Feature List.pdf

Nokia Siemens Networks GSM/EDGE BSS, Rel. RG20(BSS), Operating Documentation, Issue 03

Flexi EDGE BTS Feature Descriptions

DN70124104

Issue 7-1Approval Date 2010-12-16

Confidential

2 DN70124104Issue 7-1


Id:0900d8058082402dConfidential

The information in this document is subject to change without notice and describes only the product defined in the introduction of this documentation. This documentation is intended for the use of Nokia Siemens Networks customers only for the purposes of the agreement under which the document is submitted, and no part of it may be used, reproduced, modified or transmitted in any form or means without the prior written permission of Nokia Siemens Networks. The documentation has been prepared to be used by professional and properly trained personnel, and the customer assumes full responsibility when using it. Nokia Siemens Networks welcomes customer comments as part of the process of continuous development and improvement of the documentation.

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The same text in German:

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Installation, Betrieb, Wartung und sonstige Handhabung des Produktes darf nur durch geschultes und qualifiziertes Personal unter Beachtung der anwendbaren Sicherheits-anforderungen erfolgen.

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Table of contentsThis document has 144 pages.

1 Summary of changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2 Overview of features in Flexi EDGE BTS SW release EX4.0 . . . . . . . . 10

3 Data/Voice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113.1 BSS21270 105 km Extended Cell and BSS21277 105 km Extended Cell for

GPRS/EDGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113.2 BSS20951 RTC Support in ECELL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123.3 BSS20094 Extended Cell for GPRS/EDGE. . . . . . . . . . . . . . . . . . . . . . 133.4 Long Reach TCH TSL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153.5 BSS20088 Dual Transfer Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163.6 BSS9006 General Packet Radio Service (GPRS) . . . . . . . . . . . . . . . . . 173.7 BSS10083 Enhanced General Packet Radio Service (MCS-1 - MSC-9) 183.8 BSS7003 High Speed Circuit Switched Data and BSS7037 14.4 kbit/s Data

Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203.9 BSS10004 Adaptive Multi Rate Codec (AMR). . . . . . . . . . . . . . . . . . . . 223.10 BSS7005 Intelligent Frequency Hopping and BSS6114 Intelligent Under-

lay-Overlay. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233.11 BSS20960 Wideband AMR and BSS21118 TFO for AMR . . . . . . . . . . 243.12 BSS21309 OSC Half Rate with SAIC MS . . . . . . . . . . . . . . . . . . . . . . . 25

4 Interworking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274.1 BSS10101 GSM-WCDMA Interworking. . . . . . . . . . . . . . . . . . . . . . . . . 274.2 BSS11086 Support for Enhanced Measurement Report . . . . . . . . . . . . 28

5 Operability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295.1 BTS Trace Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295.2 Antenna VSWR measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305.2.1 BCCH antenna VSWR measurement . . . . . . . . . . . . . . . . . . . . . . . . . . 305.2.2 TCH antenna VSWR measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . 305.3 BSC download of Abis mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325.4 BSS21362 Fast BSS Restart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335.5 BSS21316 Flexi BTS Autoconnection . . . . . . . . . . . . . . . . . . . . . . . . . . 345.6 BSS20847 Automatic commissioning of the Flexi EDGE BTS . . . . . . . 355.7 BSS20817 End to End Downlink Abis Performance Monitor. . . . . . . . . 365.8 BSS20760 BTS ID shown in BTS Manager. . . . . . . . . . . . . . . . . . . . . . 375.9 BSS20063 Space Time Interference Rejection Combining . . . . . . . . . . 385.10 BSS20040 User Access Level Control (UALC) . . . . . . . . . . . . . . . . . . . 405.11 BSS11047 Intelligent shutdown for Flexi EDGE BTS . . . . . . . . . . . . . . 425.12 Remote mode of Flexi EDGE BTS Manager . . . . . . . . . . . . . . . . . . . . . 445.13 BSS10063 Rx Antenna Supervision by Comparing RSSI . . . . . . . . . . . 455.14 BSS9068 BTS SW management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475.15 BSS9067 Runtime diagnostics and BTS alarms . . . . . . . . . . . . . . . . . . 485.16 BSS9058 BTS fault recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495.17 BSS9063 Abis loop test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505.18 BSS9062 BTS supervision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515.19 BSS9061 Temperature control system . . . . . . . . . . . . . . . . . . . . . . . . . 52

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5.20 BSS9060 TRX Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535.21 TRX Loop Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 555.22 BSS9059 BTS resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 565.23 BTS Auto-detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 575.23.1 BSS9056 Auto-detection of Site Configuration . . . . . . . . . . . . . . . . . . . . 575.23.2 RF Cable Auto-detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 575.23.3 Internal power cable Auto-detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 605.24 Optical Converter Module (EOCA) autodetection and runtime polling . . 615.25 48 V DC input voltage supervision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 625.26 Antenna Hopping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 635.27 BSS20984 Flexi EDGE dual TRX automatic power down . . . . . . . . . . . 645.28 BSS20958 Energy saving mode for BCCH TRX . . . . . . . . . . . . . . . . . . 655.29 BSS21317 Automatic Commissioning Tests for Hot Inserted TRX . . . . 66

6 Site solutions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 676.1 BSS21171 IDD and diversity configuration for DTRX. . . . . . . . . . . . . . . 676.2 BSS20870 Double Power TRX for Flexi EDGE BTS . . . . . . . . . . . . . . . 686.3 BSS10046 Multi BCF Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 696.4 RG301397 Co-siting with BS2xx. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 706.5 BSS9055 Clock Synchronization between Base Stations . . . . . . . . . . . 716.6 BSS10069 Synchronised BSS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 746.6.1 BSS20371 BSS Site Synchronisation Recovery Improvement. . . . . . . . 746.6.2 BSS11073 Recovery for BSS and Site Synchronisation . . . . . . . . . . . . 746.7 Operating bands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 766.8 BTS2043 BTS External Alarms and Controls (EAC) . . . . . . . . . . . . . . . 776.9 BTS2020 RX antenna diversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 786.10 BTS configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 796.10.1 Upgrade-optimised configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 796.10.2 Cost-optimised configurations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 796.11 Flexi EDGE BTS Feederless and Distributed Site concept . . . . . . . . . . 806.11.1 Feederless site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 806.11.2 Distributed site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 826.12 Distributed BTS with Optical Converter modules (EOCA) . . . . . . . . . . . 84

7 Basic GSM operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 867.1 BSS21113 Increased dynamic SDCCH capacity . . . . . . . . . . . . . . . . . . 867.2 BSS20882 Extended Cell Range for Flexi EDGE BTS. . . . . . . . . . . . . . 877.3 BSS20872 Robust AMR signalling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 887.4 BSS20588 TRAU bicasting in AMR FR/HR handover . . . . . . . . . . . . . . 907.5 Basic GSM features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 917.6 BSS6071 Enhanced Full Rate Codec. . . . . . . . . . . . . . . . . . . . . . . . . . . 927.7 BTS2023 Downlink and uplink DTX . . . . . . . . . . . . . . . . . . . . . . . . . . . . 937.8 BTS2503 Compressed Abis timeslot allocation . . . . . . . . . . . . . . . . . . . 947.9 BTS2067 Fast Associated Control Channel (FACCH) Call Setup . . . . . 957.10 BSS21538 Extended Common Control Channel (CCCH) . . . . . . . . . . . 967.11 BSS101411 Extended BCCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 977.12 BSS7036 Dynamic SDCCH Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . 987.13 BTS2024 Synthesised frequency hopping . . . . . . . . . . . . . . . . . . . . . . . 99

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7.14 BTS2013 Baseband Frequency Hopping . . . . . . . . . . . . . . . . . . . . . . 1007.15 BTS2037 Air interface measurement pre-processing . . . . . . . . . . . . . 1017.16 BTS2012 BTS time base reference from PCM . . . . . . . . . . . . . . . . . . 1027.17 BTS2133 Short Message Service (SMS) point-to-point. . . . . . . . . . . . 1037.18 BTS2033 Short message cell broadcast . . . . . . . . . . . . . . . . . . . . . . . 1047.19 BSS6025 Short Message Service Cell Broadcast with Discontinuous Re-

ceiving (SMS-CB DRX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1057.20 BSS6083 Mobile Station (MS) speed detection. . . . . . . . . . . . . . . . . . 1067.21 BSS21445 Packet Abis Congestion reaction. . . . . . . . . . . . . . . . . . . . 1087.22 BSS11052 Dynamic Frequency and Channel Allocation (DFCA) . . . . 1097.23 BSS21161 SDCCH and PS data channels on DFCA TRX . . . . . . . . . 1117.24 BSS20093 A5/3 ciphering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1127.25 BSS21444 Packet Abis Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

8 Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1158.1 Basic transmission. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1158.1.1 Abis Trunk Transmission for E1 (ETSI) interface. . . . . . . . . . . . . . . . . 1158.1.2 Abis Trunk Transmission Allocation for T1 (ANSI) Interface . . . . . . . . 1168.1.3 Abis Trunk Signalling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1178.1.4 Network Synchronisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1188.1.5 Transmission equipment management . . . . . . . . . . . . . . . . . . . . . . . . 1198.1.6 Support for Nokia Microwave Radio Links. . . . . . . . . . . . . . . . . . . . . . 1218.1.7 BSS9065 Transmission Operability . . . . . . . . . . . . . . . . . . . . . . . . . . . 1228.1.8 BSS21234 Support for BTS PWE Counters at BSC/NetAct . . . . . . . . 1238.1.9 BSS21290 Flexi EDGE Ethernet Switching . . . . . . . . . . . . . . . . . . . . . 1248.2 Transmission solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1258.2.1 PDH traffic routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1258.2.2 BSS30280 Abis loop protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1268.2.3 Redundant Abis Trunk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1288.3 BSS21443 Packet TRS for UltraSite/BTSplus . . . . . . . . . . . . . . . . . . . 1298.4 BSS21271 Abis Delay Measurement (TDM, PWE3) . . . . . . . . . . . . . . 1308.5 BSS30285 Flexi EDGE additional 2 E1, T1 IF. . . . . . . . . . . . . . . . . . . 1318.6 BSS30305 Flexi EDGE Abis over IP/Ethernet . . . . . . . . . . . . . . . . . . . 1328.7 BSS21454 Packet Abis over Ethernet . . . . . . . . . . . . . . . . . . . . . . . . . 1348.8 BSS21440 Packet Abis over TDM. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1358.9 BSS21439 Packet Abis Sync. ToP IEEE1588v2 . . . . . . . . . . . . . . . . . 1368.10 BSS10045 Dynamic Abis allocation. . . . . . . . . . . . . . . . . . . . . . . . . . . 1378.11 BSS21438 Packet Abis over Satellite . . . . . . . . . . . . . . . . . . . . . . . . . 1388.12 BSS5850 Satellite Abis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1398.13 BSS21497 Enhanced satellite support . . . . . . . . . . . . . . . . . . . . . . . . 1408.14 BSS30450 Packet Abis Synchronous Ethernet . . . . . . . . . . . . . . . . . . 1418.15 BSS21503 FlexiPacket Radio Connectivity . . . . . . . . . . . . . . . . . . . . . 1428.16 BSS30395 Packet Abis Delay Measurement. . . . . . . . . . . . . . . . . . . . 143

9 Appendix Other features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1449.1 Other features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

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List of figuresFigure 1 Extended Cell two TRX configuration with two EGTCHs . . . . . . . . . . . . 13Figure 2 Incremental Redundancy scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Figure 3 Typical data throughputs for 14.4 kbit/s (non-transparent) and 9.6 kbit/s

coding (this depends on the NW radio conditions) . . . . . . . . . . . . . . . . . 21Figure 4 Flexi EDGE BTS Manager connected in remote mode . . . . . . . . . . . . . 44Figure 5 TRX Test block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53Figure 6 TRX Test window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54Figure 7 TRX loop (Dual Duplexer Module) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58Figure 8 TRX loop (Remote Tune Combiner Module) . . . . . . . . . . . . . . . . . . . . . 58Figure 9 Multi BCF configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69Figure 10 Synchronised BSS example in Flexi EDGE BTS chain . . . . . . . . . . . . . 75Figure 11 Common BCCH configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76Figure 12 Feederless rooftop site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81Figure 13 Feederless masthead site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81Figure 14 Optical cable installation alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . 82Figure 15 Distributed site concept (e.g. as a part of a BTS hotel) . . . . . . . . . . . . . 83Figure 16 EOCA displayed in BTS Manager Base Station view . . . . . . . . . . . . . . . 85Figure 17 TRAU bicasting in AMR FR/HR handover . . . . . . . . . . . . . . . . . . . . . . . 90Figure 18 Dynamic SDCCH allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98Figure 19 SMS-CB DRX Schedule Period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105Figure 20 MS speed detection used for handover decision . . . . . . . . . . . . . . . . . 106Figure 21 Loop principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126Figure 22 Round trip time/Abis delay measurement . . . . . . . . . . . . . . . . . . . . . . . 130Figure 23 PW network topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132Figure 24 Packet Abis over Ethernet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134Figure 25 Packet Abis over TDM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

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List of tablesTable 1 Peak data rates for single slot EGPRS . . . . . . . . . . . . . . . . . . . . . . . . 18Table 2 Corresponding maximum data rates with different channel coding . . . 20Table 3 Channel and speech codec modes for AMR . . . . . . . . . . . . . . . . . . . . 22Table 4 Number of 16 kbps DAP subchannels used with each CS and MCS 137

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DN70124104 9

Flexi EDGE BTS Feature Descriptions Summary of changes

Id:0900d80580824097Confidential

1 Summary of changes Changes between issues 7-1 and 7-0Updated Sections:

• BSS21309 OSC Half Rate with SAIC MS (chapter Data/Voice) • BSS21454 Packet Abis over Ethernet (Chapter Transmission) • BSS21439 Packet Abis Sync. ToP IEEE1588v2 (Chapter Transmission)

New Sections:

• BSS30450 Packet Abis Synchronous Ethernet (Chapter Transmission) • BSS30395 Packet Abis Delay Measurement (Chapter Transmission) • BSS21503 FlexiPacket Radio Connectivity (Chapter Transmission)

Changes between issues 7-0 and 6-5New Sections:

• BSS21309 OSC Half Rate with SAIC MS (Chapter Data/Voice) • BSS21362 Fast BSS Restart (Chapter Operability) • BSS21316 Flexi BTS Autoconnection (Chapter Operability) • RG301397 Co-siting with BS2xx (Chapter Site solutions) • BSS21444 Packet Abis Security (Chapter Basic GSM operation) • BSS21445 Packet Abis Congestion reaction (Chapter Basic GSM operation) • BSS21271 Abis Delay Measurement (TDM, PWE3) (Chapter Transmission) • BSS21454 Packet Abis over Ethernet (Chapter Transmission) • BSS21438 Packet Abis over Satellite (Chapter Transmission) • BSS21443 Packet TRS for UltraSite/BTSplus (Chapter Transmission) • BSS21439 Packet Abis Sync. ToP IEEE1588v2 (Chapter Transmission) • BSS21440 Packet Abis over TDM (Chapter Transmission)

Changes between issues 6-5 and 6-4New Section:

• BSS101411 Extended BCCH

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Overview of features in Flexi EDGE BTS SW release EX4.0

2 Overview of features in Flexi EDGE BTS SW release EX4.0Operating and Application SWNokia Siemens Networks RG20(BSS) Software consists of Operating Software and Application Software:

• Operating Software refers to basic functionalities of a product. • Application Software refers to optional features.

The RG20(BSS) system features are available in the following network element releases: S15, EX4.0

For more information on the features, see Nokia Siemens Networks GSM/EDGE BSS, rel. RG20(BSS), operating documentation.

For general guidelines related to licensing, see Licence Management in BSC in the GSM/EDGE BSS operating documentation.

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Flexi EDGE BTS Feature Descriptions Data/Voice


3 Data/Voice

3.1 BSS21270 105 km Extended Cell and BSS21277 105 km Extended Cell for GPRS/EDGEBSS21277 and BSS21270 are optional features and those can be used with Flexi-EDGE BTS to increase the cell radius to about 105 km. The cell radius in a normal cell is 35 km, and the cell radius of the extended cell is 70 km. The cell with a 105 km radius is referred to as a super-extended cell.105 km extended cell features have been built on top of the extended cell function.

The minimum software requirements for this feature are Flexi EDGE BTS SW EP2 CD1.0 and BSC SW S14 MP3.0.

g SEXT parameter, which is used to define cell radius of the super-extended cell cannot have values from 45 to 51 due to HW restrictions. Therefore, the super-extended cell radius cannot be configured as 80 - 86 km. This is a restriction with the feature usage.

Interaction with other featuresThe following features cannot be used simultaneously with features BSS21277 and BSS21270:

• Baseband hopping • RF hopping cannot be used in extended/super extended are TRXs (RF hopping can

be used in normal area non-BCCH TRX(s) if present) • Antenna hopping • Intelligent Underlay Overlay (IUO) • Dynamic Frequency Channel Allocation (DFCA) • TRX Test: TRX Test cannot be commanded for a TRX configured to cover the

extended/super extended outer area

More information on the features BSS21277 and BSS21270 can be found from Nokia Siemens Networks GSM/EDGE BSS, rel. RG10 (BSS), operating Documentation, issue 03 onwards in the following documents:

• Feature Descriptions, BSS21277: 105km Extended Cell CS, DN70664319 • Feature Descriptions, BSS21270: 105km Extended Cell for GPRS/EDGE

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3.2 BSS20951 RTC Support in ECELLWith this feature RTCs can be used with the Extended Cell feature, for both Normal and Extended area TRXs.

This is useful for Extended Cell sites where there is high traffic with most of the traffic in the extended area, for example where an off-shore island is served by a BTS on the mainland.

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3.3 BSS20094 Extended Cell for GPRS/EDGEExtended cell for GPRS/EDGE has been built on top of the extended cell function. This means that the same method is used for creating the normal and extended service areas, and the same parameters are used for dimensioning the cell for both PS and CS services.

The two service areas are part of the same cell and both areas are served by the same BCCH. In practice this means that MS movement between the service areas is handled as intra-cell reallocation instead of cell re-selection.

Only the BCCH BTS of an extended cell may serve the extended service area, that is, the TRXs serving the extended service area must be accommodated by the BCCH BTS. The minimum extended cell configuration includes two TRXs – one for the extended service area and one for the normal service area – but multiple TRXs may be used in both service areas. The basic two-TRX extended cell would be configured as shown in the following figure.

Figure 1 Extended Cell two TRX configuration with two EGTCHs

• RTSL 0 of the TRX serving the normal service area (N-TRX) configured as BCCH/RACH/SDCCH.

• RACH, through which access bursts are received from the extended service area, occupies RTSL 0 of the TRX serving the extended service area (E-TRX). E-RACH is tuned to the same frequency as the BCCH/RACH. The DL direction of the E-RACH RTSL is not used for any purpose: BCCH serves both service areas.

• RTSL 1 of the BCCH N-TRX is left unused since its reception overlaps with that of E-RACH on the same frequency.

• Six time slots in both TRXs can be used for actual GSM/GPRS user traffic.

Extended cell GPRS/EDGE channels (EGTCHs) constitute a fixed PS time slot territory, that is, the territory upgrade and downgrade procedures, which are used for dynamically adjusting CS and PS territories according to the traffic situation, are not applied to EGTCHs, and EGTCH time slots are therefore blocked from CS use.

During uplink TBF resource allocation, the correct service area of the MS is determined on the basis of access signalling: the MS is located in the normal service area if access signalling is received through RACH (N-TRX) and in the extended service area if access signalling is received through E-RACH (E-TRX). During downlink resource allocation, the correct service area is determined either by reading the service area from an existing

Normal TRX RX

f1

TCH

f1

TCH

f1

TCH

f1

TCH

f1

TCH

f1

TCH

f1f1

f1 f2 f2 f2 f2 f2 f2 f2

EGTCHEGTCHTCHTCHTCHTCH

E-TRX RX

SDCCHE-RACH

BCCH/SDCCH

Notin use

TRX

Normal

E-TRX

Delayedreceiver

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MS context, or by paging the MS if no context exists or if the location information in the context is considered invalid.

Timing Advance (TA) indicates the MS distance from the BTS. Timing advance has a range of 0-63 TA units in both service areas. The need for TBF reallocation from one service area to the other is determined by monitoring the TA for an MS: when the TA reaches a predefined upper limit for an MS located in the normal service area, it is real-located to the extended service area; when the TA reaches a predefined lower limit for an MS located in the extended service area, it is reallocated to the normal service area.

In order to provide the BSC with the required TA-information, Dynamic Abis must be applied to all TRXs used for PS traffic in both the extended and normal service areas of an extended cell.

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3.4 Long Reach TCH TSLA new RTSL type, Long Reach TSL, is used temporarily for incoming external han-dovers (from 2G or 3G), in order to allow the BTS to determine the cell area (normal or extended) where the mobile is actually located. The BTS informs the correct area to the BSC which starts an intra-cell handover to this area.

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3.5 BSS20088 Dual Transfer ModeDual Transfer Mode (DTM) provides mobile users with simultaneous circuit-switched (CS) voice and packet-switched (PS) data services. This means that users can, for example, send and receive e-mail during an ongoing phone call.

In dual transfer mode, the mobile station (MS) is simultaneously in dedicated mode and in packet transfer mode, so that the timeslots allocated for each MS are consecutive and within the same frequency.

BenefitsWith DTM, the operator can expand the service portfolio to offer users enhanced services in a GSM/EDGE network. DTM allows the operator to provide a wide range of services that demand a simultaneous CS and PS connection. Mobile users can use data services, such as file transfer, web browsing, video sharing, and mobile netmeeting, during a speech call. This makes it possible to launch services similar to UMTS class A services also in 2G networks. In addition, these services can be used to complement the 3G coverage in places where there is no 3G network coverage.

BTS functionality supportThe BTS supports DTM through the normal BTS support of CS and PS services.

Interaction with other featuresDTM supports all full rate speech codecs. The CS speech codec selection for DTM is similar to the selection mechanism used for a plain CS connection. In addition, the DTM PS channels can be multiplexed in a similar way to normal GPRS/EDGE.

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3.6 BSS9006 General Packet Radio Service (GPRS)General Packet Radio Service GPRS provides packet radio access for GSM mobile sta-tions.

By sharing the channels provided by various network elements and transmission systems, the cellular network resources are used more efficiently for data services than with circuit switched data services.

All mobile stations share the radio resources in a cell, and use the radio resources only when sending or receiving data.

The Channel Coding Unit (CCU) in the BTS performs the channel coding for the follow-ing ETSI defined coding schemes:

• Channel Coding Scheme 1 (CS1) 9.05 kbit/s • Channel Coding Scheme 2 (CS2) 13.4 kbit/s • Channel Coding Scheme 3 (CS3) 15.6 kbit/s • Channel Coding Scheme 4 (CS4) 21.4 kbit/s

In packet transfer mode, the mobile station must use the continuous timing advance pro-cedure. This procedure is carried out on all packet data channels (PDCHs).

Coding Schemes CS3 and CS4 (BSS11088) is an application software product, and it requires a valid licence in the BSC. CS3 and CS4 provide a considerable gain in data rates for GPRS mobile stations not supporting EGPRS (the mandatory RLC header octets are excluded from the data rate values).

Link Adaptation (LA)Nokia Flexi EDGE BTS supports PCU with GPRS link adaption by providing the mea-surements for the uplink radio blocks.

Interaction with other featuresCS3 and CS4 do not fit to one 16kbit/s Abis/PCU channel and require the use of Dynamic Abis Allocation.

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3.7 BSS10083 Enhanced General Packet Radio Service (MCS-1 - MSC-9)Enhanced General Packet Radio Service (EGPRS) supports high rate packet data services across varying channel conditions. EGPRS is built on top of the packet-switched data service, GPRS. As the table below shows, EGPRS supports higher data rates compared to the basic GPRS, using several Modulation and Coding Schemes (MCSs). The speed in radio resources is fixed for GMSK and 8PSK, but because the amount of channel coding varies, the user data rate varies depending on the MCS.

Gaussian Minimum Shift Keying (GMSK) modulation provides the robust mode for wide-area coverage, while 8 Phase Shift Keying (8PSK) provides higher data rates.

The MCSs are organised into families to allow a re-segmentation of the data block for link adaptation. Since higher protection means lower throughput, the protection that best fits the channel condition is chosen for maximum throughput.

Incremental Redundancy (IR)Incremental Redundancy (IR) is an efficient combination of two techniques: Automatic Repeat reQuest (ARQ) and Forward Error Correction (FEC). In the ARQ method, when the receiver detects the presence of errors in a received data block, it requests a re-transmission of the same data block from the transmitter. The process continues until an uncorrupted copy reaches the destination. The FEC method adds redundant infor-mation to the user information at the transmitter, and the receiver uses the information to correct errors caused by disturbances in the radio channel.

In the IR scheme (also known as Type II Hybrid ARQ scheme), only a small amount of redundancy is sent first, which yields a high user throughput if the decoding is success-ful. However, if the decoding fails, a re-transmission takes place according to the ARQ method. Using IR, the re-transmission of the data block is different from the initial trans-mission. The transmitter sends additional redundancy that is decoded at the destination with the previously received information to allow for error correction. Since the combina-tion includes more information than any individual transmission, the probability of correct reception is increased.

The IR mechanism in EGPRS is designed around nine Modulation and Coding Schemes (MCSs). The basic characteristics of each MCS are its fixed data rate and

MCS Modulation Code Rate Family User Rate

MCS-1 GMSK .53 C 8.8 kbps

MCS-2 GMSK .66 B 11.2 kbps

MCS-3 GMSK .80 A 14.8 kbps

MCS-4 GMSK 1 C 17.6 kbps

MCS-5 8PSK .37 B 22.4 kbps

MCS-6 8PSK .49 A 29.6 kbps

MCS-7 8PSK .75 B 44.8 kbps

MCS-8 8PSK .92 A 54.4 kbps

MCS-9 8PSK 1 A 59.2 kbps

Table 1 Peak data rates for single slot EGPRS

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fixed protection level. For each of the MCSs, it is possible to reach the same data rate with the same protection level, but with a different protection scheme.

Figure 2 Incremental Redundancy scheme

There are three protection schemes (P1, P2 and P3) for an MCS, as shown in the figure above. The data block is first protected with the P1 of a certain MCS, and sent over the air to the receiver, which tries to recover the data. If this phase fails, the received P1 is stored in the receiver's memory for future use, and the transmitter sends the data block protected with the P2 of the same MCS. The receiver combines the received P2 with the stored P1 and tries to recover the data from the combination of P1 and P2. This process continues until the data is recovered.

If after P3, the data still cannot be recovered, P1 is sent again and combined with the stored P1, P2 and P3 (which reaches a protection level of about four times P1), and so on until the data is recovered.

Link Adaptation (LA)Flexi EDGE BTS supports PCU with EGPRS link adaption by providing the measure-ments for the uplink radio blocks.

Interaction with other featuresEGPRS Modulation and Coding Schemes MCS-1 - MCS-9 require the use of Dynamic Abis Allocation.

Data Block

One MCS

P2 P3P1

P2

P2

P2

P1

P1

P1

P1

Stored

Stored

Receiver

Transmitter

No data

recovered

No data

recoveredCombination: Protection Level x 2

Protection Level 1

Combination: Protection Level x 3

Stored

P3

P3

1st transmission 1st re-transmissionupon reception failure

2nd re-transmissionupon reception failure

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3.8 BSS7003 High Speed Circuit Switched Data and BSS7037 14.4 kbit/s Data ServicesHigh Speed Circuit Switched Data uses multiple parallel channels to provide higher data rates for end-user applications, such as the World Wide Web, file transfer and facsimile.

The BSS implementation is to reserve a multiple set of basic resources for one high-speed data call. The data rate and the number of reserved timeslots vary between one and the defined maximum of the user application. The variable rate is needed for various common procedures, for example for handovers to a new cell if the requested data rate cannot be given immediately. The BSS implementation of HSCSD supports the simul-taneous usage of a maximum of four radio timeslots (RTSLs) per HSCSD call.

The table below presents the corresponding maximum data rates with different channel coding.

Both asynchronous and synchronous bearer services and transparent and non-trans-parent data services are supported. Transparent HSCSD uses fixed data rate through-out the duration of the call, but with non-transparent HSCSD, the data rate can be changed automatically during the call, because of increased traffic for example. The radio interface is either symmetric or asymmetric according to the mobile station (MS) capability.

During basic channel allocation, the system tries to keep consecutive timeslots free for multichannel HSCSD connection. If there are not enough appropriate free channels to fulfil the requested data rate, a non-transparent HSCSD connection is started with fewer channels than requested. At least one channel is allocated for a non-transparent HSCSD call request if there are available resources in the cell. By use of the resource upgrade procedure, the data rate of the HSCSD connection can be increased when an appropriate channel is available.

In a congested cell, the HSCSD load can be adjusted by BSC parameterisation. The resource downgrade procedure is used to lower the HSCSD connection data rate to release radio channels for other connections. If a transparent connection cannot be established in a cell, a directed retry can be attempted.

BSS7037 14.4 kbit/s GSM Data ServicesWith the 14.4 kbit/s GSM Data Services, the speed of one timeslot increases from 9.6 kbit/s to 14.4kbit/s.

The 14.4 kbit/s channel coding has less error correction than 9.6 kbit/s coding. There-fore, there are some areas on the cell edges where using 9.6 kbit/s coding will give a higher data throughput. The figure below shows the results of Nokia Siemens Networks simulations. Note that for transparent mode the maximum user throughput is 14.4 kbit/s, but in non-transparent mode, the maximum user throughput is 13.2 kbit/s. The

Number of RTSLs 9.6 kbit/s 14.4 kbit/s

1 9.6 kbit/s 14.4 kbit/s




Table 2 Corresponding maximum data rates with different channel coding

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maximum throughput is based on the amount of available space in the coding block. Non-transparent data requires space for error checking, but transparent data does not.

Figure 3 Typical data throughputs for 14.4 kbit/s (non-transparent) and 9.6 kbit/s coding (this depends on the NW radio conditions)

The Automatic Link Adaptation (ALA) optimises the data throughput by automatically choosing the channel coding most suitable to the radio conditions and by control of the power levels.

The 14.4 kbit/s Data Services can be combined with High Speed Circuit Switched Data (BSS7003).

Note that Flexi EDGE BTS does not support transparent data handovers because of lim-itations in fax protocols.

0

2

4

6

8

10

12

14

60 65 70 75 80 85 90 95 100

Percentage of Cell Area (%)

Da

taT

hro

ug

hp

ut

Ra

te(k

bit/s

)

14.4

9.6

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3.9 BSS10004 Adaptive Multi Rate Codec (AMR)Adaptive Multi Rate Codec provides significantly better speech quality by:

• using better source coding algorithms that give better subjective speech quality for the same link capacity

• adaptively adjusting ratio of bits used for speech coding and channel coding to always provide best subjective speech quality according to current radio conditions.

With AMR it is possible to increase speech capacity by using HR mode and still maintain the quality of current FR calls. It consists of an adaptive algorithm for codec changes and 8 different speech codecs (14 codec modes) listed in the table below.

Codec mode adaptation for AMR is based on received channel quality estimation in both the mobile station (MS) and the BTS.

The BTS and MS inform and request of codec used/to be used by in-band signalling.

Channel mode

Channel codec mode

Source coding bit-rate, speech

Net bit-rate, in-band channel

Channel coding bit-rate, speech

Channel coding bit-rate, in-band

TCH/FR CH0-FS

CH1-FS

CH2-FS

CH3-FS

CH4-FS

CH5-FS

CH6-FS

CH7-FS

12.20 kbit/s (GSMEFR)

10.20 kbit/s

7.95 kbit/s

7.40 kbit/s (IS-641)

6.70 kbit/s

5.90 kbit/s

5.15 kbit/s

4.75 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

10.20 kbit/s

12.20 kbit/s

14.45 kbit/s

15.00 kbit/s

15.70 kbit/s

16.50 kbit/s

17.25 kbit/s

17.65 kbit/s

0.30 kbit/s

0.30 kbit/s

0.30 kbit/s

0.30 kbit/s

0.30 kbit/s

0.30 kbit/s

0.30 kbit/s

0.30 kbit/s

TCH/HR CH8-HS

CH9-HS

CH10-HS

CH11-HS

CH12-HS

CH13-HS

7.95 kbit/s (*)

7.40 kbit/s (IS-641)

6.70 kbit/s

5.90 kbit/s

5.15 kbit/s

4.75 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

3.25 kbit/s

3.80 kbit/s

4.50 kbit/s

5.30 kbit/s

6.05 kbit/s

6.45 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

(*) Not supported, requires 16 kbit/s TRAU.

Table 3 Channel and speech codec modes for AMR

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3.10 BSS7005 Intelligent Frequency Hopping and BSS6114 Intelligent Underlay-OverlayWith Intelligent Frequency Hopping and Intelligent Underlay-Overlay, it is possible to reuse frequencies more intensively, and therefore achieve a higher radio network capacity. With Intelligent Frequency Hopping, it is also possible to avoid frequency dependent fading on the radio path.

When Intelligent Frequency Hopping is in use, the operator can use Intelligent Underlay-Overlay simultaneously with frequency hopping in the same cell. Either baseband (BB) or radio frequency (RF) hopping can be used.

The different interference characteristics of the regular and super-reuse layers in Intel-ligent Underlay-Overlay require that the network plan for frequency hopping is con-structed separately for each layer. Intelligent Frequency Hopping enables the use of separate Mobile Allocation Frequency Lists of radio frequency hopping for the layers of an Intelligent Underlay-Overlay cell. Baseband hopping is implemented by treating the regular layer as a normal cell and the super-reuse layer as a new hopping group.

The operator can set the regular and super-reuse layers in Intelligent Underlay-Overlay individually to hopping.

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3.11 BSS20960 Wideband AMR and BSS21118 TFO for AMRThese features introduce wideband AMR coding as specified by 3GPP and ITU-T. Wideband AMR is based on a family of new speech codecs. It is designed to achieve improvements in speech quality. The sampling rate of WB AMR speech codec is increased to 16 kHz which allows the bandwidth of the signal encoded to be extended to cover range from 50 to 7000 Hz. Wideband AMR requires end to end tandem free operation support.

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3.12 BSS21309 OSC Half Rate with SAIC MS“Orthogonal subchannel (OSC)” is a feature that increases the radio channel capacity for voice calls in GSM networks. This is provided by adopting quadrature phase shift keying (QPSK) in downlink and orthogonal subchannels in uplink. These two key tech-niques linked with adaptive multi rate (AMR) make it possible to serve two users that support single antenna interference cancellation method (SAIC) simultaneously, in the single radio traffic channel. The increase in network capacity depends on the radio con-ditions.

The feature “BSS21309 OSC Half Rate with SAIC MS” implements the OSC feature for Half Rate traffic channels. With this feature, four users can share the same radio timeslot with SAIC and AMR support from the mobile station. When OSC Half Rate with SAIC MS is used, an increased Abis transmission capacity is required because OSC Half Rate calls are multiplexed into one Half Rate traffic channel (TCH/H). The increased Abis transmission capacity is provided by circuit switched dynamic Abis pools (CSDAPs) or packet Abis.

OSC Half Rate with SAIC MS is an application software feature controlled by licensing. For detailed description of this feature, see BSS21309: OSC Half Rate with SAIC MS Feature Description document.

This feature provides the following benefits:

• The feature is applicable with existing GSM SAIC handsets, thus providing an imme-diate gain with just a software upgrade in the GSM radio network

• It increases the capacity for voice and releases capacity for data traffic without requiring new TRXs or related hardware. This reduces the number of TRXs required to realize a specific capacity or spectral efficiency

• The increased capacity per TRX reduces the energy consumption per user. This reduces the energy consumption required per Erlang significantly

• It avoids the need to add new sites, as it maintains the coverage area in capacity extensions

• The increased capacity per TRX effectively reduces site density through reduced combining losses

• When another radio technology needs to share the same site, antennas or input ports of combiners may be released by the introduction of OSC Half Rate with SAIC MS

Interaction with other featuresThe “BSS21309 OSC Half Rate with SAIC MS” feature cannot be activated on EXxA DTRX units if “BSS10083 Enhanced General Packet Radio Service (MCS-1 - MSC-9)” feature is activated on the same units. When Baseband hopping or Antenna Hopping is in use, the hopping groups cannot contain any EXxA DTRX units if EGPRS is active on any of DTRX units in those hopping groups. The EXxB DTRX unit does not have these limitations, unless in hopping group with EXxA.

OSC calls will not be placed to TRXs that have Double Power TRX (DPTRX), Intelligent Downlink Diversity (IDD) or 4-way UL Diversity features configured. OSC calls will not be placed in Extended and Super Extended areas of E-Cell feature.

“BSS10004 Adaptive Multi Rate Codec (AMR)” feature for AMR HR needs to be active Circuit Switched Dynamic Abis Pool (CSDAP) or Packet Abis over Ethernet or Packet Abis over TDM has to be in use.

Requirements

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• BSC S15 • Flexi EDGE BTS EX4.0 • NetAct OSS5.2 CD SET 3 • MS Capable of SAIC and AMR

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Flexi EDGE BTS Feature Descriptions Interworking

Id:0900d805807fbdacConfidential

4 Interworking

4.1 BSS10101 GSM-WCDMA InterworkingIn order for an operator to provide seamless coverage in areas where WCDMA is not available, such as rural areas, inter-system handovers are introduced. This feature facil-itates handovers between GSM BSS and WCDMA RAN. When the WCDMA and GSM networks overlap, also an inter-system handover from GSM to WCDMA can be made to release traffic load in the GSM system.

Flexi EDGE BTS supports this feature as a GSM EDGE Base Station.

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4.2 BSS11086 Support for Enhanced Measurement ReportSupport for Enhanced Measurement Report (EMR) provides the system with enhanced serving and neighbour cell measurements. This is achieved by requesting the mobile station (MS) to use the EMR for reporting downlink measurements.

Enhanced Measurement Report also provides the system with information such as Downlink Frame Erasure Rate (DL FER), the usage of bit error probability (BEP) instead of RX Quality during the DTX frames, and the support for reporting WCDMA RAN neigh-bour cells. In addition, the EMR also provides an extended range for the serving and neighbour cells downlink signal strength and the possibility to report altogether up to 15 GSM and/or WCDMA RAN neighbour cells in one report.

These reports can be used by the network to enhance the generic performance of the existing system, enable GSM/WCDMA interworking, and enhance several Nokia fea-tures, such as:

• Automated Planning • Dynamic Frequency Channel Allocation (DFCA) • FER Measurement • Intelligent Underlay Overlay (IUO) and Intelligent Frequency Hopping (IFH)

Interaction with other features:

• The network does not order an MS to use the EMR for reporting when an Idle Broad-cast Control Channel (BCCH) Allocation List or a Measurement BCCH Allocation List is used in active state in the serving cell.

• With Common BCCH Control, when a call is in a non-BCCH frequency band, the serving cell BCCH frequency is added to the BCCH frequency list.

• When the EMR is used for reporting, also the serving cell BSIC is added to the BSIC list before sending it to an MS.

Benefits

• Improved generic performance of the system • Enables GSM/EDGE/WCDMA interworking • Improved performance of statistics

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Flexi EDGE BTS Feature Descriptions Operability

Id:0900d805807fbde9Confidential

5 Operability

5.1 BTS Trace ToolBTS Trace Tool is built in the BTS Manager application and can be used to collect detailed logs when investigating a problem seen on a customer BTS site. The tool can be controlled either via local or remote BTS Manager minimising the need for site visits. The tool provides the functionality to collect logs remotely from the BTS site over the Abis link. In addition to a few standard logs, custom logs can be recorded as well with the help of custom trace set files provided by the NSN customer support team. The recorded log files can be decoded and analysed by NSN.

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5.2 Antenna VSWR measurementFlexi EDGE BTS provides antenna line supervision by means of voltage standing wave ratio (VSWR) monitoring in the Dual Duplexer Module (ERxA). During commissioning, the user can set the VSWR minor (7607) and major (7606) alarm limits for each antenna line separately. The minor limit can be set between 1.5...2.9:1 (that is, with a return loss 14.0 - 6.2 dB) and the major limit between 2.7...3.5:1 (6.8 - 5.1 dB). The default limits on the Flexi EDGE BTS Manager are 2.1:1 (minor) and 3.1:1 (major) which convert to 9 dB (minor) and 5.8 dB (major) return loss (RL) respectively. At the end of the commissioning process, the values are stored in the site configuration file (SCF) in the System Module's (ESMA) non-volatile memory. During normal BTS operation, the Dual TRX Module (EXxx) sends a polling request to the Dual Duplexer Module every few seconds. The Dual Duplexer Module responds with a message containing the return loss values for both antenna paths (A and B). The Dual Duplexer Module can report the return loss reliably if the TX power in its TxA or TxB input exceeds approximately +32 dBm. The BTS software converts the reported return loss values to VSWR values, and compares them with the minor and major limits found in the site configuration file. If the reported VSWR exceeds the minor limit, alarm 7607 'TRX operation degraded' is activated. If the reported VSWR exceeds the major limit, alarm 7606 'TRX faulty' is activated, and the affected TRX objects are blocked.

Typical causes for a bad VSWR are broken cables, broken connectors and the ingress of water in the antenna cable path.

5.2.1 BCCH antenna VSWR measurement If the antenna line on Dual Duplexer (ERxx) module carries BCCH, twelve consecutive return loss measurements are analysed. If the operation is suddenly degraded and a sporadic bad reading is received, the analysis is reset and a new set of measurements is collected. If all consecutive measurements are bad, a minor or major alarm is acti-vated depending on how bad the result is. Likewise, all consecutive measurements have to be OK before the alarm is cancelled. Only minor (7607) can be cancelled automati-cally while major (7606) alarm is blocking.

The BCCH antenna VSWR measurement feature works with both Dual Duplexer (ERxA) and RTC (ECxA) modules. The feature does not work in an antenna hopping sector.

5.2.2 TCH antenna VSWR measurementFor TCH only antenna lines (that is, TCH only TRX(s) are connected to this antenna), antenna boosting may be needed to generate temporary Tx signal for the Dual Duplexer (ERxx) module so that it would be able to measure the VSWR condition. If antenna boosting is needed due to lack of traffic, the first TRX object from the Dual TRX (EXxx) module connected to Dual Duplexer (ERxA) module transmits a continuous Tx signal on all traffic, idle and packet-switched time slots for two seconds. The TRX object used for boosting must be unlocked and in supervisory state. Antenna boosting is only possible when the BCCH power level is 0…2 (that is, with PMAX values 0, 2 or 4).

If the Dual Duplexer (ERxx) module has reported insufficient Tx power for TCH only antenna for one hour, antenna boosting is started. If insufficient power level is still reported after the boosting period, blocking alarm 7606 'ERxx DDU module has

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detected no Tx power at TxA/B input' is raised for all TRX objects connected to this antenna line.

If the Dual Duplexer (ERxx) module has reported bad VSWR for TCH only antenna line for one hour, antenna boosting is started as well. If bad VSWR is still reported after the boosting period, a minor or major VSWR alarm is activated depending on how bad the result is (such as with BCCH antenna VSWR measurement).

The TCH antenna VSWR measurement feature works with Dual Duplexer (ERxA) but not with RTC (ECxA) module. The feature does not work in BB nor antenna hopping sector.

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5.3 BSC download of Abis mappingAbis mapping automates the process of providing Abis allocations on the BTS. The BTS must be able to configure the allocation of the Abis using the information received from the BSC, instead of getting the information in a Site Configuration File (SCF). This con-figuration is performed by the BTS, by using mapping algorithms to convert BSC data into BTS Abis allocations. The mapping between the BSC data and the interfaces at the BTS relies on reference signals that are collectively known as the Abis Termination infor-mation of the BTS. The Abis mapping information is provided to the BTS. The Abis Ter-mination information is provided to the BTS during commissioning via SCF from the BTS Manager. One reference signal per interface is supported at the BTS.

An Abis mapping Information Element (IE) consists of Abis channels (TRXSIG and TCH) in BTS_CONF_DATA grouped into a bundle. The BTS_CONF_DATA can carry several instances of Abis mapping IE(s), one for each bundle or interface. The interface timeslots in the Abis mapping IE(s) from the BSC are the timeslots at the BSC interface. OMUSIG configuration is still taken from the Abis Termination information already stored at the BTS, and not from the Abis mapping IE. The timeslot information provided in the Abis mapping IE is converted into timeslot information for the BTS via the Abis mapping algorithm. EDAP information is provided using the Dynamic Pool Info IE(s) in the BTS_CONF_DATA. The interface timeslots in the Dynamic Pool Info IE(s) are the timeslots at the BSC interface.

The BTS Manager has been enhanced with the Abis mapping download function:

• A BSC Abis Mapping Status view menu item has been added in the Transmission menu of the BTS Manager. • The BSC Abis mapping facilitates the user to view the differences and conflicts

in the BSC and BTS allocations for a selected interface or a BSC bundle. The user can select an interface from the list of interfaces displayed in the Transmission equipment view or select a BSC bundle from an available list of bundles. As per user selection, the details of the BTS interface, reference signal and the calculated offset value are displayed.

• This is only available in online mode. • Two check boxes have been added for the BSC Abis mapping download function in

the Abis Termination screen of the Commissioning Wizard: • Enable Abis Signal Mapping allows the user to enable/disable the Abis signal

mapping. • Allow Abis Allocations from BTS Manager allows the user to enable/disable

the Abis allocations from the BTS Manager. If this check box is selected and the user enters the Abis allocations from the BTS Manager, they might later be over-written by the allocation data from the BSC.

• These options are available in both online and offline mode.

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5.4 BSS21362 Fast BSS RestartThe “BSS21362 Fast BSS Restart” feature increases the network availability by reducing the radio network (RNW) downtime in a controlled BSC restart. The reduced downtime is achieved by restarting the BSC without an RNW restart. The feature is basic software and its usage is not controlled by a license or parameter. Fast BSS Restart is not allowed if RNW Plan or RNW Fallback activation is ongoing.

Usually, a BSS system restart is performed to ensure that all the necessary parameters and information are updated inside BSC and BTS after a BSC software installation, or during maintenance. During a BSS system restart, the cells go into a barred state for a while causing downtime in the radio network. The BSC’s computer units become active and start running depending on the BSC configuration. After that, the RNW takes 1- 82.5 minutes to get active, depending on the BTS site type, BTS software, size of radio network configuration, and BTS configuration in the BSS.

With the “BSS21362 Fast BSS Restart” feature, after a BSC restart is triggered and when all its BTSs support the feature, the RNW activation phase takes only 0.5 - 4.5 minutes after all the BSC computer units are raised back to working state. The time taken depends on the size of RNW configuration in the BSC.

This feature provides the following benefits:

• Increased network availability for service usage • All BTSs under BSC support the feature

Requirements

• BSC S15 • Flexi EDGE BTS EX4.0 • NetAct OSS5.2 CD set 3

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5.5 BSS21316 Flexi BTS AutoconnectionThe feature “BSS21316 Flexi BTS Autoconnection” enables a faster, automated integra-tion of new Flexi BTSs into the BSS network, eliminating the need to use a laptop, and making the integration less prone to error. The main purpose of the “Flexi BTS Autocon-nection” feature is to allow the dedicated SCF data to be automatically transferred from the BSC to the BTS during BTS commissioning. However, when there are radio trans-mission hops, or when the PCM line is shared between BTSs, a laptop is needed as a download device. For this automated BTS integration capability, the supporting trans-mission connectivity must be in place. An integrated radio network planning process enables further automation improvements. This feature is not supported with Pseudowire Ethernet (PWE) mode. This is a licensed feature.

The Flexi BTS Autoconnection feature provides the following benefits to operators:

• Simplifies installation and reduces the rollout time for new Flexi EDGE BTSs, improving the efficiency of installation teams. Consequently, the time to service is reduced and revenue is increased

• During the maintenance phase (after the network rollout has been completed), the feature continues to support the speeding up of BTS configuration modifications, reducing errors and consequently reducing the operating costs

• Reduces the time required for installing radio hops

Requirements

• BSC S15 • Flexi EDGE BTS EX4.0

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5.6 BSS20847 Automatic commissioning of the Flexi EDGE BTSFlexi EDGE BTS is designed so that it is easy to install and commission. Easy commis-sioning needs support also from the BSC. The following functions are related to the automatic commissioning of the Flexi EDGE BTS:

• The BSC must be able to download Abis mapping to the BTS. The BTS configures the Abis allocations of the TRXSIGs, TCHs and EDAPs using the information received from the BSC, instead of getting the information in the SCF. The mapping between the BSC data and the interfaces at the BTS relies on reference signals (one per interface (E1/T1) at the BTS) which are collectively known as the Abis termina-tion information of the BTS. The Abis termination information is provided to the BTS during commissioning via SCF from the BTS Manager.

• When the site is commissioned, the BSC must automatically unlock the BCF when the BTS informs that it is ready.The 'Autounlock allowed' is a configurable functionality (a BCF-level parameter in the BSC).

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5.7 BSS20817 End to End Downlink Abis Performance Monitor BSS20065, in BSC S11.5 SW, implements counters in the BSC that check the uplink signalling channels (channels using LAPD), keeps the results in a set of counters, and every 24 hours checks the number of errors (CRC errors) against an alarm threshold.

BSS20817 is an equivalent feature for the Downlink Abis.

The BTS keeps downlink counters for each LAPD connection that terminates in the BTS. The counters measure the number of received bytes, the number of CRC errors and the number of T200 timeouts. The BTS reports the counter numbers, per channel, every hour between 10 minutes before the hour and the top of the hour according to the BTS real-time clock.

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5.8 BSS20760 BTS ID shown in BTS ManagerAt present, the BTS Manager shows "Sector" number for each Sector, but the BSC shows "BTS" number. The "BTS" number can be different from the "Sector" number. With this feature the BTS Manager will show both "Sector" number and "BTS" number, to avoid any confusion between an operator using BTS Manager and an operator using the BSC MML or NetAct. The mapping between the "Sector" number and the "BTS" number is as sent in the Abis O&M interface in the BTS_CONF_DATA message.

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5.9 BSS20063 Space Time Interference Rejection CombiningThe Space Time Interference Rejection Combining (STIRC) is a licence-based applica-tion software in the BSC that enables/disables the use of STIRC technology in the BTS.

The STIRC is an uplink (UL) receiver performance enhancement to the Interference Rejection Combining (IRC) technology. When enabled, the STIRC technology is deployed in the UL by BTS. When disabled, the current IRC technology is deployed by the BTS.

The new technology improves the spectral efficiency of the network via link performance enhancement that significantly improves the interference (co-channel and adjacent channel) rejection capability of Flexi EDGE BTS in the uplink direction. For example, the improved link level interference rejection performance of the STIRC with GMSK modu-lation will give on average a gain of 4 to 9 dB for co-channel interference compared to the IRC in 2-way Uplink Diversity (2UD) configurations. STIRC will also give similar or better gain compared to IRC when used in Flexi EDGE 4-way Uplink Diversity (4UD) BTS configurations with GMSK modulation. In addition, the current GMSK normal burst receiver sensitivity levels are not affected.

The STIRC can also help to maintain the link balance (UL and DL) needed with the deployment of Single Antenna Interference Cancellation (SAIC) technology in mobiles that improves interference cancellation capabilities in the downlink (DL).

The STIRC licensing software will be operational once the STIRC option is enabled at the BSC. The BSC will allocate the STIRC license from its available pool and send the STIRC option in the BTS_CONF_DATA to the BTS.

This feature affects alarm handling so that STIRC alarms can be cancelled without reset.

ImplementationThe STIRC feature can be enabled or disabled for the site any time the BTS is running because it does not require locking the sector or TRX. The BSC will send the STIRC option for each sector in the BTS_CONF_DATA. When receiving this option, the BTS O&M SW checks for each TRX in the sector for which STIRC is enabled, whether the HW configuration is valid for the STIRC feature. If an invalid configuration is used, an alarm is raised on the specific TRX(s) and these specific TRX(s) are blocked, and STIRC is enabled on rest of the TRX(s). BTS O&M SW enables the STIRC algorithm by informing the DSP of each valid TRX in the sector.

Note that the STIRC algorithm implementation requires 32-bit precision numerical cal-culations to minimise quantisation errors, while for the IRC algorithm 16-bit precision is sufficient. Thus, for STIRC implementation 32-bit precision is used for all the functions, some of which are common to the IRC algorithm also. As a result of this, slight gain (up to 0.2 dB) in CCI and ACI performance can be observed even when the IRC algorithm is used (STIRC=N).

In order to achieve the STIRC gain, Rx Diversity should be in use (RDIV=Y).

RequirementsThis feature is supported by the following BTS generations and SW:

• Flexi EDGE EP2 • UltraSite CX5 with EDGE TRXs (BB2E/BB2F and TSxB) and Hybrid TRX

(BB2E/BB2F and TSxA). • MetroSite CXM5 with EDGE TRXs

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• BSC S12

Interaction with other features

• All valid hopping combinations for the supported TRX types are supported. • BSS synchronisation helps in achieving full STIRC gain. • For Flexi EDGE BTS, STIRC supports the E-Cell.

BenefitsThe STIRC diversity algorithm improves the interference rejection performance and thus the overall network spectral efficiency and quality.

The STIRC ensures better uplink quality, particularly in high user density/interference limited scenarios, and better average user data throughput, as well as improved traffic and control channel performance. It also provides a possibility to use less mobile Tx power for quality-based uplink power control, which leads to reduction in the overall interference level in uplink and improves the mobile battery life.

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5.10 BSS20040 User Access Level Control (UALC)The User Access Level Control (UALC) is a solution to prevent unauthorised users from making changes that can affect the remote management and traffic. The UALC is for a remote connection only, in a local connection it is not in use.

The UALC defines two levels of access rights for the users of BTS Managers:

• Full Access (Read and Write) means that all the functions that the manager applica-tions offer are available to the user.

• Limited Access (Read only) allows only to read information from an element.

Assignment of user rights is via the existing Windows user management processes. The BTS Manager applications can start-up and operate independently regardless of the Windows User Administration.

The BTS Manager applications check if the User Access Level Control is enabled or disabled by reading the registry key 'Access Levels' under KEY_LOCAL_MACHINE/Software/Nokia/2G_Managers:

• 'ON' – UALC is enabled. • 'OFF' – UALC is disabled.

If the UALC is disabled, the application gives Full Access Rights (both Read and Write) to the user. If the registry key is not present, by default Full Access Rights are granted.

In case the UALC is 'ON', that is, enabled, the EM application checks if the user currently logged in belongs to the BTS_Administrator group or not. If yes, the user is given Full Access Rights (both Read and Write). Otherwise, Limited Access Rights (Read only) are granted. If the BTS_Administrator group is not present on the PC/domain, by default Limited Access Rights are granted.

In case Flexi EDGE BTS Manager is installed stand-alone and the BTS_Administrator group does not exist on the PC, the user can create the group either using a SiteWizard installer or manually.

Creating the BTS_Admins user group manuallyTo create the BTS_Admins user group manually, follow the instructions below. Add the PC's login ID to the BTS_Admins group using the Control panel.

1. Go to Control Panel > User Accounts.2. Click on the Advanced tab and then the Advanced button. A new window Local

users and groups is displayed.3. Select a group and then create a new group 'BTS_Admins' by right-clicking on RHS.4. Select the newly created group, right-click the Add to group option, and then click

Add. The Select Users, Computers, or Groups window is displayed.5. Enter your PC login ID to the 'Enter the object names to select' and click OK.

Creating the User Access Level Key manuallyTo create the Access Levels key manually, follow the instructions below.

Registry location: HKEY_LOCAL_MACHINE/Software/Nokia/2G_Managers

Access Level Key name: Access Levels

Value: ON

1. Open the Command Window, type regedit, and press Enter to open the 'Registry Editor'.

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2. Go to HKEY_LOCAL_MACHINE/Software.3. Create a 'Nokia' Key by right-clicking on Software > New > Key, if not present.4. Create a '2G_Managers' Key by right-clicking on Nokia > New > Key, if not present.5. Create 'Access Levels' string values by right-clicking on 2G_Managers > New >

String Values.6. Modify the value of 'Access Levels' by right-clicking on Access Levels > Modify.

Type ON in the value data and press Ok.

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5.11 BSS11047 Intelligent shutdown for Flexi EDGE BTSTo provide protection against a mains power break, the operator can equip a BTS with a battery backup system. The purpose of Intelligent Shutdown is to maintain the BTS site operation for as long as possible by reducing capacity (units turned off or reduced to low power consuming modes) so that only the essential site functions are maintained.

The BSC controls the reduction of the site capacity, which commands individual trans-ceiver units to be shut down or started up.

On a BTS site basis, the user can define the service level of the site to be maintained while the battery backup is in use. Also, two timers can be defined, allowing the execu-tion of the shutdown procedure in phases, reducing capacity in a controlled way. Three service level options are available:

• Full service – Service is maintained at full capacity for as long as the battery power supply lasts. The two timers are ignored.

• Broadcast control channel (BCCH) backup – The BTS maintains full capacity until the first timer expires. After that, all active calls on non-BCCH transceivers are handed off. The non-BCCH transceivers are blocked from carrying any new calls and the BSC commands the BTS to shut them down. The BCCH TRX(s) are main-tained to offer minimum service.

• Transmission backup – The second timer starts after the first one has expired. After the expiry of the second timer, all active calls on BCCH transceivers are handed over. The BCCH transceivers are blocked from carrying new calls and the BSC commands the BTS to shut them down. Only the BTS transmission equipment power is maintained to secure the functionality of a transmission chain for as long as the batteries last.

When the mains power is restored, the BSC commands the BTS site to power all the shut down equipment and return back to full service.

Battery backup configurations for Flexi EDGE BTS:

• Flexi with Multi Integrated Battery Backup Unit (MIBBU) • Flexi with Integrated Battery Backup Units • 3rd Party Battery Backup Solution

The optional battery backup system for the Flexi EDGE BTS is selected in the BTS Manager during the commissioning phase.

If 3rd party BBU solution is used, one external alarm (EAC) line needs to be designated to indicate a mains power loss/restoration from the BBU. The selected EAC line needs to be configured as a Mains alarm at the BSC. If BBU solution (FPxA, MIBBU or FPRx) is used, the FPA connector on the ESMA System Module can be used with no need to use nor configure any EAC lines. Note that if an EAC line is configured as a Mains alarm at the BSC, the BTS ignores the FPA connector.

With all BBU solution options, the BTS generates alarm 7995 Mains Breakdown when the BBU indicates mains power loss. The 7995 alarm then triggers the Intelligent Shutdown procedure at the BSC. If two or three phase supply is used with MIBBU or FPRx, the loss of one phase already generates the 7995 alarm.

In addition to alarm 7995, the FPA interface can also generate three other BBU-related alarms 7612/7613/7614 (note that with FPMA, only 7995 and 7613 alarms can be seen).

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BenefitsThe operation is optimal during both short and long mains breaks. Timers allow execut-ing the shutdown procedure in several phases. Each phase reduces the battery power consumption.

With intelligent shutdown, the operator can define the service level to be applied on a mains failure to optimise the trade-off between the service level and battery power life-time. A short mains break will not reduce the service unnecessarily, whereas during a longer break, the essential functions, such as BCCH or transmission chain, are main-tained for as long as possible.

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5.12 Remote mode of Flexi EDGE BTS Manager The user can control Flexi EDGE BTS equipment locally via Flexi EDGE BTS Manager. To minimise the need for site visits, Flexi EDGE BTS Manager functions can also be accessed remotely.

The user can monitor and test the BTS remotely, by connecting the Flexi EDGE BTS Manager to the BTS remotely via Nokia NetAct™. A PC with the Flexi EDGE BTS Manager software is used as a user terminal. Nokia General Communication Server (GCS) SW Suite is used for providing both local and remote connections to the BTS.

Figure 4 Flexi EDGE BTS Manager connected in remote mode

The user can connect to a remote BTS using the Flexi EDGE BTS Manager application, via a menu item and/or a toolbar button, or via the command line. The user interface of Flexi EDGE BTS Manager informs the user of the remote connection status when infor-mation is being requested from the remote BTS, and when the Flexi EDGE BTS Manager is processing received information from a remote BTS. Flexi EDGE BTS Manager connected in remote mode supports all features available via a local connec-tion, except the Control Abis interface (enable/disable) commands.

It is not possible to perform the initial BTS commissioning remotely, but it is possible to perform subsequent recommissioning or append commissioning from the Flexi EDGE BTS Manager in remote mode.

At the BTS, the messages sent from or to the Flexi EDGE BTS Manager in remote mode are re-routed, but handled in the same way as with the local connection.

The alarm 7801 MMI CONNECTED TO BASE STATION indicates whether the MMI is connected to the BTS locally (alarm text Local MMI connected) or remotely from Nokia NetAct (alarm text Remote MMI connected).

BTS

ESMA

BTS

NetAct

BSC

NetActEthernetLAN

Ethernet

BTS Manager,remote

connection

BTS Manager,remote

connection

BTSManager, local

connectionEXxx

ESMA

EXxx

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5.13 BSS10063 Rx Antenna Supervision by Comparing RSSIThe purpose of Rx Antenna Supervision by Comparing received signal strength indica-tor (RSSI) is to monitor the Rx antenna condition. Rx antennas can be monitored for major problems by taking a long-term average of the difference between the Main Rx RSSI and the Div Rx RSSI. This feature provides continuous antenna supervision for the BTSs, which have the Main Rx RSSI and the diversity in use. It also offers an alter-native solution for Tx monitoring in cells that use duplexing. This detects, for example, antennas with poor voltage standing wave ratio (VSWR) and inadequate feeders.

The monitoring is based on the principle that all received bursts where the Rx level of main or diversity branch is above the defined limit value (-100 dBm) are accepted as samples and used in the averaging process. A minimum of 160000 samples in one hour must be collected for the BTS to assume that the results are reliable and therefore could be used to raise an alarm.

The differences of the TRXs connected to the same antennas are counted up, and the average difference for main and diversity antennas is calculated. If the difference is above the threshold (default value 10 dB), and the number of samples indicate that the results should be reliable, an alarm is activated. The threshold default value of 10 dB can be changed by a parameter at the BSC between 3 and 64. The functionality of the feature can be disabled.

It is still possible that both antennas are damaged simultaneously and the samples from both antennas remain below -100 dBm limit value. Therefore, the difference algorithm cannot detect the fault. For this reason, the BSC also observes the assignment and handover success rate.

Note that the RSSI values observed from Flexi EDGE BTS Manager may not be the same on both of the carriers of a Dual TRX Module. The difference between carriers can be greater than 10 dB, depending on the Rx level of the calls made on both carriers. If the average uplink Rx level of calls (CS/PS) made on Carrier 1 is high compared to Carrier 2, this difference can be seen and this is not a problem. It implies that calls on Carrier 1 are being made from mobiles that are near to the BTS, while calls on Carrier 2 are being made from mobiles that are relatively far from the BTS. The RSSI difference between two carriers is different from the case where an RSSI alarm is raised. The alarm is raised because of the difference in the Rx level of the main and diversity paths of a carrier. However, this alarm is not valid for the comparison done across carriers. More-over, the comparison of RSSI values across carriers is not valid in UltraSite EDGE BTS, as a TRX in the UltraSite EDGE BTS supports one carrier only, whereas in the Flexi EDGE BTS, the Dual TRX Module supports two carriers.

BenefitsRx Antenna Supervision by Comparing RSSI can identify antenna problems without the need for active tests.

Collection and display of raw RSSI measurementsIn addition to the newest and last reliable received signal strength indicator (RSSI) values, the BTS also gathers the raw RSSI results periodically from the TRXs. These results are displayed in the Element Manager (EM).

Settable RSSI sample limitThe number of received signal strength indicator (RSSI) samples, needed for a valid RSSI calculation, can be configured using the Element Manager according to the traffic

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density. The RSSI sample can be configured to values: 80000, 160000 (default), 350000 and 750000. The value 80000 is preferred when the BTS is located in a rural area and when the traffic density is low. The values 350000 or 750000 are preferred when the BTS is located in an urban area and has high capacity utilization. In areas with intermediate traffic density it is preferred to use the default value 160000.

The RSSI sample value may also be configured during the commissioning phase.

Alarm Start and CancelThe BTS estimates the number of samples it would receive for high/medium traffic profiles by setting an internal threshold value, which is a multiple of the user defined RSSI sample count. This value is an internal value and is not visible to the user.

The RSSI alarm is raised when:

– In the first hour, the received sample count is greater than the internal threshold and the RSSI alarm conditions are valid.

– In the first hour the received sample count is greater than the user configured RSSI sample threshold, but less than the internal RSSI alarm threshold. Then, the BTS software waits for the next hour to determine whether the RSSI alarm is to be raised.

– In the consecutive second hour the received sample count is greater than the internal RSSI alarm threshold or the user configured RSSI sample threshold and the RSSI alarm conditions are valid. If the user configurable sample count is changed during this hour then the monitoring is reset and the process restarts from the first hour.

The alarm is cancelled automatically in the next hour if the sample count is greater than the user configured sample count and the alarm condition has been cleared.

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5.14 BSS9068 BTS SW managementThe BTS software package consists of a master file and several application files. You can update the BTS software by downloading the new BTS software remotely from the BSC. A site visit is not needed.

You can download the BTS software to a BCF in the background during normal opera-tion, without impact to ongoing traffic or any other operation of the base station. Software downloading is also automatically triggered after BCF reset if the System Module does not have the correct BTS software package stored locally (that is, the package set as default for that particular BCF at the BSC).

When the BTS software is downloaded from the BSC, the process is optimised by down-loading only those application files which have been updated. Application files that are unchanged from those already stored locally in the current BTS software package are not downloaded. This minimises the download time for a new BTS software package.

You can also download the BTS software with Flexi EDGE BTS Manager to minimise BTS boot-up time for new installations. In this case you do not need to download the BTS software package from the BSC after BCF reset.

The downloaded BTS software package is stored in the flash memory of the System Module (ESMA). The flash memory of the System Module contains two complete BTS software packages to ensure recovery in the event of a download or start-up failure.

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5.15 BSS9067 Runtime diagnostics and BTS alarmsBefore reporting certain alarms, the BTS uses a runtime diagnostic scenario where the affected objects are temporarily blocked in the BSC, during which the BTS executes internal diagnostics. If a real fault is found during the diagnostic period, the BTS sends an alarm to the BSC. The purpose of this diagnostic scenario is to filter alarms and report only those that directly affect the BTS service level.

Only one major or critical alarm per object can be active at a time. When the fault causing the alarm has been corrected, or a faulty module has been replaced, the alarm is cancelled either manually or automatically. When the BSC displays a BTS alarm, the alarm text includes a fault reason describing the cause of the alarm. For more informa-tion, see Trouble Management of Flexi EDGE BTS.

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5.16 BSS9058 BTS fault recoveryBTS fault recovery minimises the effect of service level faults within the BTS. All objects and interfaces are continuously monitored, and appropriate recovery actions are taken when needed. Alarms are raised to indicate faults, which leads to recovery actions being taken.

For more information on fault recovery and BTS alarms, see Trouble Management of Flexi EDGE BTS.

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5.17 BSS9063 Abis loop testThe purpose of the Abis loop test is to verify the Abis transmission set-up and quality. During the Abis loop test, Flexi EDGE BTS generates a test signal pattern in Abis uplink for the timeslots under test. The BSC group switch loops the selected timeslots back to Abis downlink where the BTS checks the integrity of the received signal. The Abis loop test can be run on the TCH and Dynamic Abis Pool timeslots. After the test, the BTS provides the related test reports to the BSC. The Abis loop test is run automatically during BTS commissioning. The test can also be run manually from the BSC.

Up to 12 simultaneous Abis loop tests can be tested if no Abis protection loops are used. If they are used, then up to 6 Abis loop tests can be run simultaneously.

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5.18 BSS9062 BTS supervisionThe Flexi EDGE Base Station monitors and tests itself during operation without a separate command.

Continuous monitoringBoth the software and hardware carry out monitoring. Most of the monitoring procedures are so effective that no additional testing to find the faulty module is needed. The follow-ing items are monitored continuously:

• Internal buses of the base station • Transmission equipment and interfaces • RF parts • Mast head amplifiers • Nokia Flexi Support and Flexi EDGE Base Station Battery Backup (MIBBU) • Combining units (Remote Tune Combiner Module ECxA, Dual Duplexer Module

ERxA and low-noise amplifiers LNA) • Converter modules (local and remote EOCAs) • Temperature (heating and cooling) system of the base station • Power supply voltages • Reference Oven Oscillator • Dual Transceiver modules (EXxx)

AC mains breakdownA typical short voltage drop (that lasts less than 20 ms) in the AC mains supply does not cause any detectable harm to the operation and does not cause an alarm. In case of a mains breakdown, the Flexi EDGE Base Station cannot send an alarm to the BSC without battery backup (either integrated or external).

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5.19 BSS9061 Temperature control systemFlexi EDGE Base Station monitors its temperature continuously with several sensors located in the System Module (ESMA), Dual TRX Module (EXxx), System Extension Module (ESEA), Remote Tune Combiner Module (ECxA) and Optical Converter Module (EOCA).

The BTS controls its temperature with cooling fans to provide as stable operational con-ditions as possible. Heating and cooling is controlled gradually depending on the ambient temperature to ensure low temperature gradients and noise level.

During commissioning, a climate control profile can be selected from three options depending on the BTS site environment:

• LOW NOISE minimises fan noise for low and moderate ambient temperatures. • OPTIMISED COOLING (default profile) maximises unit reliability by running fans

with maximum speed already in moderate ambient temperatures. • LINEAR RESPONSE is an intermediate profile which increases fan speed linearly

as the temperature increases.

If the temperature of a module rises too high, a temperature alarm is issued. If the System Module is overheated, the BCF is blocked. If the Dual TRX Module is over-heated, the associated TRXs are blocked. Power supply units have their own internal shutdown and recovery in case they are overheated.

All Flexi EDGE BTS modules operate over full operational temperature range without the need for external heaters.

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5.20 BSS9060 TRX TestThe total performance of the TRX is tested with a multi-purpose TRX Test. The test covers:

• Digital and RF parts • RX operation and TX level • Both RX branches

The TRX test time is approximately 15 seconds.

When the TRX test is carried out according to a regular schedule, it can be used in TRX performance supervision.

Both RX branches are tested separately during the same TRX test. If diversity is not con-figured, only the main branch is tested.

The TRX Test tests both the Tx and Rx RF paths of the selected TRX via an uplooped burst to the Air interface, including the Dual TRX Module (EXxx) and Dual Duplexer Module (ERxx) or Remote Tune Combiner Module (ECxx). The looped back signal is fed back to the Rx path where the BER, Rx Level and Rx Result are measured. The reported Tx power is derived from the received RX level.

The TX power level used during the TRX test is the same as the power level of the broadcast control channel (BCCH). To avoid unwanted disturbances to the TRXs, the training sequence is not the same as the one normally used.

Figure 5 TRX Test block diagram

g Reported TX Power result is indicative only and a certain tolerance (up to +/- 6 dB compared to the actual value) can be expected. If the exact TX output power needs to be known, it must always be measured with external and calibrated test equipment.

Rx1FSH

DRX1

Rx2FSH

DRX2

MRX1

RXA O

Power supplyand digital I/O

TX signal isdown converted to relevantRX frequency

TxA

TxB

TX A

Ext A

RXA I

RXA 1...4

TX B

Ext B

RXB 1...4

Exxx generatesTX transmission

RX signal is sent toExxx RX for signallevel measurements

RF

RxA

RxAdiv

RxB

RxBdiv

4UD

4UD

No/2UD

No/2UD

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g Reported RX Result is not based on BER so it does not measure the absolute sensitivity of the TRX. If the exact sensitivity needs to be known, it must always be measured with external and calibrated test equipment.

Figure 6 TRX Test window

All TRXs in the BTS can be tested either remotely from the BSC or the NetAct or locally/remotely with Flexi EDGE BTS Manager. If the TRX test which is run from NetAct or the BSC fails, the test must be rerun remotely or locally with BTS Manager. The BTS Manager then informs the detailed failure reason, which can be used for troubleshooting with the instructions that can be found in the document, Trouble Management of Flexi EDGE BTS.

It is possible to run the TRX Test after the TRX object is blocked from the BTS Manager. With EP2 CD1.0 (and later BTS SW releases), it is also possible to run the TRX Test after the TRX object is locked from the BSC.

Note that the TRX test can be performed only in traffic channel (TCH) timeslots. Two free timeslots are needed for the test.

The TRX test is not possible when baseband or antenna hopping is used.

Also TRX Test cannot be commanded for a TRX configured to cover the extended/super extended outer area.

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5.21 TRX Loop TestFlexi EDGE BTS provides a TRX Loop Test facility. In a TRX loop test, data generated by SW in digital parts of the TRX is looped from the TX to RX side inside the Dual TRX module (EXxx) and the Dual Duplexer Module (ERxx) or the Remote Tune Combiner Module (ECxx), so that the TX and RX chains excluding antennas and antenna feeder cables are tested. Main or diversity paths can be tested.

The BTS checks the looped test data, and the test result is given as BER values.

The TRX Loop Test can be performed with GMSK TCH/FS or 8PSK PDTCH/MCS-5 test channels.

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5.22 BSS9059 BTS resetsYou can separately trigger a reset of BCF, BTS or TRX objects. An object reset can be triggered from the BSC, NetAct and from Flexi EDGE BTS Manager. In addition, the Flexi EDGE BTS Manager can also command HW resets for the System Module (ESMA) and Dual TRX Module (EXxx).

Object resets

• BCF (site) reset: resets all modules/units in the site except transmission sub-modules (FIxA), which ensures that active cross-connections are not interrupted.

• BTS (sector) reset: resets a single BTS object, including all TRXs that are part of the BTS object configuration. It has no impact on other BTS objects which are part of the site.

• TRX reset: resets a single TRX. Only the targeted TRX object is impacted.

Module resetsModule resets are provided as a recovery mechanism for exceptional conditions. In normal operation, there should be no need to invoke this type of reset.

• System Module reset: reinitialises all hardware and software in the System Module. This is equivalent to a power on reset. Transmission is also re-initialised, and there will be a brief interruption in the cross-connect traffic.

• Dual TRX Module reset: reinitialises all hardware and software in the targeted Dual TRX Module. Both TRX objects mapped to the Dual TRX Module are affected.

You can also issue a specific sector or BCF object reset from Flexi EDGE BTS Manager to force the RF Cable Auto-detection to the reset sector object, or to the whole BTS (all sectors). For more information on RF Cable Auto-detection, see section Auto-detection of Site Configuration and RF Cable Auto-detection.

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5.23 BTS Auto-detection

5.23.1 BSS9056 Auto-detection of Site ConfigurationFlexi EDGE Base Station detects the site configuration automatically, including all active modules and versions, their serial numbers and the frequency band used. This informa-tion is stored in the flash memory of the System Module (ESMA), and it can be displayed in Flexi EDGE BTS Manager.

The user needs to set the operator-specific settings, such as external alarm line settings, from the BSC or the NetAct, for example with the Remote MML session.

A possible change in any of the modules or in the configuration causes an automatic site configuration update in the flash memory of the System Module. The configuration is detected both in normal start-up situations and when extra capacity (more TRXs) is added, modules are removed, or a faulty module is replaced with a new one.

The transmission configuration is part of the site configuration file (SCF), which is stored in the System Module.

There is no auto-detection for the following units/modules: mast head amplifier, power modules, and Wideband Combiner Sub-module (EWxx).

5.23.2 RF Cable Auto-detectionThe RF Cable Auto-detection (RFCAD) feature enables the auto-detection of RF cables connected between the Dual TRX Modules (EXxx) and the Dual Duplexer Modules (ERxA) or Remote Tune Combiner Modules (ECxA), when a sector or the BCF comes up after reset, and the prerequisites for RF Cable Auto-detection are fulfilled.

The configurations for which the RF cabling is automatically detected are listed in the Flexi EDGE BTS Commissioning document, Appendix RF auto-detection supported configurations.

Functionality of RF Cable Auto-detectionA TRX starts to transmit a TX test signal, which the TRX loop module in the Dual Duplexer or Remote Tune Combiner Module down-converts to a corresponding RX fre-quency. The TRX loop switch then sweeps through all RX ports and the TRXs listen for the received signals (see figures TRX loop (Dual Duplexer Module) and TRX loop (Remote Tune Combiner Module)).

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Figure 7 TRX loop (Dual Duplexer Module)

Figure 8 TRX loop (Remote Tune Combiner Module)

TX B

TX A

CoRx out

PowerSupply &Digital I/O

RXA1...4

TRX Loop

RXB1...4

ANT A

Ext B

RXA ORXA IRX Signal is sent to

EXxx RX for signallevel measurements

TX signal iscoupled off TXpath

TX Signal isdown convertedto relevant RXfrequency

Ext A

BiasTee/

VS WRalarm

Digitallogic

ANT B

BiasTee/

VS WRalarm

Gain /alarmlogic

DN70292782

Down convertedsignal is sweptthrough all RX paths

EXxx generates TXtransmission

RX

TX

RX1...3

RX4...6

TX1...6

RXEO

RXEI

Tee

TX / RXANT

EXxx generates TXtransmission

RX Signal is sent toEXxx RX for signallevel measurements

TX Signal isdown convertedto relevant RXfrequency

BiasTee/

VS WRalarm

RX ANT

BiasTee

TX Signal iscoupled offTX path

TRX

Loop

DN70292779

Down convertedsignal is sweptthrough all RX paths

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The BTS software determines the connectivity between the Dual TRX Module and the Dual Duplexer or Remote Tune Combiner Modules based on the analysis of the RX measurement reports received from the Dual TRX Modules.

At the BCF start-up, BTS SW shall sweep through the Tx and Rx paths of the DDUs even if any Tx path has already been associated with an existing sector. This would enable the RFCAD to detect Tx and Rx cables for DDUs which are shared across two sectors. Furthermore, there may be several Rx cables shared (= flyover Rx cables) between another DDU that is associated to the same sector as the DDU to which the local Tx is associated to.

The RFCAD is attempted sector-wise and on each attempt the previously detected RF cabling is cleared. Even if the operator has not modified any physical cabling and attempted the RFCAD on a sector which shares a DDU with another sector, TRXs having Tx and Rx cabling with the shared DDU between two sectors will have their RF cabling information cleared. This will result in appropriate alarms on these TRXs. To correct the situation (in case of a shared DDU), the operator needs to do a BCF reset with the RFCAD, in which case all the cables will be successfully detected as connected.

When the BTS software cannot decide on the presence of the RF cables based on the received reports, the BTS software starts, for example, one of the following alarms on the relevant TRX objects:

• 7606 TRX Faulty (for example 'EXxx TRX module detected no connection to ERxx DDU via RF cable autodetection')

• 7607 TRX Operation Degraded ('EXxx TRX module detected only one Rx signal during RF cable autodetection')

The following RF connectivity can be auto-detected:

• Tx cables between the Dual TRX Modules and Dual Duplexer Modules. The Wideband Combiner Sub-modules (EWxx) are included in the detection process but they are not shown in the Flexi EDGE BTS Manager as separate objects.

• Tx cables between the Dual TRX Modules and Remote Tune Combiner Modules. • Main and diversity Rx cables between the Dual TRX Modules and Dual Duplexer

Modules. • Main and diversity Rx cables between the Dual TRX Modules and Remote Tune

Combiner Modules.

Prerequisites for RF Cable Auto-detection

• The Abis connection to the BSC must be available, and the BCF must be configured at the BSC (that is, the 'BTS_CONF_DATA' is received).

• The TRX and BTS object(s) are not locked or blocked (manually or because of a blocking alarm). However, in commissioning phase the TRX and BTS object(s) can be locked.

• RF cables were not defined manually during commissioning.This user selection is stored in the site configuration file (SCF) in the System Module's (ESMA) non-volatile memory, and you can check it with the Flexi EDGE BTS Manager as follows: Commissioning → Fetch SCF from BTS... Detail tab. In the detailed view, locate the line containing 'rfCablingSource', which can have two values: • 'AUTODETECTED': RF Cable Auto-detection was used during commissioning

or

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• 'SCF': RF cabling was entered manually during commissioning (which means that RF Cable Auto-detection was not used during commissioning and cannot be used later on either)

If all the three prerequisites are met, the RF Cable Auto-detection is run, when:

• The BTS_CONF_DATA is received in the commissioning phase. • There are changes to the configuration: added/deleted TRXs or sectors, and then a

BTS/BCF reset for the affected sectors. (The receive of a new BTS_CONF_DATA in an already commissioned site is not enough to start the RFCAD.)

• A BTS or BCF reset is given, and the previous RF Cable Auto-detection on a BTS (sector) had partially failed.

• A BTS or BCF reset is given (from the Flexi EDGE BTS Manager) with the 'With RF detection' option (the so-called ‘forced RFCAD’).

5.23.3 Internal power cable Auto-detectionDuring BTS commissioning an internal power cabling test is automatically performed to verify that the power cabling from the System Module (ESMA) to the corresponding Dual TRX Module (EXxA) is correct in the BTS configuration and is as specified in the power cabling rules. If the internal power cabling validation fails, then an Alarm 7601 "Module power cable connections are incorrectly configured" is started directly after the BTS commissioning has been completed.

Incorrect internal power cabling will directly affect the Intelligent shutdown feature (BSS11047) that requires that the internal power cables are connected as per the power cabling rules to function correctly.

Note that the internal power cabling verification only takes place during the BTS first commissioning or a complete BTS re-commissioning.

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5.24 Optical Converter Module (EOCA) autodetection and runtime pollingAll Optical Converter Modules (EOCA) are autodetect. The BTS Manager is able to obtain information about the local and remote EOCA(s), EOCA pair hot-insertion and RF Modules (Dual TRX Module and Dual Duplexer Module) connected behind remote EOCA at times of BTS startup. The EOCAs are always detected in pairs (local and remote) provided that at least one Dual TRX Module is connected behind the remote EOCA.

Once the EOCA Module(s) are detected successfully, they are polled periodically to get alarm statuses. If an EOCA Module fails to respond to the status poll request the BTS starts a respective alarm.

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5.25 48 V DC input voltage supervisionBoth the System Module (ESMA) and the System Extension Module (ESEA) supervise the 48 V DC input voltage continuously. When the input voltage decreases below 44.0 V DC or increases above 58.0 V DC, BCF notification alarm 7602 Supply voltage to ESMA near low/high limit and / or 7602 Supply voltage to ESEA near low/high limit is activated to indicate that the input voltage is close to exceeding its normal operating range.

For configurations where both the ESMA module and ESEA modules are present, if the input voltage continues to decrease below 39.0 V DC or increase above 60.0 V DC, all the Dual TRX Modules (EXxA) connected to the ESMA module and ESEA module are shut down to protect their hardware. Alarm 7606 PDU Control has switched off EXxx TRX Module is activated to indicate that the BTS has shutdown the Dual TRX Module due to out of range input voltage.

When the input voltage increases up to and above 39.0V DC or falls down to and below 58.0 V DC, the Dual TRX Modules (EXxA) are powered up and the 7606 alarm is can-celled. Once the input voltage increases above 45.0 V DC or decreases below 57.0 V DC the 7602 notification alarm is cancelled.

When EOCA modules are installed, the 48 V DC input voltage is monitored in the EOCA. When the input voltage decreases to 40 V DC or increases to 58 V DC, alarm 7614 Site Powering Notification : Supply voltage to EOCA crossed low/high limit is raised. The alarm will be raised for each affected EOCA module.

When the input voltage increases up to and above 40.0 V DC or falls down to and below 58 V DC, the 7614 alarm is cancelled.

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5.26 Antenna HoppingAntenna Hopping is a further improvement for the performance of RF or BB hopping. In antenna hopping, also the BCCH frequency is fully hopping between 2 or more anten-nas.

Antenna Hopping enables the TRXs in an RF hopping BTS to transmit with all the TX antennas in the BTS. Antenna Hopping uses the existing baseband (BB) hopping func-tionality in the BTS.

Antenna Hopping can be used either with or without the RF hopping feature. With RF hopping, cyclic and all random frequency hopping sequences can be used together with Antenna Hopping. Antenna Hopping pattern will be automatically optimised based on the frequency hopping sequence. The BCCH TRX is included in the Antenna Hopping configuration, that is the BCCH transmission is moved from one antenna to another antenna (TRX).

With Antenna Hopping, it is possible to achieve space diversity to the regular RF hopping configuration, which means that there is a distance that separates two or more transmitting antennas providing uncorrelated signals. At the MS, a separation of half a wavelength is the minimum for obtaining uncorrelated signals. At the base station fre-quency, the antenna height and antenna spacing make the correlation efficient.

RestrictionsThe following functionalities cannot be used simultaneously with Antenna Hopping:

• BB hopping or DFCA hopping in the same BTS • Baseband hopping • BCCH antenna VSWR measurement • Remote Tune Combiner (RTC) in the same BTS • Feederless Site Configuration with over 150 m multimode fiber

Antenna Hopping is OFF in the BTS

• when TRX(s) are down • if the number of working TRXs decreases below 2 TRXs per BTS

When Antenna Hopping is in use the following tests are not possible:

• the TRX test • the TRX loop test

The minimum configuration for Antenna Hopping is two TRXs/cell where both TRXs are used for Antenna Hopping.

BenefitsThe Antenna Hopping feature helps to avoid network level interference and link level fre-quency selective fading.

With the Antenna Hopping feature, the user can achieve in average 2 dB gain on the link level. With low antenna correlation, Antenna Hopping can gain 1.5 to 4 dB depending on the mobile speed (typical urban, 3 to 50 km/h, no FH) compared to a single antenna.

With Antenna Hopping, it is possible to gain better network level spectral efficiency on the BCCH layer. In a very narrow band environment (3.6 MHz), better network capacity can be achieved by tightening the BCCH re-use (for example from 5/15 to 4/12) without an extra TRX). By tighter BCCH re-use, more frequencies can be used in the hopping traffic layer, thus providing better capacity for narrow band networks.

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5.27 BSS20984 Flexi EDGE dual TRX automatic power downThe feature introduces an energy saving mechanism for the Flexi EGE BTS. This feature automatically shuts down dual TRX modules when traffic is low.

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5.28 BSS20958 Energy saving mode for BCCH TRXThe feature introduces a configurable power saving mode for the BCCH TRX. It aims to achieve lower electricity consumption by reducing the average transmit power of the BCCH TRX.

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5.29 BSS21317 Automatic Commissioning Tests for Hot Inserted TRXWhen a BTS is commissioned (either for the first time or following an undo commission-ing activity), TRX tests and Abis loop tests are automatically run to check the correct BTS operation.

Now the same tests will also be run automatically after new hot inserted TRX objects (i.e. a new Dual TRX module inserted into the BTS) have been commissioned into use without the need to undo previous commissioning first.

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Flexi EDGE BTS Feature Descriptions Site solutions

Id:0900d805807fbe00Confidential

6 Site solutions

6.1 BSS21171 IDD and diversity configuration for DTRXThe Flexi EDGE Dual TRX module (EXxx) includes two complete TRXs: two transmit-ters and four receive chains. Normally the module is used for two separate radio channels with two separate TRX objects.

Intelligent Downlink Diversity (IDD) extends the cell coverage over a single TRX by boosting the BTS downlink transmission performance up to 5 dB (min. 3 dB). A minimum of two EDGE transceivers and two antennas (or X-polarised antenna) are needed for one cell. The same downlink signal is transmitted simultaneously through two antennas while using one TRX for capacity. Extension from 1 TRX/cell to 2 TRXs/cell needs 4 antennas per cell if the same downlink coverage area has to be met. One carrier of the EXxx DTRX module is configured as the Main and the other as the Auxiliary carrier. Both TRXs transmit on the same frequency, but the transmission of the Auxiliary carrier is delayed 1-1.5 symbol periods, which gives good performance for all modulation schemes. Random Phase hopping decreases correlation between the main and auxil-iary transmitter. Correlation between the antennas has to be low.

4-way uplink diversity (4UD) means that four received signals are combined together by using Interference Rejection Combining (IRC) or Space Time Interference Rejection Combining (STIRC) and Maximum Ratio Combining (MRC) techniques. For one TRX (carrier), four antennas and a minimum of two DDUs are required. 4UD provides 2.5 dB coverage gain compared to 2-way diversity. If the number of antennas is limited, also 2-way uplink diversity is possible. 4UD can be used together with IDD, but cannot be defined without IDD.

IDD and 4UD are application software products and require a valid licence in the BSC.

ImplementationThe IDD and 4UD configuration is enabled and controlled from the BSC, The IDD-enabled object consists of IDD Main and Auxiliary TRXs. No specific commissioning action is required for the IDD TRX. The BTS Manager will provide site configuration file (SCF) templates for IDD TRX standard configurations. The IDD TRX is exclusively con-figured via BSC parameters. The BTS Manager displays the IDD TRX as a single logical TRX object on the Base Station view. Only the Main IDD TRX is visible on the BTS Manager.

g Remote Tune Combiner (RTC) module is not supported in IDD 2UD and IDD 4UD con-figurations.

Requirements

• Flexi EDGE BTS with EP2 • Flexi EDGE BTS Manager version EP2 • BSC SW version S13 • 4UD can only be configured for IDD or DP TRX objects

BenefitsDownlink diversity improves the downlink radio signal in two ways:

• Signal power is double by using two transmitters • Introducing two strong uncorrelated signal paths decreases the effect of fading

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6.2 BSS20870 Double Power TRX for Flexi EDGE BTSDouble Power TRX for Flexi EDGE BTS is an application software product and requires a valid licence in the BSC. With a Double Power TRX (DP TRX), a module with two transmitters and four receivers can be exploited to gain radio performance of one radio channel. In downlink, radio performance can be implemented with DP TRXs or with Intelligent Downlink Diversity (IDD) TRXs. In uplink, also 2-way (2UD) or 4-way (4UD) uplink diversity can be configured.

All Flexi EDGE TRX modules support Double Power TRX functionality. Flexi EDGE TRX licence is also needed. When creating or modifying a TRX, the user decides whether a DP TRX or IDD TRX is used or not. As a default these are disabled.

Only odd numbered TRXs can be configured to be DP TRXs or IDD TRXs, and the next even numbered TRX cannot exist at all. This means that every DP TRX and IDD TRX reduces the maximum number of TRXs in the BCF and BTS by one. In the BTS, only either IDD TRXs or DP TRXs can exist at the same time.

No specific commissioning action is required for DP TRX. The BTS Manager will provide SCF templates for the DP TRX configurations. The DP TRX is exclusively configured via BSC parameters.

g Remote Tune Combiner (RTC) module is not supported in Double Power TRX configu-rations.

Interaction with other features

• Dynamic Frequency and Channel Allocation (DFCA) cannot be used in the same segment with DP TRXs or IDD TRXs in the BTS.

• If DP TRX or IDD TRX is used together with Extended Range Cell, all the TRXs must be DP TRX enabled or IDD-enabled TRXs with the same uplink diversity (2UD or 4UD) in the BCCH BTS.

• If DP TRX or IDD TRX is used together with BB hopping, all the TRXs must be DP TRXs or IDD TRXs with the same uplink diversity (2UD or 4UD) in the BTS.

• If DP TRX or IDD TRX is used together with Antenna hopping, all the TRXs must be DP TRXs or IDD TRXs with the same uplink diversity (2UD or 4UD) in the BTS.

BenefitsDouble Power TRX for Flexi EDGE BTS brings extra coverage, because it allows 2-3 dB higher transmit power compared to a bypass-combined TRX. Intelligent Downlink Diver-sity (IDD) transmission increases the coverage area of cells by enhancing the downlink radio performance and antenna diversity gain of the BTS.

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Id:0900d805807fbdecConfidential

6.3 BSS10046 Multi BCF ControlMulti BCF Control allows the combination of several BTSs into one logical cell, enabling the operator to increase the capacity of a cell while maintaining the maximum spectral efficiency. Multi BCF Control increases the cell capacity for Flexi EDGE BTSs to 36 TRXs while requiring no extra BCCH. Multi BCF also provides a path for site expansion from UltraSite EDGE BTS to Flexi EDGE BTS.

Multi BCF Control requires that BSS9055 Clock Synchronisation between base stations, or BSS10069 Synchronised BSS is used.

The operator can arrange base stations so that the TRXs in different base stations (operating on the same frequency band) can serve the same cell with a single BCCH. At the base station site, the operator needs to make some installations, for example syn-chronisation is needed between the base stations. All the base stations will have a separate O&M link to the BSC. At the BSC, a SEGMENT (SEG) object must be used to set all the BTS objects sharing the same BCCH.

Figure 9 Multi BCF configuration

Multi BCF cell (= SEG)

f1 f2 f3

f4 f5

UltraSite TRX group

Flexi TRX group

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6.4 RG301397 Co-siting with BS2xxThe feature "RG301397 Co-siting with BS2xx" extends the support of BSxx to the Multi BCF implementation described in BSS10046 Multi BCF Control by allowing co-siting of BTSplus BTS with Flexi EDGE BTS. The baseline of this feature is the "BSS21469 BS2xx@Flexi BSC product family" feature that already interfaces BS2xx to Flexi BSC.

The aim of this feature is to allow site capacity extension by deploying new TRXs, and to provide BR operators with features that are no more developed in the BR line. In a co-sited configuration, the Flexi BTS is always placed before BTSplus in a common transport E1/T1 chain. Antenna equipment, TMA/MHA modules and RF cabling are shared by BTSplus and Flexi BTS in order to accomplish RX diversity, whereas for transmission, dedicated antennas are used. The (common) BCCH carrier is configu-rable both, in the Flexi BTS and BTSplus BCF.

In order to support Abis over IP/Ethernet (Pseudo Wire Emulation PWE) in a co-siting scenario it is necessary that Flexi BTS performs the PWE/TDM conversion (described in BSS21443 Packet TRS for UltraSite/BTSplus). In this scenario, no impacts are foreseen on the BTSplus BTS.

The benefits of this feature are:

• This feature allows the deployment of Flexi EDGE BTS at existing BTSplus sites in a co-sited configuration. Segments (radio cells) are composed of transceivers belonging to both BCFs

• Investment savings for BR operators who may further use existing BTSplus TRXs while adding Flexi BTS both in order to accomplish site capacity expansion and in order to provide users with new features

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Id:0900d805807fbdf8Confidential

6.5 BSS9055 Clock Synchronization between Base StationsClock Synchronization between Base Stations enables synchronous handovers between base stations. The sectors defined to different base stations can use common hopping frequencies with RF hopping, which increases the channel capacity. The maximum site configuration is nine Flexi EDGE BTSs in a chain.

The Flexi EDGE Base Station has an external clock interface that can be used to syn-chronize the air interface between several Flexi EDGE Base Stations located on one site.

When several Flexi EDGE Base Stations are synchronized, the master base station (master BTS) functions as the frame clock source to the slave BTSs. The master BTS transmits the frame clock and frame number signals to the external clock line, while the other BTSs (slave BTSs) receive these signals. The slave BTS uses the received frame clock signal as a reference clock signal to adjust its main frequency source. The master BTS uses the reference clock signal derived from the Pulse Code Modulation (PCM) signal.

It is possible to synchronize a Flexi EDGE Base Station to a UltraSite EDGE BTS to serve the adjacent sectors. In this case the clock master is always a UltraSite EDGE BTS.

With the FIQx or FIYx transmission submodule operating in Pseudowire Emulation (PWE) mode, the following Synchronization sources are offered:

• Adaptive clock recovery based on a PW • Synchronization via E1 • Synchronization via 2 MHz input (ITU-T G.703) • Synchronization to a system reference clock (that is, a clock used by the BTS like a

GPS)

With the FIQB or FIYB transmission submodule operating in Packet Abis synchroniza-tion, the following Synchronization methods are offered:

• Timing over Packet (IEEE1588v2) • Adaptive Clock Recovery

The performance of the adaptive clock recovery is very much dependent on the perfor-mance of the packet-switched network. It is recommended to trial use the adaptive clock recovery for gaining information about if the network performance is sufficient for this option.

Physical propertiesThe maximum cable length for the total system is 100 meters. The Synchronization chain between the BTSs is made using RS-485 connection for the transferred clock signals.

Synchronization recoveryIf there is a failure in the Synchronization between the base stations, the slave BTS gen-erates an alarm and the BSC then blocks all TRXs of the alarming BCF. When the fault disappears, cancellation to the alarm is sent to the BSC. The BSC then unblocks the TRXs under the alarming BCF object.

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Fast tuning

• If the clock reference is taken from Abis:If the BTS is being commissioned, the fast oven-controlled crystal oscillator (OCXO) tuning is executed for the maximum duration of 8.6 seconds. The target accuracy is 0.02 ppm. The adjustments can be 10 times larger than in normal tuning. After fast tuning, the BTS starts normal tuning, and allows the BTS configuration to be com-pleted.

• If the clock reference is taken from an external Synchronization source (other BTS or LMU):If the BTS is being commissioned, the fast OCXO tuning is executed for an indefinite duration until the target accuracy of 0.02 ppm is met. Typically, the external clock reference is stable, therefore the fast tuning is completed in 36.92 seconds (eight rounds). The adjustments can be much larger than in normal tuning. After fast tuning, the BTS starts normal tuning, and allows the BTS configuration to be com-pleted.When an already commissioned BTS is started, the BTS starts performing fast tuning and starts configuration on TRXs. Since fast tuning configuration on TRXs are running in parallel, there is a possibility of handover failures for approximately one minute. However, this failure is seen only when the slave BTS is started with cali-brated DAC word which is far from the stable value. No handover failure is seen when the slave BTS is started with stable calibrated DAC word.

• With PWE and the adaptive clock recovery as the Abis Synchronization source, the performance of the lock-in to adaptive clock recovery will take approximately 10 minutes, but depending on the condition of the packet-switched network, can take considerably more time. The BTS will wait at commissioning until the lock-in is achieved before continuing with fast tuning.If the commissioning is aborted due to exceeding lock-in time allowance, the BTS will continue to achieve the lock-in and proceed to supervisory mode.

Normal tuningWith Abis as reference, the digital-to-analogue converter (DAC) word adjustment may occur every 20 minutes. The purity of Abis is monitored continuously, and the adjust-ment is only performed if the purity is good enough.

With an external clock as reference, the DAC word adjustment may occur every 20 minutes. The presence of the external clock source is monitored, the purity is not. When the external clock is present, the adjustment is made.

With both clock sources, the current DAC word is written as a new calibrated DAC word, if the current DAC word eventually drifts far enough from the calibrated DAC word. This ensures that in later start-ups (in any environmental conditions), the BTS starts immedi-ately with a value as accurate as possible, and the C-plane and U-plane signaling and traffic remain undisturbed.

With PWE and the adaptive clock recovery, it is possible to use the 4th E1 interface for relaying Synchronization to, for example, a co-sited BTS. This output is compliant to wander network interface requirements (ITU-T G.823). By not adhering to the Synchro-nization interface requirements, the output should only be used for a BTS Synchroniza-tion application.

If the adaptive clock recovery Synchronization source is lost due to a degraded packet-switched network, the BTS will use a high stable OCXO for hold over. For approximately

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13 minutes, the BTS is still showing the adaptive clock recovery as the Synchronization source and does not raise an alarm, filtering those short term intermediate disturbances.

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6.6 BSS10069 Synchronised BSSWith Synchronised BSS, all the clocks of the different sites in the network are synchro-nised, so that the GSM frame timing is aligned between all sites.

This is done by using a Location Masurement Unit (LMU), which gets a GPS time refer-ence, and uses this to generate clock signals for the BTSs.

Syncronising all BTS sites in the network minimises timing differences between TDMA bursts of different sites. That significantly improves performance of Interference Rejec-tion Combining and DFCA. The benefits are:

• Improved quality (higher data throughput, lower frame error rate (FER)) • Possibility of tighter frequency reuse • More effective cell re-selection and handover processes • More accurate MS locationing functionality

6.6.1 BSS20371 BSS Site Synchronisation Recovery ImprovementBSS Site Synchronisation Recovery Improvement is an enhancement to BSS11073 Recovery for BSS and Site Synchronisation. With BSS Synchronisation Recovery Improvement, the BTS site continues in the BSS synchronised service even if the GPS coverage is lost for up to 24 hours. The BTS site also continues in the BSS synchronised service throughout an LMU software update.

The transmission link(s) to the BTS site meet the Jitter and Wander requirements of ANSI T1.403 for T1 links, or ITU G.823 for E1 / 2048 kbit/sec hierarchy links.

Interaction with other featuresImproved BSS Synchronisation Recovery is used in any networks which use BSS Syn-chronisation.

6.6.2 BSS11073 Recovery for BSS and Site SynchronisationThe main purpose of Recovery for BSS and Site Synchronisation is to give automatic recovery for BSS Synchronised sites (sites with LMU) if the BSS 20371 Site Synchroni-sation recovery improvement is not used.

• when the Location Measurement Unit (LMU) clock signal is lost, to get the chained BTS cabinet (site) into unsynchronised mode

• when the LMU clock signal is again available, to return the chained cabinet back into synchronised mode

Recovery for BSS and Site Synchronisation also offers synchronisation recovery for a Multi BCF site using BSS9055 Clock Synchronisation.

When the BTS chain is defined in the BSS radio network database, Recovery for BSS and Site Synchronisation automates the recovery if the BTSs in the chain are synchro-nised and the clock signal is lost and regained. On the other hand, if the chain is not defined or the BSS or Site synchronisation of the chain has not been activated, the sites need to be locked and unlocked in the correct order to enable system synchronisation. The BSC receives the information for recovery from Q1 and BTS alarms.

Recovery for BSS and Site Synchronisation can be used together with the Dynamic Fre-quency and Channel Allocation (DFCA) when the LMU is defined as a clock source in the BSS radio network database and the BCF is in synchronised mode, and with the

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Multi BCF configuration, provided that all the unlocked BCFs are defined to the same chain operating in synchronised mode.

For a Flexi EDGE BTS chain, the maximum number of BTSs is nine.

Figure 10 Synchronised BSS example in Flexi EDGE BTS chain

The BSS is synchronised by a Global Positioning System (GPS), that is, LMUs are installed to every site with GPS antennas. The clock source is a GPS satellite via the LMU. When the LMU feeds the clock, all BTSs are working as slaves. When the LMU clock feed is lost, the BSC starts a timer. The synchronised operation continues uninter-rupted based on the BTS internal clock. If the BSC timer expires, the first BTS in the chain becomes a clock master and starts supplying the clock signal to the other BTSs. The BTS synchronisation status indication in the BSC is changed to 'unsynchronised'. When the LMU clock is recovered, the BTS becomes synchronised again.

BenefitsAutomatic recovery for the loss of LMU clock, when the BTS chain is defined in the BSS radio network database:

• Automatic BSC-controlled recovery to unsynchronised operation • Automatic BSC-controlled return to synchronised operation • Timeslot offset parameter sending to LMU • BTS synchronisation configuration and mode information available from the BSC by

MML and NetAct

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BTS(Flexi)(slave)

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6.7 Operating bandsFlexi EDGE BTS supports the following operating bands:

• GSM 800 • GSM 900 (including E-GSM and P-GSM) • GSM 1800 • GSM 1900

Dual and Tri Band Common BCCHCommon BCCH allows the combination of two or more sectors into a single logical cell, with a single BCCH carrier. With common BCCH sectors in different frequency bands such as 900/1800 MHz (or 800/1900 MHz, or 800/1800 MHz) can be configured with a common BCCH carrier.

The main advantages of the common BCCH functionality are:

• Improved trunking gain • Use of signalling channels is optimised by sharing them between bands • Tighter reuse of all carriers in the non-BCCH bands • Better call quality because of decreased number of handovers

To ensure proper operation of the network, take into account issues related to the differ-ence of propagation between the different bands when performing cell planning.

Figure 11 Common BCCH configuration

Frequency hopping between bands in the same sector is not supported.

Common BCCH cell

f1 f2 f3

f6 f7 f8

f4 f5

PGSM 900 TRX group

EGSM 900 TRX group

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6.8 BTS2043 BTS External Alarms and Controls (EAC)External Alarms and Controls (EAC) signals can be defined to the BTS.

BenefitsThe external alarms and controls allow alarms to be sent from external equipment attached to the BTS, and allow control of external equipment attached to the BTS.

External Alarms caused on the site, such as the intruder alarm, are sent to the NetAct via the Abis. The alarms are TTL level signals, all referred to 5 V. The operator can define whether an alarm is raised when the alarm input line is grounded or disconnected from the ground potential (this is known as alarm polarity). This allows more flexibility for the alarming device.

The External Controls allow the user to control external equipment remotely from the BSC. The External Controls are of open-collector type.

The EAC settings (such as name, alarm polarity, control state) are defined at the BSC. The EAC names can be viewed at the BSC.

RestrictionsThere are 24 user-definable external alarms and 6 user-definable external controls. The System Module (ESMA) provides 12 alarm inputs and 6 control outputs. Another 12 alarm inputs are available with the optional Flexi System External Alarm Module (FSEB).

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6.9 BTS2020 RX antenna diversityReceiver diversity (spatial diversity) improves the uplink performance. It is available as operation software for all configurations having at least two antennas in a sector. Two RF signals are demodulated jointly using an interference rejection combining algorithm, which increases tolerance to interference. Sensitivity is improved, particularly in fading scenarios.

Diversity is defined for every sector separately from the BSC.

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6.10 BTS configurationsFlexi EDGE BTS is optimised for high capacity as well as high coverage for macrocel-lular applications. It also enables evolution paths by providing a flexible expansion capa-bility. A configuration of up to 24 TRXs is supported in a Flexi EDGE BTS, but only with Dual Duplex Modules (ERxA). With Remote Tune Combiner Modules (ECxA), the maximum number is 18 TRXs. When the number of TRXs is close to 24, the combining usually has to be either 2-way or 4-way. Also three to six sectors are required. With mixed configurations (RTC sector(s) and DDU sector(s)), the maximum number is 18 TRXs.

Flexi EDGE BTS offers flexible combining options to increase the BTS capacity without a need to increase the number of BTS antennas. There are also combining options to maximise the cell coverage or capacity.

For details of Flexi EDGE BTS configurations, see Hardware Configuration Reference Guide and Flexi EDGE BTS Product Description in Flexi EDGE BTS Product Documen-tation.

6.10.1 Upgrade-optimised configurationsAn upgrade-optimised Flexi EDGE BTS configuration with a 1-way or 2-way diversity can be installed in a stack, wall, pole, in Flexi Cabinet for Indoor (FCIA) and Flexi Cabinet for Outdoor (FCOA). In an upgrade-optimised configuration, the Dual TRX Modules (EXxx) and Dual Duplexer Modules (ERxA) are allocated to one sector. In case of odd configurations, the number of Dual TRX Modules and Dual Duplexer Modules can be one or two more than could be built in a cost-optimised way. An example 3+3+3 con-figurations with 2-way diversity requires six Dual TRX Modules where three carriers are unconfigured.

6.10.2 Cost-optimised configurationsA cost-optimised 3+3 Flexi EDGE BTS configuration with 2-way diversity can be installed in a stack, in Flexi Cabinet for Indoor (FCIA) and Flexi Cabinet for Outdoor (FCOA).

For creating this configuration, the following modules are needed:

• one System Module (ESMA) • three Dual TRX Modules (EXxx) • two Dual Duplexer Modules (ERxA) • four Wideband Combiner Sub-modules (EWxx).

Also other cost-optimised Flexi EDGE BTS configurations can be built: 3+3+3 (2-way combining), 5+5 (4-way combining) with 2-way diversity. With cost-optimised configura-tions, one Dual TRX Module is split between two sectors, and its Rx1div and Rx2div con-nectors are used to make 2-way diversity functional.

Also an antenna-optimised variant along with cost-optimised configuration may be pos-sible, and then also the number of antennas minimised and still the coverage is kept higher. In antenna-optimised configurations, the DDU can be shared between two sectors.

The Remote Tune Combiner (RTC) supports the following cost-optimized configura-tions: 3+3+3, 5+5+5, 7+7+7 and 9+9+9.

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6.11 Flexi EDGE BTS Feederless and Distributed Site conceptFlexi EDGE BTS Feederless and Distributed Site Solutions refer to a situation where the System Module (ESMA) and Dual TRX Modules (DTRX) are installed apart from each other. The Optical Converter Module (EOCA) is used at both ends of the optical fibre for interfacing the System Module/Dual TRX Module. The bus cable between the modules is optical.

The benefits of the Feederless and Distributed Site Solutions compared to a traditional BTS site are listed below:

• Overall site RF performance is better compared to antenna feeders installation (the gain can be 2...5dB).

• The solutions open easier, new and optimized installation possibilities especially in difficult places.

• There is no need for mast head amplifiers.

Flexi EDGE BTS Feederless and Distributed Site solutions utilise various power distri-bution solutions. DC feed to the feederless or distributed site is provided either by a Nokia Siemens Networks power system or 3rd party products. The input for the Optical Converter Module is floating 48 VDC. There are the following basic power supply alter-natives for the BTS site and its modules:

• Flexi Power Module (FPMA) or MIBBU concept with a site support module, batter-ies, and cabinet

• FPMA installed near the Dual TRX Module • 3rd party AC/DC system (must meet the ETSI 300 132-2 standard)

6.11.1 Feederless siteIn the feederless site solution, the distance between the System Module and the Dual TRX Module can be up to 150 m with full functionality and up to 300 m with BB hopping and antenna hopping disabled. The feederless site solution is typically used either on a rooftop BTS site as shown in figure Feederless rooftop site or as mast head BTS site. In both cases the Dual TRX Module (EXxx) can be installed very close to the antenna. This enables connecting the Dual TRX Module to the antenna with a short jumper cable.

When DC is fed from the DC power system to the Dual TRX Module, the maximum distance is 100 m (measured from the power system equipment to the Dual TRX Module input). The BTS site can be either DC or AC powered (this concerns all the modules that require 48 VDC). In the latter case, an AC/DC converter (either the FPMA or a 3rd party converter) is required and the maximum length of the optical cable to be used is 150/300 m.

For information on installation distances see the Creating Flexi EDGE BTS Feederless Site Configurations document.

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Figure 12 Feederless rooftop site

Figure 13 Feederless masthead site

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Sector 2:DTRX +Opt. Converter

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Optical cable installation between the System Module and the Dual TRX Module can be done with the following alternatives:

• One 50, 100 or 200 m Nokia optical cable. • By splicing and cutting Nokia optical cables on sites where a certain optical cable

length is required. • 150 m or 300 m distances can be created by connecting two of these Nokia cables

using a multimode adapter together with a locally sourced IP55 box. • Other cable lenghts are available for special order (10 m, 20 m, 30 m, 40 m, 75 m).

Only NSN optical cables are allowed.

If a distance longer than 150 m with BB/antenna hopping enabled is needed, see Dis-tributed site.

Figure 14 Optical cable installation alternatives

The Optical Converter Module provides Overvoltage protection by induction or indirect lightning (Class II).

6.11.2 Distributed siteIn the distributed site solution, the distance between the System Module and Dual TRX Modules can be up to 10 km. The existing optical fibres can be utilised and equal benefits are possible in the feederless site concept utilised. The Optical Converter Modules can be attached to the existing optical fibre network by using a 2 m single mode optical cable that has IP55 protection in the Optical Converter Module end of the cable.

OpticalConverter

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AlternativeNokia IP55 OpticalMultimode Cable

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Single mode components and single mode transceivers are used in Optical Converter Modules.

The power distribution to the Dual TRX Module is local and can be either DC or AC (an FPMA next to the RF Module or a 3rd party system). Optical Converter Modules have integrated Class II overvoltage protection, so no external OVP is required when DC input is used. In case AC input is used, overvoltage protection has to be carried out locally. The distributed site concept is illustrated in the following figure.

Figure 15 Distributed site concept (e.g. as a part of a BTS hotel)

Local EOCA

System Module

Local EOCA

Local EOCA

Singlemodeoptical

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*optionalDN70461251

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6.12 Distributed BTS with Optical Converter modules (EOCA)Distributed BTS conceptWith Flexi EDGE SW release EP2 you can take advantage of the Nokia Distributed BTS concept. With the distributed BTS, certain parts of the BTS can be physically separated from each other. On a roof site, for example, the radio parts can be located at the corners of the building and the common parts (O&M, transport, BBU) can be located in the middle of the roof (or with one of the radio parts at a corner). This can lower the site investment costs whilst improving the coverage, as the total length of antenna feeder line required is reduced.

Optical Converter modules (EOCA)To implement the Distributed BTS concept, pairs of Optical Converter modules (EOCA) act as a single optical link for up to three Dual TRX modules (EXxx). The optical links allow the separation of System module (ESMA) and Dual TRX modules (EXxx). The separated Dual TRX modules (EXxx) then work as remote radio parts.

To provide the optical link, two Optical Converter modules (EOCA) are used together as a pair. One Optical Converter module (EOCA) is connected via 1, 2 or 3 BUS ports of the System module (ESMA), and this module is known as the Local EOCA module (LEOCA); the second Optical Converter module (EOCA) of the pair is equipped near the antennas and is known as the Remote EOCA module (REOCA). The Remote Optical Converter module (REOCA) then connects to up to 3 Dual TRX modules (EXxx) using BUS ports. The Local Optical Converter module (LEOCA) and Remote Optical Con-verter module (REOCA) are connected together with an optical link.

Both the Local Optical Converter module (LEOCA) and Remote Optical Converter module (REOCA) require a 48V input source. The Remote Optical Converter module (REOCA) provides power for up to 3 Dual TRX modules (EXxx) via the PWR ports of the Remote Optical Converter module (REOCA). Intelligent shutdown and BTS Manager power control features still function with remote Dual TRX modules (EXxx).

fThe PWR connections of the System module (ESMA) and Local Optical Converter module (LEOCA) should NOT need to be connected together. Only the BUS connec-tions for the Dual TRX modules (EXxx) need to be connected to the Local Optical Con-verter module (LEOCA).

Display of Optical Converter modules (EOCA) with the Flexi BTS ManagerSee the following figure for an example of Optical Converter modules (EOCA) displayed in Flexi EDGE BTS Manager Base Station view:

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Figure 16 EOCA displayed in BTS Manager Base Station view

In the above example, two pairs of Optical Converter modules (EOCA) are present. Pair 1, identified as LEOCA1 and REOCA1, connect the System module (ESMA) to EXDA1 and EXDA2. Pair 2, identified as LEOCA2 and REOCA2, connect the System module (ESMA) to EXDA3 and EXDA4. Dual TRX modules EXDA5 and EXDA6 are connected directly to the System module (ESMA) as per normal BUS connections.

A single pair of EOCA modules can connect up to 3 Dual TRX modules (EXxx). To display the connections in the Base Station view of the BTS Manager, the EOCA pairs may appear 1, 2 or 3 times in the view. To make it easy to see which pairs are displayed multiple times, each pair has a unique color border around the LEOCA and REOCA modules in the display. In the example screenshot above, Pair 1 (LEOCA1 and REOCA1) are shown with a dark blue-green colour border. Pair 2 (LEOCA2 and REOCA2) are shown with a light green colour border.

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Basic GSM operation

7 Basic GSM operation

7.1 BSS21113 Increased dynamic SDCCH capacityThis feature is related to BSS7036 Dynamic SDCCH Allocation feature. When BSS21113 feature has been turned on at the BSC, the maximum number of SDCCH channels for each TRX is increased from 16 to 24 or 32, depending on the type of the TRX. It is increased to a maximum of 24 channels in BCCH TRXs and to a maximum of 32 channels in non-BCCH TRXs.

Feature BSS21113 is optional and requires a license. This feature is supported from BSS13 (EP2) release onwards with Flexi EDGE BTS.

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7.2 BSS20882 Extended Cell Range for Flexi EDGE BTSThe BSC supports the Extended cell radius in the Base Transceiver Station (BTS). Two cells with different timing advance ranges, that is, inner and outer cells, are used. An inner cell has a regular coverage area and an outer cell has an extended radius of the coverage area. The handover and power control algorithm in the BSC triggers a handover when the MS is approaching the inner cell while still being served by the outer cell. The triggering is based on the timing advance.

Extended cell is application software in the BSC.

ImplementationThe extended cell implementation is based on one-BCCH and two-TRX solution. Differ-ent TRXs serve the normal and the extended area. The TRX, which serves the normal area, is normally configured with the BCCH/SDCCH and TCHs. The timing of the receiver of the TRX which serves the extended area (E-TRX) has been delayed so that it can serve the area beyond 35 kilometres. The timeslot 0 of E-TRX is tuned to the BCCH frequency in order to get RACH-bursts from the extended area. The timing of transmitters is the same in both TRX and E-TRX. If more capacity is required either in the normal area or extended area, more TRXs can be added to serve those areas.

• The Extended Cell Range for Flexi EDGE BTS is supported for all Flexi frequency bands.

• MHA units should be used in the Flexi EDGE BTS configuration to ensure transmit-ted signal strength can reach the maximum range.

An optional information element (IE), ‘Extended Cell Radius’, is taken into use in the ‘Information Status’ message to the BTS Manager. From EP2 onwards, this IE is for all TRXs but indicates an extension radius of 0 Km for a TRX in the inner coverage area. For a TRX covering the outer area, the ‘Radius Extension’ is shown in Km.

Interaction with other featuresThe following features cannot be used simultaneously with the Extended Cell Range for Flexi EDGE BTS:

• Baseband hopping • RF hopping cannot be used in extended area TRXs (RF hopping can be used in

normal area non-BCCH TRX(s) if present) • Antenna hopping • IUO • DFCA

TRX Test:

• TRX Test cannot be commanded for a TRX configured to cover the extended outer area.

BenefitsThe extended cell feature is best suited for applications in coastal areas, rural areas and corresponding ones where coverage exceeds typical GSM maximum cell size of 35 km.

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7.3 BSS20872 Robust AMR signallingRobust AMR signalling is an application SW product and requires a valid licence in the BSC. The SW product consists of four separate features:

1. FACCH and SACCH repetition for “repeated ACCH” capable mobiles on AMR TCH 2. FACCH repetition for legacy mobiles on AMR FR 3. FACCH repetition for legacy mobiles on AMR HR 4. FACCH Power Increment on AMR TCH

FACCH/SACCH repetition and FACCH Power Increment proposals are specified together as a single repeat/power increment function so that the BTS can optimise the use of the power increment and repetition according to the BTS Tx power level, mobile capability and channel (AMR FR, AMR HR) used.

The BSC's role is to provide parameters related to this feature to the BTS. The BSC checks the mobile’s capability and sends parameters related to this feature to the BTS at the beginning of a call (Channel Activation message). The BTS then uses the com-manded features according to the radio conditions. The BTS indicates the usage of FACCH/SACCH repetition and soft combining of repeated blocks in the Measurement Result message to the BSC. This information is used for monitoring of Robust AMR sig-nalling.

With FACCH repetition, the time taken to get a command to a mobile increases, so rep-etition should only be applied when needed. Uplink SACCH repetition reduces the fre-quency of measurements from the mobile, so it should also be used only when needed. Repetition of the same measurement reports also affects the averaging of measure-ments and the reaction speed of handover and power control algorithm.

Repeated AMR SACCH and FACCH in 3GPP Release 6With 3GPP Release 6 and onwards, mobiles and BTSs can ask for SACCH frames to be repeated exactly on transmit so that the original frame and its repeat can be decoded together using Incremental Redundancy (soft combining) type decoding, similar to the IR defined for EDGE data. Similarly, transmit repeat and Incremental Redundancy on decode can also be used with downlink FACCH frames.

This gives about a 4 dB improvement in the C/I needed to decode the SACCH and FACCH so that these channels are as robust as the lowest rate AMR codecs.

BSS13 supports the 3GPP protocol for repeated SACCH and FACCH, and will use the Incremental Redundancy on the uplink SACCH when needed for good normal operation of the control channels.

Repeated AMR FACCH for existing mobilesFor mobiles designed according to ‘old’ 3GPP releases (that is, releases up to and including Release 5), 3GPP has enhanced the radio interface protocol so that the downlink FACCH can be repeated, to give the mobile two chances to decode the FACCH before each link timeout and retry of the protocol. This gives about a 2 dB improvement in the C/I needed to decode the FACCH, so that this channel is more robust and the dropped call rate in handovers is reduced.

BSS13 will use the repeated downlink FACCH when the mobile is indicating poor downlink quality by requesting a low-rate AMR CODEC.

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The 2 dB improvement in the C/I is not enough for reliable operation with the very lowest rate AMR/FR codecs, so Nokia Siemens Networks also offers the FACCH Power Incre-ment feature for the existing mobiles.

FACCH Power Increment for existing mobilesWith this feature, for 3GPP Release 5 and earlier mobiles, the BTS Tx power for (down-link) AMR FACCH bursts can be increased by 2 dB, up to the maximum power capability of the TRX. The Power Increment is not used when transmitting on the BCCH frequency.

This will give an improved C/I for FACCH so that the dropped call rate in handovers is reduced, but without adding significant interference to other ongoing calls. Combining this feature and the Repeated AMR FACCH for the existing mobiles, BSS13 offers up to 4 dB improvement in the C/I for FACCH decode, and a corresponding reduction in the handover dropped call rate.

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7.4 BSS20588 TRAU bicasting in AMR FR/HR handoverAMR speech codec is a key voice codec in Nokia Siemens Networks GSM/EDGE BSS. AMR packing/unpacking is one of the most important system level capacity/quality tools of the Nokia Siemens Networks AMR system feature. AMR packing/unpacking uses intra-cell handovers in order to change speech coding between AMR HR and AMR FR.

In order to reduce audio breaks during a handover, the BSC establishes a unidirectional connection in the downlink towards the target channel (bicasting) before the handover. For an AMR FR/FR (or AMR HR/HR) handover, bicasting means that TRAU frames carrying 16k (or 8k) TRAU coming from the transcoder (TC) are transmitted by the BSC simultaneously to the source and target channels in 16k (or 8k) format depending on the channel rate.

This method, presented in the following figure, tries to ensure that valid speech frames are being transmitted in the downlink over the air interface before the MS moves from the source to the target channel.

Figure 17 TRAU bicasting in AMR FR/HR handover

With this approach, it is possible to reduce the potential for breaks in audio in the downlink during a handover. TRAU bicasting in AMR FR/HR handover also enables to establish a unidirectional connection in AMR FR/HR intra-BSC handovers. When this feature is used, source and target BTSs and TC are all using 8 kbit/s TRAU frame format for Abis and Ater transmissions during an AMR packing/unpacking handover. In prac-tice, this means that the 8 kbit/s TRAU frames are submultiplexed onto a 16 kbit/s Abis channel of the BTS that is sending/receiving TCH/AFS radio frames.

TC

BSC

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BSC

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7.5 Basic GSM featuresFlexi EDGE BTS supports the following basic GSM channel combinations:

• Combined broadcast control channel (BCCH) including • frequency correction channel (FCCH) • synchronisation channel (SCH) • common control channel (CCCH) • standalone dedicated control channel (SDCCH/4) • slow associated control channel (SACCH/C) • random access channel (RACH)

• Non-combined broadcast control channel (BCCH) including • frequency correction channel (FCCH) • synchronisation channel (SCH) • common control channel (CCCH) • random access channel (RACH)

• Standalone dedicated control channel (SDCCH) including • Standalone dedicated control channel (SDCCH/8) • Slow associated control channel (SACCH/C)

• Full rate speech (TCH/FS, TCH/EFS, TCH/AFS) with • Slow associated control channel (SACCH/T) • Fast associated control channel (FACCH)

• Half rate speech (TCH/HS, TCH/AHS) with • slow associated control channel (SACCH/T) • fast associated control channel (FACCH)

• Full rate circuit-switched data (TCH/F24, TCH/F48, TCH/F96, TCH/F144) with • slow associated control channel (SACCH/T) • fast associated control channel (FACCH)

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7.6 BSS6071 Enhanced Full Rate CodecEnhanced Full Rate Codec (EFR) uses the existing GSM 900/1800 full rate channel coding but provides a considerably better performance in all channel conditions. More-over, in good channel conditions, the codec ensures equal or better quality than Adaptive Differential Pulse Code Modulation (ADPCM).

The EFR can coexist with Half Rate (HR) or Full Rate (FR) 'dual codec'.

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7.7 BTS2023 Downlink and uplink DTXDiscontinuous transmission (DTX) is a mechanism allowing the radio transmitter to be switched off during speech pauses. This feature reduces the power consumption of the transmitter, which is important for mobile phones, and decreases the overall interfer-ence level on the radio channels affecting the capacity of the network.

The DTX function is supported both in downlink and uplink for the following speech channels: TCH/FS, TCH/EFS, TCH/AFS, TCH/HS, and TCH/AHS.

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7.8 BTS2503 Compressed Abis timeslot allocationIn traditional transmission solutions, some capacity is left unused, especially in the case of BTSs with one TRX, because one radio interface time slot is always used for the broadcast control channel (BCCH). The compressed Abis time slot allocation makes it possible to use this capacity for TRX signalling (so-called "compressed TRXSIG") or for O&M signalling (so-called "compressed OMUSIG"). This slot can 'steal' the traffic channel (TCH) transmission slot, which leaves capacity for six full rate TCHs or twelve half rate TCHs for that TRX.

In environments where it is not necessary to use the full traffic capacity of a TRX, com-pressed Abis time slot allocation offers an ideal solution for using the transmission medium more efficiently. With this configuration, it is possible to fit 15 TRXs to one 2 Mbit/s PCM.

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7.9 BTS2067 Fast Associated Control Channel (FACCH) Call SetupWith Fast Associated Control Channel (FACCH) Call Setup, it is possible to establish a call without using a stand-alone dedicated control channel (SDCCH). A traffic channel (TCH) is set to 'signalling only' and switched over to normal speech operation when needed. FACCH Call Setup is for emergency calls only.

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7.10 BSS21538 Extended Common Control Channel (CCCH)The “BSS21538 Extended CCCH” feature increases the CCCH channel capacity in the cell. It may be used for alleviating CCCH paging and access grant capacity problems if these appear in the network.

With this feature, the operator can define one, two, or three extended CCCH channels in the BCCH TRX. The non-combined channel structure of a CCCH is meant for bigger cells. This feature aims to introduce more non-combined CCCHs, thus extending the range of non-combined configurations that a cell can assume in compliance with GSM specifications.

The Extended CCCH feature provides the following benefits:

• The paging capacity is enhanced by increasing the number of CCCH channels in the cell. The paging success rate is improved with large location areas

• Increased use of packet switched (PS) services is possible without being con-strained by the access grant channel (AGCH) capacity

• Due to the increased rate of success in paging, calls are established faster • The revenue is improved with more established/served calls

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7.11 BSS101411 Extended BCCHThe "BSS101411 Extended BCCH” feature allows the reduction of the number of SI2 quarter messages that are sent in a normal BCCH channel. When this feature is in use, all the individual SI2 quarter messages are sent in an extended BCCH sub-channel instead of the normal BCCH, increasing the static CCCH channel capacity in a cell.

When this feature is in use, it reduces the amount of SI2 quarter messages that are sent to the mobile stations (MS) and increases the capacity of these messages. Reducing the number of SI2 quarter messages reduces the time taken by the MS to read them. As a result of this, when 3G/TD-SCDMA is deployed within the GSM/EDGE network, the MS takes reduced time for handovers and location updates. This feature improves the KPIs on GSM and 3G/TD-SCDMA interworking.

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7.12 BSS7036 Dynamic SDCCH AllocationDynamic Stand-alone Dedicated Control Channel (SDCCH) Allocation allows the SDCCH resources to be configured according to the actual SDCCH traffic situation of a cell. When the BTS temporarily needs greater SDCCH capacity than normal, the BSC configures the idle traffic channel (TCH) resources for SDCCH use. For an example of this, see the figure below. A maximum of two additional SDCCH/8 can be configured. When the SDCCH congestion situation is over, the extra SDCCH resources are config-ured back to TCH resources. Dynamic SDCCH Allocation can be used with both combined and non-combined Broadcast Control Channel (BCCH).

The BTS only needs to be configured to the minimum static SDCCH capacity sufficient to handle the normal SDCCH traffic.

Figure 18 Dynamic SDCCH allocation

An extra SDCCH resource is allocated only when the existing SDCCH is fully loaded. When the dynamic SDCCH radio resource is totally free again, it is immediately recon-figured for TCH use. Thus, the maximum number of TCHs is always in use depending on the actual need of the SDCCH resources at each moment.

Dynamic SDCCH Allocation benefits traffic cases in which signalling is the only trans-mission to the network, for example Short Message Service (SMS) traffic and location updates. In some special places, such as airports and stations, the location updates can produce sudden short-term SDCCH congestion. With Dynamic SDCCH Allocation, this can be handled without any need to configure extra permanent SDCCH capacity.

TCH(busy)

TCH TCH(busy)

TCH(busy)

SDCCH/8

BCCH SDCCH/8 TCH(busy)

TCH(busy)

TCH(busy)

TCH(IDLE)

TCH(busy)

TCH

TRXwith staticSDCCH/8

New TRXconfiguration

with additionalSDCCH/8

SDCCH congestion triggersdynamic allocation of SDCCH for free FR RTSL

BCCH SDCCH/8 TCH(busy)

TCH(busy)

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7.13 BTS2024 Synthesised frequency hoppingSynthesised frequency hopping is available for configurations that have at least two TRXs per sector. Synthesised frequency hopping enables all TRXs to change frequen-cies in successive timeslots, so that the carriers can hop at many different frequencies in quick succession. Both random and cyclic hopping can be used. The maximum number of frequencies per BTS site is 64. The number of frequencies can be greater than the number of TRXs.

Note that the BCCH carrier must remain at a fixed frequency and at a fixed power level to enable the MS to measure the signal strength.

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7.14 BTS2013 Baseband Frequency HoppingIn Flexi EDGE BTS, the Dual TRX Modules are interconnected through a Gigabit Ethernet L2 switch to facilitate baseband hopping. Both random and cyclic hopping can be used for baseband hopping. The number of frequencies used in the baseband hopping frequency hopping sequence is the same as the number of carriers in the sector. Baseband hopping is allowed for all BTS configurations except with over 150 m multimode fiber used with Feederless Site configuration.

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7.15 BTS2037 Air interface measurement pre-processingThe measurement results for the active channels may be averaged for the TRX. This option is useful when 16 kbit/s signalling is used because it reduces the capacity needed on the Abis link. The averaging period may be set to consist of 1 - 4 SACCH multiframes. Both uplink and downlink measurements are averaged. As a result, the BSC receives a measurement report once at the end of the averaging period rather than after every SACCH multiframe.

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7.16 BTS2012 BTS time base reference from PCMThe PCM clock is used as a reference when tuning the long-term accuracy of the BTS internal clock. The requirement for the accuracy is 0.015 ppm in order to meet the GSM requirement (0.05 ppm) for the clock signal accuracy in the Air interface.

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7.17 BTS2133 Short Message Service (SMS) point-to-pointBase Station supports the short message service (point-to-point) for both mobile origi-nating and mobile terminating calls.

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7.18 BTS2033 Short message cell broadcastThe short message service (cell broadcast) defined in the GSM recommendations is supported.

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7.19 BSS6025 Short Message Service Cell Broadcast with Dis-continuous Receiving (SMS-CB DRX)SMS-CB DRX enables phase-2 Mobile Stations (MSS) to receive only the needed blocks of the CBCH (Cell Broadcast Channel). This decreases battery consumption.

The BSC has a user interface for SMS-CB (Short Message Services Cell Broadcast) and it stores CB messages in the BSS. After the BTS initialisation, the BTS operates in non-DRX (Discontinuous Receiving) mode until SMS-CB DRX is activated in the BSC. When SMS-CB DRX is employed, the BTS starts transmitting Schedule Messages to the cell area. A Schedule Message includes information about a number of immediately following consecutive CB messages, planned for that cell. The time between two Schedule Messages is called the Schedule Period. The Schedule Period is one minute (see the figure below).

The MS starts operating in DRX mode after the power up when it has received the first Schedule Message. If the MS does not receive a Schedule Message, it has to read at least the first block of each CB message.

Figure 19 SMS-CB DRX Schedule Period

In DRX mode, in the first block of the Schedule Message, the MS receives information about

• How many CB messages there are • In which slot they will be transmitted • Message identifiers (if there are fewer than 6 new messages)

If there are:

• No new CB messages in successive schedule periods, the MS ends up reading only the first block in each Schedule Message.

• 1 to 5 new CB messages, the MS does not need to read other blocks in the Schedule Message, but it still needs to read the new CB messages.

• More than 5 new CB messages, the MS has to read more than one block in the Schedule Message plus all the new CB messages.

SchCB1

CB2

CB31

Sch Sch

60 s

.... ....

CB1

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7.20 BSS6083 Mobile Station (MS) speed detectionThe purpose of this feature is to determine the speed of the Mobile Stations (MSS) in GSM networks so that the fast moving MSS can be directed to macro cells and the slower moving MSS respectively to micro cells whenever configured so by the BSC. Fur-thermore, BSC statictics also collects this information.

The benefit of this feature is that it decreases the number of handovers in a micro-cell network and thus increases network capacity.

The BTS estimates the MS's speed by using the Crossing-rate algorithm. The algorithm is based on a comparison between the signal levels obtained from each burst and their averaged value over one SACCH multiframe. The algorithm counts the rate at which the signal level crosses the averaged signal level. The crossing rate is relative to the MS's speed. The BTS sends the measured MS-speed information to the BSC by including it in the 'Meas_res' message. The MS-speed indication can vary between 0 and 254 km/h (0 – 159 mph) in 2-km (1.25-mile) steps. If measurement averaging is used, MS-speed measurement results are also averaged (see the figure below).

Figure 20 MS speed detection used for handover decision

The handover-decision algorithm in the BSC takes into account the MS-speed results sent by the BTS. Furthermore, the MS-speed based handover parameters (nx, px, upper speed limit (USL) together with lower speed limit (LSL)) and the adjacent cell layer definitions are also used with this feature.

The handover (HO) and power control (PC) algorithm determines the need for the handover as follows:

• If px averaged MS-speed indications out of last nx averaged MS-speed indications exceed the USL, the MS is considered as a fast moving MS and the call will be handed over to a suitable upper-layer cell (macro cell) if any.

• If px averaged MS-speed indications out of last nx averaged MS-speed indications are lower than the LSL, the MS is considered as a slow moving MS and the call will be handed over to a suitable lower-layer cell (micro cell) if any.

Layer information and the umbrella handover criteria are used as the target cell selection criteria. This means that the RX level in the target cell has to exceed the umbrella handover requirement HO_UMBRELLA_LEVEL defined for every adjacent cell.

BSCBTS

BTS

Macro cell

Micro cell(s)

Fast MSs

Slow MSs

Meas_res

Crossing-rate algorithm

HOs

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g The algorithm does not work with frequency hopping.

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7.21 BSS21445 Packet Abis Congestion reactionThe feature “BSS21445 Packet Abis Congestion reaction” introduces congestion control procedures that control the packet transmission rate into Packet Abis network. This feature detects and reacts to congestion and also monitors the bandwidth usage. Packet Abis offers a fully shared dynamic bandwidth with an upper limit that can be configured. Further, it also increases the optimization gain, and prevents violations of PSN SLA agreements.

With this feature, the BTS detects congestion at the BCF level and informs the BSC. Even though the BSC does not detect congestion by itself, it acts upon the congestion detection message sent by the BTS. The goal of congestion control procedures is to avoid the overload of intermediate nodes and networks between the BTS and BSC, and to avoid exceeding congestion thresholds (set as a percentage of the agreed CIR) on the Abis link.

Congestion reactions:

• PS Data and AMR CODEC Adaptation • Handover • Call Admission Control

Requirements

• BSC S15 • Flexi EDGE BTS EX4.0 • NetAct OSS 5.2 CD Set 3 • BSC (BSC3i 1000 (one cabinet): 2+2 ETP Modules, BSC3i 2000 (two cabinets): 6+6

ETP Modules, Flexi BSC: 6 + 6 ETP Modules, ETP interface modules required, with the ETP Module, the LAN switch extension for BSC3i 1000/2000 and Flexi BSC with the latest LAN switch version (ESB24-D) is necessary)

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7.22 BSS11052 Dynamic Frequency and Channel Allocation (DFCA)Dynamic Frequency and Channel Allocation (DFCA) is a radio channel allocation software for dynamically assigning the optimum radio channel for a new connection.

DFCA uses interference estimations derived from mobile station downlink (DL) mea-surement reports and combines them with the timeslot and frequency usage informa-tion. DFCA channel allocation algorithm selects the radio channel for a connection from a dedicated channel pool based on carrier/interference (C/I) ratio criteria. The idea in DFCA channel selection is to provide enough quality in terms of C/I, so that each con-nection will meet its Quality of Service (QoS) requirements. The different degrees of interference tolerance of different connection types are taken into account in the channel selection process. Examples of the connection types are connections using enhanced full rate speech codec (EFR) or full rate (FR) and half rate (HR) connections using adaptive multi-rate speech codec (AMR).

The main DFCA functionality is located in the BSC. The DFCA channel allocation algo-rithm in the BSC controls the radio channel assignments of all DFCA TRXs in all BTSs controlled by the BSC. The BTSs using DFCA must be synchronised to a global clock reference provided by the GPS satellite system. This is achieved by having a Location Measurement Unit (LMU) installed in every BTS site. The LMU incorporates a GPS sat-ellite receiver and provides a common clock signal that is used by all BTSs in the site.

DFCA is used for circuit switched traffic. Packet switched traffic is not handled by this software. The (E)GPRS territory is placed on a regular TRX which has been assigned to a separate portion of the frequency band and controlled by the conventional channel allocation algorithm. DFCA is a licence-based application software. Its use is controlled by a capacity licence based on the number of TRXs. To activate DFCA, the state of the licence must be set to ON.

DFCA frequency hopping is a new frequency hopping mode supported by Flexi EDGE base stations with wide band combining from EP1.1 software release onwards. DFCA hopping is based on the basic principle of synthesised frequency hopping where the TRX unit changes the used frequency according to the given hopping sequence. With DFCA hopping, the TRX supports independent cyclic hopping sequences for each timeslot that can be freely selected with each channel activation. With DFCA hopping, the BSC can freely select the MA-list, MAIO and TSC for each TCH activation allowing the DFCA algorithm to choose the most suitable radio channel for each new connection or handover based on C/I criteria. This full channel selection freedom allows DFCA to achieve the best performance with DFCA hopping mode. The DFCA hopping mode is applied only in the TRXs dedicated to DFCA use (DFCA TRXs).

Requirements

• The Flexi EDGE base station requires wideband combining or no combiners. • DFCA is not supported with RTC combiners. • DFCA requires BSS synchronisation, which means that one LMU unit must be

installed in every BTS site.

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• Within a BTS, the use of DFCA is controlled on a 'per TRX' basis.In a BTS using DFCA, there are both DFCA and regular TRXs. The DFCA TRXs do not support any signalling channels and therefore the BCCH TRX of a BTS and a TRX carrying SDCCH channels must be a regular TRX. Also (E)GPRS is not supported in the DFCA TRXs. Depending on the requirements for the (E)GPRS territory size, this may require the operator to define another regular TRX, in addition to the BCCH TRX of a BTS for carrying (E)GPRS.The usage of DFCA frequencies for regular TRXs may cause some local DFCA per-formance degradation because of the uncontrolled interference.

Interaction with other featuresThe following features cannot be used in a BTS using DFCA:

• IUO/IFH: DFCA will replace these features • Dynamic Hotspots • ICE • Antenna hopping

The following features cannot be used in a TRX using DFCA:

• Dynamic SDCCH (not usable for the DFCA TRXs) • FACCH call set up (not usable for the DFCA TRXs) • Interference Band Recommendation: DFCA will replace this functionality • Power optimisation in handover: DFCA will replace this functionality • (E)GPRS: PS territory is not allowed in DFCA TRX but only in regular TRXs in DFCA

Benefits

• Enhanced quality: DFCA is able to handle different circuit switched traffic classes (EFR, HR, AMR, 14.4 kbit/s data) individually, and it provides the operator with means to differentiate between users. This is especially powerful when the full benefit of AMR connections is wanted without 100% AMR penetration. By guaranteeing a sufficient C/I level for each user, the network performance in terms of received signal quality (RXQUAL), frame error rate (FER) and dropped call rate can be significantly improved.

• Capacity booster: The criteria of sufficient C/I for each connection optimises also the interference caused to other connections. This leads to significant capacity gain, as the use of the valuable frequency resources is dynamically optimised. By decreasing the effective frequency reuse distance in the network, DFCA enables the operator to accommodate more circuit switched traffic by adding more TRXs to the existing BTSs without quality deterioration. Alternatively, more frequencies can be used on the regular layer, thus increasing the performance and capacity available for (E)GPRS.

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7.23 BSS21161 SDCCH and PS data channels on DFCA TRXThis feature is an enhancement of the Dynamic frequency and channel allocation (DFCA) featute. If DFCA is used without this new feature then DFCA TRXs can only carry CS traffic, and the SDCCH and PS data channels use the BCCH TRX. In this case, if more capacity is required for the SDCCH or PS data channels, additional regular TRXs need to be created.

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7.24 BSS20093 A5/3 cipheringThe ciphering algorith A5/3 is a strong block cipher and provides improved security over air interface links when compared to A5/1 encryption. If the network capabilities are suf-ficient, A5/3 encryption should be deployed for maximum privacy over the air interface. Nevertheless, the A5/1 algorithm can be used as fallback solution.

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7.25 BSS21444 Packet Abis SecurityThe feature “BSS21444 Packet Abis Security” introduces integrated IP Security (IPSec) for Packet Abis over Ethernet applications. The IPSec is integrated in the BTS only. At the BSC side, an external security gateway provides security. IPSec authentication provides measures against the "man in the middle" attacks and is implemented for the CS and PS-Userplanes, C-Plane, and M-Plane. IPSec encryption measures ensure privacy (against eavesdropping) and are implemented for the M-plane, U-plane CS and SSE traffic. IPSec integrity measures provide protection against unauthorized data mod-ification for the CS & PS-Userplanes, C-Plane, and M-Plane. Also, the firewall protection is integrated in the BTS against the DoS attacks. The main functional areas of this feature are security protocol measures (IKE/IPSec configuration), X.509 Certificate Management, Firewall features (packet filter and Dos protection), and Export Classifica-tion Control (ECC). This is a licensed feature.

This feature increases the security of the network (Abis) and network elements (NEs) (BSC and BTS) without drastically increasing the operational expenses, as it is easy to use and configure.

Security protocol measuresThis is an optional feature and configurable. In IP Sec, following modes are used:

• Tunnel mode if external Security Gateways are used in order to protect the related traffic

• Transport mode if security protocols are directly terminated on the BSC

g This mode is not supported by the BTS.

U-Plane CS, M-plane, and site support traffic are protected by encryption, authentication and integrity checks. Here encryption is optional.

C-Plane, U-Plane PS, and PTP (IEEE1588v2) are protected by authentication and integrity checks.

The use of ESP introduces an overhead comparable with an additional IP header (~20 byte). The use of IPsec Tunnel mode introduces an additional IP header.

X.509 Certificate ManagementThe BTS obtains the Certification Authority (CA) Certificate, the BTS Certificate and the BTS private key in two different ways depending on operator infrastructure:

• Certificate Management (Certificate Management Protocol (CMP) not enabled): The BTS Element Manager (EM) provides to BTS CA Certificate, BTS Certificate and BTS private key. Certificates are not retrieved automatically from CA and keys pair is not generated internally in BTS.

g This configuration is done only by the local EM.

• Certificate Management (CMP enabled, RefNum & PSK_CA)1. EM provides PSK_CA, RefNum and CA Root Certificate to the BTS. RefNum is

a unique identifier of BTS and Pre-Shared Key_CA is a secret value shared between BTS and Certification Authority.

2. The BTS generates private/public key pair.3. The BTS retrieves CA Certificate from CR server (LDAP protocol in used).4. The BTS (CMP Client) retrieves BTS Certificate from CA (CMP server).

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BSC/BTS firewall functionalitiesThe main functionality of the firewall is to protect a network from external attacks by fil-tering the traffic. The filtering is done in a way that the service provided by NE still works fine. Usage of firewalls for incoming Abis packets is recommended for all the planes.

Export Classification Control (ECC)ECC in general does not allow exporting cryptographic algorithms to some countries. ECC is not a static topic. It may change, every day, to which countries encryption algo-rithms can be exported.

Requirements

• BSC S15 • Flexi EDGE BTS EX4.0 • NetAct OSS 5.2 CD Set 3 • BSC (BSC3i 1000 (one cabinet): 2+2 ETP modules, BSC3i 2000 (two cabinets): 6+6

ETP modules, Flexi BSC: 6 + 6 ETP modules, ETP interface modules required, with the ETP Module, the LAN switch extension for BSC3i 1000/2000 and Flexi BSC with the latest LAN switch version (ESB24-D) is necessary)

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Flexi EDGE BTS Feature Descriptions Transmission


8 Transmission

8.1 Basic transmission

8.1.1 Abis Trunk Transmission for E1 (ETSI) interfaceUp to four full rate (FR) or Enhanced Full Rate (EFR) speech channels, or up to eight Half Rate (HR) speech channels, are multiplexed on a single 64 kbit/s PCM timeslot. It is possible to create point-to-point star, multidrop chain or remote star transmission con-nections between BSC and BTS sites. This flexibility ensures that all kinds of transmis-sion needs are fulfilled: traditional star configuration, economical multidrop chains, and reliable multidrop loops are all possible.

Up to 12 TRXs are supported on a single 2 Mbit/s PCM line. See also BTS2503 Com-pressed Abis timeslot allocation.

Abis Trunk Transmission Allocation is implemented using the standard G.703 2 Mbit/s PCM frame structure.

For more information, see BSS Transmission Configuration in BSC/TCSM Product Doc-umentation.

Interaction with other featuresBSS30285 Activation of additional two E1/T1 interfaces

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8.1.2 Abis Trunk Transmission Allocation for T1 (ANSI) InterfaceUp to four full rate/enhanced full rate (FR/EFR), and eight with Half Rate (HR) speech channels are multiplexed on a single 64 kbit/s PCM timeslot. It is possible to create point-to-point star, multidrop chain or remote star transmission connections between BSC and BTS sites. This flexibility ensures that all kinds of transmission needs are ful-filled: traditional star configuration, economical multidrop chains, and reliable multidrop loops are all possible.

Up to 10 TRXs are supported on a single 1.5 Mbit/s PCM line. See also BTS2503 Com-pressed Abis timeslot allocation. This feature is implemented using the standard T1.403 PCM frame structure.

The T1 TRAU supports Extended Super Frame (ESF) and SF/D4 framing. The ESF supports CRC-6 checks and 4 kbit/s data link for performance management.

Interaction with other featuresBSS30285 Activation of additional two E1/T1 interfaces

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8.1.3 Abis Trunk SignallingRadio Signalling Link is a logical link between the BSC and the BTS in Layer 2. The RSL is identified by a functional address known as Service Access Point, SAPI=0. Radio sig-nalling links over the Abis interface are addressed to different units by Terminal Endpoint Identifiers, TEI. The TEI values are fixed and correspond to the TRX-id. The TEI man-agement is not used.

One signalling channel is used for each transceiver (TRX) and one for each BTS base control function (BCF). Alternative signalling speeds are available: 16 kbit/s, 32 kbit/s, or 64 kbit/s. The selection of the signalling speed is done in the commissioning phase on BTS basis. The same selection is also done on the BSC site when channel configu-ration is defined.

Normally, 16 kbit/s TRX signalling speed is recommended for the FR operation. 32 kbit/s TRX signalling rate is recommended for the HR use.

At the BCF signalling rate of 64 kbit/s, the SW downloading time needed is approxi-mately four times shorter than with 16 kbit/s signalling.

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8.1.4 Network SynchronisationIn normal network conditions, synchronisation information is carried by selected E1 or T1 paths from upper to lower hierarchical levels according to the synchronisation plan, from the MSC down to the BTSs.

Flexi EDGE BTS selects the E1 or T1 signal that has the highest priority from a group of pre-selected digital paths as the active synchronisation signal. The operator can change the group of signals using the Flexi EDGE BTS Manager application. Selection of a new signal is automatic in case of input failure and input recovery.

In addition to using E1 or T1 signals for synchronisation, it is possible to synchronise with an external clock signal, such as the LMU clock signal.

For PseudoWire Emulation (PWE) or Abis over IP mode, the following external synchro-nisation sources are available:

• One out of the 8 supported PWs • One out of four TDM 2 Mbit/s (E1) signals • An external 2 MHz signal or LMU • FIQB and FIYB modules support Packet Abis Synchronization

In the PWE mode, the synchronisation information can be forwarded via TDM IF 4 as E1 signal.

For Packet Abis synchronization, Synchronous Ethernet (SyncE) external synchronisa-tion method is available.

Network Synchronisation can be protected via PDH Loop Protection. See BSS30280 Abis loop protection for more details.

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8.1.5 Transmission equipment managementThe management protocol for Nokia’s transmission equipment is Q1. The transmission equipment can be external or internal to the BTS. The external equipment can be con-nected to the Flexi EDGE Base Station using a Q1 cable or a configured Q1 embedded operations channel (EOC). In PseudoWire Emulation (PWE) mode, EOC configuration is not supported in the BTS.

Either the base station controller (BSC) or Flexi EDGE Base Station can supervise the transmission equipment. The Q1 protocol is a master/slave protocol. The master regu-larly polls the slaves. If the BSC is the master, the transmission equipment is said to be under 'BSC polling'. If the Flexi EDGE BTS is the master, the transmission equipment is said to be under 'BTS polling'. In PWE mode, the BTS does not support the BSC polling because the EOC configuration is not supported. Note that the BSC polling can still be configured for a BTS running in the PWE mode; the consequence is that transmission alarms are not reported to the BSC, the BSC may also show an alarm that any polling command sent via EOC configured in the BSC is not replied.

The alarms that the transmission equipment generates are transmitted to the BSC, which further transfers them to Nokia NetAct.

If the BTS is the master, the BTS reports the transmission alarms to the BSC via the OMUSIG channel.

If the BSC is the master, the BSC polls the alarms directly. A management channel must be configured throughout the radio network between the BSC and the transmission equipment. The management channel configuration at the BSC (service channel) must match the configuration at the transmission equipment (embedded operations channel). The BSC polling is only supported in the TDM/Packet Abis over TDM mode.

All equipment on the same channel must have a unique address (polling address) to avoid conflicts. Only one master polls all transmission equipment. Loops are not allowed, because Q1 is a bus protocol.

With Flexi EDGE BTS, it is not necessary to manually configure any Q1 switches to establish the internal Q1 paths. The configuration is done automatically based on the Q1 polling mode. As a consequence, all internal or external transmission devices connected to the BTS must be either BTS-polled or BSC-polled. A combination of polling modes is not possible. This is important to keep in mind particularly when configuring the external devices (which are connected to the BTS either via a Q1 cable or the EOC).

It is not possible to change the polling mode for the internal transmission equipment manually at the Flexi EDGE BTS. It is the result of the configuration at the BSC. If the Q1 polling mode is 'BSC Polling', the Q1 address value is read from the BSC (0-3999). The Q1 address can be manually configured from the Flexi EDGE BTS Manager. This should, however, be avoided to prevent conflicts.

With the Q1 Interface Handling BSC MML commands, the user creates the service channels used in communication between the BSC and the transmission equipment. The Q1 service channels are asynchronous serial communications channels. The default maximum number of Q1 service channels in the BSC is 18. The user must define every supervised equipment at the BSC. Altogether 512 pieces of equipment can be defined into Q1 service channels under the BSC.

Supervision of transmission units supplied by other manufacturersWhen transmission units supplied by other manufacturers are supervised via External Alarm and Control (EAC) lines, the alarms can be sent to the BSC and NetAct. When

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the alarms are sent to the BSC and NetAct, the System Module (ESMA) supervises the alarm handling, and alarms are reported as normal external alarms.

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8.1.6 Support for Nokia Microwave Radio LinksThe FlexBus transmission sub-module (FIFA) forms the integrated microwave unit support with Flexi EDGE BTS.

One FIFA transmission sub-module is used per Flexi EDGE BTS with two FlexBus inter-faces, allowing for microwave radio tail and chain site topologies using Nokia FlexiHop-per and MetroHopper.

The FIFA sub-module offers E1 bypass cross-connections from one FlexBus interface to the other, and up to 16xE1 add/drop capability to Flexi EDGE BTS and sub 2M cross-connect function of which up to 8xE1 can be dropped to the BTS itself.

The FIFA sub-module is visible as a separate managed element at Nokia NetAct. The operator can manage the FIFA sub-module locally and remotely using Nokia FlexiHub manager. Flexi EDGE BTS provides functions for alarm, performance data polling and forwarding to the BSC.

Some features related to Nokia Microwave Radio require an application SW licence, for example the L55341.05 licence for an additional FlexBus interface.

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8.1.7 BSS9065 Transmission OperabilityFlexi transmission equipment is measured with several counters:

• All equipment can be measured within 15-minute/24-hour periods. This measure-ment gives a fixed set of counters, which are near-end G.826 signal quality counters. These counters are: • Total time • Available time • Errored seconds • Severely errored seconds • Background block errors • Errored block

• In the PWE mode, the following packet based counters are also available: • Received Ethernet Packets • Transmitted Ethernet Packets • Ethernet Received Errored Packets • Received PW packets in tunnel • Transmitted PW packets in tunnel • Packets not matching any PW* • Number of PW packets lost • Early Packets • Late Packets • Received PW packets with L bit set* • Delay Variation Average • Delay Variation Minimum • Delay Variation Maximum • Counters marked with a * are not reported to the BSC or NetAct

• A certain set of Flexi transmission equipment can be defined. Flexi transmission equipment refers either to the whole equipment or part of it (functional entity and supervision block). It is also possible to define the counters that are collected from the equipment. To do this, the topology of the transmission network must be known so that the measurement subject can be chosen.

• Packet Abis counters, for more detail see section Measurements and counters in the Packet Abis feature descriptions document

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8.1.8 BSS21234 Support for BTS PWE Counters at BSC/NetActPseudoWire Emulation (PWE) provides the transparent transport of a TDM signal (E1 or T1) via a packet switched network (IP/Ethernet/UDP). The existing set of transmis-sion alarms and counters was adapted to enable gathering performance data from BTS at NetAct. This facilitates network performance analysis for troubleshooting and opti-mazation of packet switced network.

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8.1.9 BSS21290 Flexi EDGE Ethernet SwitchingWith Ethernet Switching on the Flexi EDGE plug-ins FIQx and FIYx it is possible to use more the one Ethernet Interface; currently two FE’s and one GE are available. Thereby external IP/Eth equipment/networks can be connected, such as DCN (Data Communi-cation Network).

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8.2 Transmission solutions

8.2.1 PDH traffic routingCross-connections define how signals are routed from a transmission interface to another transmission interface. They are the basic building blocks for creating the path for transmitting the Abis capacity from the Nokia BSC to the BTS via interconnecting nodes.

Note that the cross-connections are only available in TDM/Packet Abis over TDM mode.

Cross-connection granularitiesThere are several types of cross-connections available, and each has a different gran-ularity. Granularity means the bit rate at which a cross-connection is made, that is, the number of bits connected into a specific direction in a cross-connection. In 2 Mbit/s mode, the available granularities are:

• 8k (1 bit) • 16k (2 bits) • 32k (4 bits) • 64k (all 8 bits in a time slot) • n x 64k (where n = 1 - 31)

BSS21129 GroomingThe cross-connection feature of the transmission units makes traffic grooming possible.

Flexi EDGE BTS is capable of grooming traffic at for example 8 kbit/s granularity, which enables fully optimised and flexible use of the available transmission resources. This ensures that the path used for transmitting Abis capacity can be used efficiently.

Note that the grooming is only available in TDM/Packet Abis over TDM mode.

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8.2.2 BSS30280 Abis loop protectionNokia PDH loop protection is an efficient way to protect traffic in a transmission network such as a base station subsystem (BSS). In a live telecommunications network it is important to secure, in addition to the actual payload traffic, the network synchronisation and the centralised network management during any period of abnormal circumstances.

For these reasons, Nokia PDH loop protection protects:

• payload traffic • network synchronisation • network management connections

A transmission loop formed with Nokia elements consists of a loop master and one or more loop slaves. Usually the loop master is a transmission node, whereas the loop slaves can be either transmission nodes, BTSs or a combination of both inside one loop.

The loop principle is that the transmitted signal is always sent in both directions, but the received signal is selected from one direction only. The loop master sends pilot bits on the basis of which the switching decision is made. Each individually protected slave station needs one pilot bit.

Network synchronisation must also be ensured in a loop network, and it follows the loop principle in a similar way. The synchronisation switching takes place independently from the pilot bits by having master clock bit (MCB) and loop control bit (LCB).

Based on the configured priorities, each network element decides individually from which direction the signal and the synchronisation will be received, and, thus, it does not require any external or additional supervision for its decision.

Figure 21 Loop principle

Nokia Siemens Networks's way of implementing loop protection is ultimately secure, providing very fast route switching that recovers the transmission connections instantly. Nokia loop protection is embedded and thus very fast. The loop protection protects

Loopmaster

= Loop slave

Normal receive direction

Reverse receive direction

Pilot bitsPilot bits

Direction 1Direction 2

Transmissionnetwork

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against failures, such as cable-cuts, equipment failures, heavy rain and multipath fading, and against obstacles in the line-of-sight, such as cranes and growing trees.

Compared to an unprotected wireless network, Nokia PDH loop protection increases site availability at least tenfold and prevents end-of-chain availability degradation.

The protection functionality is compatible with the existing BSS transmission.

Flexi EDGE BTS can only act as a slave node in a Nokia PDH Loop protected network.

Note that the loop protection is only available in TDM/Packet Abis over TDM mode.

For more information refer to the Nokia PDH Loop Protection in GSM Networks document that can be obtained upon request.

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8.2.3 Redundant Abis TrunkIf a failure or a problem in the transmission connection occurs between the BSC and the BTS sites, an alternative transmission route (redundancy) is desirable.

Two alternative strategies are available for redundancy:

• a duplicated point-to-point type connection • a redundant multi-drop loop connection

These two alternatives provide solutions for different transmission needs: either the tra-ditional redundant point-to-point configuration or the economical multidrop loop config-uration.

Redundant Abis Trunk for E1 interface (ETSI) is implemented by using the standard G.703 2 Mbit/s PCM frame structure.

Redundant Abis Trunk for T1 interface (ANSI) is implemented by using the standard T1.403 1.5 Mbit/s PCM frame structure.

Note that the Redundant Abis Trunk is only available in TDM/Packet Abis over TDM mode.

For more information, see BSS Transmission Configuration in BSC/TCSM Product Doc-umentation.

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8.3 BSS21443 Packet TRS for UltraSite/BTSplusThe feature “BSS21443 Packet TRS for UltraSite/BTSplus” enables Abis transport over packet switched networks for signaling and traffic (payload) between legacy BTSs (UltraSite and BTSplus) and the BSC. This feature is launched into the installed base of UltraSite or BTSplus BTS, on Flexi EDGE BTS by co-location of the BTSs. The feature is controlled by a capacity based license key. The license controls E1/T1 usage of the Flexi EDGE BTS.

This feature enables Abis transport over Ethernet based PSNs for existing UltraSite and BTSplus base station systems (BSS) by means of a Flexi EDGE System Module (ESMA). The ESMA module converts legacy time division multiplexing (TDM) Abis to Ethernet via Circuit Emulation Service over Packet Switched Networks (CESoPSN). This helps in sharing the same backhaul, like Packet Abis.

The feature supports packet transport in the legacy systems by co-siting with Flexi EDGE BTS in a Multi BCF setup. Multi BCF control allows the combination of several BTSs into one logical cell, enabling the operator to increase the capacity of a cell while maintaining the maximum spectral efficiency. This helps to join Flexi BTS and UltraSite/ BTSplus into one virtual BTS. The Flexi EDGE BTS supports the standalone mode and it is possible to configure the converting BCF without any TRXs.

This feature provides the following benefits to operators:

• Significant OPEX savings by employing packet-switched network (PSN) to support the transport backhaul for the Abis traffic

• Allows upgrading the existing base stations with the new Flexi EDGE System Module (ESMA), thereby allowing a smooth upgrade to support the “BSS21309 OSC Half Rate with SAIC MS” feature

Requirements

• BSC3i 1000/2000 or Flexi BSC S15 • Flexi EDGE BTS EX4.0 with FIQx/FIYx transmission sub-module • UltraSite BTS CX8.0 • BTSplus BTS BRG2 • NetAct OSS5.2 CD Set 3

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8.4 BSS21271 Abis Delay Measurement (TDM, PWE3)The feature “BSS21271 Abis Delay Measurement (TDM, PWE3)” provides the Abis delay measurement for time division multiplexing (TDM) based networks or networks utilizing integrated/standalone Pseudowire equipment solutions. The feature introduces a new BSC transmission measurement, "120 - TDM/PW Abis Delay Measurement" for measuring the round trip time of data frames/packets. This measurement provides per-formance measurement (PM) data about the transmission delay occurring in the Abis interface. The feature is controlled by an ON/OFF type license key.

Figure 22 Round trip time/Abis delay measurement

This feature provides the benefit of improving the call success rate and EDGE through-put by allowing operators to monitor the SLA levels of their TDM and PSN backhaul leased lines released with Pseudowire solutions.

Requirements

• Flexi EDGE BTS EX4.0 • NetAct OSS5.2 CD Set 3 • BSC BSC3i or Flexi BSC with BSC S15 SW

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8.5 BSS30285 Flexi EDGE additional 2 E1, T1 IFFlexi EDGE additional 2 E1, T1 IF is an application SW product and controlled by a capacity licence.

The maximum number of E1/T1 interfaces is independent of the PIU which is used in the System Module. The maximum number of E1/T1 interfaces is eight. Therefore, the TRS licence value is set to 3 ( 2 + 3*2 = 8).

Two E1/T1 interfaces are free of licence control. Licences for additional E1/T1 interfaces can be only bought in blocks of 2. One licence is given as free. The Flexi EDGE addi-tional 2 E1, T1 IF means that one licence will enable two E1 T1 interfaces. Therefore, OMUSIG is allowed to be configured on these free E1 T1 licences.

Note that the Flexi EDGE additional 2 E1, T1 IF SW product is only available in TDM/Packet Abis over TDM mode.

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8.6 BSS30305 Flexi EDGE Abis over IP/EthernetThe purpose of this feature is to start with the traditional Abis over TDM (E1/ T1) inter-faces and move to Abis over IP/Ethernet in Flexi EDGE BTS with a new plug-in card (FIQx, FIYx) without changing the HW. The Abis over IP/Ethernet interface is an appli-cation SW product and under licence control. The Flexi EDGE IP/Ethernet interfaces are controlled by a capacity licence.

PWE overviewA PseudoWire (PW) is a point-to-point connection between a pair of provider edge (PE) devices. PseudoWire Emulation (PWE) provides the transparent transport of a TDM signal (E1 or T1) via a packet-switched network (IP/Ethernet/UDP). PWE according to the Circuit Emulated Services over Packet Switched Network (CESoPSN) standard is supported. Physically, the PE function is realised by a new PWE plug-in type (FIQx or FIYx) inserted into the System Module. The PWE plug-in is controlled by the SW running on the System Module. The PWE system itself consists of the BTS Manager, the BTS SW and the PWE PIU (PWE HW).

Figure 23 PW network topology

In addition to the 3 Ethernet interfaces, the PWE PIUs provide 4 external E1/T1 (FIQx) or 4 external E1 (FIYx) interfaces. During commissioning, the PWE PIU can be config-ured to run either in TDM/Packet Abis over TDM mode or PW/Packet Abis over Ethernet mode. The E1/T1 or E1 interfaces, available in the TDM/Packet Abis over TDM mode, are used for the transport of E1 or T1 signals, whereas the Ethernet interfaces, available in the PW/Packet Abis over Ethernet mode, are used for the transport of PW packets. Up to 8 PWs can be used in the PW/Packet Abis over Ethernet mode. Each PW has the capacity of 31 time slots.

For more information on PW, see Appendix PWE configuration parameters in the Flexi EDGE BTS Commissioning document.

PWE at BTS ManagerThe BTS Manager provides the following support for the PWE:

• Commissioning of the PWE PIU in PWE/TDM/PAoTDM/PAoPSN/PAoPSN relay/PWE relay

• Fetching the PWE status and performance statistics during commissioning • Changing the PWE settings through Q1 commands while commissioning is ongoing • Configuration of the Ethernet port (EIF1, EIF3 for SFP) • Configuration of the PWE tunnel • Synchronization settings • Configuration of the PseudoWires • Fetching performance statistics

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• Fetching ARP table entries • Monitoring the statistics and sending PWE configuration parameters before sending

the SCF during commissioning • Modifying the PWE configuration parameters after sending the SCF during commis-

sioning

EthernetAccess to an Ethernet network is required for the physical transport of PW packets. The PWE PIU has three Ethernet interfaces: 2 Fast Ethernet (EIF1, EIF2) and one Gigabit Ethernet interface (EIF3 for SFP). In the PW/Packet Abis over Ethernet mode, none or one Ethernet interface can be in use. By default, the Fast Ethernet interface EIF1 is in use. Use of Ethernet interface EIF2 is not supported in EP2. 1000 Base-LX and 1000 Base-SX SFP transceiver types are supported for Gigabit Ethernet. The user can hot replace the SFP transceiver. To change from the TDM/Packet Abis over TDM mode to the PW/Packet Abis over Ethernet mode requires un-commissioning with the removal of bypass capacity. A single VLAN is supported. All Ethernet traffic generated uses the specified VLAN; this includes for instance ARP packets. The VLAN priority bits are con-figurable.

PWE configurationA PseudoWire packet is constructed by putting the selected time slots of TDM frame data with a CES header to a UDP packet which is then sent via Ethernet. The PW payload will collect the selected time slots of a configurable number of frames. One time slot occupies exactly one byte. The maximum PW payload size is 512 bytes. With padding in FE and full duplex in Gigabit Ethernet, the minimum restriction on payload is 1 byte, in order to avoid empty PW packets.

Tunnels are used for network layer connectivity over an IP network. Within each PW tunnel, one or up to eight PWs can be transmitted. One local IP address for PW system and one remote IP address per PSN tunnel can be configured. A gateway IP address is only needed in case the PW tunnel destination is at the Ethernet domain different from the connected domain.

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8.7 BSS21454 Packet Abis over EthernetThe feature “BSS21454 Packet Abis over Ethernet” enables the transport of Abis infor-mation using native IP over Ethernet networks. The Packet Abis solution removes the traditional TDM Abis structure, where the static relationship between the Air and the Abis interfaces is eliminated. This allows cellular network operators to migrate from the tradi-tional static TDM to PSN, in a more efficient and cost effective way than with already available solutions adopting PWE3 Circuit Emulation Service over Packet Switched Network (CESoPSN). For implementing this feature, a new functional unit, Exchange Terminal for Packet Abis over Ethernet (ETPE) is introduced. This is a licensed feature.

Figure 24 Packet Abis over Ethernet

This feature provides following benefits:

• The feature provides a better solution than PWE in terms of delay, cost, usability, performance, and operability

• Cost reduction due to simplified operation • Support for the already identified transport enhancements, such as A interface over

IP, and paving the way for the future transport and telecom GSM/EDGE features • Synergy savings by exploiting co-siting with other radio access technologies

(WCDMA, LTE) and sharing the same type of transport network

Requirements

• BSC S15 • Flexi EDGE BTS EX4.0 with FIQx/FIYx transmission sub-module • NetAct OSS 5.2 CD Set 3 • BSC (BSC3i 1000 (one cabinet): 2+2 ETP Modules, BSC3i 2000 (two cabinets): 6+6


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8.8 BSS21440 Packet Abis over TDMThe feature BSS21440 “Packet Abis over TDM” enables the transport of Abis informa-tion using native IP over Time Division Multiplexed (TDM) networks. For implementing this feature, a new functional unit, Exchange Terminal for Packet Abis over TDM (ETPT) is introduced. This feature is controlled by a TRX capacity based license key.

In Packet Abis over TDM, the transport technology solution is still based on the TDM, but Abis is packet based with the adoption of IP layer on top of ML/Multi Class PPP (MCPPP) and HDLC over TDM (E1/T1).

Figure 25 Packet Abis over TDM

The TDM interface is used as a packet transport pipe. There is no longer a static mapping to timeslots but each traffic type can occupy the complete transport pipe. The main advantage of this interface is the simplified configuration and the reduced band-width required compared to legacy Abis. The Packet Abis interface transfers only the packets that contain data, compared to legacy Abis that required empty timeslots to maintain a constant bit rate. Due to this, significant bandwidth savings are achieved with Packet Abis. This is important when upgrading the BTS with a new TRX or new features.

This feature provides following benefits:

• Cost reduction due to simplified operation • Support for already identified transport enhancements, like A interface over IP, and

paving way for the future transport and telecom GSM/EDGE features such as BSS21309 OSC Half Rate with SAIC MS

Requirements



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8.9 BSS21439 Packet Abis Sync. ToP IEEE1588v2The feature “BSS21439 Packet Abis Sync. ToP IEEE1588v2” takes care of synchroni-zation of the traffic in BSS transmission using Packet Abis over Ethernet with the trans-mission sub-modules FIYB and FIQB in the System Module (ESMA). Timing over Packet (IEEE1588v2) is a transparent synchronization solution for packet-switched net-works, where a standardized protocol is employed to transparently synchronize the base stations across Layer 2 or Layer 3 networks. The protocol utilized is IEEE1588v2 (also known as the Precision Timing Protocol (PTP)). The Timing over Packet (ToP) server clock is located at the BSC and provides the synchronization information to the BTSs at the sites. The integrated BTS capability (or ToP Slave Clock) recovers the clock signal from the Timing over Packet data it receives.

Since no external equipment (GPS receiver) or E1 link is necessary for synchronization at the BTS site, capital expenditure savings can be derived. Further, there is also the possibility to employ a single timing server (Master) solution for both WCDMA and GSM/EDGE networks. Operational expenditure savings result from the improved band-width efficiency beyond that which is achievable with CESoPSN Adaptive Timing. Fur-thermore, this solution is more robust to network impairments than Adaptive Timing, thus lower quality packet-switched networks can be employed for the transport backhaul solution.

Requirements

• BSC S15 • Flexi EDGE BTS EX4.0 with FIQB/FIYB transmission sub-module • NetAct OSS 5.2 CD Set 3 • BSC (BSC3i 1000 (one cabinet): 2+2 ETP Modules, BSC3i 2000 (two cabinets): 6+6


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8.10 BSS10045 Dynamic Abis allocationDynamic Abis provides an efficient transport mechanism for GPRS and EGPRS to use more than one 16 kbps subchannel on the Abis interface for each packet data channel (PDCH) on the Air interface. The continuous areas of PCM timeslots on PCM links are configured as Dynamic Abis pools (DAPs) to provide the needed capacity.

The dual TRX modules support two carriers, each of which belongs to one logical TRX. Each logical TRX utilising Dynamic Abis is associated with a DAP in addition to the standard fixed traffic channel (TCH) area. Any packet data channel would be continu-ously using a master PCU channel located on a fixed area. Depending on the traffic load on each Air interface channel, more capacity would be allocated from the DAP. See the table below for the number of 16 kbps DAP subchannels used with each CS and MCS.

The PCU controls the downlink and uplink slave allocation on a radio block basis. Any 20 ms period on Abis is controlled based on real traffic demand. Downlink and uplink allocations are controlled separately. The slave allocation is informed to the BTS by in-band signalling on the corresponding downlink master channel.

Multiple logical TRXs can share a DAP. Multiple DAPs can be configured for each BTS and for each physical Abis link.

O&M signalling, TRX signalling, and circuit-switched channels are used with Dynamic Abis in the same way as they are used with the Nokia conventional Abis solution.

CS/MCS Number of DAP subchannels

CS1 0

CS2 1

CS3 1

CS4 1

MCS-1 0

MCS-2 1

MCS-3 1

MCS-4 1

MCS-5 1

MCS-6 2

MCS-7 3

MCS-8 4

MCS-9 4

Table 4 Number of 16 kbps DAP subchannels used with each CS and MCS

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8.11 BSS21438 Packet Abis over SatelliteThe feature BSS21438 “Packet Abis over Satellite” enables the possibility for Packet Abis to be used across satellite links (either TDM or Ethernet based). Packet Abis over Satellite is robust to the impairments introduced by traditional satellite links. A BCF is interpreted to be Packet Abis over Satellite configured if its OMUSIG Dchannel RTO.init parameter value is 800ms or higher. This feature "BSS21438 Packet Abis over satellite” is controlled by a TRX capacity based license key.

Packet Abis is a fully integrated solution, and provides the Abis optimization function. This reduces the bandwidth requirements, and investment in additional external Abis optimization equipment, resulting in significant capital and operational expenditure savings.

Requirements



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8.12 BSS5850 Satellite AbisSatellite Abis allows the use of satellite connections on the Abis interface between the BSC and the BTS. Satellite Abis enables you to create network coverage in areas where the coverage could not otherwise be implemented because of the limitation of the trans-mission media. Typically, these remote BTSs are used in low-capacity and temporary applications. The BTS software adapts to the satellite delay (max 280 ms in one direc-tion) and the BSC and BTS perform the necessary alignments. Note that satellite Abis restricts the BTS performance in higher capacity activities on CS and PS data. It is rec-ommended to configure the BTS so that a non-combined BCCH configured and a SDCCH/8 to the TCHs only TRX, whenever possible. It is also recommended to config-ure PS data so that high coding schemes are used only in one timeslot or that low coding schemes are used in multiple timeslots.

This feature is activated for each BSS individually. It is activated by an Abis_type param-eter switch in both the BSC and the BTS.

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8.13 BSS21497 Enhanced satellite supportNew IP-based satellite services with dynamic bandwidth allocation have delays up to 400 ms in one direction. BTS SW EP3 MP1.0 supports satellite Abis with delays up to 420 ms.

The extended delay requires also BSC support, which is implemented in BSC SW S14 MP3.0.

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8.14 BSS30450 Packet Abis Synchronous EthernetThe feature “BSS30450 Packet Abis Synchronous Ethernet” provides a further synchro-nization option for Packet Abis over IP/Ethernet networking scenarios.

Synchronous Ethernet is an end-to-end synchronization solution for packet based backhaul networks. It provides a frequency synchronization capability, but without time / phase synchronization. The solution employs the received Ethernet signal edges, com-paring the arrival times, and then adjusts the clock signal accordingly.

Synchronous Ethernet provides a stable synchronization solution for Packet Switched Networks which is not dependent upon the network loading or any other network impair-ments. It provides OPEX savings since the realization is more efficient than any other Timing over Packet (ToP) solution. It is the only possible synchronization solution that does not require an external synchronization source for Packet Radio links. Further-more, SSM (Synchronization Status Message) management is supported by the solu-tion, which enhances the synchronization overview and fault management across the overall network for the operator.

Requirements

• BSC3i 1000/2000 or Flexi BSC with BSC S15 SW • Flexi EDGE BTS EX4.0 with FIYB or FIQB transmission sub-module • NetAct OSS 5.2 CD Set 3

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8.15 BSS21503 FlexiPacket Radio ConnectivityThe feature “BSS21503 FlexiPacket Radio Connectivity” provides transmission support for chain and spur networking applications, enabling a direct interfacing between Flexi-Packet Radio and the Flexi EDGE BTS. FlexiPacket Radio (FPR) is the packet micro-wave radio (MWR) of Nokia Siemens Networks, which provides support without an indoor unit for tail/chain sites in co-sited BTSs.

FPR runs independently and provides Ethernet connectivity towards Flexi EDGE BTS. FPR support with Flexi BTS extends the scope of Nokia Siemens Networks’ unique "Zero Footprint" solution realized with the Flexi BTS platform.

This complete solution is fully outdoor compatible and supports wide range of applica-tions, consequently offering an ideal and optimized integrated site solution.

This feature provides the following benefits to operators:

• It can be applied to tail and chain sites without the need for an indoor unit (Flexi-Packet Hub).

• Reduces the number of modules and interfaces by supporting direct interfacing between the Flexi BTS and FlexiPacket Radio.

• Reduces CAPEX as a result of minimized cabling and reduced hardware. • Enhances MTBF for the complete solution with no interoperability issues. • Simpler and more efficient installation, commissioning, maintenance processes, and

operations. • Local commissioning and troubleshooting for FlexiPacket Radio links is possible

without any changes to cabling from BTS to MWR and without interrupting Abis traffic.

• Reduces OPEX through the extension of the "Zero Footprint" capability to include the transmission solution.

• Reduces total cost of MWR solution due to lesser number of active components used, thus reducing the site power consumption.

Requirements

• BSC S15 • Flexi EDGE BTS EX4.0 with FIQx/FIYx transmission sub-module • NetAct OSS 5.2 CD Set 3

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8.16 BSS30395 Packet Abis Delay MeasurementThe feature “BSS30395 Packet Abis Delay Measurement” introduces a new transmis-sion measurement for measuring the two-way delay of data packets, that is, the bi-direc-tional round trip time (RTT). In addition to RTT values, the variation and sliding averages of RTT are also measured. It provides packet delay performance measurement (PM) for packet transport networks in the Abis interface that employ the features Packet Abis over TDM or Packet Abis over IP/Ethernet. The feature is controlled by an ON/OFF type license key.

Requirements

• BSC3i 1000/2000 or Flexi BSC with BSC S15 SW • Flexi EDGE BTS EX4.0 with FIQA, FIYA, FIQB, and FIYB modules in case of

PAoPSN and FIQA, FIYA, FIQB, FIYB, FIEA, FIPA, and FIFA modules in case of PAoTDM.

• NetAct OSS 5.2 CD Set 3

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Appendix Other features

9 Appendix Other features

9.1 Other featuresFlexi EDGE BTS also supports the following feature enhancements made in UltraSite EDGE BTS:

• Enhanced Automatic Frequency Correction (E-AFC) • BSS10022 Frame Erasure Rate (FER) Measurement • BSS9064 Real Time Update to BTS • BSS7048 CCCH Improvements • BSS6074 Active Channel Interference Estimation • BSS5072 Better Random Access Channel Detection • BTS2041 BTS Local Blocking

Documents

Feature List.pdf