTS

SITES

FIBRE OPTIC LINKS

2 Mbit/s LINKS

2 Mbit/s LINKS

DUAL IEEE LAN

DUAL MCAP BUS

Figure 9-2 Fully redundant BSC controlling 34 BTS

GSM-001-103 Typical BSS configurations


68P02900W21-G


9–5

Transcoder

The digital module configuration for a BSSC cabinet equipped to provide transcoding isshown in Figure 9-3.


DUAL SERIAL BUS

RXU SHELF 1

MSI0

MSI1

XCDR0

XCDR15

RMTKSWX

A

GCLK

CLKX

�

REMOTE TRANSCODER CABINET

LCLKSWX

BBTC

BTC

RXU SHELF 2

LCLKSWX

A

KSWB

REDUNDANT

GCLK

REDUNDANT

FIBRE OPTIC LINKS

KSWA

CLKX

LCLKSWX

A

A

B

A

B

RMTKSWX

BXCDR

15

BTC

BTC MSI0

MSI1

XCDR0

DUAL IEEE 802.5 LAN

GPROC0

LANX A

LANXA

GPROC 0

LANX B

GPROC1

DUAL MCAP BUS


DUAL IEEE LAN

LCLKSWX

B

GPROC1

LANX B

2.048 Mbit/s LINKINTERFACES FROM/TO

BSCS

2.048 Mbit/s LINKINTERFACES FROM/TO

MSC

DUAL MCAP BUS

DUAL SERIAL BUS

Figure 9-3 BSSC cabinet equipped to provide transcoding

GSM-001-103Picocell configurations (M-Cellaccess)



Picocell configurations (M-Cell access )

Single site

Optical fibre links The digital module and RF configuration for a PCC cabinet with six PCUs (RF carriers)and optical fibre links is shown in Figure 9-4.

DUAL SERIAL BUS

DUAL MCAP BUS

TO/FROM TRANSMIT/RECEIVE ANTENNA

BSC

MSIBTC

DRIM1

DRIM2

DRIM3

DRIM4

DRIX4

DRIX3

DRIX2

DRIX1

DUAL IEEE802.5 LAN

PCC CABINET

PCU1

GCLK TSWA


ONE RF CARRIERCONSISTS OF ONEDRIM, DRIX AND PCU

BTC

LANXA

A

B

BSU SHELF FIBRE OPTIC LINKS

GPROCGPROC GPROC

PCU2

PCU3

PCU4

DRIM5

DRIM6

DRIX6

DRIX5

PCU5

PCU6

LINKS FROM/TO BSC

Figure 9-4 Single BTS site with six PCUs using optical fibre links

GSM-001-103 Picocell configurations (M-Cellaccess)


68P02900W21-G


9–7

HDSL links The digital module and RF configuration for a PCC cabinet with six PCUs (RF carriers)and HDSL links is shown in Figure 9-5.

DUAL SERIAL BUS

DUAL MCAP BUS

TO/FROM TRANSMIT/RECEIVE ANTENNA

BSC

MSIBTC

DRIM1

DRIM2

DRIM3

DRIM4

HRIX4

HRIX3

HRIX2

HRIX1

DUAL IEEE802.5 LAN

PCC CABINET

PCU1

GCLK TSWA


ONE RF CARRIERCONSISTS OF ONEDRIM, HRIX AND PCU

BTC

LANXA

A

B

LOWER BSU SHELF

GPROCGPROC GPROC

PCU2

PCU3

PCU4

DRIM5

DRIM6

HRIX6

HRIX5

PCU5

PCU6

LINKS FROM/TO BSC

TOP OF CABINET

HIM-75/HIM-120 HIM-75/HIM-120 HIM-75/HIM-120

Figure 9-5 Single BTS site with six PCUs using HDSL links

GSM-001-103Picocell configurations (M-Cellaccess)



Two site cabinet

Optical fibre links The digital module and RF configuration for a PCC cabinet with 12 PCUs (RF carriers)and optical fibre links is shown in Figure 9-6.

FIBRE OPTIC LINKS

DUAL SERIAL BUS

DUAL MCAP BUS

BSC

MSIBTC

DRIM1

DRIM2

DRIM3

DRIM4

DRIX4

DRIX3

DRIX2

DRIX1

DUAL IEEE802.5 LAN

PCC CABINET

GCLK TSWA


BTC

LANXA

A

B

LOWER BSU SHELF

GPROCGPROC GPROC

DRIM5

DRIM6

DRIX6

DRIX5

LINKS FROM/TO BSC

DUAL SERIAL BUS

DUAL MCAP BUS

MSIBTC

DRIM1

DRIM2

DRIM3

DRIM4

DRIX4

DRIX3

DRIX2

DRIX1

DUAL IEEE802.5 LAN

GCLK TSWA


BTC

LANXA

A

B

UPPER BSU SHELF

GPROCGPROC GPROC

DRIM5

DRIM6

DRIX6

DRIX5

LINKS FROM/TO BSC

FIBRE OPTIC LINKS

PCU 1 to 6 PCU 7 to 12

Figure 9-6 Two BTS site with 12 PCUs using optical fibre links

GSM-001-103 Picocell configurations (M-Cellaccess)


68P02900W21-G


9–9

HDSL links The digital module and RF configuration for a PCC cabinet with 12 PCUs (RF carriers)and HDSL links is shown in Figure 9-7.

DUAL SERIAL BUS

DUAL MCAP BUS

BSC

MSIBTC

DRIM1

DRIM2

DRIM3

DRIM4

HRIX4

HRIX3

HRIX2

HRIX1

DUAL IEEE802.5 LAN

PCC CABINET

GCLK TSWA


BTC

LANXA

A

B

LOWER BSU SHELF

GPROCGPROC GPROC

DRIM5

DRIM6

HRIX6

HRIX5

LINKS FROM/TO BSC

TOP OFCABINET

DUAL SERIAL BUS

DUAL MCAP BUS

MSIBTC

DRIM1

DRIM2

DRIM3

DRIM4

HRIX4

HRIX3

HRIX2

HRIX1

DUAL IEEE802.5 LAN

GCLK TSWA


BTC

LANXA

A

B

GPROCGPROC GPROC

DRIM5

DRIM6

HRIX6

HRIX5

LINKS FROM/TO BSCUPPER BSU SHELF

PCU 9/10PCU 7/8PCU 5/6PCU 3/4PCU 1/2

HIM-75/HIM-120 HIM-75/HIM-120 HIM-75/HIM-120HIM-75/HIM-120 HIM-75/HIM-120 HIM-75/HIM-120

PCU 11/12

Figure 9-7 Two BTS site with 12 PCUs using HDSL links

GSM-001-103One cabinet configurations



One cabinet configurations

Macrocell BTSwith oneHorizon macrocabinet

The configuration shown in Figure 9-8 is an example of a one-cabinet Horizonmacro.This configuration supports six carriers.

(FORREDUNDANCY)

MCUF

NIU

22

MCUF

NIU

�BCU

22

22

22

22

22

12 12

CTU

CTU

CTU

CTU

CTU

CTU

HorizonmacroCABINET

Figure 9-8 Macrocell BTS with one Horizonmacro cabinet

GSM-001-103 One cabinet configurations


68P02900W21-G


9–11

Macrocell BTSwith one M-Cell 6cabinet

The configuration shown in Figure 9-9 is an example of a one-cabinet M-Cell6 BTS. Thisconfiguration supports six carriers.

(FORREDUNDANCY)

M-CELL6 BTS CABINET

MCU

NIU

�BCU

TCU

TCU

22

MCU

NIU

�BCU

22

TCU

TCU

22

22

TCU

TCU

22

22

FOX

12

FOX

12

12 12

Figure 9-9 M-Cell BTS with one M-Cell6 cabinet

GSM-001-103One cabinet configurations



Macrocell BTSwith one M-Cell 2cabinet

The configuration shown in Figure 9-10 is an example of a one-cabinet M-Cell2 BTS.This configuration supports two carriers.

(FORREDUNDANCY)

M-CELL2 CABINET

MCU

NIU

�BCU

TCU

TCU

22

MCU

NIU

�BCU

22

Figure 9-10 Macrocell BTS with one M-Cell2 cabinet

GSM-001-103 Two cabinet configuration


68P02900W21-G


9–13

Two cabinet configuration

Macrocell BTSwith twoHorizon macrocabinets

The configuration shown in Figure 9-11 is an example of a two cabinet Horizonmacro.This configuration supports 12 carriers. The MCUF interface to the CTUs in the secondcabinet, through an FMUX in the second cabinet.

MCUF

NIU

12

2

�BCU

12

FMUX

�BCU

CTU

CTU

CTU

2222 22

CTU

CTU

CTU

CTU

CTU

CTU

2222 22

CTU

CTU

CTU

HorizonmacroCABINET

HorizonmacroCabinet

Figure 9-11 Macrocell BTS with two Horizonmacro cabinets

GSM-001-103Two cabinet configuration



Macrocell BTSwith two M-Cell 6cabinets

The configuration shown in Figure 9-12 is an example of a two cabinet M-Cell6 BTS.This configuration supports 12 carriers. The MCUs interface to the TCUs through theFOX or the FMUX/FOX.

M-CELL6 BTS CABINET

M-CELL6BTS CABINET

MCU

TCU

TCU

TCU

TCU

TCU

TCU

NIU

FMUX

FOX

2222 2

12

212

12

2

�BCU

TCU

TCU

TCU

TCU

TCU

TCU

2222 22

12

FMUX

FOX

�BCU

Figure 9-12 Macrocell BTS with two M-Cell6 cabinets

GSM-001-103 Three cabinet configuration


68P02900W21-G


9–15

Three cabinet configuration

Macrocell BTSwith threeHorizon macrocabinets

The configuration shown in Figure 9-13 is an example of a three cabinet Horizonmacro.This configuration supports 18 carriers. The MCUFs interface to the CTUs in the othercabinets through the FMUXs.

CTU

CTU

MCUF

CTU

NIU

2222 2

12

2

2

2

�BCU

FMUX

�BCU

12

12

FMUX

�BCU

CTU

CTU

CTU

CTU

CTU

CTU

2222 22

CTU

CTU

CTU

CTU

CTU

CTU

2222 22

CTU

CTU

CTU

HorizonmacroCABINET

HorizonmacroCABINET

HorizonmacroCABINET

Figure 9-13 Macrocell BTS with three Horizonmacro cabinets

GSM-001-103Three cabinet configuration



Macrocell BTSwith threeM-Cell 2 cabinets

The configuration shown in Figure 9-14 is an example of a three cabinet M-Cell2 BTS.This configuration supports six carriers.

M-CELL2 CABINET

M-CELL2 CABINET

M-CELL2 CABINET

44

MCU

NIU

FOX

12

�BCU

12

TCU

TCU

TCU

TCU

TCU

TCU

22

2

2

2

2

Figure 9-14 Macrocell BTS with three M-Cell2 cabinets

GSM-001-103 Four cabinet configuration


68P02900W21-G


9–17

Four cabinet configuration

Macrocell BTSwith fourHorizon macrocabinets

The configuration shown in Figure 9-15 is an example of a four cabinet Horizonmacro.This configuration supports 24 carriers. The MCUFs interface to the CTUs in the othercabinets through the FMUXs.

CTU

CTU

FMUX

MCUF

CTU

NIU

2222 2

12

2

2

212

2

�BCU

12

FMUX

�BCU

FMUX

�BCU

12

12

FMUX

�BCU

CTU

CTU

CTU

CTU

CTU

CTU

2222 22

CTU

CTU

CTU

CTU

CTU

CTU

2222 22

CTU

CTU

CTU

CTU

CTU

CTU

2222 22

CTU

CTU

CTU

HorizonmacroCABINET

HorizonmacroCABINET

HorizonmacroCABINET

HorizonmacroCABINET

Figure 9-15 Macrocell BTS with four Horizonmacro cabinets

GSM-001-103Four cabinet configuration



Macrocell BTSwith four M-Cell 6cabinets

The configuration shown in Figure 9-16 is an example of a four cabinet M-Cell6 BTS.This configuration supports 24 carriers. The MCUs interface to the TCUs through theFOX or the FMUX/FOX.

FMUX

M-CELL6 BTS CABINET

M-CELL6BTS CABINET

MCU

TCU

TCU

TCU

TCU

TCU

TCU

NIU

FMUX

FMUX

FOX

2222 2

12

2

2

2

12

12

12

12

2

�BCU

TCU

TCU

TCU

TCU

TCU

TCU

2222 22

TCU

TCU

TCU

TCU

TCU

TCU

2222 22

12

FMUX

TCU

TCU

TCU

TCU

TCU

TCU

2222 22

M-CELL6 BTS CABINET

M-CELL6 BTS CABINET

FOX

�BCU

FMUX

FOX

�BCU

12

12

FMUX

FOX

�BCU

Figure 9-16 Macrocell BTS with four M-Cell6 cabinets

GSM-001-103 Macrocell RF configurations


68P02900W21-G


9–19

Macrocell RF configurations

Overview ofconfigurationdiagrams

The Horizonmacro cabinets are presented as follows:

� Horizonmacro single cabinet.

� Horizonmacro multiple cabinets.

The following series of Horizonmacro RF configuration diagrams show suggested waysof connecting together Horizonmacro SURF and Tx blocks to meet different operationalrequirements. The series of diagrams is by no means exhaustive, and numerousalternative configurations may be adopted to achieve the same aim.

Each diagram is applicable to either EGSM 900 or DCS 1800 operation though the SURFmodule illustrated is an 1800 SURF. For EGSM 900 operation a 900 SURF (dual band) isrequired. Connections to the 900 SURF are identified in the same way as those to the1800 SURF, with two additional connectors provided for dual band 1800 use.

The M-Cell cabinets/enclosures are presented as follows:

� M-Cell6 single cabinet.

� M-Cell6 multiple cabinets.

� M-Cell2 single cabinet.

� M-Cellarenamacro enclosures.

� Horizonmacro cabinets.

GSM-001-103Macrocell RF configurations



Horizon macrocabinets

[DCS1800] 4 carrier Omni, with duplexed hybrid and air combining

A single cabinet, four CTU configuration with duplexed hybrid and air combining, isshown in Figure 9-17. Table 9-1 provides a summary of the equipment required for thisconfiguration. The following rules apply:

� In an Horizonmacro cabinet, a maximum of six CTUs can be accommodated.

� An external equipment cabinet is not necessary.

DCF

CTU

AB

CTU

AB

CTU

AB

CTU

AB

SURF

B

Tx/RxANTENNA

HorizonmacroCABINET

Tx/RxANTENNA

1 02B A A1 02

DCF

A B

Figure 9-17 [GSM1800] 4 carrier Omni with duplexed hybrid and air combining



68P02900W21-G


9–21

Table 9-1 Equipment required for single cabinet, four CTU configurationwith duplexed hybrid and air combining

Quantity Unit

2 Antennas

1 Horizonmacro cabinet

4 CTU

Receiver

1 SURF

Transmitter/receiver

2 DCF




[DCS1800] 6 carrier Omni, with duplexed dual-stage hybrid and aircombining

A single cabinet, six CTU configuration with duplexed dual-stage hybrid and aircombining, is shown in Figure 9-18. Table 9-2 provides a summary of the equipmentrequired for this configuration. The following rules apply:



CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

A B

Tx/RxANTENNA

Tx/RxANTENNA

HorizonmacroCABINET

DDF

SURF

B1 02B A A1 02

FEEDTHROUGHDDF

Figure 9-18 [GSM1800] 6 carrier Omni with duplexed dual-stage hybrid and aircombining



68P02900W21-G


9–23

Table 9-2 Equipment required for single cabinet, six CTU configuration with duplexeddual-stage hybrid and air combining

Quantity Unit

2 Antennas


6 CTU

Receiver

1 SURF

Transmitter/eceiver

2 DDF

1 Feed through, with two through connectors




[DCS1800] 2 sector (3/3), with duplexed dual-stage hybrid combining

A single cabinet, six CTU configuration with duplexed dual-stage hybrid combining, isshown in Figure 9-19. Table 9-3 provides a summary of the equipment required for thisconfiguration. The following rules apply:



CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

A

Tx/RxANTENNA

RxANTENNA

B B

RxANTENNA

Tx/RxANTENNA

(SECTOR 1) (SECTOR 2) (SECTOR 2)(SECTOR 1)

HorizonmacroCABINET

A

DDF

SURF

B1 02B A A1 02

FEEDTHROUGH

DDF

Figure 9-19 [GSM1800] 2 sector (3/3) with duplexed dual-stage hybrid combining



68P02900W21-G


9–25

Table 9-3 Equipment required for single cabinet, six CTU configuration with duplexeddual-stage hybrid combining

Quantity Unit

4 Antennas


6 CTU

Receiver

1 SURF


2 DDF





[DCS1800] 2 sector (6/6), with duplexed dual-stage hybrid and aircombining

A multiple cabinet, 12 CTU configuration with duplexed dual-stage hybrid and aircombining, is shown in Figure 9-20. Table 9-4 provides a summary of the equipmentrequired for this configuration. The following rules apply:



CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

EXTENDER Horizonmacro CABINET

CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

MASTER Horizonmacro CABINET

Tx/RxANTENNA

(SECTOR 2)

Tx/RxANTENNA

(SECTOR 2)

Tx/RxANTENNA

(SECTOR 1)

Tx/RxANTENNA

(SECTOR 1)

DDF DDF DDF

FEEDTHROUGH

DDF

SURF

B1 02B A A1 02

SURF

B1 02B A A1 02

A B BA

FEEDTHROUGH

Figure 9-20 [GSM1800] 2 sector (6/6) with duplexed dual-stage hybrid and aircombining



68P02900W21-G


9–27

Table 9-4 Equipment required for multiple cabinet, 12 CTU configuration with duplexeddual-stage hybrid and air combining

Quantity Unit

4 Antennas

2 Horizonmacro cabinets

12 CTU

Receiver

2 SURF

Transmitter/eceiver

4 DDF





[DCS1800] 3 sector (2/2/2), with duplexed hybrid combining

A single cabinet, six CTU configuration with duplexed hybrid combining, is shown in .provides a summary of the equipment required for this configuration. The following rulesapply:



CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

AB

Tx/RxANTENNA

RxANTENNAS

AB

RxANTENNAS

AB

RxANTENNAS

Tx/RxANTENNA

Tx/RxANTENNA

(SECTOR 2) (SECTOR 1)(SECTOR 3) (SECTOR 2)(SECTOR 3) (SECTOR 1)

HorizonmacroCABINET

DCF

SURF

B1 02B A A1 02

DCFDCF

Figure 9-21 [GSM1800] 3 sector (2/2/2) with duplexed hybrid combining



68P02900W21-G


9–29

Table 9-5 Equipment required for single cabinet, six CTU configuration with duplexedhybrid combining

Quantity Unit

6 Antennas


6 CTU

Receiver

1 SURF


3 DCF




[DCS1800] 3 sector (4/4/4), with duplexed hybrid and air combining

A multiple cabinet, 12 CTU configuration with duplexed hybrid and air combining, isshown in . provides a summary of the equipment required for this configuration. Thefollowing rules apply:



CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

EXTENDER HorizonmacroCABINET

CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

MASTER HorizonmacroCABINET

Tx/RxANTENNA

(SECTOR 2)

Tx/RxANTENNA

(SECTOR 1)

Tx/RxANTENNA

(SECTOR 3)

Tx/RxANTENNA

(SECTOR 1)

DCF DCF DCF DCF DCF DCF

SURF

B1 02B A A1 02

SURF

B1 02B A A1 02

A B BAAB

Figure 9-22 [GSM1800] 3 sector (4/4/4) with duplexed hybrid and air conditioning



68P02900W21-G


9–31

Table 9-6 Equipment required for multiple cabinet, 12 CTU configuration with duplexedhybrid and air combining

Quantity Unit

6 Antennas

2 1999macroBTS cabinets

12 CTU


2 SURF

6 DCF




[DCS1800] 3 sector (8/8/8), with duplexed dual-stage hybrid and aircombining

A four cabinet, 24 CTU configuration with duplexed dual-stage hybrid and air combining,is shown in . provides a summary of the equipment required for this configuration. Thefollowing rules apply:



CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

EXTENDER 3 HorizonmacroCABINET

CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB


TOEXTENDER 1Horizonmacro

CABINETSURF A0

SURF

B1 02B A A1 02

SURF

B1 02B A A1 02

A

Tx/RxANTENNA

B

Tx/RxANTENNA

Tx/RxANTENNA

(SECTOR 1)(SECTOR 3) (SECTOR 3)

A

DDF

HCU

SURF B

HCU

DDF

HCU

DDF

Figure 9-23 [GSM1800] 3 sector (8/8/8) with duplexed dual-stage hybrid and aircombining (Part 1)



68P02900W21-G


9–33

CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB


CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

CTU

AB

MASTER HorizonmacroCABINET

Tx/RxANTENNA

(SECTOR 2)

Tx/RxANTENNA

(SECTOR 2)

Tx/RxANTENNA

(SECTOR 1)

TOEXTENDER 2Horizonmacro

CABINET

SURF B0

SURF A

SURF

B1 02B A A1 02

SURF

B1 02B A A1 02

DDF

HCU HCU

DDF

BAB

DDF

HCU

Figure 9-24 [GSM1800] 3 sector (8/8/8) with duplexed dual-stage hybrid and aircombining




Table 9-7 Equipment required for four cabinet, 24 CTU configuration with duplexeddual-stage hybrid and air combining

Quantity Unit

6 Antennas

4 Horizonmacro cabinets

24 CTU

Transmitter

6 Hybrid combiner unit (HCU)

Receiver

4 SURF


6 DDF



68P02900W21-G


9–35

M-Cell 6 cabinets

[GSM900] 3 carrier Omni, with hybrid combining and diversity

A single cabinet, four TCU configuration with hybrid combining and diversity, is shown inFigure 9-25. Table 9-8 provides a summary of the equipment required for thisconfiguration. The following rules apply:

� In an M-Cell6 BTS cabinet, a maximum of six TCUs can be accommodated.


3-INPUTCBF

TCU

AB

TCU

AB

TCU

AB

IADU

DLNB

A B

4 4

Tx ANTENNA Rx ANTENNAS

MCell6 BTS CABINET

RF INPUT

RF LOAD

Non-HCOMB

Figure 9-25 [GSM900] 3 carrier Omni with hybrid combining and diversity




Table 9-8 Equipment required for single cabinet, four TCU configuration with hybridcombining and diversity

Quantity Unit

3 Antennas

1 M-Cell6 BTS cabinet

3 TCU

Transmitter

1 3-input CBF

1 Non-hybrid combiner (Non-HCOMB)

Receiver

1 DLNB



68P02900W21-G


9–37

[GSM900] 3 carrier Omni, with hybrid combining, diversity, andmedium–power duplexer




3-INPUTCBF

TCU

AB

TCU

AB

TCU

AB

IADU

DLNB

4 4

Tx/Rx ANTENNA Rx ANTENNA

MCell6 BTS CABINET

RF INPUT

RF LOAD

DUPLEXER

Non-HCOMB





Table 9-9 Equipment required for single cabinet, four TCU configuration with hybridcombining, diversity, and medium–power duplexer

Quantity Unit

2 Antennas


3 TCU

Transmitter

1 3-input CBF


Receiver

1 DLNB


1 medium–power duplexer



68P02900W21-G


9–39

[GSM900] 4 carrier Omni, with hybrid combining and diversity




3-INPUTCBF

TCU

AB

TCU

AB

TCU

AB

TCU

AB

IADU

DLNB

A B

4 4


MCell6 BTS CABINET

HCOMB

RF INPUT

RF LOAD





Table 9-10 Equipment required for single cabinet, four TCU configuration with hybridcombining and diversity

Quantity Unit

3 Antennas


4 TCU

Transmitter

1 3-input CBF

1 Hybrid combining block (HCOMB)

Receiver

1 DLNB



68P02900W21-G


9–41

[GSM900] 4 carrier Omni, with hybrid combining, diversity, andmedium–power duplexer

A single cabinet, four TCU configuration with hybrid combining, diversity, andmedium–power duplexer, is shown in Figure 9-28. Table 9-11 provides a summary of theequipment required for this configuration. The following rules apply:



3-INPUTCBF

TCU

AB

TCU

AB

TCU

AB

TCU

AB

IADU

DLNB

4 4

Rx ANTENNA

MCell6 BTS CABINET

HCOMB

RF INPUT

RF LOAD

Tx/Rx ANTENNA

DUPLEXER

Figure 9-28 [GSM900] 4 carrier Omni with hybrid combining, diversity, andmedium–power duplexer




Table 9-11 Equipment required for single cabinet, four TCU configuration with hybridcombining, diversity, and medium–power duplexer

Quantity Unit

2 Antennas


4 TCU

Transmitter

1 3-input CBF

1 Hybrid combining block (HCOMB)

Receiver

1 DLNB





68P02900W21-G


9–43

[GSM900] 6 carrier Omni, with cavity combining and diversity

A single cabinet, six TCU configuration with cavity combining and diversity, is shown inFigure 9-29. Table 9-12 provides a summary of the equipment required for thisconfiguration. The following rules apply:



TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

IADU

DLNB

CCB(EXTENSION)

CCB(OUTPUT)

A B

6 6


MCell6 BTS CABINET

Figure 9-29 [GSM900] 6 carrier Omni with cavity combining and diversity




Table 9-12 Equipment required for single cabinet, six TCU configuration with cavitycombining and diversity

Quantity Unit

3 Antennas


6 TCU

Transmitter

1 CCB (Output)

1 CCB (Extension)

Receiver

1 DLNB



68P02900W21-G


9–45

[GSM900] 6 carrier Omni, with cavity combining, diversity, and high–powerduplexer

A single cabinet, six TCU configuration with cavity combining, diversity, and high–powerduplexer, is shown in Figure 9-30. Table 9-13 provides a summary of the equipmentrequired for this configuration. The following rules apply:


� In an M-Cell6 side cabinet, a maximum of three high–power duplexers can beaccommodated.

� An external equipment rack/cabinet is required, for a high–power duplexer, in anindoor installation.

IADU

DLNB

AB

66

RxANTENNA

Tx/RxANTENNA

Tx

Rx

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

CCB(OUTPUT)

CCB(EXTENSION)

ANT

M-Cell6 BTS CABINET M-Cell6 SIDE CABINET

high–powerduplexer

Figure 9-30 [GSM900] 6 carrier Omni with cavity combining, diversity, and high–powerduplexer




Table 9-13 Equipment required for single cabinet, six TCU configuration with cavitycombining, diversity, and high–power duplexer

Quantity Unit

2 Antennas


1 M-Cell6 side cabinet

6 TCU

Transmitter

1 CCB (Output)

1 CCB (Extension)

Receiver

1 DLNB


1 high–power duplexer



68P02900W21-G


9–47

[GSM900] 8 carrier Omni, with combining and diversity

A multiple cabinet, eight TCU configuration with combining and diversity, is shown inFigure 9-31. Table 9-14 provides a summary of the equipment required for thisconfiguration. The following rules apply:



IADU

DLNB

A B

66

RxANTENNA

TxANTENNA

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

CCB(OUTPUT)

CCB(EXTENSION)

MASTER M-Cell6 BTS CABINET

IADU

2 2

TCU

AB

TCU

AB

EXTENDER M-Cell6 BTS CABINET

Tx/RxANTENNA

CBF

DUPLEXER

Rx EXTBLOCK

Figure 9-31 [GSM900] 8 carrier Omni with combining and diversity




Table 9-14 Equipment required for multiple cabinet, 8 TCU configuration withcombining and diversity

Quantity Unit

3 Antennas


8 TCU

Transmitter

1 CBF

1 CCB (Output)

1 CCB (Extension)

Receiver

1 DLNB

1 Rx extension block





68P02900W21-G


9–49

[GSM900] 2 sector (3/3), with hybrid combining and diversity

A single cabinet, six TCU configuration with hybrid combining and diversity, is shown inFigure 9-32. Table 9-15 provides a summary of the equipment required for thisconfiguration. The following rules apply:



TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

IADU

A

6 6

TxANTENNA

RxANTENNA

DLNB

B

DLNB

B

RxANTENNA

TxANTENNA

(SECTOR 2) (SECTOR 1) (SECTOR 2) (SECTOR 1)

M-Cell6 BTS CABINET

3-INPUTCBF

3-INPUTCBF

RF INPUT

RF LOADRF LOAD

RF INPUT

A

Non-HCOMB

Figure 9-32 [GSM900] 2 sector (3/3), with hybrid combining and diversity




Table 9-15 Equipment required for single cabinet, six TCU configuration with hybridcombining and diversity

Quantity Unit

6 Antennas


6 TCU

Transmitter

2 3-input CBF


Receiver

2 DLNB



68P02900W21-G


9–51

[GSM900] 2 sector (3/3), with hybrid combining, diversity, andmedium–power duplexers

A single cabinet, six TCU configuration with hybrid combining, diversity, andmedium–power duplexers, is shown in Figure 9-33. Table 9-16 provides a summary ofthe equipment required for this configuration. The following rules apply:



TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

IADU

A

6 6

Tx/RxANTENNA

RxANTENNA

DLNB

B

DLNB

A B

RxANTENNA

Tx/RxANTENNA

(SECTOR 2) (SECTOR 1) (SECTOR 2) (SECTOR 1)

M-Cell6 BTS CABINET

DUPLEXER

DUPLEXER

3-INPUTCBF

3-INPUTCBF

RF INPUT

RF LOADRF LOAD

RF INPUT

Non-HCOMB

Figure 9-33 [GSM900] 2 sector (3/3), with hybrid combining, diversity, andmedium–power duplexer




Table 9-16 Equipment required for single cabinet, six TCU configuration withcombining, diversity, and medium–power duplexer

Quantity Unit

4 Antennas


6 TCU

Transmitter

2 3-input CBF


Receiver

2 DLNB





68P02900W21-G


9–53

[GSM900] 3 sector (2/2/2), with combining and diversity

A single cabinet, six TCU configuration with combining and diversity, is shown inFigure 9-34. Table 9-17 provides a summary of the equipment required for thisconfiguration. The following rules apply:



TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

IADU

DLNB

CBF

A B

6 6

TxANTENNA

RxANTENNAS

DLNB

A B

RxANTENNAS

DLNB

A B

RxANTENNAS

CBF CBF

TxANTENNA

TxANTENNA

(SECTOR 2) (SECTOR 3)(SECTOR 1) (SECTOR 1) (SECTOR 2) (SECTOR 3)

M-Cell6 BTS CABINET

Figure 9-34 [GSM900] 3 sector (2/2/2), with combining and diversity




Table 9-17 Equipment required for single cabinet, six TCU configuration withcombining and diversityprogress on the W01 or W21

Quantity Unit

9 Antennas


6 TCU

Transmitter

3 CBF

Receiver

3 DLNB



68P02900W21-G


9–55

[GSM900] 3 sector (2/2/2), with cavity combining, diversity, andmedium–power duplexers

A single cabinet, six TCU configuration with cavity combining, diversity, andmedium–power duplexers, is shown in Figure 9-35. Table 9-18 provides a summary ofthe equipment required for this configuration. The following rules apply:



TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

IADU

DLNB

CBF

A B

6 6

Tx/RxANTENNA

RxANTENNA

DLNB

A B

RxANTENNA

DLNB

A B

RxANTENNA

CBF CBF

Tx/RxANTENNA

Tx/RxANTENNA


M-Cell6 BTS CABINET

DUPLEXER

DUPLEXER

DUPLEXER

Figure 9-35 [GSM900] 3 sector (2/2/2), with combining, diversity, and medium–powerduplexer




Table 9-18 Equipment required for single cabinet, six TCU configuration withcombining, diversity, and medium–power duplexer

Quantity Unit

6 Antennas


6 TCU

Transmitter

3 CBF

Receiver

3 DLNB





68P02900W21-G


9–57

[GSM900] 3 sector (4/4/4), with air combining, diversity, andmedium–power duplexer (3 antenna per sector)

A multiple cabinet, 12 TCU configuration with air combining, diversity, andmedium–power duplexer, is shown in Figure 9-36. Table 9-19 provides a summary of theequipment required for this configuration. The following rules apply:



66

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB


6 6

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB


CBF0CBF1CBF2

IADU

DLNB Rx EXTBLOCK

DU

PLE

XE

R

Tx/RxANTENNA

(SECTOR 1)

TxANTENNA

(SECTOR 2)

IADU

DLNB DLNB

DU

PLE

XE

R

DU

PLE

XE

R

CBF0CBF1CBF2

Tx/RxANTENNA

(SECTOR 2)

Tx/RxANTENNA

(SECTOR 3)

RxANTENNA

(SECTOR 1)

TxANTENNA

(SECTOR 1)

RxANTENNA

(SECTOR 2)

TxANTENNA

(SECTOR 3)

RxANTENNA

(SECTOR 2)

Figure 9-36 [GSM900] 3 sector (4/4/4), with air combining, diversity, andmedium–power duplexer (3 antenna per sector)




Table 9-19 Equipment required for multiple cabinet, 12 TCU configuration with aircombining, diversity, and medium–power duplexer (3 antenna per sector)

Quantity Unit

9 Antennas


12 TCU

Transmitter

6 CBF

Receiver

3 DLNB






68P02900W21-G


9–59

[GSM900] 3 sector (4/4/4), with air combining, diversity, andmedium–power duplexer (2 antenna per sector)

A multiple cabinet, 12 TCU configuration with air combining, diversity, andmedium–power duplexer, is shown in Figure 9-37. Table 9-20 provides a summary of theequipment required for this configuration. The following rules apply:



66

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB


6 6

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB


CBF0CBF1CBF2

IADU

DLNB Rx EXTBLOCK

DU

PLE

XE

R

Tx/RxANTENNA

(SECTOR 1)

Tx/RxANTENNA

(SECTOR 2)

IADU

DLNB DLNB

DU

PLE

XE

R

DU

PLE

XE

R

DU

PLE

XE

R

DU

PLE

XE

R

DU

PLE

XE

R

CBF0CBF1CBF2

Tx/RxANTENNA

(SECTOR 2)

Tx/RxANTENNA

(SECTOR 3)

Figure 9-37 [GSM900] 3 sector (4/4/4), with air combining, diversity, andmedium–power duplexer (2 antenna per sector)




Table 9-20 Equipment required for multiple cabinet, 12 TCU configuration with aircombining, diversity, and medium–power duplexer (2 antenna per sector)

Quantity Unit

6 Antennas


12 TCU

Transmitter

6 CBF

Receiver

3 DLNB






68P02900W21-G


9–61

[GSM900] 3 sector (4/4/4), with cavity combining and diversity

A multiple cabinet, 12 TCU configuration with cavity combining and diversity, is shown inFigure 9-38. Table 9-21 provides a summary of the equipment required for thisconfiguration. The following rules apply:



TCU

AB

TCU

AB

TCU

AB

TCU

AB

IADU

DLNB

CCB(EXTENSION)

CCB(OUTPUT)

A B

4 4


Extender 1 and Extender 2 M-Cell6 cabinets configured similar to the Master cabinet for Sectors 2 and 3.

(SECTOR 1)(SECTOR 1)

MASTER M-Cell6 CABINET

Figure 9-38 [GSM900] 3 sector (4/4/4), with cavity combining and diversity




Table 9-21 Equipment required for multiple cabinet, 12 TCU configuration with hybridcombining and diversity

Quantity Unit

6 Antennas


12 TCU

Transmitter

3 CCB (Output)

3 CCB (Extension)

Receiver

3 DLNB



68P02900W21-G


9–63

[GSM900] 3 sector (4/4/4), with 3-input CBF, hybrid combining and diversity

A multiple cabinet, 12 TCU configuration with 3-input CBF, hybrid combining anddiversity, is shown in Figure 9-39. Table 9-22 provides a summary of the equipmentrequired for this configuration. The following rules apply:



66

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB


6 6

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB


IADU

DLNB Rx EXTBLOCK

TxANTENNA

(SECTOR 1)

TxANTENNA

(SECTOR 2)

IADU

DLNB DLNB

RxANTENNA

(SECTOR 3)

TxANTENNA

(SECTOR 3)

HCOMB3-INPUT

CBF3-INPUT

CBF3-INPUT

CBF HCOMBHCOMB

RxANTENNA

(SECTOR 1)

RF INPUT

RF LOAD

RF INPUT

RF LOAD

RF INPUT

RF LOAD

RxANTENNA

(SECTOR 2)

Figure 9-39 [GSM900] 3 sector (4/4/4), with 3-input CBF, hybrid combining and diversity




Table 9-22 Equipment required for multiple cabinet, 12 TCU configuration with 3-inputCBF, hybrid combining, diversity, and medium–power duplexer

Quantity Unit

9 Antennas


12 TCU

Transmitter

3 3-input CBF

3 Hybrid combiner module (HCOMB)

Receiver

3 DLNB




68P02900W21-G


9–65

[GSM900] 3 sector (4/4/4), with 3-input CBF, air combining, diversity, andmedium–power duplexer

A multiple cabinet, 12 TCU configuration with 3-input CBF, air combining, diversity, andmedium–power duplexer, is shown in Figure 9-40. Table 9-23 provides a summary of theequipment required for this configuration. The following rules apply:



66

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB


6 6

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB


IADU

DLNB Rx EXTBLOCK

Tx/RxANTENNA

(SECTOR 1)

Tx/Rx & RxANTENNA

(SECTOR 2)

IADU

DLNB DLNB

DU

PLE

XE

R

DU

PLE

XE

R

DU

PLE

XE

R

RxANTENNA

(SECTOR 3)

Tx/RxANTENNA

(SECTOR 3)

HCOMB3-INPUT

CBF3-INPUT

CBF3-INPUT

CBF HCOMBHCOMB

RxANTENNA

(SECTOR 1)

RF INPUT

RF LOAD

RF INPUT

RF LOAD

RF INPUT

RF LOAD

Figure 9-40 [GSM900] 3 sector (4/4/4), with 3-input CBF, air combining, diversity, andmedium–power duplexer




Table 9-23 Equipment required for multiple cabinet, 12 TCU configuration with 3-inputCBF, air combining, diversity, and medium–power duplexer

Quantity Unit

6 Antennas


12 TCU

Transmitter

3 3-input CBF


Receiver

3 DLNB






68P02900W21-G


9–67

[GSM900] 3 sector (5/5/5), with 3-input CBF, air combining, diversity, andmedium–power duplexers (3 antenna per sector)

A three cabinet, 15 TCU configuration with 3-input CBF, air combining, diversity, andmedium–power duplexers, is shown in Figure 9-41. Table 9-24 provides a summary ofthe equipment required for this configuration. The following rules apply:



TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

IADU

6 6

Tx/RxANTENNA

DLNB

RxANTENNA

TxANTENNA

(SECTOR 1) (SECTOR 1) (SECTOR 1)


DUPLEXER

Non-HCOMB

3-INPUTCBF

3-INPUTCBF

RF INPUT

RF LOAD


Figure 9-41 [GSM900] 3 sector (5/5/5), with 3-input CBF, air combining, diversity, andmedium–power duplexer (3 antenna per sector)




Table 9-24 Equipment required for three cabinet, 15 TCU configuration with 3-inputCBF, air combining, diversity, and medium–power duplexer (3 antenna per sector)

Quantity Unit

9 Antennas


15 TCU

Transmitter

6 3-input CBF


Receiver

3 DLNB





68P02900W21-G


9–69

[GSM900] 3 sector (5/5/5), with 3-input CBF, combining, diversity, andmedium–power duplexers (2 antenna per sector)

A three cabinet, 15 TCU configuration with 3-input CBF, combining, diversity, andmedium–power duplexers, is shown in Figure 9-42. Table 9-25 provides a summary ofthe equipment required for this configuration. The following rules apply:



TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

IADU

6 6

Tx/RxANTENNA

DLNB

(SECTOR 1) (SECTOR 1)


DUPLEXER

Non-HCOMB

3-INPUTCBF

3-INPUTCBF

RF INPUT

RF LOAD


DUPLEXER

Tx/RxANTENNA

Figure 9-42 [GSM900] 3 sector (5/5/5), with 3-input CBF, combining, diversity, andmedium–power duplexer (2 antenna per sector)




Table 9-25 Equipment required for three cabinet, 15 TCU configuration with 3-inputCBF, combining, diversity, and medium–power duplexer (2 antenna per sector)

Quantity Unit

6 Antennas


15 TCU

Transmitter

6 3-input CBF


Receiver

3 DLNB





68P02900W21-G


9–71

[GSM900] 3 sector (6/6/6), with cavity combining, diversity, andhigh–power duplexer

A multiple cabinet, 18 TCU configuration with cavity combining, diversity, and high–powerduplexers, is shown in Figure 9-43. Table 9-26 provides a summary of the equipmentrequired for this configuration. The following rules apply:




IADU

DLNB

AB

66

RxANTENNA

Tx/RxANTENNA

Tx

Rx

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

CCB(OUTPUT)

CCB(EXTENSION)

ANT

MASTER M-Cell6 BTS CABINET M-Cell6 SIDE CABINET

high–powerduplexer

Extender 1 and Extender 2 M-Cell6 cabinets configured similar to the Master cabinet for Sectors 2 and 3.Each extender cabinet terminates in a high–power duplexer in the side cabinet.

Figure 9-43 [GSM900] 3 sector (6/6/6), with cavity combining, diversity, and high–powerduplexer




Table 9-26 Equipment required for three RF cabinets, 18 TCU configuration with cavitycombining, diversity, and high–power duplexer

Quantity Unit

6 Antennas



18 TCU

Transmitter

3 CCB (Output)

3 CCB (Extension)

Receiver

3 DLNB





68P02900W21-G


9–73

[GSM900] 3 sector (6/6/6), with 3-input CBF, air combining, diversity, andmedium–power duplexers (3 antenna per sector)

A three cabinet, 18 TCU configuration with 3-input CBF, air combining, diversity, andmedium–power duplexers, is shown in Figure 9-44. Table 9-27 provides a summary ofthe equipment required for this configuration. The following rules apply:



TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

IADU

6 6

Tx/RxANTENNA

DLNB

RxANTENNA

TxANTENNA

(SECTOR 1) (SECTOR 1) (SECTOR 1)


DUPLEXER

Non-HCOMB

3-INPUTCBF

3-INPUTCBF

RF INPUT

RF LOADRF LOAD

RF INPUT






Table 9-27 Equipment required for three cabinet, 18 TCU configuration with 3-inputCBF, air combining, diversity, and medium–power duplexer (3 antenna per sector)

Quantity Unit

9 Antennas


18 TCU

Transmitter

6 3-input CBF


Receiver

3 DLNB





68P02900W21-G


9–75

[GSM900] 3 sector (6/6/6), with 3-input CBF, combining, diversity, andmedium–power duplexers (2 antenna per sector)

A three cabinet, 18 TCU configuration with 3-input CBF, combining, diversity, andmedium–power duplexers, is shown in Figure 9-45. Table 9-28 provides a summary ofthe equipment required for this configuration. The following rules apply:



TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

IADU

6 6

Tx/RxANTENNA

DLNB

(SECTOR 1) (SECTOR 1)


DUPLEXER

Non-HCOMB

3-INPUTCBF

3-INPUTCBF

RF INPUT

RF LOADRF LOAD

RF INPUT


DUPLEXER

Tx/RxANTENNA





Table 9-28 Equipment required for three cabinet, 18 TCU configuration with 3-inputCBF, combining, diversity, and medium–power duplexer (2 antenna per sector)

Quantity Unit

6 Antennas


18 TCU

Transmitter

6 3-input CBF


Receiver

3 DLNB





68P02900W21-G


9–77




[GSM900] 3 sector (8/8/8), with cavity combining and diversity

A four cabinet, 24 TCU configuration with cavity combining, diversity, andmedium–power duplexers, is shown in Figure 9-46/ Figure 9-47. Table 9-29 provides asummary of the equipment required for this configuration. The following rules apply:



TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

IADU

6 6

Tx/RxANTENNA

CBF 0

Tx/RxANTENNA

Tx/RxANTENNA



DU

PLE

XE

R 2

DU

PLE

XE

R 1

DU

PLE

XE

R 0

CBF 1CBF 2

Rx REVBLOCK 0

IADU IN EXTENDER 1 M-Cell6 BTS CABINET


Rx REVBLOCK 1

Rx REVBLOCK 2

DLNB 0 IN EXTENDER 2 M-Cell6 BTS CABINET







68P02900W21-G


9–79

IADU

DLNB

66

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

CCB(OUTPUT)

CCB(EXTENSION)

EXTENDER 1 M-Cell6 BTS CABINET

Extender 2 and Extender 3 M-Cell6 cabinets configured similar to the Extender 1 cabinet for Sectors 2 and 3.

TOMASTERM-Cell6

BTS CABINET

Rx REV BLOCK 0Rx REV BLOCK 1Rx REV BLOCK 2

RxANTENNA

(SECTOR 1)

TxANTENNA

(SECTOR 1)

DUPLEXER 2DUPLEXER 1DUPLEXER 0





Table 9-29 Equipment required for four RF cabinets, 24 TCU configuration with cavitycombining and diversity

Quantity Unit

9 Antennas


24 TCU

Transmitter

3 CCB (Output)

3 CCB (Extension)

3 CBF

Receiver

3 DLNB

3 Rx extender block





68P02900W21-G


9–81




[GSM900] 3 sector (8/8/8), with cavity combining, diversity and duplexing

A multiple cabinet, 24 TCU configuration with cavity combining, diversity and both highand medium–power duplexers, is shown in Figure 9-48/ Figure 9-49. Table 9-30 providesa summary of the equipment required for this configuration. The following rules apply:




TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

IADU

6 6

Tx/RxANTENNA

CBF 0

Tx/RxANTENNA

Tx/RxANTENNA



DU

PLE

XE

R 2

DU

PLE

XE

R 1

DU

PLE

XE

R 0

CBF 1CBF 2

Rx REVBLOCK 0



Rx REVBLOCK 1

Rx REVBLOCK 2





Figure 9-48 [GSM900] 3 sector (8/8/8), with cavity combining, diversity and both highand medium–power duplexers



68P02900W21-G


9–83

IADU

DLNB

A

66

Tx

Rx

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

CCB(OUTPUT)

CCB(EXTENSION)

ANT

EXTENDER 1 M-Cell6 BTS CABINET M-Cell6 SIDE CABINET

high–powerduplexerS

Extender 2 and Extender 3 M-Cell6 cabinets configured similar to the Extender 1 cabinet for Sectors 2 and 3.The Master, Extender 1 and Extender 2 cabinets terminate in a high–power duplexer in the side cabinet.

Tx

Rx

ANT

Tx

Rx

ANT

AA





TOMASTERM-Cell6

BTS CABINET

DUPLEXER 2

Rx REV BLOCK 0

DUPLEXER 1DUPLEXER 0

Rx REV BLOCK 1Rx REV BLOCK 2

Tx/RxANTENNA

Tx/RxANTENNA

Tx/RxANTENNA


Figure 9-49 [GSM900] 3 sector (8/8/8), with cavity combining, diversity and both highand medium–power duplexers




Table 9-30 Equipment required for four RF cabinets, 24 TCU configuration with cavitycombining, diversity and both high and medium–power duplexers

Quantity Unit

6 Antennas



24 TCU

Transmitter

3 CCB (Output)

3 CCB (Extension)

3 CBF

Receiver

3 DLNB

3 Rx extender block






68P02900W21-G


9–85




[GSM900] 3 sector (8/8/8), with 3-input CBF, air combining, diversity, andmedium–power duplexer (3 antenna per sector)

A four cabinet, 24 TCU configuration with 3-input CBF, air combining, diversity, andmedium–power duplexer, is shown in Figure 9-50/ Figure 9-51. Table 9-31 provides asummary of the equipment required for this configuration. The following rules apply:



66

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

6 6

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

IADU

Rx EXTBLOCK

Tx/RxANTENNA

(SECTOR 3)

IADU

DLNB

DU

PLE

XE

R

RxANTENNA

(SECTOR 3)

TxANTENNA

(SECTOR 3)

HCOMB3-INPUT

CBF3-INPUT

CBF3-INPUT

CBF HCOMBHCOMB

TxANTENNA

(SECTOR 2)

RF INPUT

RF LOAD

RF INPUT

RF LOAD

RF INPUT

RF LOAD

Rx EXTBLOCK

TOEXTENDER 1

M-Cell6BTS CABINET

IADU

EXTENDER 2 M-Cell6 BTS CABINETEXTENDER 3 M-Cell6 BTS CABINET




68P02900W21-G


9–87

66

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB


6 6

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB


IADU

DLNB Rx EXTBLOCK

Tx/RxANTENNA

(SECTOR 1)

TxANTENNA

(SECTOR 1)

IADU

DLNB

DU

PLE

XE

R

DU

PLE

XE

R

RxANTENNA

(SECTOR 2)

Tx/RxANTENNA

(SECTOR 2)

HCOMB3-INPUT

CBF3-INPUT

CBF3-INPUT

CBF HCOMBHCOMB

RxANTENNA

(SECTOR 1)

RF INPUT

RF LOAD

RF INPUT

RF LOAD

RF INPUT

RF LOAD

TOEXTENDER 2

M-Cell6BTS CABINET

Rx EXT BLOCK





Table 9-31 Equipment required for four cabinet, 24 TCU configuration with 3-inputCBF, air combining, diversity, and medium–power duplexers (3 antenna per sector)

Quantity Unit

9 Antennas


24 TCU

Transmitter

6 3-input CBF


Receiver

3 DLNB






68P02900W21-G


9–89




[GSM900] 3 sector (8/8/8), with 3-input CBF, combining, diversity, andmedium–power duplexer (2 antenna per sector)

A four cabinet, 24 TCU configuration with 3-input CBF, combining, diversity, andmedium–power duplexer, is shown in Figure 9-52/ Figure 9-53. Table 9-32 provides asummary of the equipment required for this configuration. The following rules apply:



66

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB


6 6

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB


IADU

Rx EXTBLOCK

Tx/RxANTENNA

(SECTOR 3)

IADU

DLNB

DU

PLE

XE

R

DU

PLE

XE

R

TxANTENNA

(SECTOR 3)

HCOMB3-INPUT

CBF3-INPUT

CBF3-INPUT

CBF HCOMBHCOMB

RF INPUT

RF LOAD

RF INPUT

RF LOAD

RF INPUT

RF LOAD

Rx EXTBLOCK

TOEXTENDER 1

M-Cell6BTS CABINETIADU

DUPLEXER




68P02900W21-G


9–91

66

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB


6 6

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB


IADU

DLNB Rx EXTBLOCK

Tx/RxANTENNA

(SECTOR 1)

Tx/RxANTENNA

(SECTOR 1)

IADU

DLNB

DU

PLE

XE

R

DU

PLE

XE

R

DU

PLE

XE

R

Tx/RxANTENNA

(SECTOR 2)

Tx/RxANTENNA

(SECTOR 2)

HCOMB3-INPUT

CBF3-INPUT

CBF3-INPUT

CBF HCOMBHCOMB

RF INPUT

RF LOAD

RF INPUT

RF LOAD

RF INPUT

RF LOAD

TOEXTENDER 2

M-Cell6BTS CABINET

DUPLEXER

Rx REV BLOCK 1

DU

PLE

XE

R





Table 9-32 Equipment required for four cabinet, 24 TCU configuration with 3-inputCBF, combining, diversity, and medium–power duplexer (2 antenna per sector)

Quantity Unit

6 Antennas


24 TCU

Transmitter

6 3-input CBF


Receiver

3 DLNB






68P02900W21-G


9–93




[DCS1800] 3 sector (2/2/2), with hybrid combining and diversity

A single cabinet, six TCU configuration with hybrid combining and diversity, is shown inFigure 9-54. Table 9-33 provides a summary of the equipment required for thisconfiguration. The following rules apply:



TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

LNA

HYBRID

A B

2

TxANTENNA

RxANTENNAS

LNA

A B

RxANTENNAS

LNA

A B

RxANTENNAS

HYBRID HYBRID

TxANTENNA

TxANTENNA


M-Cell6 BTS CABINET

2 2 2 2 2

TxBPFTxBPFTxBPF

Figure 9-54 [DCS1800] 3 sector (2/2/2), with hybrid combining and diversity



68P02900W21-G


9–95

Table 9-33 Equipment required for single cabinet, six TCU configuration with hybridcombining and diversity

Quantity Unit

9 Antennas


6 TCU

Transmitter

3 TxBPF

3 Hybrid combiner

Receiver

3 LNA




[DCS1800] 3 sector (2/2/2), with hybrid combining, diversity, andmedium–power duplexer

A single cabinet, six TCU configuration with hybrid combining, diversity, andmedium–power duplexers, is shown in Figure 9-55. Table 9-34 provides a summary ofthe equipment required for this configuration. The following rules apply:



TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

TCU

AB

LNA

HYBRID2

Tx/RxANTENNA

RxANTENNAS

LNA

RxANTENNAS

LNA

RxANTENNAS

HYBRID HYBRID

Tx/RxANTENNA

Tx/RxANTENNA


M-Cell6 BTS CABINET

2 2 2 2 2

DU

PLE

XE

R

DU

PLE

XE

R

DU

PLE

XE

R

Figure 9-55 [DCS1800] 3 sector (2/2/2), with hybrid combining, diversity, andmedium–power duplexers



68P02900W21-G


9–97

Table 9-34 Equipment required for single cabinet, six TCU configuration with hybridcombining, diversity, and medium–power duplexers

Quantity Unit

6 Antennas


6 TCU

Transmitter

3 Hybrid combiner

Receiver

3 LNA






M-Cell 2 cabinets

[GSM900] 2 carrier, single sector, with hybrid combining and diversity

A single cabinet, two TCU configuration with hybrid combining and diversity, is shown inFigure 9-56. Table 9-35 provides a summary of the equipment required for thisconfiguration. The following rules apply:

� In an M-Cell2 BTS cabinet, a maximum of two TCUs can be accommodated.


2

TCU

AB

TCU

AB

CBF 2

RxANTENNAS

DLNB

A B

TxANTENNA

M-Cell2 BTS CABINET

Figure 9-56 [GSM900] 2 carrier, single sector, with hybrid combining and diversity



68P02900W21-G


9–99

Table 9-35 Equipment required for single cabinet, two TCU configuration with hybridcombining and diversity

Quantity Unit

3 Antennas


2 TCU

Transmitter

1 CBF

Receiver

1 DLNB




[GSM900] 2 carrier, single sector, with hybrid combining, diversity, andmedium–power duplexer

A single cabinet, two TCU configuration with hybrid combining, diversity, andmedium–power duplexer, is shown in Figure 9-57. Table 9-36 provides a summary of theequipment required for this configuration. The following rules apply:



2

TCU

AB

TCU

AB

CBF 2

RxANTENNA

DLNB

A B

Tx/RxANTENNA

M-Cell2 BTS CABINET

DUPLEXER

Figure 9-57 [GSM900] 2 carrier, single sector, with hybrid combining, diversity, andmedium–power duplexer



68P02900W21-G


9–101

Table 9-36 Equipment required for single cabinet, two TCU configuration with hybridcombining, diversity, and medium–power duplexer

Quantity Unit

2 Antennas


2 TCU

Transmitter

1 CBF

Receiver

1 DLNB






[GSM900] 2 sectors (1 carrier per sector), with diversity

A single cabinet, two TCU configuration with diversity, is shown in Figure 9-58.Table 9-37 provides a summary of the equipment required for this configuration. Thefollowing rules apply:



TCU

AB

TCU

AB

RxANTENNAS

DLNB

A B

TxANTENNA

M-Cell2 BTS CABINET

RxANTENNAS

DLNB

A B

CBF

TxANTENNA

CBF

Figure 9-58 [GSM900] 2 sectors (1 carrier per sector), with diversity



68P02900W21-G


9–103

Table 9-37 Equipment required for single cabinet, two TCU configuration with diversity

Quantity Unit

6 Antennas


2 TCU

Transmitter

2 CBF

Receiver

2 DLNB




[DCS1800] 2 carrier, single sector, with air combining and diversity

A single cabinet, two TCU configuration with air combining and diversity, is shown inFigure 9-59. Table 9-38 provides a summary of the equipment required for thisconfiguration. The following rules apply:



2

TCU

AB

TCU

AB

2

RxANTENNA

LNA

AB

TxANTENNA

M-Cell2 BTS CABINET

TxBPF

DUPLEXER

Tx/RxANTENNA

Figure 9-59 [DCS1800] 2 carrier, single sector, with air combining and diversity



68P02900W21-G


9–105

Table 9-38 Equipment required for single cabinet, two TCU configuration withoutdiversity

Quantity Unit

3 Antennas


2 TCU

Transmitter

1 TxBPF

Receiver

1 LNA






[DCS1800] 2 sectors, with diversity

A single cabinet, two TCU configuration with diversity, is shown in Figure 9-60.Table 9-39 provides a summary of the equipment required for this configuration. Thefollowing rules apply:



TCU

AB

TCU

AB

RxANTENNAS

LNA

A B

TxANTENNA

M-Cell2 BTS CABINET

TxBPF

RxANTENNAS

LNA

A B

TxBPF

TxANTENNA

Figure 9-60 [DCS1800] 2 sectors, with diversity



68P02900W21-G


9–107

Table 9-39 Equipment required for single cabinet, two TCU configuration withoutdiversity

Quantity Unit

6 Antennas


2 TCU

Transmitter

2 TxBPF

Receiver

2 LNA

M-Cell arena macro

enclosure

[GSM900/DCS1800] 2 carrier

A single BTS enclosure, double TRX configuration, with boosted output (in a separateenclosure), two antennas are provided.

GSM-001-103Microcell RF configuration



Microcell RF configuration

M-Cell arenaenclosure

–[GSM900/DCS1800] 2 carrier

A single BTS enclosure, double TRX configuration, single antenna is provided.


68P02900W21-G


i

Chapter 10

Previous BSC planning steps and

rules

GSM-001-103



GSM-001-103


68P02900W21-G


iii

Chapter 10Previous BSC planning steps and rules i. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .





Determining the RSLs required 10–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 10–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 10–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Standard traffic model 10–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Non-standard traffic model 10–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC to BTS E1 interconnect planning actions 10–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC to BTS T1 interconnect planning actions 10–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Calculate the number of LCFs for RSL processing 10–13. . . . . . . . . . . . . . . . . . . . . . . . . Assigning BTSs to LCFs 10–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Generic processor (GPROC, GPROC2) 10–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 10–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC functions and types 10–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BSC types 10–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 10–23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC planning actions (GSR3) 10–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC planning actions (GSR2 and earlier) 10–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cell broadcast link 10–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OMF GPROC required 10–27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Code storage facility processor 10–27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC redundancy 10–28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Transcoding 10–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 10–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GDP/XCDR planning considerations 10–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T1 conversion 10–30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning actions transcoding at the BSC 10–31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


GSM-001-103
















68P02900W21-G


10–1

Chapter overview

Introduction

This chapter provides the planning steps and rules for the previous generation BSCequipment. The planning steps and rules for the previous generation BTS equipment arein Chapter 11 of this manual. This chapter contains:

� BSC planning overview.

� Capacity calculations.

– Determining the required BSS signalling link capacities.

– Determine the number of RSLs required.

– Determine the number of MTLs required.

– BSC GPROC functions and types.

� BSC planning.

– Planning rules for BSC to BTS links (E1/T1).

– Planning rules for BSC to BTS links (RSL).

– Planning rules for BSC to MSC links (MTL).



GSM-001-103BSC planning overview



BSC planning overview

Introduction

To plan the equipage of a BSC certain information must be known. The major itemsinclude:

� The number of BTS sites to be controlled.

� The number of RF carriers (RTF) at each BTS site.

� The number of TCHs at each site.

� The total number of TCHs under the BSC.

� The number of cells controlled from each BSC site should not exceed themaximum per BSC given in the BSC system capacity section of Chapter 5.

� The physical interconnection of the BTS sites to the BSC.

� The location of the XCDR function.

� The path for the OML links to the OMC.



� The traffic load to be handled (also take future growth into consideration).

� The number of MSC to BSC trunks.

GSM-001-103 BSC planning overview


68P02900W21-G


10–3


Planning a BSC involves the following steps:

1. Plan the number of E1 or T1 links between the BSC and BTS site(s), refer to thesection Determine the required BSS signalling link capacities in this chapter.

2. Plan the number of RSL links between the BSC and BTS site(s), refer to thesection Determine the number of RSLs required in this chapter.

3. Plan the number of MTL links between the BSC and MSC, refer to the sectionDetermine the number of MTLs required in this chapter.

4. Plan the number of GPROCs required, refer to the section Generic processor(GPROC, GPROC2) in this chapter.

5. Plan the number of XCDR/GDPs required, refer to the section Transcoding in thischapter.



8. Plan the number of BSU shelves, refer to the section BSU shelves in this chapter.









17. Verify the planning process, refer to the section Verify the number of BSUshelves and BSSC cabinets in this chapter.





Introduction

The throughput capacities of the BSC processing elements (for example, GPROC,GPROC2) and the throughput capacities of its data links, determines the number ofsupported traffic channels (TCHs). These capacities are limited by the ability of theprocessors, and links to handle the signalling information associated with these TCHs.

This section provides information on how to calculate processor requirements, signallinglink capacities and BSC processing capacities. This section describes:

� Traffic models.

� The required BSS signalling link capacities.

� BSC GPROC functions and types.

� The number of GPROCs required.



68P02900W21-G


10–5

Determining the required BSS signalling link capacities

BSC signallingtraffic model

For a GSM system the throughput of network entities, including sub-components,depends upon the assumed traffic model used in the network design or operation. Trafficmodels are fundamental to a number of planning actions.

The capacity of the BSC as a whole, or the capacity of a particular GPROC, depends onits ability to process information transported through signalling links connecting it to theother network elements. These elements include MSC, BTSs, and the OMC-R.Depending on its device type and BSC configuration, a GPROC may be controllingsignalling links to one or more other network elements. A capacity figure can be statedfor each GPROC device type in terms of a static capacity such as the number of physicalsignalling links supported, and a dynamic capacity such as processing throughput.

In general telephony environments, processing and link throughput capacities can bestated in terms of the offered call load. To apply this for the GSM BSC, all signallinginformation to be processed by the BSC, is related to the offered call load (the amount oftraffic offered/generated by subscribers). When calls are blocked due to all trunks or allTCHs busy, most of the signalling associated with call setup and clearing still takes place,even though few or no trunk resources are utilized. Therefore, the offered call load(which includes the blocked calls) should be used in planning the signalling resources (forexample; MTLs and RSLs).

In the case where the BSC has more than enough trunks to handle the offered traffic,adequate signalling resources should be planned to handle the potential carried traffic.The trunk count can be used as an approximate Erlang value for the potential carriedload.

As a result, the signalling links and processing requirements should be able to handle thegreater of the following:

� The offered load.

� The potential carried load.

To determine the link and processing requirements of the BSC, the number of trunks orthe offered call load in Erlangs (whichever is greater) should be used.

BSC capacity planning requires a model that associates the signalling generated from allthe pertinent GSM procedures: call setup and clearing, handover, location updating andpaging, to the offered call load. To establish the relationship between all the procedures,the traffic model expresses processing requirements for these procedures as ratios to thenumber of call attempts processed. The rate at which call attempts are processed is afunction of the offered call load and the average call hold time.

Figure 10-1 graphically depicts various factors that should be taken into account whenplanning a BSS.




MSC









OR MSC SITE






TRANSCODER

BSC

BTS






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Typicalparameter values

The parameters required to calculate BSC processing and signalling link capacities arelisted in Table 10-1 with their typical values.

Two methods for determining capacity are given. The first method is based on thetypical call parameters given in Table 10-1 and simplifies planning to lookup tables, orsimple formulae indicated in standard traffic model planning steps. When the callparameters being planned for differ significantly from the standard traffic model given inTable 10-1 in this case more complex formulae must be used as indicated innon-standard traffic model planning steps.








Location update factor L = 2

Paging rate in pages per second P = 3


Percent link utilization (MSC to BSS) U (MSC – BSS) = 0.20

Percent link utilization (BSC to BTS) U (BSC – BTS) = 0.25

Blocking for TCHs PB–TCHs = 2%

Blocking for MSC–BSS Trunks PB–Trunks = 1%

The location update factor (L) is a function of the ratio of location updates to calls (l), theratio of IMSI detaches to calls (I ) and whether the short message sequence (type 1) orlong message sequence (type 2) is used for IMSI detach; typically I = 0 (that is IMSIdetach is disabled) as in the first formula given below. When IMSI detach is enabled, thesecond or third of the formulas given below should be used. The type of IMSI detachused is a function of the MSC.


L = I


L = I + 0.2 * �


L = I + 0.5 * �




Table 10-2 Other parameters used in determining GPROC and link requirements


Number of MSC – BSC trunks N

Number of BTSs per BSS B

Number of cells per BSS C

Pages per call PPC = P * (T/N)

Assumptionsused in capacitycalculations

To calculate link and processing capacity values, certain signalling message sequencepatterns and message sizes have been assumed for the various procedures included inthe signalling traffic model. New capacity values may have to be calculated if the actualmessage patterns and message sizes differ significantly from those assumed. Theassumptions used for the capacity calculations in this manual are summarized below.The number of uplink and downlink messages with the respective average messagesizes (not including link protocol overhead) for each procedure are provided inTable 10-3.

Table 10-3 Procedure capacities

Procedure MSC to BSC link

Call setup and clearing 5 downlink messages with average size of 30 bytes6 uplink messages with average size of 26 bytes

Handover, incoming andoutgoing


Location update 5 downlink messages with average size of 30 bytes6 uplink messages with average size of 26 bytes

SMS-P to P (see note below)




Paging 1 downlink message with average size of 30 bytes

The actual number and size of messages required by SMS depend on theimplementation of the SMS service centre. The numbers given are estimatesfor a typical implementation. These numbers may vary.

NOTE

An additional assumption, which is made in determining the values listed in Table 10-3, isthat the procedures not included in the traffic model are considered to have negligibleeffect.



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Link capacities

The level of link utilization is largely a matter of choice of the system designer. A designthat has more links running at a lower message rate can have the advantage of offeringbetter fault tolerance since the failure of any one link affects less signalling traffic.Reconfiguration around the fault could be less disruptive. Such a design could offerreduced queueing delays for signalling messages. A design that utilizes fewer links at ahigher message rate, reduces the number of 64 kbit/s circuits required for signalling, andpotentially reduces the number of resources (processors, data ports) required in theMSC. It is recommended that the C7 links be designed to operate at no more than 20%link utilization. If higher link utilizations are used, the controlling GPROCs (LCF–MTLs)may become overloaded.

C7, the protocol used for the MSC to BSC links, allows for the signalling traffic from thefailed link to be redistributed among the remaining functioning links. A C7 link setofficially has at least two and at most 16 links. The failure of links, for any reason, causethe signalling to be shared across the remaining members of the link set. Therefore, thedesign must plan for reserve link and processing capacity to support a certain number offailed signalling links.




Determining the RSLs required

Introduction

Each BTS site which is connected directly to the BSC, including the first site in a daisychain, must be considered individually. Once individual RSL requirements are calculatedthe total number of LCFs can be determined for the BSC.


The following factors should be considered when planning the provision of RSL (LAPDsignalling) links from the BSC to BTS sites:

� With the Motorola BSC/BTS interface there is a need for an RSL link to every BTSsite. One link can support multiple collocated cells. As the system grows,additional signalling links may be required. Refer to the section Determining therequired BSS signalling link capacities in this chapter to determine the numberof RSL links required.

� If closed loop daisy chains are used, each site requires an RSL in both directions.

� The provision of additional RSL links for redundancy.


The number of BSC to BTS signalling links (RSL) must be determined for each BTS.This number depends on the number of TCHs at the BTS. Table 10-4 gives the numberof RSLs required for a BTS to support the given number of TCHs. These numbers arebased on the typical call parameters given in the standard traffic model column ofTable 10-1. If the call parameters differ significantly from the standard traffic model, usethe formulae for the non-standard traffic model .




n <= 30 1 1

30 < n <= 60 1 2

60 < n <= 90 1 3

90 < n <= 120 1 4

120 < n <= 150 2 5

150 < n <= 180 2 6

180 < n <= 210 2 7

210 < n <= 240 2 8


NOTE



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NBSC�BTS �

(n * (95 � 67 * S � 35 * H � 25 * L))(1000 * U * T)

�6 * P

(1000 * U)


NBSC�BTS � �(n * (95 � 67 * S � 35 * H � 25 * L))

(1000 * U * T)�

6 * P(1000 * U)

� * 4

Where: NBSC to BTS is: the number of MSC to BSC signalling links.

n the number of TCHs at the BTS site.


H the number of handover per call.


U the percent link utilization (0.25).



BSC to BTS E1interconnectplanning actions

Determine the number of E1 links required to connect to a BTS. Redundant links may beadded, if required.

N �

[(nTCH + L16) / 4] + L6431

Where: N is: the minimum number of E1 links required (rounded upto an integer).





NOTE




BSC to BTS T1interconnectplanning actions

Determine the number of T1 links required to connect to a BTS. Redundant links may beadded, if required.

N �

[(nTCH + L16) / 4] + L6424

Where: N is: the minimum number of T1 links required (rounded upto an integer).





NOTE



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Calculate thenumber of LCFsfor RSLprocessing

LCFs for BSC to BTS links and Layer 3 call processing

There are three steps needed to determine the number of LCF GPROCs required tosupport the BSC to BTS signalling links (RSL) and layer 3 call processing.

1. Calculate the number of LCFs required to support the RSLs.

2. Calculate the number of LCFs required to support the layer 3 call processing.

3. The larger of the numbers calculated in steps 1 and 2 is the number of LCFsrequired to support the RSLs signalling links and layer 3 call processing.

Step 1

Determine the number of LCFs required to support RSLs. There are two equations; onefor release GSR3; and one for GSR2 and 1.4.x.x.

For GSR3 using only GPROC2.

GRSL �(R � 2 * B)

120

For GSR2 and 1.4.x.x, or GSR3 using GPROC.

GRSL �(R � 2 * B)

40

Where: GRSL is: the number of LCFs required to support the BSC toBTS signalling links (RSL).

R the number RTFs (radio carriers).


Step 2

The second step is to determine the number of GPROCs required to support the layer 3call processing. There are two methods for calculating this number. The first is usedwhen the call parameters are similar to those listed in Table 10-1. The second method isto be used when call parameters differ significantly from those listed in Table 10-1.

Standard traffic model

For a GPROC2:

GL3 � �n

440�

B15

�C35� * � 1

2.5�

For a GPROC:

GL3 �n

440�

B15

�C35

Where: GL3 is: the number of LCF GPROCs or LCF GPROC2srequired to support the layer 3 call processing.

n the number of TCH under the BSC.






Non-standard traffic model

If the call parameters differ significantly from those given in Table 10-1, the alternativeformula given below should be used to determine the recommended number of LCFs.

For a GPROC2:

GL3 � �n * (1 � 0.7 * S � 0.5 * H * (1 � 0.3 * i) � 0.5 * L)

(11.3 * T)� (0.006 � 0.02 * P) * B �

C35� * � 1

2.5�

For a GPROC:

GL3 �(n * (1 � 0.7 * S � 0.5 * H * (1 � 0.3 * i) � 0.5 * L))

(11.3 * T)� (0.006 � 0.02 * P) * B �

C35

Where: GL3 is: the number of LCF GPROCs or LCF GPROC2srequired to support the layer 3 call processing.

n the number of TCHs under the BSC.



i the ratio of intra-BSC handover to all handover.






Step 3

The number of LCFs required is the greater of GRSL and GL3.

Assigning BTSsto LCFs

The BTSs must be assigned to the LCFs in such a way as to not overload any one LCF.Verify that the following conditions are met for each LCF:

For a GPROC2:

2 * (number of RSLs) + number of carriers supported is NOT greater 120 for GSR3.

For a GPROC:

2 * (number of RSLs) + number of carriers supported is NOT greater than 40.

If these conditions are exceeded, one or more additional processors will beneeded to share the load.

NOTE



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Determining the number of MTLs required

Introduction

MTLs carry signalling traffic between the MSC and BSC. The number of required MTLsdepends upon the BSS configuration size and traffic model. MTLs are carried on E1 orT1 links between the MSC and BSC, which are also used for traffic.


The following factors should be considered when planning the links from the BSC toMSC:

� Determine traffic requirements for the BSC. Traffic may be determined usingeither of the following methods:

– Multiply the number of subscribers expected to use the BSC by the averagetraffic per subscriber.

or

– Sum the traffic potential of each BTS under the BSC; determined by thenumber of TCHs available, the number of TCHs required or the subscriberpotential.

� Determine the number of trunks to support the traffic requirements of the BSCusing Erlang B tables at the required blocking rate.





The number of MSC to BSC signalling links (MTL) required depends on the desired linkutilization, the type and capacity of the GPROCs controlling the MTLs. C7 uses a 4 bitnumber, the Signalling Link Selection (SLS) generated by the upper layer to load sharemessage traffic among the in service links of a link set. When the number of in servicelinks is not a power of 2, some links may experience a higher load than others.

The number of MTLs is a function of the number of MSC to BSC trunks or the offeredcall load. Table 10-5 gives the recommended minimum number of MSC to BSCsignalling links based on the typical call parameters given in Table 10-1. The value for Nis the greater of the following:

� The offered call load (in Erlangs) from all the BTSs controlled by the BSCwhichever is greater.

� The potential carried load (approximately equal to the number of MSC to BSCtrunks).

The offered call load for a BSS is the sum of the offered call load from all of the cells ofthe BSS. The offered call load at a cell is a function of the number TCHs and blocking.As blocking increases the offered call load increase. For example, for a cell with15 TCHs and 2% blocking, the offered call load is 9.01 Erlangs.

Table 10-5 Number of MSC to BSC signalling links

N = the number of MSC to BSC Trunksor the offered load from the BTSs

( hi h i th t t)

Minimum numberof MTLs

Recommendednumber of MTLs

(whichever is the greatest) (each MTL at <= 20% link utilization)

N <= 145 1 2

145< N <=290 2 3

290 < N <= 385 3 4

385 < N <= 580 4 5

580 < N <= 775 6 7

775 < N <= 1160 8 9

1160 < N <= 1375 16 16

The capacities shown are based on the standard traffic model shown inTable 10-1.

NOTE



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10–17


If the call parameters differ significantly from those given in Table 10-1, the followingprocedure is used to determine the required number of MSC to BSC signalling links:

1. Use the formula given below to determine the maximum number of Erlangssupported by a C7 signalling link (nl link ).

nl link �

(1000 * U * T)((67 � 47 * S � 31 * H * (1 � 0.8 * i) � 25 * L) � 14 * PPC)

2. Use the formula given below to determine the maximum number of Erlangssupported by a GPROC or GPROC2 (LCF–MTL) supporting a C7 signalling link(nl LCF–MTL).

For a BSC with a mix of GPROC and GPROC2:

nl LCF�MTL �3.6 * T

((1 � 0.7 * S � 0.5 * H * (1 � 0.6 * i) � 0.5 * L) � PPC * (0.01 * B � 0.05))

For a BSC with only GPROC2:

nl LCF�MTL �2.5 * (3.6 * T)

((1 � 0.7 * S � 0.5 * H * (1 � 0.6 * i) � 0.5 * L) � PPC * (0.01 * B � 0.05))

3. The maximum amount of traffic a MTL (a physical link) can handle (nl min ) is thesmaller of the two numbers from Steps 1 and 2.

4. Since the signalling traffic is uniformly distributed over 16 logical links, and theselogical links will be assigned to the MTLs (physical links). We need to firstdetermine the amount of traffic each logical link holds (nl logical ):

nl logical �N16

5. Next we need to determine the number of logical links each MTL (physical link)can handle (nlog-per-MTL ):

n log�per�MTL � ROUND DOWN � nl min

nl logical�

6. Finally, the number of required MTLs (mtls ) is:

mtls � ROUND UP � 16n log�per�MTL

�� R � 16

mtls should not exceed 16

NOTE




Where: U is: the percent link utilization (0.25).




i the ratio of intra-BSC handover to all handover.


PPC

B

mtls

the number of pages per call.

the number of BTSs supported by the BSC.

the number of MSC to BSC signalling links (MTL).

� to the power of.

ROUNDUP rounding up to the next integer.

N the greater of either the offered traffic load orpotential traffic load carried (approximately equal tothe number of MSC to BSC trunks).



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Calculate thenumber of LCFsfor MTLprocessing

The purpose of the LCF GPROC or LCF GPROC2 device type is to support the functionsof MSC link protocol, layer 3 call processing, and the BTS link protocol. It isrecommended that an LCF GPROC supports either an MTL or one to eight BTSs, withup to 15 RSLs and layer 3 call processing; and that an LCF GPROC2 supports either twoMTLs or one to 15 BTSs (GSR3), with up to 31 RSLs and layer 3 call processing.

It is not recommended that an LCF support both an MTL and BSC to BTSsignalling links.

The higher capacities available with GPROC2 are only achieved if GPROC2sare the only processor type in use in a GSR3 system. If GPROC is also usedthen GPROC planning formulae should be used, even for GPROC2.

NOTE

LCFs for MSC to BSC links

Since one LCF GPROC can support one MTL, the number of required LCF is the sameas the number of required MTLs (MSC to BSC links) obtained from Table 10-1 or frommtls calculated in the non-standard traffic model from the previous section.

For GPROC2, if the number of required MTLs is obtained from Table 10-1 the number ofLCF is:

NLCF � ROUNDUP�MTLs2�

However, if the traffic model does not conform to the standard model:

NLCF � mtls, if 2 � nl link � nl LCF�MTL

otherwise:

NLCF � ROUND UP �mtls2�

Where: NLCF is: the number of LCF GPROC2s required.


mtls calculated in the previous section.

nllink calculated in the previous section.

nlLCF-MTL calculated in the previous section.




MSC to BSCsignalling over asatellite link

The BSC supports preventative cyclic retransmission (PCR) to interface to the MSC overa satellite link. PCR retransmits unacknowledged messages when there are no newmessages to be sent. This puts an additional processing load on the GPROCs(LCF–MTLs) controlling the C7 signalling links. It is recommended that when PCR isused, that the number of MTLs (and thus the number of LCF–MTLs) be doubled from thenumber normally required.



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Introduction

The generic processor (GPROC, GPROC2) is used throughout the Motorola BSS as ageneric control processor board. GPROCs are assigned functions and are then knownby their function names.

This section describes the BSC GPROC types and their functions. The BSCconfiguration type and GPROC device type, are essential factors for BSC planning.

GPROCfunctions andtypes

There are two GPROC hardware types, GPROC and GPROC2. GPROC2 is needed, inGSR3, for master processor functionality.

The GPROC is the basic building block of a distributed architecture. The GPROCprovides the processing platform for the BSC. By using multiple GPROCs software taskscan be distributed across GPROCs to provide greater capacity. The set of tasks that aGPROC is assigned, depends upon the configuration and capacity requirements of theBSC. Although every GPROC is similar from a hardware standpoint, when a group oftasks are assigned to a GPROC, it is considered to be a unique GPROC device type orfunction in the BSC configuration management scheme.

There are a limited number of defined task groupings in the BSC, which result in thenaming of four unique GPROC device types for the BSC. The processing requirement ofa particular BSC determines the selection and quantity of each GPROC device type.

The possible general task groupings or functions for assignment to GPROCs are:

� BSC common control functions.

� OMC communications – OML (X.25) including statistic gathering.

� MSC link protocol (C7).

� BSS Layer 3 call processing (BSSAP) and BTS link protocol, RSL (LAPD).

� Cell broadcast centre link (CBL).

The defined GPROC devices and functions for the BSC are:

� Base Site Control Processor (BSP).

� Link Control Function (LCF).

� Operations and Maintenance Function (OMF).

� Code Storage Facility Processor (CSFP).

At a combined BSC BTS site the BTF and DHP are additional GPROC function and typein the network element.

Prior to GSR3 a separate OMF was needed if OML traffic exeeded a definedthreshold. With GSR3 and GPROC2 the use of a separate OMF becomesoptional.

NOTE

GSM-001-103Generic processor (GPROC, GPROC2)



BSC types

The BSC is configured as one of two types; the type is determined by the GPROCspresent.

With GSR3, and the use of GPROC2s, BSC type 1 is the only configurationrequired.

NOTE

� BSC type 0

– Master GPROC.

Running the BSP.

BSC type 0 is not recommended for operating BSC. Beginning with release1.4.0.x, BSC type 0 is not supported.

NOTE

� BSC type 1

– Master GPROC.

Running the base site control processor (BSP) and carring out operationsand maintenance functionalities.

– Link control function (LCF).

Running the radio signalling link (RSL) and layer 3 processing or MTL (C7signalling link) communications links.

� BSC type 2

– Master GPROC.

Running the BSP.

– LCF.

– OMF.

Running the O&M, including statistics collection, and OML link (X.25 controllinks to the OMC-R).

The number of serial links per GPROC must be determined for each site. The currentvalues are either 8 or 16, with 16 being the default value. One link is reserved for eachmodule, so the number of available serial links is either 7 or 15.



68P02900W21-G


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The following factors should be considered when planning the GPROC complement:

� Each BSC requires:

– One master GPROC or GPROC2 (BSP).

– One OMF (if it is a type 2 BSC).

– A number of LCFs for MTLs, see Link control processor below.

– LCFs to support the RSL and control of the BTSs.

� Optional GPROCs Include:

– One redundant master GPROC or GPROC2 (BSP).

– At least one redundant pool GPROC (can cover LCFs, OMF, and BTF).

– An optional dedicated CSFP.

� A maximum of eight GPROCs can be supported in a BSU shelf.

� The master GPROC slot (20) in the first shelf should always be populated toenable communication with the OMC-R.

� For redundancy each BSC should be equipped with a redundant BSP and anadditional GPROC to provide redundancy for the signalling LCFs. Where multipleshelves exist, each shelf should have a minimum of two GPROCs to provideredundancy within that shelf.




Link control function, using GPROC2 exclusively (GSR3 only)

The planning rules for LCFs exclusively using GPROC2 are:

� A single GPROC2 will support two MTLs, each working at 20% link utilization.

� A single GPROC2 will support up to 15 BTS sites and 31 RSLs, limited to thefollowing calculation:




NOTE



1. If both GPROC2 and GPROC are used in the same BSC then the GPROCmaximums apply to GPROC2. That is, the GPROC2s can handle only asmuch traffic as a GPROC.

2. In some cases the software will allow maximums greater than the planningguide, to allow ease of capacity expansion in future releases, but it is notsupported with this software release.

3. Combining MTL and RSL processing on a single GPROC2 is notrecommended.

NOTE

� A maximum of 15 BTS sites can be controlled by a single LCF. All RSLs (LAPDlinks) for the BTSs must terminate on the same GPROC2, so if return loops areused the maximum number of BTS sites will be 15 (if GPROC_slot parameter =31). If the GPROC_slot parameter is set to 16 then at most 15 RSLs may existwhich would support up to seven BTS sites.

The number of serial links per GPROC must be determined for each site, thecurrent values are either:

For GPROC2; 16 or 32, with 16 being the default value.

For GPROC; 8 or 16, with 16 being the default value.

One link is reserved for each board (GPROC test purposes) so the number ofavailable serial links is either 15 or 31 for GPROC2, and is 7 or 15 for GPROC.

NOTE

When GPROC2s are not used exclusively, the LCF planning rules using GPROCs in thenext section should be used.



68P02900W21-G


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Link control function, using GPROC

LCF planning rules using GPROC are:

� A single GPROC will support a single MTL working at 20% link utilization.

� A single GPROC will support up to 8 BTS sites and 15 RSLs, limited to thefollowing calculation:




NOTE



Combining MTL and RSL processing on a single GPROC is notrecommended.

NOTE

� A maximum of 8 BTS sites can be controlled by a single LCF. All RSLs (LAPDlinks) for the BTSs must terminate on the same GPROC, so if return loops areused the maximum number of BTS sites will be seven (if GPROC_slotparameter =16). If the GPROC_slot parameter is set to 8 then at most 7 RSLsmay exist which would support up to 3 BTS sites.

The number of serial links per GPROC must be determined for each site.

For GPROC the valid values are:Eight or 16 (default). One link is reserved for each board (GPROCtestpurposes) so that the number of available serial links is either 7 or 15.

NOTE




GPROC planningactions (GSR3)

Determine the number of GPROC or GPROC2s required.

NGPROC2 � 2B � L � C � R

Where: NGPROC2 is: the total number of GPROC or GPROC2s required.

B the number of BSP GPROC or GPROC2s (2B forredundancy).

L the number of LCF GPROC or GPROC2s.

C the number of CSFP GPROC or GPROC2s.

R the number of pool GPROC or GPROC2s (forredundancy).

If dedicated GPROC or GPROC2s are required for either the CSFP or OMFfunctions then they should be provisioned separately.

NOTE

GPROC planningactions (GSR2and earlier)

Determine the number of GPROCs required.

NGPROC � 2B � L � C � O � R

Where: NGPROC is: the total number of GPROCs required.

B the number of BSP GPROCs (2B for redundancy).

L the number of LCF GPROCs.

C the number of CSFP GPROCs.

O OMF GPROCs.

R the number of pool GPROCs (for redundancy).

Cell broadcastlink

The cell broadcast link (CBL) connects the BSC to the cell broadcast centre. For typicalapplications (less than ten messages per second), this link can exist on the same LCF asthat used to control BTSs. The CBL should not be controlled by a LCF–MTL (a GPROCcontrolling an MTL).



68P02900W21-G


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OMF GPROCrequired

The BSC type 2 configuration offloads many of the O&M functions and control of theinterface to the OMC-R from the BSP. One of the major functions off loaded from theBSP is the central statistics process. When determining the total number of statistics,consider the number of instances of that statistic.

NST � (ECS � C) � (TCS � n) � SX25LAPD (L � X � B)

Where: NST is: the total number of statistics.

ECS the number of enabled cell statistics


Tcs the number of traffic enabled channel statistics.

n the number of traffic channels.

SX25LAPD the number of X.25/LAPD statistics.

L the number of RSLs.

X the number of OMLs.

B the number of XBLs

The formula assumes that the same cell and channel statistics are enabledacross all cells.

NOTE


The BSS supports a GPROC acting as the code storage facility processor (CSFP). TheCSFP allows pre-loading of a new software release while the BSS is operational.

If a dedicated GPROC is to exist for the CSFP, an additional GPROC will be required.

When M-Cell BTSs are connected to the BSC, a dedicated CSFP is required at the BSCand a second dedicated CSFP should be equipped for redundancy.

The BSS supports a method whereby a dedicated CSFP GPROC is not required. Thismethod is called configure CSFP and works as follows:

The system can borrow certain devices and temporarily convert them into a CSFP, andwhen the CSFP functionality is no longer needed the device can be converted back intoits previous device. The devices the system can borrow are a redundant BSP/BTP or apooled GPROC.

This functionality allows an operator who already has either a redundant BSP/BTP or apooled GPROC in service to execute a command from the OMC-R to borrow the deviceand convert it into a CSFP. The operator can then download the new software load ordatabase and execute a CSFP swap. Once the swap has been completed and verifiedas successful, the operator can return the CSFP back to the previous redundant orpooled device type via a separate command from the OMC-R.

See the Technical Description: BSS/RXCDR (GSM-100-323A) or Service Manual:BSC/RXCDR (GSM-100-030) for more details.




GPROCredundancy

BSP redundancy

The failure of the BSP GPROC will cause a system outage. If the BSC is equipped witha redundant BSP GPROC, then the system will restart under the control of the redundantBSP GPROC. If the BSC is not equipped with a redundant BSP and the BSP GPROCwere to fail, the BSC would be inoperable.

Pooled GPROCs for LCF and OMF redundany

The BSS supports pooled GPROCs for LCF and OMF redundancy. By equippingadditional GPROCs for spares, if an LCF or the OMF GPROC were to fail, the systemsoftware will automatically activate a spare GPROC from the GPROC pool to replace thefailed GPROC.



68P02900W21-G


10–29

Transcoding

Introduction

Transcoding reduces the number of cellular subscriber voice/data trunks required by afactor of four. If transcoding takes place at the switch using a RXCDR, the number oflinks between the RXCDR and the BSC is reduced to approximately one quarter of thenumber of links between the RXCDR and the MSC.

The capacity of one BSU shelf is 12 MSI slots, six of which may contain a transcoder(XCDR) or generic DSP processor (GDP); this limitation is due to power constraints. Thecapacity of one RXU shelf can support up to 16 GDP/XCDRs or GDPs and typicallyprovides a better solution of the transcoding function for larger commercial systems.Refer to the section Remote transcoder planning overview in Chapter 6.







NOTE




T1 conversion


When required, MSI-2s can be used to provide T1 to E1 conversion. This can be done inone of two ways. In either case the conversion may be part of an existing networkelement or a standalone network element which would appear as a RXCDR.


A single MSI-2 can be programmed to be E1 on one port and T1 on the other. This is thesimplest method, but uses at most 24 of the transcoding circuits on the XCDR. Thismethod has no impact on the TDM bus ports, but does require MSI slots. This methodrequires the number of GDP/XCDRs and additional MSI-2s to be equal to the number ofT1 links.

With KSW switching

For better utilization of the GDP/XCDRs, a mapping of five T1 circuits onto four E1circuits may be done. This uses the ability of the KSW to switch between groups usingnailed connections. Although more efficient in XCDR utilization, this method may causeadditional KSWs to be used. Each MSI-2 requires an MSI slot. The number of MSI-2sneeded for T1 to E1 conversion is:

m = T + E

2






68P02900W21-G


10–31

Planning actionstranscoding atthe BSC

Planning transcoding at the BSC must always be performed as it determines the numberof E1 or T1 links for the A interface. This text should be read in conjunction with the BSSplanning diagram Figure 10-1.

Using E1 links


N = T30

N = C + X + T

31



X the number of OML links (X.25 control links tothe OMC) through the MSC.


Using T1 links

The minimum number of T1 links required is the greater of two calculations that follow(fractional values should be rounded up to the next integer value).

N = T23

N = C + X + T

24



X the number of OML links (X.25 control links tothe OMC) through the MSC.






Introduction

A multiple serial interface provides the interface for the links between a BSSC cabinetand other network entities in the BSS, BSC to BTS and BSC to RXCDR. An MSI caninterface only E1 links, an MSI-2 can interface both E1 and T1 links, but notsimultaneously.




� Each MSI-2 can interface two T1 links.

Although the MSI-2 is configurable to support either E1 or T1 on each of its twoports, it is not recommended for E1 systems.

NOTE





If the OML links go directly to the MSC the master slot should be filled with anGDP/XCDR, otherwise the slot should be filled with an MSI/MSI-2 whichterminates the E1/T1 link carrying the OML link to the OMC-R. These E1/T1 linksdo not need to go directly to the OMC-R, they may go to another network elementfor concentration.



68P02900W21-G


10–33


The following formulae assume local transcoding. Refer to the Multiple serial interface(MSI, MSI-2) section of Chapter 6 RXCDR planning steps and rules for MSI planningformulae for remote transcoding.

With E1 links

Determine the number of MSIs required.

M = B2

Where: M is: the number of MSIs required.


With T1 links

Determine the number of MSI-2s required.

M = B2� m

Where: M is: the number of MSI/MSI-2s required.


m the number of MSI/MSI-2s used for T1 to E1conversion.





Introduction

The kiloport switch (KSW) card provides digital switching for the TDM highway of theBSC.


The following factors should be considered when planning the KSW complement:

� A minimum of one KSW is required for each BSC site.

� The KSW capacity of 1,024 64 kbit/s ports can be expanded by adding up to threeadditional KSWs, giving a total switching capacity of 4, 096 64 kbit/s ports ofwhich, eight timeslots are reserved by the system for test purposes and are notavailable for use.

� For planning purposes assume fourteen MSI maximum per KSW. Each MSI maybe replace with four GDP/XCDRs.

� Using twelve MSIs per KSW may reduce the number of shelves required at a costof additional KSWs. For example, a BSC with 28 MSIs could be housed in threeshelves with three KSW modules or four shelves with two KSW modules.

� Verify that each KSW uses fewer than 1016 ports. There are three devices in aBSC that require TDM timeslots. They are:





– The number of TDM timeslots is given by.

N = (G * n) + (R * 16) + (M * 64)

Where: N is: the number of timeslots required.




M the number of MSI/MSI-2s (do not count MSI-2swhich are doing on board E1 to T1 conversion,when determining TDM bandwidth).


Any BSC site which contains a DRIM has 352 timeslots allocated to DRIMsirrespective of the number of DRIMs equipped.

NOTE

GSM-001-103 Kiloport switch (KSW)


68P02900W21-G


10–35

KSW planningactions

Determine the number of KSWs required:

N = (G * n) + (R * 16) + (M * 64)

(1016)






GSM-001-103BSU shelves



BSU shelves

Introduction

The number of BSU shelves is normally a function of the number of GPROC/GPROC2,MSI/MSI-2s, and GDP/XCDRs required.


The following factors should be considered when planning the number of BSU shelves:

� Each BSU shelf supports up to eight GPROCs or GPROC2s, if the number ofthese exceed the number of slots available an additional BSU shelf is required.

� Each shelf is allocated to a single KSW and extension shelves are differentiated bythe presence of the KSW; extension shelves are those which do not contain aprimary KSW.

� A BSU shelf can support up to 12 MSI/MSI-2 boards.

� A BSU shelf can support up to six GDP/XCDRs boards.(reducing appropriately, the number of MSI/MSI-2 boards).

BSU shelfplanning actions

Determine the number of BSU shelves required.

The number of BSU shelves required is the greater of three calculations that follow(fractional values should be rounded up to the next integer value).

Bs = G8

Bs = M + R

12

Bs = R6

Where: Bs is: the minimum number of BSU shelves required.




The number of shelves may be larger if an attempt to reduce the number ofKSWs is made.For GSR3 the number of shelves (cages) = 94For GSR3 the number of cabinets = 90There is a database limitation of 50 cabinets/shelves.M-Cell sites do not require a cage to be equipped, only a cabinet.

NOTE

GSM-001-103 Kiloport switch extender (KSWX)


68P02900W21-G


10–37


Introduction

The kiloport switch extender (KSWX) extends the TDM highway of a BSU to other BSUsand supplies clock signals to all shelves in multi-shelf configurations. The KSWX isrequired whenever a network element grows beyond a single shelf.









� The maximum number of KSWX slots per shelf is 18, 9 per KSW.


The number of KSWXs required is the sum of the KSWXE, KSWXL and KSWXR.


NKXE � K � (K � 1)

NKXR � SE

NKXL � K � SE






SE the number of extension selves.


NOTE




For example

Table 10-6 KSWX (non-redundant)

Extensionshelves

KSW (non redundant)shelves

1 2 3 4

0 1 4 9 16

1 3 6 11 18

2 5 8 13 20

3 7 10 15 22

4 9 12 17 24

Table 10-7 KSWX (redundant)

Extensionshelves

KSW (redundant)shelves

1 2 3 4

0 2 8 18 32

1 6 12 22 36

2 10 16 26 40

3 14 20 30 44

4 18 24 34 48



68P02900W21-G


10–39


Introduction

The generic clock (GCLK) generates all the timing reference signals required by a BSU.



� One GCLK is required at each BSC.

� The maximum number of GCLK slots per shelf is two.

� For redundancy add a second GCLK at each site in the same cabinet as the firstGCLK.








Introduction

A clock extender (CLKX) board provides expansion of GCLK timing to more than oneBSU.



� One CLKX is required in the first BSU shelf, which contains the GCLK, whenexpansion beyond the shelf occurs.


� There are three CLKX slots for each GCLK, allowing each GCLK to support up to18 shelves (LAN extension only allows 14 shelves in a single network element).



NOTE





NCLKX � ROUNDUP�E6� * (1 � RF)





GSM-001-103 LAN extender (LANX)


68P02900W21-G


10–41

LAN extender (LANX)

Introduction









NLANX � NBSU * (1 � RF)




BSU � 14





Introduction






PIX planningactions

Choose the number of PIXs required.


or

PIX � 8.



68P02900W21-G


10–43


Introduction




� To match a balanced 120 ohm (E1 2.048 Mbit/s) or balanced 110 ohm (T11.544 Mbit/s) 3 V (peak pulse) line use a BIB.

� To match a single ended unbalanced 75 ohm (E1 2.048 Mbit/s) 2.37 V (peakpulse) line use a T43 Board (T43).


� Up to four BIBs or T43s per shelf can be mounted on a BSSC2 cabinet

– A maximum of 24 E1/T1 links can be connected to a BSU shelf.

– A BSSC2 cabinet with two BSU shelves can interface 48 E1/T1 links.





Minimum number of BIBs or T43s = Number of MSIs

3 =


GSM-001-103Digital shelf power supply




Introduction



The following factors should be considered when planning the PSU complement:

� Two DPSMs are required for each shelf in the BSSC.

� Two IPSMs are required for each shelf in the BSSC2 (–48/–60 V dc).

� Two EPSMs are required for each shelf in the BSSC2 (+27 V dc).

� For redundancy, add one DPSM, IPSM, or EPSM for each shelf.


Determine the number of PSUs required.



GSM-001-103 Battery backup board (BBBX)


68P02900W21-G


10–45


Introduction

The battery backup board (BBBX) provides a backup supply of +5 V dc at 8 A from anexternal battery to maintain power to the GPROC DRAM and the optical circuitry on theLANX in the event of a mains power failure.



� One BBBX is required per shelf; if the battery backup option is to be used.





GSM-001-103Verify the number of BSU shelves and BSSC2 cabinets



Verify the number of BSU shelves and BSSC2 cabinets

Verification


� The number of shelves is greater than one eighth the number of GPROC (orGPROC2) modules.



� The number of KSWX, LANX, CLKX, and GPROCs is correct.

� The number of MSI/MSI-2 and GDP/XCDR


� The number of GDP/XCDR


� The number of BTS sites

� 40.

� The number of BTS cells

� 126.

� RSLs

� 80.

� Carriers

� 255.

� Erlangs

� 1375.

If necessary, add extra BSU shelves. Each BSSC2 cabinet supports two BSU shelves.


68P02900W21-G


i

Chapter 11

Previous generation BTS planning

and equipment descriptions

GSM-001-103



GSM-001-103


68P02900W21-G


iii

Chapter 11Previous generation BTS planning and equipment descriptions i. . . . . . . . Chapter overview 11–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction 11–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BTS planning steps and rules 11–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Outline of planning steps 11–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Control channel calculations 11–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Calculations for determining BTS GPROC, GPROC2 requirements 11–7. . . . . . . . . . . . . . . . Introduction 11–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Call processing functions 11–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC, GPROC2 management 11–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC, GPROC2 planning 11–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BTS shelf configurations 11–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Shelf configurations for typical call mix 11–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Shelf configurations for border location area call mix 11–12. . . . . . . . . . . . . . . . . . . . . . .

BTS equipment cabinets 11–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cabinet planning actions 11–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Receiver front end 11–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RFE in cabinet types EG, FG and BTS6 11–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RFE in cabinet types AG, BG and DG 11–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Distributing Rx signals between multiple cabinets 11–15. . . . . . . . . . . . . . . . . . . . . . . . . . RFE planning actions 11–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Transmit combiner shelf 11–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transmit combining equipment 11–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 11–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transmit combiner shelf planning actions 11–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Duplexer 11–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 11–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Duplexer planning actions 11–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Carrier equipment (DRCU/SCU/TCU, DRIM, DRIX) 11–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 11–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Carrier equipment planning actions 11–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .



GSM-001-103



Generic processor (GPROC, GPROC2) 11–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 11–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPROC, GPROC2 planning actions 11–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Timeslot switch (TSW) 11–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 11–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSW planning actions 11–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .




Local area extender (LANX) 11–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 11–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LANX planning actions 11–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Digital radio interface extender (DRIX3c) 11–31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Planning considerations 11–31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DRIX planning actions 11–31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .



BTS RF configurations 11–34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 11–34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Typical BTS configurations 11–35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BTS configuration 11–35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TopCell BTS configuration 11–36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Single cabinet RF configurations 11–37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Single cabinet, single DRCU/SCU without diversity 11–37. . . . . . . . . . . . . . . . . . . . . . . . Single cabinet, single DRCU/SCU with diversity 11–39. . . . . . . . . . . . . . . . . . . . . . . . . . . Single cabinet, five DRCU/SCUs with combining 11–40. . . . . . . . . . . . . . . . . . . . . . . . . . Single cabinet, six DRCU/SCUs with combining and diversity 11–42. . . . . . . . . . . . . . . Single cabinet, multiple antennas 11–45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Single cabinet, multiple antennas with diversity 11–47. . . . . . . . . . . . . . . . . . . . . . . . . . . .

GSM-001-103


68P02900W21-G


v

Multiple cabinet RF configurations 11–49. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Multiple cabinet, single antenna, four DRCU/SCUs 11–49. . . . . . . . . . . . . . . . . . . . . . . . Multiple cabinet, single antenna, ten DRCU/SCUs 11–51. . . . . . . . . . . . . . . . . . . . . . . . . Multiple cabinet, multiple antenna 11–53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Six sector configuration 11–54. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Six–sector BTS6 configuration 11–56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GSM-001-103





68P02900W21-G


11–1

Chapter overview

Introduction

This chapter (included for reference only) is divided into two sections and describes:

� BTS planning steps and rules.

� BTS RF configurations.

GSM-001-103BTS planning steps and rules



BTS planning steps and rules

Introduction

This section provides the planning steps and rules for the BTS, including ExCell andTopCell. This chapter contains:

� BTS planning overview:

� Capacity calculations for the number of control channels required.

� Capacity calculations for the number of GPROCs required.

– Planning rules for BTS cabinets.

– Planning rules for the receiver front end.

– Planning rules for the transmit combiner shelf.

– Planning rules for the carrier equipment.

– Planning rules for the line interconnections.



GSM-001-103 BTS planning steps and rules


68P02900W21-G


11–3


BTS site

The steps required to plan a BTS site (including ExCell and TopCell sites) are listedbelow:

1. Determine if the site has equipment shelters.

2. Determine the number of BTS cabinets required, refer to the section BTScabinets in this chapter.

3. Determine the receiver front end configuration, refer to the section Receiver frontend in this chapter.

4. Determine the transmit combining configuration, refer to the section Transmitcombiner shelf in this chapter.

5. Determine the number of bandpass filters required, refer to the section Duplexerin this chapter.

6. Determine the antenna configuration, refer to the section Duplexer in this chapter.

7. Determine the amount of carrier equipment required, refer to the section Carrierequipment (DRCU/SCU/TCU, DRIM, DRIX) in this chapter.

8. Determine the number of E1/T1 line interfaces required, refer to the section Lineinterface (BIB, T43) in this chapter.

9. Determine the number of MSIs required, refer to the section Multiple serialinterfaces (MSI, MSI-2) in this chapter.

10. Determine the number of GPROC, GPROC2s required, refer to the sectionGeneric processor (GPROC, GPROC2) in this chapter.

11. Determine the number of TSWs required, refer to the section Timeslot switch(TSW) in this chapter.

12. Determine the number of KSWXs required, refer to the section Kiloport switchextender (KSWX) in this chapter.

13. Determine the number of GCLKs required, refer to the section Generic clock(GCLK) in this chapter.

14. Determine the number of CLKXs required, refer to the section Clock extender(CLKX) in this chapter.

15. Determine the number of LANXs required, refer to the section LAN extender(LANX) in this chapter.

16. Determine the number of PIXs required, refer to the section Parallel interfaceextender (PIX ) in this chapter.

17. Determine the number of DRIX3cs required, refer to the section Digital radiointerface extender (DRIX3c ) in this chapter.

18. Determine the number of BBBXs boards required, refer to the section Batterybackup board (BBBX) in this chapter.

19. Determine the power requirements, refer to the section Digital shelf powersupply in this chapter.





Introduction

This section provides information on how to determine the number of control channelsand the number of GPROC, GPROC2s required at a BTS.

This information is required for the sizing of the links to the BSC, and is required whencalculating the exact configuration of the BSC required to support a given BSS.

Typical callparameters

The number of control channels and GPROC, GPROC2s required at a BTS depend on aset of call parameters; typical call parameters for BTS planning are given in Table 11-1.





Ratio of location updates to calls: non-border location area l = 2

Ratio of location updates to calls: border location area l = 7

Ratio of IMSI detaches to calls �d = 0

Location update factor: non-border location area (see below) L = 2

Location update factor: border location area (see below) L = 7


Paging Rate in pages per second P = 3

Time duration for location update TL = 4 seconds

Time duration for SMSs TSMS = 6seconds

Time duration for call setups TC = 5 seconds


GSM-001-103 Capacity calculations


68P02900W21-G


11–5



Probability of blocking for TCHs PB-TCH < 2%

Probability of blocking for SDCCHs PB-SDCCH < 1%

The location update factor (L) is a function of the ratio of location updates to calls (I), theratio of IMSI detaches to calls (�d) and whether the short message sequence (type 1) orlong message sequence (type 2) is used for IMSI detach; typically �d = 0 (that is IMSIdetach is disabled) as in the first formula given below. When IMSI detach is enabled, thesecond or third of the formulas given below should be used. The type of IMSI detachused is a function of the MSC.

If IMSI detached is disabled:

L = I


L = I + 0.2 * �d


L = I + 0.5 * �d




Control channel calculations

Introduction

There are four types of air interface control channels, they are:

� Broadcast control channel (BCCH).

� Common control channel (CCCH).

� Standalone dedicated control channel (SDCCH).

� Cell broadcast channel (CBCH), which uses one SDCCH.

There are three configurations of control channels, each occupies one radio timeslot:

� A combined control channel.

One BCCH plus three CCCH plus four SDCCH.

� A non-combined control channel.

One BCCH plus nine CCCH (no SDCCH).

� An SDCCH control channel.

Eight SDCCH.

Each sector/cell requires a BCCH, so at least one of the first two configurations is alwaysrequired.

The number of air interface control channels required for a site, is dependent on the:

� Number of pages.

� Location updates.

� Short message services.

� Call loading.

� Setup time.

Only the number of pages and access grants affects the CCCH. The other informationuses the SDCCH.

GSM-001-103 Calculations for determining BTS GPROC, GPROC2 requirements


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11–7

Calculations for determining BTS GPROC, GPROC2 requirements

Introduction

This section discusses the basic planning dependencies for determining the number ofGPROC, GPROC2s required for a BTS site. Some background information regardingthe call processing functions at the BTS is also provided.

Call processingfunctions

Three major call processing functions exist at a BTS. These are:

� Cell resource manager (CRM).

� Radio resource state machine (RRSM).

� Radio subsystem (RSS).

The CRM and RRSM are associated with the call processing function for the entire BTSsite. The BTS site supports a single instance of the CRM and RRSM and multipleinstances of RSS. An instance of RSS controls a number of RTFs. Each instance ofRSS only performs call processing for its assigned, individual, or group of digital radiointerfaces (DRIMs). A DRIM is controlled by one instance of RSS, and must reside in thesame shelf as the GPROC, GPROC2 running the instance of RSS. A DRIM provides theprocessor interface to one DRCU/SCU/TCU. The DRIM, DRIX, and DRCU/SCU/TCUare viewed as providing one carrier by the GPROC, GPROC2.

For a remote BTS site, that is a site that is remote from the BSC, the base transceiverprocessor (BTP), undertakes the master operations and maintenance (O&M) function forthe site, together with the CRM and RRSM functions. The term BTP refers to theGPROC, GPROC2 performing the CRM and RRSM functions. The term digital hostprocessor (DHP) refers to the GPROC, GPROC2 performing the call processing functionof RSS. When the BTS is colocated with the BSC, the CRM and RRSM functions areperformed by the BTF. The same planning rules apply to a BTF as the BTP.

GSM-001-103Calculations for determining BTS GPROC, GPROC2 requirements



GPROC, GPROC2management

This section discusses topics associated with the GPROC, GPROC2. These are themax_dris parameter, the reassign command, and redundancy considerations.

Maximum number of DRIMs

The max_dris parameter defines the maximum number of DRIMs that may be controlledfrom the BTP or DHP. The parameter can be changed on an individual BTP or DHPbasis.

When the sum of max_dris for all BTPs and DHPs in a shelf is less than the number ofDRIMs in the shelf, only the number of DRIMs equivalent to the sum of max_dris willcome into service. For example, if a shelf has five DRIMs with two DHPs (and no BTP),and assuming that the max_dris parameter is set to 2, for both the DHPs (giving a totalof four), then only four of the DRIMs will come into service, and will be able to supportactive RTFs.

For the purposes of redundancy, when equipping additional DHPs in a BTS shelf, themax_dris parameter for each DHP must be set to take account if a DHP fails. Thismeans that the sum of max_dris must still be equal to, or greater than, the number ofDRIMs equipped in the specific shelf after the failure of a GPROC, GPROC2 in the shelf.

Control of DRIM loading

The system software attempts to balance the DRIM process load across the GPROC,GPROC2s in a shelf. Unbalanced conditions can arise where certain GPROC,GPROC2s are heavily loaded, while others are lightly loaded. The DRIM process loadcan be redistributed using the reassign command.

The reassign command allows the moving of DRIM control from one GPROC, GPROC2to another: one DHP to another DHP, the BTP to a DHP, DHP to the BTP. The GPROC,GPROC2s must be in the same shelf as the DRIM.

When a site has been reset, the system will revert to the original pre-reset allocation ofDRIMs to GPROC, GPROC2s. During execution of the reassign command, the DRIMand RTF supported by the DRIM is momentarily taken out of service.

Redundancy considerations

A BTS should always be configured with sufficient redundancy such that a singleGPROC, GPROC2 failure will not:

� Degrade system performance.

� Reduce capacity.

� Cause the BTS site to become inoperative.

Each BTS site should be equipped with a redundant BTP, since failure of the BTP willresult in an inoperative BTS.

An additional DHP should be equipped in each BTS shelf already containing a DHP. Thisredundant DHP will allow for a DHP to fail in any shelf and not cause the other GPROC,GPROC2s in that shelf to become overloaded or a RTF to become inoperable. If a DHPwere to fail, and the sum of the max_dris for the remaining DHP(s) was less than thenumber of DRIMs, some RTF(s) would become inoperative. Under these conditions, ifthere were only a single DHP in a shelf, all RTFs using DRIMs in that shelf would beinoperative. If a DHP were to fail in the shelf with the BTP and the BTP was controlling anumber of RTFs less than its max_dris setting, the BTP will take control of the RTF(s)that were controlled by the failed DHP, up to a number of RTFs equivalent to itsmax_dris setting.

Where the number of DHPs is greater than the number of RTFs, some DHPs will remainin an idle condition.



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11–9

GPROC, GPROC2planning

The number of GPROC, GPROC2s required at a given BTS site is dependent on carrierand channel configuration together with the projected call mix at the BTS. The projectedcall mix must be done on an individual BTS basis. When determining the requirednumber of GPROC, GPROC2s for a given BTS shelf, the call mix associated with thecells supported by the RTFs in the shelf, must be used.

BTS type 0

A BTS type 0 only supports one active GPROC, which is referred to as the BTP.Although a second BTP may exist to meet redundancy requirements, only one may beactive at any given time.

For the typical call mix a type 0 BTS supports up to two RTFs. For a BTS with morethan three RTFs then a type 1 BTS should be used. For the border location area call mixa type 0 BTS supports up to two RTFs. If the call parameters differ significantly fromthose given in Table 3-1 then the formula given below should be used.

BTS type 1

A BTS type 1 supports multiple active GPROC, GPROC2s. The RRSM and CRMfunctions reside on the BTP, in addition to an optional instance of the RSS. A BTS type 1also supports DHPs.

The number of RTFs a BTP can control depends on the total number of RTFs at the BTSsite. Table 11-2 gives the max_dris setting (the number of RTFs a BTP can control) forthe BTP for the typical and border location area call mix for a given number of RTFs andErlangs for a BTS. If the call parameters differ significantly from those given in Table 3-1,the formula given below should be used. If the formula gives two RTFs per DHP, thenthe border location area call mix rules should be used. If the formula gives one RTF perDHP, then the BTP may control one RTF for BTS sites of less than three RTFs.

Table 11-2 Maximum number of Erlangs supported by the BTP

max_drisval e for

Typical call mix Location area border call mixvalue for

BTPMaximum

RTFsMaximumErlangs

MaximumRTFs

MaximumErlangs

0 30 200 20 120

1 22 140 15 85

2 14 80 10 50




Call mixes

The factors that determine call mixes are highly site dependent. The main factors beingthe ratio of location updates to calls and call hold time. Those BTSs that contain cells onthe edge of location areas, will have a greater loading of location updates. This impactsthe number of required DHPs and control channel configurations and the maximumnumber of RTFs supported by a BTS site.

An RTF is controlled by one DHP or the BTP. For the typical call mix a DHP supports upto three RTFs and for the border location area call mix a DHP supports up to two RTFs.If the call parameters differ significantly from those given in Table 3-1, the formula givenhere should be used to determined the maximum number of RTFs a DHP or the BTPshould control; the result should be rounded down to an integer value.

NRTF �0.8

0.2 + (1 + 1.4 � L + 0.9 � S + 0.5 � H) / T

Where: NRTF is: the maximum number of RTFs supported perDHP (type 0 BTS).


S the ratio of SMSs per call.



BTS shelfconfigurations

The number of RTFs supported by a DHP and the BTP must be determined beforedetermining the BTS shelf configurations.

The sections Shelf configurations for typical call mix and Shelf configurations for borderlocation area call mix respectively, provide recommended shelf configurations for thenormal call mixes given in Table 11-3 and Table 11-4, and border location area call mixesgiven in Table 11-5 and Table 11-6. The number of RTFs referred to in these sections isthe number of active RTFs. Inactive, or standby carriers do not utilize GPROC,GPROC2 resources. The numbers given are the number of GPROC, GPROC2srequired with and without redundancy. For redundancy the number of GPROC,GPROC2s given is the number required such that no single GPROC, GPROC2 failurewill cause a loss of RTFs or capacity. See redundancy considerations below for moredetails on GPROC, GPROC2 redundancy.

Command max_dris

The max_dris setting for the DHP should be the same as the number of RTFs per DHP.For the BTP the max_dris setting should be the value from Table 11-3, Table 11-4,Table 11-5 and Table 11-6; or from the formula given above.

Redundant GPROC, GPROC2s

For redundancy the BTP should be duplicated. The letter R next to the max_drisnumber in the following tables indicates that this DHP is optional and only required forredundancy.



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11–11

Shelfconfigurationsfor typical callmix

Table 11-3 and Table 11-4 give the recommended number of GPROC, GPROC2s andmax_dris values for the first shelf and the other shelves, respectively for a BTS with thetypical call mix parameters. The BTP is duplicated when redundancy (R) is specified.

Table 11-3 Recommended BTP/DHP configurations and max_dris values for thefirst shelf of a BTS (three RTFs per DHP)

Number max_dris values Total GPROCs

of RTFs BTP DHP1 DHP 2 DHP 3 Withoutredundancy

Withredundancy

With 6 or fewer RTFs at BTS site

1 – 2 2 1 2

3 – 5 2 3 3(R) 2 4

6 2 3 3(R) 3 5

With 7 to 14 RTFs at BTS site

2 2 3 1 2

3 – 5 2 3 3(R) 2 4

6 2 3 3 3(R) 3 5

With 15 to 22 RTFs at BTS site

1 1 3 1 2

2 – 4 1 3 3(R) 2 4

5 – 6 1 3 3 3(R) 3 5

With more than 22 RTFs at BTS site

1 – 3 0 3 3(R) 1 2

4 – 6 0 3 3 3(R) 2 3

Table 11-4 Other shelves (three RTFs per DHP)


of RTFs DHP1

DHP 2 DHP 3 DHP 4 Withoutredundancy

Withredundancy

1 – 3 3 3(R) N/A 1 2

3 – 6 3 3 3(R) N/A 2 3




Shelfconfigurationsfor borderlocation area callmix

Table 11-5 and Table 11-6 give the recommended number of GPROC, GPROC2s andmax_dris values for the first shelf and the other shelves, respectively for a BTS with theborder location area call mix parameters. The BTP is duplicated when redundancy (R) isspecified.

Table 11-5 Recommended BTP/DHP configurations and max_dris values for the firstshelf of a BTS (three RTFs per DHP)


of RTFs BTP DHP1 DHP2 DHP3 DHP 4 Withoutredundancy

Withredundancy


1 – 2 2 1 2

3 – 4 2 2 2(R) 2 4

5 – 6 2 2 2 2(R) 3 5


1 1 1 2

2 – 3 1 2 2(R) 2 4

4 – 5 1 2 2 2(R) 3 5

6 1 2 2 2 2(R) 4 6


1 – 2 0 2 2(R) 2 4

3 – 4 0 2 2 2(R) 3 5

4 – 6 0 2 2 2 2(R) 4 6

Table 11-6 Other shelves (three RTFs per DHP)


of RTFs DHP1 DHP 2 DHP 3 DHP 4 Withoutredundancy

Withredundancy

1 – 3 2 2(R) 1 2

3 – 4 2 2 2(R) 2 3

5 – 6 2 2 2 2(R) 3 4

GSM-001-103 BTS equipment cabinets


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BTS equipment cabinets

Introduction

Each BTS6 cabinet can support up to six cells and six carriers, earlier cabinets supportedfewer carriers. The minimum number of cabinets required can be determined by dividingthe total number of carriers by six. Keeping all the carrier equipment in a cell in theminimum number of cabinets makes interconnection simpler.

However, consider a three cell site with two carriers per cell. This fits well in a singlecabinet. When this site needs to expand, an additional cabinet must be added and atleast one cell needs to move to the second cabinet.

A three cell site which will grow to four carriers per cell can be accommodated in twoBTS cabinets, if the cell which is split between cabinets can use hybrid combining. If aremotely tuneable combiner (RTC) is to be housed in an external equipment cabinet, athird BTS cabinet may provide a better alternative as well as room to expand later.

Cabinet planningactions


� Determine if ExCell or TopCell cabinets are required.

� Determine the number of cabinets required and number of cells to be supported byeach cabinet.

GSM-001-103Receiver front end



Receiver front end

Introduction

The receiver front end (RFE) provides the termination and distribution of the receivedsignals from the Rx antennas. RFE equipment is required for each Rx signal in everycabinet in which it is used. Each Rx antenna must terminate on a single cabinet. It willnormally be one of the BTS cabinets but it may be the external equipment cabinet. If thesignal needs to go to multiple cabinets it will be distributed from the first cabinet. ForRFE planning purposes include inactive RF carriers in the number of carriers considered.

RFE in cabinettypes EG, FG andBTS6

Cabinet types EG, FG, BTS6 come equipped with a DPP shelf which has the capacity tohold up to three modules of the following types:

� Dual path preselector (DPP) modules.

One DPP is required for every two Rx signals.

and/or

� Single path preselector (SPP) modules.

One SPP is required for each Rx signal.

and/or

� Passive splitter modules.

One passive splitter is required for every two Rx signals (may be fed from anunused output of a DPP or from the expansion port of a DPP2 in the cabinetterminating the Rx antenna).

Each module has the ability to distribute the Rx signal to six DRCU/SCU/TCUs in thecabinet.

RFE in cabinettypes AG, BGand DG

Cabinet types AG, BG, DG come equipped with a preselector shelf which has thecapacity to hold up to three preselectors each with its own 6-way splitter. If more thanthree Rx antennas need to be terminated, a second preselector shelf is required. Thissecond shelf displaces Tx equipment.

One Preselector with 6-way splitter is required for each Rx signal.

The splitter/preselector shelf can be removed from the BG and DG cabinets and a DPPshelf fitted.

GSM-001-103 Receiver front end


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Distributing Rxsignals betweenmultiple cabinets

When one Rx signal is feeding multiple cabinets additional equipment and cabling isrequired. There are several options which depend primarily on other equipment at thesite, the number of cabinets to which the signal must be brought, and the number ofDRCU/SCU/TCUs in each of the cabinets. Care must be taken to ensure that the BTScabinet has enough RF ports for the termination and expansion of the Rx signals. This isonly a potential issue when diversity is used.

In order to terminate the Rx antenna on a BTS cabinet when the cell’s DRCU/SCU/TCUsare spread across multiple cabinets, check the number of Rx ports on the cabinet andthe availability of RFE outputs not being used for carriers in the cabinet. Without usingthe Tx ports and combiner coupler ports there is a total of six Rx ports available. The sixports allow for up to three cells with diversity and without extension. If there are threecells with diversity supported in the cabinet, any cell which has DRCU/SCU/TCUs inother cabinets must have the Rx antenna terminated on the other cabinet.

The cabinet which terminates the Rx antenna should provide the input to all othercabinets supporting the cell. If the cell is spread across three or more cabinets, ensurethat there are cabinet Rx ports and available RFE outputs for each cabinet.

Single cabinet rules

The following rules apply for a cabinet to be able to support the Rx termination andextension when the cabinet supports:

� Single cell.

Rx ports exist. Must have a DPP2 or fewer than six DRCU/SCU/TCUs.

� Two cell.

Ability to extend only one cell if diversity is used. Splitter port(s) exist.

� Three cell.

No ability to extend, if diversity is used. Splitter port(s) exist.

Distribution methods

There are three methods of distributing Rx signals between cabinets:

� BTS Cabinet with DPP2

The DPP2 has an additional test/extender port which may be used to drive apassive splitter in the DPP slot in an adjacent BTS cabinet.

� BTS Cabinet without DPP2

Unused splitter outputs may be used for extension to an adjacent cabinet. Eachoutput requires a 6 dB attenuator to feed the preselector/DPP/SPP in the adjacentBTS cabinet.

� Receiver multicoupler

When the Rx antenna distribution is to a large number of cabinets, a GSM receivermulticoupler can be equipped in an external equipment cabinet at the site.

One of the four types of multicoupler extender is required on each activemulticoupler output.

A multicoupler should be installed in an external equipment cabinet.

GSM-001-103Receiver front end



RFE planningactions


1. Determine the number of cells.

2. Determine number of cells which have DRCU/SCU/TCUs in more than onecabinet.

3. Determine the number of Rx antennas per cell supported in each cabinet.

A cell without diversity requires one Rx antenna. A cell with diversity requires twoRx antennas.

4. Determine the type and quantity of RFE equipment required.

GSM-001-103 Transmit combiner shelf


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Transmit combiner shelf

Introduction

The transmit combiner shelf is mounted directly above the upper bank of fans. If asecond preselector shelf is equipped, the Tx combining must be done externally.

Transmit RF signals to be combined inside a BTS cabinet can come either fromDRCU/SCU/TCUs within the cabinet or from a second BTS cabinet. A BTS cabinet hassix Tx ports and two combiner coupling ports.

Transmitcombiningequipment

The following equipment may be mounted on the transmit combiner shelf:

� Up to five hybrid combiner modules.

A hybrid combiner combines two inputs into one antenna, five combiners willcombine six inputs.

Unused ports must be terminated with a suitable load.

or

� One remotely tuneable combiner.

A RTC combines up to five inputs (four for a four cavity combiner) into oneantenna.

The channels to which RTC cavities are tuned, must be separated by 800 kHz.

With a phasing harness, up to ten channels (eight for four-cavity combiners) maybe combined together into one antenna.

The cavities of an RTC do not have to be connected to a single antenna.

and

� Up to three transmit bandpass filters.

A Tx BPF is a mandatory requirement for every transmitting antenna.

If an RTC or more than four hybrid combiners are installed, a maximum of two TxBPFs can be accommodated, allowing two cells to be serviced.

or

� Up to two cavity combining blocks (CCB).

A CCB (output) combines up to three inputs into one antenna.

The channels to which CCB cavities are tuned, must be separated by X kHz.

A CCB (extention) enables up to six inputs into one antenna.

GSM-001-103Transmit combiner shelf




The following factors should be considered when planning the combining equipment:

� When there is only one carrier for each sector, combining is not required.

� When two or more DRCU/SCU/TCUs are combined on to one antenna, therequired power output must be known in order to determine the type of combinerto be used.

� There is a greater than 3 dB power loss through each hybrid combiner stage.

� With all cavities of an RTC connected to one antenna, the maximum signal loss forany one input is approximately 3 dB.

� All combining may be done in an external equipment cabinet if desired, thisreduces heat generated in the BTS cabinet.

The remotely tuneable combiner and multicoupler have not been EMC testedfor use in the external equipment rack. Since the end of 1995 these itemshave not been available for use in this configuration within the EuropeanUnion.

CAUTION

Transmitcombiner shelfplanning actions


1. Determine the number of cells required.

2. Determine the output power required.

3. Determine the number and type (hybrid or remotely tuneable) of combinersrequired.

GSM-001-103 Duplexer


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Duplexer

Introduction

If a single antenna is shared between a Tx and an Rx, a duplexer must be fitted.Performance may be degraded and the use of separate Tx and Rx antennas isrecommended.


The following factors should be considered when planning combined antennas:

� A duplexer can be installed in an ExCell cabinet.

� A duplexer can be fitted to a TopCell cabinet.

� A duplexer cannot be fitted into a BTS4, BTS5, or BTS6 cabinet.

� Duplexers may be installed in an external equipment cabinet.

� The inter-modulation performance may be degraded due to the use of commonantenna/feeder, putting the receiver at risk.

� Duplexers have approximately a 0.5 dB loss in both transmit and receive directions.

Duplexerplanning actions


1. Determine if a common antenna is to be used for Tx and Rx.

2. If common antennas are to be used for Tx and Rx, determine the number ofduplexers required.

An external equipment cabinet will be required when duplexers are used withBTS4, BTS5, or BTS6 cabinets.

GSM-001-103Carrier equipment (DRCU/SCU/TCU, DRIM, DRIX)



Carrier equipment (DRCU/SCU/TCU, DRIM, DRIX)

Introduction

A carrier equipment kit consists of:

� For BTS; a DRCU/SCU/TCU, DRIM, and DRIX.

Together these three units provide a single RF carrier, which can be referred to as anRTF.


The following factors should be considered when planning carrier equipment:

� The number of carriers should be based on traffic considerations.

� Plan for future growth.

� Allowance must be made for BCCH and SDCCH control channels.

Information about how to determine the number of control channels required is inthe section Control channel calculations in this chapter.

� Normally, one carrier equipment kit is required to provide each RF carrier.

� Include redundancy requirements; redundancy can be achieved by installingexcess capacity in the form of additional carrier equipment kits.

Carrierequipmentplanning actions


1. Determine the number of carriers required.

2. Make an allowance for redundancy.

3. Determine the number of carrier equipment kits required.



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Introduction

The line interfaces, balanced line interface board (BIB) and T43 board (T43), provideimpedance matching for E1 and T1 links.



� To match a balanced 120 ohm (E1 2.048 Mbit/s) or balanced 110 ohm (T1 1.544Mbit/s) 3 V (peak pulse) line use a BIB.

� To match a single ended 75 ohm 2.37 V (peak pulse) line use a T43 Board (T43).

� Each BIB or or T43 can interface six E1/T1 links.

� The BTS cabinet can interface up to twelve bidirectional E1/T1 links using twoBIBs (six links connected to each board).

� The BTS cabinet can interface up to twelve bidirectional E1 links using two T43boards (six links connected to each board).



1. Determine the number and type of link (E1 or T1) to be driven.

2. Determine the number of BIBs or T43s required.

Number of BIBs or T43s = Number of MSIs

3 =


Refer to the TS Concentration section in Chapter 2 for the planningconsideration of the BTS Concentration feature.

NOTE





Introduction

A multiple serial interface provides the interface between a BTS cabinet and the linksfrom the BSC. An MSI can interface only E1 links, an MSI-2 can interface both E1 andT1 links.


The following factors should be considered when planning the MSI complement:

� To calculate the required number of 64 kbit/s channels, the site must be viewed asconsisting of its own equipment and that of other sites which are connected to it bythe drop and insert method.

Two 64 kbit/s channels are required for each active RTF.

A 64 kbit/s channel is required for every RSL (LAPD signalling channel) to the site.In the drop and insert configuration, every site requires its own RSL for signalling.With closed loop, two RSLs are required per site, one in each direction.

More information can be found in the Multiple serial interface (MSI, MSI-2)Chapter 15, Previous BTS planning steps and rules.


� Each MSI-2 can interface two E1/T1 links.



� A minimum of one MSI/MSI-2 is required for each BTS site.


� Plan for a maximum of ten MSIs in each BTS site (with no BSC).

� Plan for a maximum of eight MSIs or ten MSI-2s for each KSW/TSW.

� The master MSI slot of the first shelf should always be populated to enablecommunication with the BSC.

� Refer to Table 11-7 for the number of traffic channels (TCH) per radio signallinglink (RSL).



68P02900W21-G


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n <= 30 1 1

30 < n <= 60 1 2

60 < n <= 90 1 3

90 < n <= 120 1 4

120 < n <= 150 2 5

150 < n <= 180 2 6

180 < n <= 210 2 7

210 < n <= 240 2 8


NOTE



1. Determine the number and type of link (E1 or T1) to be interfaced.

2. Determine, M, the number of MSIs or MSI-2s required.

M = Number of E1/T1 links

2





Introduction

The generic processor (GPROC, GPROC2) is used throughout the Motorola BSS as ageneric control processor.


The following factors should be considered when planning the GPROC, GPROC2complement:

� At least one GPROC, GPROC2 is required for each digital shelf.

� If more than one cabinet is used, the first cabinet requires a minimum of two activeGPROCs to support the additional cabinets.

� Additional GPROC, GPROC2s may be required to cope with additional load.

� The master GPROC, GPROC2 slot of the BSU shelf should always be populatedto enable communication with the BSC.

GPROC, GPROC2planning actions

Determine the number of GPROC, GPROC2s required.

Use the information to be found in the section Calculations for determining BTSGPROC, GPROC2 requirements in this chapter.

GSM-001-103 Timeslot switch (TSW)


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Timeslot switch (TSW)

Introduction

The timeslot switch (TSW) provides digital switching on the TDM highway of the BTS.

The TSW is designed for use in BTSs, although the KSW can continue to be used.

It should be borne in mind that the KSW provides all the TSW functionality plus subrateswitching and third-party conference functionality, but at an increased cost.


The following factors should be considered when planning the TSW complement:

� A minimum of one TSW is required for each BTS site.

� In a BTS, one TSW can support up to eight MSIs or ten MSI-2s.

� As a site grows beyond 25 DRCU/SCU/TCUs, an additional TSW will be requiredfor switch expansion.

� All DRIMs which support RTFs in a cell must be on a single TDM bus controlled bythe same TSW.

� For redundancy, duplicate all TSW boards.

TSW planningactions

Determine the number of TSWs required.





Introduction

The kiloport switch extender (KSWX) extends the TDM highway of a BSU to other BSUsand supplies clock signals to all shelves in multi-shelf configurations. The KSWX isrequired whenever a network element grows beyond a single shelf. Although notrequired in a single BTS cabinet configuration, if expansion to multiple cabinets isexpected, equipping the KSWX (and CLKX) will allow for easier expansion.



� For redundancy, duplicate all KSWX boards (requires redundant KSW/TSW).






� The maximum number of KSWX slots per shelf is 18, 9 per KSW/TSW.


The number of KSWXs required is the sum of the KSWXE, KSWXL, and KSWXR.


NKXE � K � (K � 1)

NKXR � SE

NKXL � K � SE








NOTE



68P02900W21-G


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Introduction

The generic clock (GCLK) generates all the timing reference signals required by a BTS.



� One GCLK is required at each BTS site.

� For redundancy add a second GCLK at each site in the same cabinet as the firstGCLK.








Introduction

A clock extender (CLKX) provides expansion of GCLK timing to more than one BSU.Although not required in a single BTS cabinet configuration; if expansion to multiplecabinets is expected, equipping the CLKX (and KSWX) will allow for easier expansionlater.



� One CLKX is required if expansion is planned.




NCLKX � ROUNDUP �E6�� (1 � RF)





Each BTS cabinet has one BSU shelf.

NOTE

GSM-001-103 Local area extender (LANX)


68P02900W21-G


11–29

Local area extender (LANX)

Introduction

The local area network extender (LANX) provides a LAN interconnection forcommunications between all GPROC, GPROC2s at a site.








NLANX � NBSU � (1 � RF)




BSU � 14





Introduction






PIX planningactions

Determine the number of PIXs required.


or

PIX � 8.

GSM-001-103 Digital radio interface extender (DRIX3c)


68P02900W21-G


11–31

Digital radio interface extender (DRIX3c)

Introduction

The Digital radio interface extender (DRIX3c) provides the electrical-optical interface forthe downlink (Tx) data and the optical-electrical interface for the uplink (Rx) data betweenthe DRCU/SCU/TCU/PCU and the DRIM.


The following factors should be considered when planning the DRIX3c complement:

� The maximum number of DRIX3c board slots per shelf is six.

� The maximum number of DRIX3c board slots per site is six.

DRIX planningactions

Determine the number of DRIX3cs required.

GSM-001-103Battery backup board (BBBX)




Introduction

The battery backup board (BBBX) provides a backup supply of +5 V dc at 8 A from anexternal battery. It maintains power to the GPROC, GPROC2 DRAM and the opticalcircuitry on the LANX, in the event of a mains power failure.



� One BBBX is required in each shelf.





GSM-001-103 Digital shelf power supply


68P02900W21-G


11–33


Introduction

A BTS and PCC cabinet can be supplied to operate from either a +27 V dc or –48/–60 Vdc power source.


The following factors should be considered when planning the power supply module(PSM) complement:

� The +27 V dc BTS4/BTS5 cabinet option includes two digital power supplymodules (DPSM) required to power the BSU shelf. An additional DPSM may beequipped for redundancy.

� The –48/–60 V dc BTS4 cabinet option includes the two DPSMs required to powerthe BSU shelf, and a power converter unit for the DRCU/SCU/TCUs. An additionalDPSM may be added for redundancy.

The power converter unit is required to supply +27 V dc to the DRCU/SCU/TCUs,and includes three dc/dc converter modules housed in the fifth DRCU/SCU slot. Afourth converter module can be ordered separately to provide redundancy.

� The BTS6 cabinet power supplies, required to power both the digital shelf andDRCU/SCU/TCUs, are provided:

– In a +27 V dc cabinet, by one enhanced power supply module (EPSM) perthree DRCU/SCU/TCUs (two EPSM for a six DRCU/SCU fit). A third EPSMcan be fitted for redundancy.

– In a –48/–60 V dc cabinet, by one integrated power supply module (IPSM)per three DRCU/SCU/TCUs (two IPSM for a six DRCU/SCU fit). A thirdIPSM can be fitted for redundancy.

The EPSM and IPSM fitted to a BTS6 cabinet are not interchangeable with theDPSM fitted to BTS4 and BTS5 cabinets.

NOTE

� ExCell operates internally from +27 V dc and contains up to three EPSMs. ExCellalso contains a battery backup facility. A –48/–60 V dc supply is available forcustomer supplied communications equipment.

� TopCell operates internally from +27 V dc and uses the EPSM. Battery backup isprovided for each cabinet. A –48/–60 V dc supply is available forcustomer-supplied communications equipment.


Determine the number of PSMs required.

GSM-001-103BTS RF configurations



BTS RF configurations

Introduction

This section provides diagrams of the logical interconnections of the RF components invarious standard BTS site configurations, including ExCell and TopCell.


� Typical BTS configurations.

� Single cabinet RF configurations.

� Multiple cabinet RF configurations.

GSM-001-103 Typical BTS configurations


68P02900W21-G


11–35

Typical BTS configurations

BTSconfiguration

The digital module and RF configuration for a BTS cabinet with four RF carriers andhybrid combining is shown in Figure 11-1.

Tx BPF

DUAL SERIAL BUS

DUAL MCAP BUS

FROM RECEIVE ANTENNATO TRANSMIT ANTENNA

BSC

KSWB

REDUNDANT

MSIGCLK

REDUNDANT

BTC

DRIM1

DRIM2

DRIM3

DRIM4

DRIX4

DRIX3

DRIX2

DRIX1

DUAL IEEE802.5 LAN

PRESELECTOR/6-WAY SPLITTERORDUAL PATH PRESELECTOR

BTS CABINET

1

GCLK KSW A

MSI

PIX

LINKS FROM/TO BSC


ONE RF CARRIER CONSISTS OF ONEDRIM, DRIX AND DRCU/SCU

BTC

LANX A

RF EQUIPMENT

A

B

LANXB

BSU SHELF

HYBRID

HYBRIDHYBRID

FIBRE OPTIC LINKS

GPROCGPROC GPROC

2 3 4

DRCU/SCUs

Figure 11-1 Single BTS or ExCell site with four RF carriers using hybrid combining

GSM-001-103Typical BTS configurations



TopCell BTSconfiguration

The digital module and RF configuration for a TopCell BTS cabinet with six RF carriersand hybrid combining is shown in Figure 11-2. TopCell supports a maximum of sixcarriers.

Tx BPF

DUAL MCAP BUS

RxTx

BSC

MSIBTC

DRIM1

DRIM2

DRIM3

DRIM4

DRIX4

DRIX3

DRIX2

DRIX1

DUAL IEEE802.5 LAN

DPP

GCLK KSW

LINKS FROM/TO BSC


BTC

LANXA

A

B

LANXB

TDU

HYBRID

FIBRE OPTIC LINKS

GPROCGPROC GPROC

1 2

DRIM5

DRIX5

DRIM6

DRIX6

Tx BPF

RxTx

DPP

HYBRID

5 6

Tx BPF

RxTx

DPP

HYBRID

3 4

TRU1 TRU2 TRU3

DRCU/SCUs

DRCU/SCUs

DRCU/SCUs

Figure 11-2 TopCell with six RF carriers using hybrid combiners

GSM-001-103 Single cabinet RF configurations


68P02900W21-G


11–37

Single cabinet RF configurations

Single cabinet,singleDRCU/SCUwithout diversity

A single cabinet, single DRCU/SCU configuration is shown in Figure 11-3. Table 11-8provides a summary of the equipment required for this configuration. The following rulesapply:

� As only one DRCU/SCU is used a combiner is not required.

� One dual path preselector is required for the receive signal entering the cabinet.


DUAL PATHPRESELECTOR

DRCU/SCU

BTS CABINET

Tx BPF

Tx Rx

Figure 11-3 Single cabinet, single DRCU/SCU configuration without diversity

GSM-001-103Single cabinet RF configurations



Table 11-8 Equipment required for single cabinet, single DRCU/SCU configuration

Quantity Unit

2 Antennas

1 BTS cabinet

1 DRCU/SCU

Transmitter

1 Bandpass filter

Receiver

1 Dual path preselector



68P02900W21-G


11–39

Single cabinet,singleDRCU/SCU withdiversity

A single cabinet, single DRCU/SCU configuration with diversity is shown in Figure 11-4.Table 11-9 provides a summary of the equipment required for this configuration. Thefollowing rules apply:

� As only one DRCU/SCU is used a combiner is not required.

� One dual path preselector is required for every two receive signals entering thecabinet.


DRCU/SCU

BTS CABINET

Tx BPF

Tx Rx Rx


Figure 11-4 Single cabinet, single DRCU/SCU configuration with diversity




Table 11-9 Equipment required for single cabinet, single DRCU/SCU configuration withdiversity

Quantity Unit

3 Antennas

1 BTS cabinet

1 DRCU/SCU

Transmitter

1 Bandpass filter

Receiver


Single cabinet,five DRCU/SCUswith combining

A single cabinet, five DRCU/SCU configuration with remotely tuneable or hybridcombining but without diversity is shown in Figure 11-5. Table 11-10 provides a summaryof the equipment required for this configuration. The following rules apply:

� In a BTS6 or ExCell6 cabinet, a maximum of six DRCU/SCUs can beaccommodated.

� If operation from a negative power supply voltage is required, only fourDRCU/SCUs can be accommodated in a BTS4 cabinet. The fifth slot will beoccupied by the dc/dc converters.

� If, when using hybrid combining, there are unequal levels of loss, the output powerfor the BTS (sector) is that of the DRCU/SCU with the greatest loss. The otherDRCU/SCUs should be adjusted to lower their output to provide the same outputpower level.




68P02900W21-G


11–41


BTS CABINET

Tx BPF

1 2 3 4 5

Tx Rx

DRCU/SCUs

REMOTELY TUNEABLE COMBINER

HYBRIDHYBRID

HYBRID

HYBRID

Tx BPF

HYBRIDCOMBINERS

Figure 11-5 Single cabinet, five DRCU/SCU configuration with remotely tuneable orhybrid combining and without diversity




Table 11-10 Equipment required for single cabinet, five DRCU/SCU configuration withremotely tuneable or hybrid combining

Quantity Unit

2 Antennas

1 BTS cabinet

5 DRCU/SCU

Transmitter

1 Bandpass filter

4 Hybrid combiner

or

1 Remotely tuneable combiner

Receiver


Single cabinet,six DRCU/SCUswith combiningand diversity

A single cabinet, six DRCU/SCU configuration with remotely tuneable or hybridcombining is shown in Figure 11-6. Table 11-11 provides a summary of the equipmentrequired for this configuration. The following rules apply:

� In a BTS6 or ExCell6 cabinet, a maximum of six DRCU/SCUs can beaccommodated.

� If operation from a negative power supply voltage is required, only fourDRCU/SCUs can be accommodated in a BTS4 cabinet. The fifth slot will beoccupied by the dc/dc converters.

� If, when using hybrid combining, there are unequal levels of loss, the output powerfor the BTS (sector) is that of the DRCU/SCU with the greatest loss. The otherDRCU/SCUs should be adjusted to lower their output to provide the same outputpower level.




68P02900W21-G


11–43

6

Tx BPF

1 2 3 4 5

Tx Rx

BTS CABINET

DRCU/SCUs


HYBRIDHYBRIDHYBRID

HYBRID

HYBRID

Rx

Figure 11-6 Single cabinet, six DRCU/SCU configuration with diversity and remotelytuneable or hybrid combining




Table 11-11 Equipment required for single cabinet, six DRCU/SCU configuration withdiversity and remotely tuneable or hybrid combining

Quantity Unit

3 Antennas

1 BTS cabinet

6 DRCU/SCU

Transmitter

1 Bandpass filter

5 Hybrid combiner

or

1 Remotely tuneable combiner

1 Hybrid combiner

Receiver




68P02900W21-G


11–45

Single cabinet,multipleantennas

A single cabinet, multiple antenna configuration is shown in Figure 11-7. Table 11-12provides a summary of the equipment required for this configuration. The following rulesapply:

� If only one DRCU/SCU is used per carrier, combining is not required.


BTS CABINET

1 2 3

Tx Rx

DRCU/SCUs

Tx BPFs DUAL PATHPRESELECTORS

Tx Tx Rx Rx

Figure 11-7 Single cabinet, multiple antenna (three sector minimum) configuration




Table 11-12 Equipment required for single cabinet, multiple antenna configuration

Quantity Unit

6 Antennas

1 BTS cabinet

3 DRCU/SCU

Transmitter

3 Bandpass filter

Receiver




68P02900W21-G


11–47

Single cabinet,multipleantennas withdiversity

A single cabinet, multiple antenna configuration with diversity is shown in Figure 11-8;this configuration provides for three sectors. Table 11-13 provides a summary of theequipment required for this configuration. The following rules apply:

� A maximum of six receive signals, two per DRCU/SCU, are allowed per BTScabinet.

� If only one DRCU/SCU is used per carrier, combining is not required.


DUAL PATHPRESELECTORS

BTS CABINET

1 2 3

Tx

Tx BPF

Rx

DRCU/SCUs

Tx Tx Rx Rx Rx Rx Rx

Figure 11-8 Single cabinet multiple antenna configuration with diversity




Table 11-13 Equipment required for single cabinet, multiple antenna configuration withdiversity

Quantity Unit

9 Antennas

1 BTS cabinet

3 DRCU/SCU

Transmitter

3 Bandpass filter

Receiver


GSM-001-103 Multiple cabinet RF configurations


68P02900W21-G


11–49

Multiple cabinet RF configurations

Multiple cabinet,single antenna,four DRCU/SCUs

A multiple cabinet, single antenna configuration without diversity is shown in Figure 11-9.This configuration provides eight carriers on one antenna using hybrid combiners.Table 11-14 provides a summary of the equipment required for this configuration. Thefollowing rules apply:

� DRCU/SCUs can be connected to the combiners in any order. The transmit powerof a DRCU/SCU at the top of the cabinet depends on the number of combinerlevels it goes through. Each level of hybrid combining results in a loss of up to 3.2dB of carrier power.

� The antenna feed to cabinet 2 originates from the test (unused) 6-way splitter portin cabinet 1. An inline attenuator is required to ensure specified performance.

� This configuration may not be implemented using ExCell.


BTS CABINET 1

1 2 3 4

Rx

BTS CABINET 2

Tx BPF

1 2 3 4

Tx

ATTENUATOR

HYBRID

HYBRID HYBRID HYBRID HYBRID

HYBRID

HYBRID

DRCU/SCUs DRCU/SCUs



Figure 11-9 Multiple cabinet, single antenna, four DRCU/SCU configuration

GSM-001-103Multiple cabinet RF configurations



Table 11-14 Equipment required for multiple cabinet, single antenna four DRCU/SCUconfiguration

Quantity Unit

2 Antennas

2 BTS cabinet

8 DRCU/SCU

Transmitter

7 Hybrid combiners

1 Bandpass filter

Receiver

1 Attenuator




68P02900W21-G


11–51

Multiple cabinet,single antenna,ten DRCU/SCUs

A multiple cabinet, single antenna configuration is shown in Figure 11-10. Thisconfiguration provides ten carriers on one antenna using hybrid combiners. Table 11-15provides a summary of the equipment required for this configuration. The following rulesapply:

� If one site/sector requires ten carriers, this configuration provides the best solutionfrom the point of view of output power.

� If the antenna feed to cabinet 2 originates from the auxiliary port on the rear of theDPP2 in cabinet 1, a passive splitter is required to ensure specified performance.

� If the antenna feed to cabinet 2 originates from a DPP or a preselector in cabinet1, an Rx extender is required to ensure specified performance.



PASSIVESPLITTER

BTS CABINET 1

1 2 3 4 5

Rx ANTENNA

BTS CABINET 2

Tx BPF

1 2 3 4 5

Tx ANTENNA

PHASINGHARNESS

REMOTELY TUNEABLECOMBINER

DRCU/SCUs

DRCU/SCUs

DPP2

REMOTELY TUNEABLECOMBINER

DPP2

Figure 11-10 Multiple cabinet, single antenna, ten DRCU/SCU configuration usingremotely tuneable combiners




Table 11-15 Equipment required for multiple cabinet, single antenna ten DRCU/SCUconfiguration using remotely tuneable combiners

Quantity Unit

2 Antennas

2 BTS cabinet

10 DRCU/SCU

Transmitter

2 Remotely tuneable combiners

1 Phasing harness

1 Bandpass filter

Receiver

1 Passive splitter

2 Dual path preselector 2



68P02900W21-G


11–53

Multiple cabinet,multiple antenna

A multiple cabinet, multiple antenna configuration is shown in Figure 11-11. Thisconfiguration represents the minimum amount of equipment that will provide for sixsectors. Table 11-16 provides a summary of the equipment required for thisconfiguration. The following rules apply:

� If only one DRCU/SCU is used per sector, a combiner is not required.



BTS CABINET 1

Tx BPF

BTS CABINET 2

Tx BPF

4 5 6

Tx

2 31

Rx

DRCU/SCUs DRCU/SCUs



TxTx

RxRx Rx

RxRx Tx

TxTx

Figure 11-11 Multiple cabinet, multiple antenna (six sector minimum) configuration

Table 11-16 Equipment required for multiple cabinet, multiple antenna configuration

Quantity Unit

12 Antennas

2 BTS cabinet

6 DRCU/SCU

Transmitter

6 Bandpass filter

Receiver





Six sectorconfiguration

A four–cabinet six–sector configuration is shown in Figure 11-12; this configurationprovides for three sectors. Table 11-17 provides a summary of the equipment requiredfor this configuration. The following rules apply:

� The site configuration can make a difference to the equipment required.

� When a receiver multicoupler is used, a multicoupler extender must also be used.One of four types is used depending on the number of cabinets the signal is routedto.

� The multicoupler may not be required for all sectors, if this is the case, theantennas connects directly to the BTS cabinet preselectors and bypasses themulticoupler.

� The large multicoupler extender could be replaced by three 6 dB splitters.

� In this configuration, while DRCU/SCUs 3, 8, 13, 16–18 meet the Motorola-statedtop of cabinet output power specification, DRCU/SCUs 1, 2, 4, 5, 6,7, 9, 10–12,14, and 15 do not because of two levels of hybrid combining. The site does notmeet the specification and the DRCU/SCUs with the higher available transmitpower would have their power reduced.

� The remotely tuneable combiner and multicoupler have not been EMC tested foruse in the external equipment rack. Since the end of 1995 these items have notbeen available for use in this configuration within the European Union.

� This configuration may not be implemented using ExCell or TopCell.

� An external equipment cabinet is required.



68P02900W21-G


11–55

Rx Rx Rx Rx Rx Rx

EXTERNALEQUIPMENT

CABINET

BTS CABINET 1 BTS CABINET 2 BTS CABINET 3

1 2 3 4 5

BTS CABINET 4

15

11

12

13

6 7 8 9 10

16

17

18

Tx Tx TxTx Tx Tx

14

MULTICOUPLER

LARGEMULTICOUPLER

EXTENDER

Figure 11-12 Four–cabinet six–sector configuration

Table 11-17 Equipment required for a four cabinet, six sector configuration

Quantity Unit

12 Antennas

4 BTS cabinet

1 External equipment cabinet

18 DRCU/SCU

Transmitter

6 Bandpass filter

12 Hybrid combiners

Receiver


1 Multicoupler

1 Multicoupler extender




Six–sector BTS6configuration

A six–sector configuration using BTS6s is shown in Figure 11-13; this configurationprovides for three sectors with only three cabinets. Table 11-18 provides a summary ofthe equipment required for this configuration. The following rules apply:

� The site configuration can make a difference to the equipment required.

� In this configuration, while DRCU/SCUs 3, 4, 9, 10, 15, and 16 meet theMotorola-stated top of cabinet output power specification DRCU/SCUs 1, 2, 5, 6,7, 8, 11, 12, 13, 14, 17, and 18 do not because of two levels of hybrid combining.Therefore, the site does not meet the specification and the DRCU/SCUs with thehigher available transmit power would have their power reduced.

� This configuration may not be implemented using ExCell or TopCell.


17

18

11

12

BTS CABINET 2 BTS CABINET 3

Tx

BTS CABINET 1

TxRx Rx Tx Rx

1 2 3 4 15

13

7 8 9 10

16

14

5 6

Tx Rx Tx Rx Tx Rx

Figure 11-13 Multiple cabinet, six–sector BTS6 (three carriers per sector) configuration

Table 11-18 Equipment required for multiple cabinet, six–sector BTS6 configuration

Quantity Unit

12 Antennas

3 BTS cabinet

18 DRCU/SCU

Transmitter

6 Bandpass filter

12 Hybrid combiners

Receiver



68P02900W21-G


i

Index

GSM-001-103



GSM-001-103


68P02900W21-G


iii

Aair filter, 5–30

air flow control, circuit switched, 5–15

air interfaceplanning process, 3–46throughput, 3–51

alarm, panel, 5–30

alarms, consolidation, 5–12

allocation method, BSS timeslots, 3–37

antenna configuration planning, 4–10

assigning BTSs to LCFs, 10–14

assumptions, process, 3–43

assumptions used in capacity calculations, 5–10, 10–8

authorized M–Cell configurations, order creation, 8–2

AUX, 5–30

Bbaseband hopping, 1–7

battery backup (BBBX) planning, 5–82, 6–21, 10–45, 11–32

BSC, provisioning impact, 8–23

BSC capacity calculationsNumber of LCF GPROCs required, 5–60number of LCF GPROCs required at a BSC, 5–60

BSC GPROC functions, GPROC types, 5–61, 10–21

BSC planningbattery backup (BBBX) planning, 5–82, 10–45BSC to BTS link planning, 5–38, 10–10BSC to MSC link planning, 5–56, 10–15BSU shelves, 5–73, 10–36clock extender (CLKX) planning, 5–77, 10–40digital shelf power supply planning, 5–81, 10–44generic clock (GCLK) planning, 5–76, 10–39generic processor (GPROC, GPROC2) planning, 10–21generic processor (GPROC2) planning, 5–61kiloport switch (KSW) planning, 5–71, 10–34kiloport switch extender (KSWX) planning, 5–74, 10–37line interface (BIB, T43) planning, 5–80, 10–43local area network extender (LANX) planning, 5–78, 10–41multiple serial interface (MSI, MSI–2) planning, 5–69, 10–32parallel interface extender (PIX) planning, 5–79, 10–42transcoder planning, 5–66, 10–29

T1 conversion, 5–67, 10–30

BSC planning overview, 10–2outline of planning steps, 5–3, 10–3

BSC system capacity, scaleable BSC, 5–6

BSC to BTS link planning, 5–38, 10–10E1 links, 5–50, 10–11T1 links, 5–51, 10–12

GSM-001-103



BSC to BTS singalling link capacity, 5–38, 10–10

BSC to MSC link planning, 5–56, 10–15transcoding at the BSC, 5–68, 10–31

E1 links, 5–68, 10–31T1 links, 5–68, 10–31

BSC to RXCDR link planning. See BSC to BTS link planning

BSC types, 5–62, 10–22

BSC capacity calculationsNumber of LCF GPROCs required, 10–19number of LCF GPROCs required at a BSC, 10–19

BSC/RXCDR capacity calculations, 5–4, 10–4assigning BTSs to LCFs, 10–14BSC GPROC functions

cell broadcast link, 5–64, 10–26code storage facility processor, 5–65, 10–27GPROC redundancy, 10–28GPROC types, 5–61, 10–21

BSC GPROC redundancy, 5–65BSS signalling link capacities, 5–7, 10–5

assumptions used in capacity calculations, 5–10, 10–8BSC to BTS signalling link (RSL), 5–38, 10–10MSC to BSC signalling over a satellite link, 5–60, 10–20MSC to BSC sinalling link (MTL), 5–56, 10–15typical call parameters, 5–9, 10–7

number of LCF GPROCs required at a BSCLCFs for BSC to BTS links and Layer 3 call processing, 5–52, 10–13LCFs for MSC to BSC links, 5–60, 10–19

BSC-PCUsignalling, 5–42traffic, 5–42, 5–50

BSSplanning, 3–27planning introduction, 5–12statistics, 5–15

BSS equipment overviewsystem architecture, 1–3system components, 1–4

BSS features, 1–6code storage facility processor, 1–7diversity, 1–6frequency hopping, 1–6

baseband hopping, 1–7synthesizer hopping, 1–7

short message service, cell broadcast, 1–7

BSS planning overview, 1–9initial information required, 1–9planning methodology, 1–11

BSS signalling link capacities, 5–7, 10–5assumptions used in capacity calculations, 5–10, 10–8BSC to BTS singalling link (RSL), 5–38, 10–10MSC to BSC singalling link (MTL), 5–56, 10–15MSC to BSC signalling over a satellite link, 5–60, 10–20typical call parameters, 5–9, 10–7

GSM-001-103


68P02900W21-G


v

BSS standard configurations, 9–2BTS configurations

PCC with 12 PCU (RF carriers) and HDSL links, 9–9PCC with 12 PCU (RF carriers) and optical fibre links, 9–8PCC with six PCU (RF carriers) and HDSL links, 9–7PCC with six PCU (RF carriers) and optical fibre links, 9–6

multiple cabinet RF configurations, 11–49four cabinet six sector configuration, 11–54four DRCU/SCUs with a single antenna, 11–49multiple antennas, 11–53ten DRCU/SCUs with a single antenna, 11–51three cabinet (BTS6) six sector configuration, 11–56

picocell configurations, 9–6single cabinet RF configurations, 11–37

five DRCU/SCUs with combining, 11–40multiple antennas, 11–45multiple antennas and diversity, 11–47single DRCU/SCU, 11–37single DRCU/SCU with diversity, 11–39six DRCU/SCUs with combining, 11–42

typical BSS configurations, 9–3BSC with 24 BTSs, 9–3BSC with full redundancy, 9–4transcoder, 9–5

typical BTS configurations, 11–35BTS with four RF carriers, 11–35TopCell with six RF carriers, 11–36

BSS timeslots, allocation method, 3–37

BSS upgrade, provisioning rules, 5–24

BSU shelves, 5–73, 10–36

BTS, provisioning impact, 8–24

BTS cabinet planning, 4–4, 11–13

BTS capacity calculations, 3–11, 11–4BTS GPROC requirements, 11–7control channel calculations, 3–13, 11–6

calculate the number of CCCH, 3–19calculate the number of SDCCH, 3–21control channel configurations, 3–22factors affecting the number of CCCH, 3–18factors affecting the number of SDCCH, 3–20

typical call parameters, 3–11, 11–4

BTS enclosure planning, 4–5

BTS GPROC requirements, 11–7

GSM-001-103



BTS planningantenna configuration planning, 4–10cabinet interconnection (FOX/FMUX), 4–17cabinet planning, 4–4, 11–13

1999macroBTS, 4–4M–Cell2, 4–4M–Cell6, 4–4

carrier equipment planning, 4–11, 11–20clock extender (CLKX) planning, 11–28digital radio interface extender (DRIX) planning, 11–31duplexer planning, 11–19enclosure planning, 4–5

M–Cellarena, 4–5M–Cellarena macro, 4–5

kiloport switch extender (KSWX) planning, 11–26line interface (BIB, T43) planning, 4–14main control unit (MCU), 4–16main control unit, with dual FMUX (MCUF), 4–15micro base control unit, 4–12network interface unit (NIU), 4–13parallel interface extender (PIX) planning, 11–30power supply planning, 4–19receive configuration planning, 4–6receiver front end planning, 11–14

distributing signals between cabinets, 11–15transmit combiner shelf planning, 11–17transmit configuration planning, 4–8

BTS planning overview, 4–2outline of planning steps, 4–3, 11–3

BTS standard configurations, 9–2four cabinet RF configuration, 9–13, 9–17

four cabinet Horizonmacro configuration, 9–15, 9–17four cabinet M–Cell6 configuration, 9–18

single cabinet RF configurations, 9–10single Horizonmacro configuration, 9–10single M–Cell2 configuration, 9–12single M–Cell6 configuration, 9–11

three cabinet RF configuration, 9–15three cabinet M–Cell2 configuration, 9–16

two cabinet RF configurationtwo cabinet Horizonmacro configuration, 9–13two cabinet M–Cell6 configuration, 9–14

BTS to BSC link planning. See BSC to BTS link planning

BTS-BSC (abis), E1 links, 5–39

burst excess, rate, 5–49

Ccabinet, PCU, 5–30

cabinet interconnection (FOX/FMUX), 4–17

calculating the number of CCCH, 3–19

calculating the number of SDCCH, 3–21

GSM-001-103


68P02900W21-G


vii

calculationGBL links, 8–21GDS E1 links, 8–21GSL links, 8–21increased data traffic load, 8–22increased GPRS traffic load, 8–23increased signalling traffic load, 8–23PCU hardware support, 8–21

carrier equipment planning, 4–11, 11–20

carrier timeslot allocationexamples, 3–34examples A and B, 3–35examples C, D, and E, 3–36

cell broadcast, SMS, 5–15

cell broadcast link, 5–64, 10–26

cell planningchannel coding for enhanced full rate, 3–96control channel encoding, 3–97data channel encoding, 3–98discontinuous transmission, 3–105environmental effects on propagation, 3–66error protection and detection, 3–92frequency re–use, 3–84freznel zone, 3–61GSM frequency spectrum, 3–4hardware and software techniques to overcome propagation effects, 3–90introduction, 3–1introduction to decibels, 3–60mapping logical channels onto the TDMA frame structure, 3–99multipath propagation, 3–69planning factors, 3–2planning tools, 3–3propagation effects on GSM frequencies, 3–59radio refractive index, 3–62speech channel encoding, 3–94subscriber environment, 3–108the expansion solution, 3–115voice activity detection, 3–105

cell resource manager, dynamic reconfiguration, 5–13

circuit error rate, monitor, 5–13

circuit switchedair flow control, 5–15calls, 5–13

clock extender (CLKX) planning, 5–77, 6–16, 10–40, 11–28

code storage facility processor, 1–7, 5–65, 10–27

committed burst, rate, 5–49

committed information, rate, 5–48

common antenna for Tx and Rx. See duplexer planning

compatibility, features, 5–12

concentration, at BTS, 5–12

concentric cells, 5–13

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congestion relief, 5–13

control channel calculations, 3–13, 11–6calculate the number of CCCH, 3–19calculate the number of SDCCH, 3–21control channel configurations, 3–22factors affecting the number of CCCH, 3–18factors affecting the number of SDCCH, 3–20

control channel configurations, 3–22

customer inputs, planning process, 3–27

Ddaisy chain connection, 2–6

daisy chain planning, 2–6

determinationexpected load, 3–26GPRS carrier timeslots, 8–20

digital radio interface extender (DRIX) planning, 11–31

digital shelf power supply planning, 5–81, 6–20, 10–44, 11–33

directed retry, 5–13

distributing receive signals between cabinets, 11–15

diversity, 1–6

DPROC, PICP or PRP, 5–30

duplexer planning, 11–19

dynamic reconfiguration, cell resource manager, 5–13

dynamic timeslots, mode switching, 3–32

EE1 links, BTS-BSC (Abis), 5–39

emergency call, pre-emption, 5–14

equipment planningM–Cell configurations, M–Cell2 cabinets, 9–100Macrocell configurations

Horizonmacro cabinets, 9–20M–Cell6 cabinets, 9–37

Microcell configurationsM–Cellarena enclosure, 9–110M–Cellarena macro enclosure, 9–109

estimation, network traffic, 3–27

examplescarrier timeslot allocation, 3–34planning, 3–27

examples A and B, carrier timeslot allocation, 3–35

examples C, D, and E, carrier timeslot allocation, 3–36

expected load, determination, 3–26

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extended range cells, 5–14

Ffactors affecting the number of CCCH, 3–18

factors affecting the number of SDCCH, 3–20

fan/power supplies, 5–30

fault containment, RTF path, 5–15

features, compatibility, 5–12

four cabinet Horizonmacro configuration, 9–15, 9–17

four cabinet M–Cell6 configuration, 9–18

frame relay, parameter values, 5–47

frequencyhopping, 5–14redefinition, 5–14

frequency hopping, 1–6baseband hopping, 1–7synthesizer hopping, 1–7

GGBL links, calculation, 8–21

GDS E1 links, calculation, 8–21

GDS LAPD GSL, 5–42

GDS TRAU, 5–42, 5–50

generic clock (GCLK) planning, 5–76, 6–15, 10–39, 11–27

generic processor (GPROC, GPROC2) planning, 10–21, 11–24

generic processor (GPROC) planning, 6–7

generic processor (GPROC2) planning, 5–61

global reset, 5–14

GPROC functions and types, 5–61, 10–21

GPROC redundancy at the BSC, 5–65

GPRS, key concepts, 3–27

GPRS carrier timeslots, determination, 8–20

GPRS control channel, RF provisioning, 3–13

GPRS network, statistics for replanning, 3–27

GPRS signalling, LCF GPROC2 provisioning, 5–53

GPRS timeslots, traffic, 5–39

GSL links, calculation, 8–21

GSN, planning, 3–27

Hhandovers, multiband, 5–14

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HDSL interface, integrated M-Cell, 5–14

Iincreased data traffic load, calculation, 8–22

increased GPRS traffic load, calculation, 8–23

increased signalling traffic load, calculation, 8–23

integrated HDSL interfaceHDSL cable installation, 2–42HDSL cable selection, 2–42HDSL range, 2–42

integrated M-Cell, HDSL interface, 5–14

interconnecting BTSs and the BSC. See interconnecting the BSC and BTSs

interconnecting the BSC and BTSs, 2–3interconnection rules, 2–3network topology, 2–4

daisy chain connection, 2–6daisy chain planning, 2–6star connection, 2–5

interconnecting the InCell and M–Cell equipment, interconnection rules, 2–3

interface planning, PCU-to-SSGN, 5–23

introductionkey concepts, 3–29network traffic estimation, 3–29

Kkey concepts

GPRS, 3–27introduction, 3–29overview, 3–28

kiloport switch (KSW) planning, 5–71, 6–12, 10–34

kiloport switch extender (KSWX) planning, 5–74, 6–14, 10–37, 11–26

LLCF GPROC2 provisioning, GPRS signalling, 5–53

LCFs for BSC to BTS links and Layer 3 call processing, 5–52, 10–13

line interface (BIB, T43) planning, 4–14, 5–80, 6–19, 10–43, 11–21

line interface module (HIM–75, HIM–120) planning, 4–22

local area network extender (LANX) planning, 5–78, 6–17, 10–41, 11–29

MM–Cell power supply planning, 4–19

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Macrocell configurations1999macroBTS cabinet

[DCS1800] 2 sector (3/3), with duplexed dual–stage hybrid combining, 9–24[DCS1800] 2 sector (6/6), with duplexed dual–stage hybrid and air combining, 9–26[DCS1800] 3 sector (2/2/2), with duplexed hybrid combining, 9–28[DCS1800] 3 sector (4/4/4), with duplexed hybrid and air combining, 9–30[DCS1800] 3 sector (8/8/8), with duplexed dual–stage hybrid and air combining, 9–32[DCS1800] 4 carrier Omni, with duplexed hybrid and air combining, 9–20[DCS1800] 6 carrier Omni, with duplexed dual–stage hybrid and air combining, 9–22

M–Cell2 cabinet[DCS1800] 2 carrier, single sector, with air combining and diversity, 9–106[DCS1800] 2 sectors, with diversity, 9–108[GSM900] 2 carrier, single sector, with hybrid combining and diversity, 9–100[GSM900] 2 carrier, single sector, with hybrid combining, diversity and medium power duplexer, 9–102[GSM900] 2 sectors (1 carrier per sector), with diversity, 9–104

M–Cell6 cabinet[DCS1800] 3 sector (2/2/2), with hybrid combining and diversity, 9–96[DCS1800] 3 sector (2/2/2), with hybrid combining, diversity and medium power duplexers, 9–98[GSM900] 2 sector (3/3), with hybrid combining and diversity, 9–51[GSM900] 2 sector (3/3), with hybrid combining, diversity and medium power duplexer, 9–53[GSM900] 3 carrier Omni, with hybrid combining and diversity, 9–37[GSM900] 3 carrier Omni, with hybrid combining, diversity and medium power dulplexer, 9–39[GSM900] 3 sector (2/2/2), with combining and diversity, 9–55[GSM900] 3 sector (2/2/2), with hybrid combining, diversity and medium power duplexer, 9–57[GSM900] 3 sector (4/4/4), with air combining, diversity and medium power duplexer, 9–67[GSM900] 3 sector (4/4/4), with air combining, diversity and medium power duplexer (3 antenna per sector),

9–59[GSM900] 3 sector (4/4/4), with cavity combining and diversity, 9–63[GSM900] 3 sector (4/4/4), with hybrid combining and diversity, 9–65[GSM900] 3 sector (4/4/4), with hybrid combining, diversity and medium power duplexer (2 antenna per

sector), 9–61[GSM900] 3 sector (4/4/4), with hybrid combining, diversity and medium power duplexer (3 antenna per

sector), 9–88[GSM900] 3 sector (5/5/5), with 3–input CBF, air combining, diversity and medium power duplexer (3

antenna per sector), 9–69[GSM900] 3 sector (5/5/5), with 3–input CBF, combining, diversity and medium power duplexer(2 antenna

per sector), 9–71[GSM900] 3 sector (6/6/6), with 3–input CBF, air combining, diversity and medium power duplexer (3

antenna per sector), 9–75[GSM900] 3 sector (6/6/6), with 3–input CBF, combining, diversity and medium power duplexer (2 antenna

per sector), 9–77[GSM900] 3 sector (6/6/6), with cavity combining, diversity and high power duplexer, 9–73[GSM900] 3 sector (8/8/8), with cavity combining, diversity and both high and medium power duplexers,

9–84[GSM900] 3 sector (8/8/8), with cavity combining, diversity and medium power duplexer, 9–80[GSM900] 3 sector (8/8/8), with combining, diversity and medium power duplexer (2 antenna per sector),

9–92[GSM900] 4 carrier Omni, with hybrid combining and diversity, 9–41[GSM900] 4 carrier Omni, with hybrid combining, diversity and medium power duplexer, 9–43[GSM900] 6 carrier Omni, with cavity combining and diversity, 9–45[GSM900] 6 carrier Omni, with cavity combining, diversity and high power duplexer, 9–47[GSM900] 8 carrier Omni, with combining and diversity, 9–49

Macrocell standard configurations, RF configurations, 9–19

main control unit (MCU), 4–16

main control unit, with dual FMUX (MCUF), 4–15

Managed HDSL on micro BTS, 2–41

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maximum configuration, 5–31

micro base control unit, 4–12

Microcell configurationsM–Cellarena enclosure, [GSM900/DCS1800] 2 carrier, 9–110M–Cellarena macro enclosure, [GSM900/DCS1800] 2 carrier, 9–109

Microcell standard configurations, RF configurations, 9–110

microcell system planningdaisy chain, 2–45E1 link, 2–45star configuration, 2–45

mode switching, dynamic timeslots, 3–32

MPROC, 5–30

MSC to BSC link planning. See BSC to MSC link planning

MSC to BSC signalling link capacity, 5–56, 10–15

MSC to BSC signalling over a satellite link, 5–60, 10–20

MSC to RXCDR link planning. See RXCDR to MSC link planning

MTL capacity. See MSC to BSC signalling link capacity

multiband, handovers, 5–14

multiple cabinet, multiple antenna configuration, 11–53

multiple cabinet, single antenna, four DRCU/SCU configuration, 11–49

multiple cabinet, single antenna, ten DRCU/SCU configuration, 11–51

multiple serial interface (MSI, MSI–2) planning, 5–69, 6–10, 10–32, 11–22

NN+1 equipment, redundancy supported, 5–30

network, planning process, 3–27

network expansion using M–Cell BTS, 4–20

network interconnection rules, 2–3

network interface unit (NIU), 4–13

network planning, aggregate A–bis, 2–9

network provisioning, switchable timeslots, 3–39

network topologydaisy chain connection, 2–6daisy chain planning, 2–6star connection, 2–5

network traffic, estimation, 3–27

network traffic estimationbackground, 3–33introduction, 3–29overview, 3–28

Number of LCF GPROCs required, 5–60, 10–19

number of LCF GPROCs required at a BSC, 5–60, 10–19LCFs for BSC to BTS links and Layer 3 call processing, 5–52, 10–13LCFs for MSC to BSC links, 5–60, 10–19

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number of LCFs for MSC to BSC links, 5–60, 10–19

number of LCFs required for the RSLs. See number of LCFs required for the RSLs; Number of LCFs to supportthe BSC to BTS signalling links

OOMC-R, provisioning impact, 8–24

order creation, OMC–R example, 8–18

overviewkey concepts, 3–28network traffic estimation, 3–28planning process, 3–24provisioning rules, 5–24

Pparallel interface extender (PIX) planning, 5–79, 6–18, 10–42, 11–30

parameter values, frame relay, 5–47

PCC cabinet planning, 4–21

PCC planningbattery backup (BBBX) planning, 11–32cabinet planning, 4–21digital shelf power supply planning, 11–33generic clock (GCLK) planning, 11–27generic processor (GPROC, GPROC2) planning, 11–24line interface (BIB, T43) planning, 11–21line interface module (HIM–75, HIM–120) planning, 4–22local area network extender (LANX) planning, 11–29multiple serial interface (MSI, MSI–2) planning, 11–22timeslot switch (TSW) planning, 11–25

PCUcabinet, 5–30provisioning rules, 5–25

PCU hardware support, calculation, 8–21

PCU-SGSN, traffic and signalling, 5–45

PCU-to-SSGN, interface planning, 5–23

PICP boards, recalculation, 8–22

planningBSS, 3–27examples, 3–27GSN, 3–27recommended guidelines, 3–27redundancy, 5–34

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planning exercise, 8–1calculations using alternative call models, 8–25

determine the number of CCCHs per cell, 8–27determine the number of GPROC2s, 8–29determine the number of SDCCHs per cell, 8–28parameters used, 8–25

determine the BTS 10 hardware requirements, 8–9determine the BTS 2 hardware requirements, 8–6determine the BTS hardware requirements, 8–12determine the OMC–R hardware requirements, 8–18determine the RXCDR hardware requirements, 8–15initial requirements, 8–3introduction to the exercise, 8–5

planning introduction, BSS, 5–12

planning methodology, 1–11

planning processair interface, 3–46customer inputs, 3–27network, 3–27overview, 3–24

pre-emption, emergency call, 5–14

process, assumptions, 3–43

provisioning impactBSC, 8–23BTS, 8–24OMC-R, 8–24

provisioning rulesBSS upgrade, 5–24overview, 5–24PCU, 5–25

Rrate

burst excess, 5–49committed burst, 5–49committed information, 5–48

recalculation, PICP boards, 8–22

receive configuration planning, 4–6

receiver front end planning, 11–14distributing signals between cabinets, 11–15

recommendation, 3–43

recommended guidelines, planning, 3–27

redundancy, planning, 5–34

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remote trancoder planningbattery backup (BBBX) planning, 6–21clock extender (CLKX) planning, 6–16digital shelf power supply planning, 6–20generic clock (GCLK) planning, 6–15generic processor (GPROC) planning, 6–7kiloport switch (KSW) planning, 6–12kiloport switch extender (KSWX) planning, 6–14line interface (BIB, T43) planning, 6–19local area network extender (LANX) planning, 6–17multiple serial interface (MSI, MSI–2) planning, 6–10parallel interface extender (PIX) planning, 6–18RXCDR to BSC link planning, 6–4RXCDR to MSC link planning, 6–6RXU shelves, 6–13transcoder planning, 6–8

T1 conversion, 6–9

remote transcoder planning overview, 6–2outline of planning steps, 6–3

RF plan, choice, 8–20

RF provisioning, GPRS control channel, 3–13

RSL, signalling, 5–39

RSL capacity. See BSC to BTS singalling link capacity

RTF path, fault containment, 5–15

RXCDR to BSC link planning, 6–416 k XBL links, 2–18E1 links, 6–5T1 links, 6–5

RXCDR to MSC link planning, 6–6E1 links, 6–6T1 links, 6–6

RXU shelves, 6–13

Sscaleable BSC, 5–6

scaleable OMC–Roptions, 7–6outline of planning steps, 7–2server composition, 7–6workstation composition, 7–6

short message service, cell broadcast, 1–7

signallingBSC-PCU, 5–42RSL, 5–39

single cabinet configuration with multiple antennas and diversity, 11–47

single cabinet, five DRCU/SCU configuration with combining, 11–40

single cabinet, multiple antenna configuration, 11–45

single cabinet, single DRCU/SCU configuration, 11–37

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single cabinet, single DRCU/SCU configuration with diversity, 11–39

single cabinet, six DRCU/SCU configuration with combining, 11–42

single Horizonmacro configuration, 9–10

single M–Cell2 configuration, 9–12

single M–Cell6 configuration, 9–11

six sector BTS6 configuration, 11–56

six sector configuration, 11–54

SMS, cell broadcast, 5–15

star connection, 2–5

statistics, BSS, 5–15

statistics for replanning, GPRS network, 3–27

supported redundancy, N+1 equipment, 5–30

switchable timeslots, network provisioning, 3–39

synthesizer hopping, 1–7

system architecture, 1–3

system components, 1–4

TT1 conversion, 5–67, 6–9, 10–30

three cabinet M–Cell2 configuration, 9–16

throughput, air interface, 3–51

throughput estimationstep 1, 3–52step 2, 3–53step 3, 3–56step 4, 3–57

timeslot allocation, Figure 3–11, 3–38

timeslot switch (TSW) planning, 11–25

timeslots, use, 3–29

trafficBSC-PCU, 5–42, 5–50GPRS timeslots, 5–39

traffic and signalling, PCU-SGSN, 5–45

transcoder (XCDR, GDP) planning, 5–66, 6–8, 10–29

transmit combiner shelf planning, 11–17

transmit configuration planning, 4–8

two cabinet Horizonmacro configuration, 9–13

two cabinet M–Cell6 configuration, 9–14

typical call parameters for BSS planning, 5–9, 10–7

typical call parameters for BTS planning, 3–11, 11–4

Uuse, timeslots, 3–29

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Documents

Motorola BSS Planning Guide