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GSM Radio Acees Network
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Chapter 1 UTRAN Interface Protocols and Functions 1-1.................................
1.1 Overview 1-1................................................................................................1.2 Uu Interface 1-2............................................................................................
1.2.1 Uu Protocol Structure 1-2.....................................................................1.2.2 RRC Functions 1-4...............................................................................1.2.3 L2 Functions 1-5..................................................................................1.2.4 L1 Functions 1-6..................................................................................
1.3 Iub interface 1-6............................................................................................1.3.1 Iub Protocol Structure 1-6....................................................................1.3.2 Functions of NBAP 1-8.........................................................................1.3.3 NBAP Procedures 1-8..........................................................................1.3.4 Iub FP for Common Transport Channel Data Transfer 1-10..................1.3.5 Iub FP for Dedicated Transport Channel Data Transfer 1-14................
1.4 Iur Interface 1-18............................................................................................1.4.1 Iur Protocol Structure 1-18.....................................................................1.4.2 Functions of RNSAP 1-19......................................................................1.4.3 RNSAP Procedures 1-20.......................................................................1.4.4 Iur FP for Transport Channel Data Transfer 1-22..................................
1.5 Iu Interface 1-22.............................................................................................1.5.1 Iu Protocol Architecture 1-22..................................................................1.5.2 Functions of RANAP 1-25......................................................................1.5.3 RANAP Procedures 1-26.......................................................................1.5.4 Functions of Iu UP 1-28.........................................................................1.5.5 GTP-U 1-33............................................................................................1.5.6 Functions of SABP 1-33.........................................................................
Chapter 2 Transport Network Layer Procedure Analysis 2-1............................
2.1 Overview 2-1................................................................................................2.2 SAAL 2-1......................................................................................................
2.2.1 Overview 2-1........................................................................................2.2.2 SSCOP 2-2..........................................................................................2.2.3 SSCF 2-7.............................................................................................2.2.4 CPCS 2-8.............................................................................................2.2.5 SAR 2-8................................................................................................2.2.6 LM 2-9..................................................................................................2.2.7 SSCOP Message 2-10...........................................................................
2.3 MTP3-B 2-11..................................................................................................2.3.1 Overview 2-11........................................................................................2.3.2 Function 2-12.........................................................................................2.3.3 Message Structure 2-14.........................................................................
2.3.4 Changeover/Changeback/ Management prohibit 2-19..........................2.3.5 Signaling Network Management and Status of Signaling Link 2-20......2.3.6 Signaling Network Management and Signaling Route Status 2-22.......2.3.7 MTP3-B Upper User Message 2-23.......................................................2.3.8 MTP3-B Test Message 2-24..................................................................2.3.9 MTP3-B Management Message 2-25....................................................
2.4 ALCAP 2-26....................................................................................................2.4.1 Overview 2-26........................................................................................2.4.2 Function 2-27.........................................................................................2.4.3 Message structure 2-29.........................................................................2.4.4 Establish Request Message 2-30..........................................................
2.5 SCCP 2-31.....................................................................................................2.5.1 Overview 2-31........................................................................................2.5.2 Function 2-32.........................................................................................2.5.3 Message Structure 2-33.........................................................................2.5.4 Connection Request Message 2-34.......................................................
Chapter 3 Cell Related Procedure Analysis 3-1..................................................
3.1 Overview 3-1................................................................................................3.2 Procedures Involved in Cell Setup 3-1.........................................................
3.2.1 Resource Status Indication Procedure 3-1..........................................3.2.2 Resource Audit Procedure 3-2.............................................................3.2.3 Cell Setup Procedure 3-3.....................................................................3.2.4 Common Transport Channel Setup Procedure 3-4..............................3.2.5 Iub Interface User Plane Setup 3-4......................................................3.2.6 System Information Update 3-5...........................................................3.2.7 Common Measurement Initiation Procedure 3-5.................................3.2.8 Cell Reconfiguration Procedure 3-6.....................................................3.2.9 Cell Deletion Procedure 3-7.................................................................3.2.10 Resource Status Indication Message 3-7..........................................3.2.11 Audit Response Message 3-12............................................................3.2.12 Cell Setup Request Message 3-16......................................................3.2.13 Common Transport Channel Setup Request Message 3-20...............3.2.14 System Information Update Request Message 3-25...........................
3.3 Example of Cell Setup Procedures 3-28........................................................
Chapter 4 System Information Procedure Analysis 4-1.....................................
4.1 Overview 4-1................................................................................................4.1.1 System Information Structure 4-1........................................................4.1.2 System Information Monitoring Mechanism 4-2...................................4.1.3 Functions of System Information 4-2...................................................
4.2 System Information Broadcast and Update 4-3............................................4.2.1 System Information Broadcast 4-3.......................................................4.2.2 System Information Update 4-3...........................................................4.2.3 System Information Message 4-4........................................................
4.3 System Information Modification 4-6............................................................4.3.1 Modification by a value tag 4-7............................................................4.3.2 Modification by a timer 4-7...................................................................4.3.3 Paging Type 1 Message 4-7................................................................
Chapter 5 Call Setup and Release Procedure Analysis 5-1...............................
5.1 Overview 5-1................................................................................................5.2 Paging 5-1....................................................................................................
5.2.1 Overview 5-1........................................................................................5.2.2 Paging for UEs in Idle Mode or in PCH State 5-2................................5.2.3 Paging for UEs in CELL_DCH or CELL_FACH State 5-3....................5.2.4 Paging Type 1 Message 5-3................................................................5.2.5 Paging Type 2 Message 5-4................................................................
5.3 RRC Connection Setup 5-5..........................................................................5.3.1 Overview 5-5........................................................................................5.3.2 RRC Connection Setup on Dedicated Channel 5-6.............................5.3.3 RRC Connection Setup on Common Channel 5-7...............................5.3.4 RRC Connection Reject 5-7.................................................................5.3.5 RRC Connection Request Message 5-8..............................................5.3.6 RRC Connection Setup Message 5-10..................................................5.3.7 RRC Connection Reject Message 5-13.................................................5.3.8 Radio Link Setup Request Message 5-14..............................................
5.4 Direct Transfer Messages 5-18......................................................................5.4.1 Overview 5-18........................................................................................5.4.2 Initial Direct Transfer 5-18......................................................................5.4.3 Uplink Direct Transfer 5-19....................................................................5.4.4 Downlink Direct Transfer 5-20................................................................5.4.5 Initial Direct Transfer Message 5-21......................................................5.4.6 Uplink Direct Transfer Message 5-22.....................................................5.4.7 Downlink Direct Transfer Message 5-23................................................
5.5 UE Capability Information 5-24.......................................................................5.5.1 UE Capability Enquiry 5-25....................................................................5.5.2 UE Capability Information Update 5-25..................................................
5.6 RAB Setup 5-26..............................................................................................5.6.1 Overview 5-26........................................................................................5.6.2 DCH-DCH 5-27......................................................................................5.6.3 CCH-DCH 5-30......................................................................................
5.6.4 CCH-CCH 5-32......................................................................................5.6.5 RAB Assignment Request Message 5-33..............................................5.6.6 RAB Assignment Response Message 5-36...........................................5.6.7 Radio Bearer Setup Message 5-38........................................................
5.7 Call Release 5-43...........................................................................................5.7.1 Overview 5-43........................................................................................5.7.2 Iu Signaling Connection Release 5-44...................................................5.7.3 RAB Release 5-45.................................................................................5.7.4 Combined Release of CS Domain Iu Signaling Link and RAB 5-47......5.7.5 RRC Connection Release 5-48..............................................................
Chapter 6 Mobility Management Procedure Analysis 6-1..................................
6.1 Overview 6-1................................................................................................6.2 Forward handover 6-1..................................................................................
6.2.1 Overview 6-1........................................................................................6.2.2 Cell Update 6-1....................................................................................6.2.3 URA Update 6-3...................................................................................6.2.4 Cell Update Message 6-4.....................................................................6.2.5 URA Update Message 6-6...................................................................
6.3 Soft Handover 6-8........................................................................................6.3.1 Overview 6-8........................................................................................6.3.2 Radio Link Addition 6-9........................................................................6.3.3 Radio Link Deletion 6-10........................................................................6.3.4 Radio Link Addition and Deletion 6-12...................................................6.3.5 Radio Link Setup Request Message 6-13..............................................6.3.6 Active Set Update Message 6-13...........................................................
6.4 Hard Handover 6-15.......................................................................................6.4.1 Overview 6-15........................................................................................6.4.2 Compressed Mode 6-16.........................................................................6.4.3 Iur Interface Hard Handover 6-17..........................................................6.4.4 Combined Hard Handover 6-19.............................................................6.4.5 Radio Link Setup Request Message 6-22..............................................6.4.6 Physical Channel Reconfiguration Message 6-22.................................
6.5 Inter-RAT Handover 6-24...............................................................................6.5.1 Overview 6-24........................................................................................6.5.2 WCDMA->GSM Inter-RAT Handover 6-25............................................6.5.3 GSM->WCDMA Inter-RAT Handover 6-27............................................6.5.4 GSM/GPRS->WCDMA Cell Reselection 6-29.......................................6.5.5 WCDMA->GSM/GPRS Cell Reselection 6-29.......................................6.5.6 Handover from UTRAN Command Message 6-32.................................6.5.7 Handover to UTRAN Command Message 6-33.....................................
6.6 Relocation 6-35..............................................................................................6.6.1 Overview 6-35........................................................................................6.6.2 Static Relocation 6-35............................................................................6.6.3 Relocation with Hard Handover 6-39.....................................................6.6.4 Relocation with Forward Handover 6-41................................................6.6.5 Relocation Required Message 6-42.......................................................6.6.6 Relocation Request Message 6-45........................................................6.6.7 Relocation Command Message 6-46.....................................................6.6.8 UTRAN Mobility Information Message 6-49...........................................6.6.9 Uplink Signaling Transfer Indication Message 6-51...............................
Chapter 7 Dynamic Resource Control Procedure Analysis 7-1........................
7.1 Overview 7-1................................................................................................7.2 RAB Modification 7-1....................................................................................
7.2.1 Overview 7-1........................................................................................7.2.2 RAB Modification (DCH-DCH) 7-1.......................................................7.2.3 RAB Assignment Request Message 7-3..............................................7.2.4 Radio Bearer Reconfiguration Message 7-3........................................
7.3 Dynamic Channel Reconfiguration 7-6.........................................................7.3.1 Overview 7-6........................................................................................7.3.2 RB Reconfiguration 7-7........................................................................7.3.3 Radio Bearer Reconfiguration Message 7-8........................................
Appendix A Tracing Tools A-1..............................................................................
A.1 About Tracing Tools A-1...............................................................................A.1.1 RNC Tracing Tool A-1..........................................................................A.1.2 NodeB Tracing Tool A-1.......................................................................
Appendix B Call Example B-1...............................................................................
B.1 Overview B-1................................................................................................B.2 Originating Call Procedure B-1.....................................................................B.3 Terminated Call procedure B-4....................................................................
Appendix C Acronyms and Abbreviations C-1....................................................
Index .................................................................................................................
HUAWEI
HUAWEI UMTS Radio Access Network Protocols and Signalling Analysis
HUAWEI UMTS Radio Access Network
Protocols and Signalling Analysis
Manual Version T2-030223-20041001-C-1.22
Product Version BSC6800V100R002 NodeB V100R003
BOM 31026523
Huawei Technologies Co., Ltd. provides customers with comprehensive technical support and service. Please feel free to contact our local office or company headquarters.
Huawei Technologies Co., Ltd.
Address: Administration Building, Huawei Technologies Co., Ltd.,
Bantian, Longgang District, Shenzhen, P. R. China
Postal Code: 518129
Website: http://www.huawei.com
Email: [email protected]
Copyright © 2004 Huawei Technologies Co., Ltd.
All Rights Reserved
No part of this manual may be reproduced or transmitted in any form or by any means without prior written consent of Huawei Technologies Co., Ltd.
Trademarks
, HUAWEI, C&C08, EAST8000, HONET, , ViewPoint, INtess, ETS, DMC,
TELLIN, InfoLink, Netkey, Quidway, SYNLOCK, Radium, M900/M1800, TELESIGHT, Quidview, Musa, Airbridge, Tellwin, Inmedia, VRP, DOPRA, iTELLIN, HUAWEI OptiX, C&C08 iNET, NETENGINE, OptiX, iSite, U-SYS, iMUSE, OpenEye, Lansway, SmartAX, infoX, TopEng are trademarks of Huawei Technologies Co., Ltd.
All other trademarks mentioned in this manual are the property of their respective holders.
Notice
The information in this manual is subject to change without notice. Every effort has been made in the preparation of this manual to ensure accuracy of the contents, but all statements, information, and recommendations in this manual do not constitute the warranty of any kind, express or implied.
Summary of Updates
This section provides the update history of this manual and introduces the contents of subsequent updates.
Update History
This manual is updated for a major product version to maintain consistency with system hardware or software versions and to incorporate customer suggestions.
Manual Version Notes
T2-030223-20041001-C-1.22 Initial commercial release
Updates of Contents
None
About This Manual
Release Notes
This manual applies to BSC6800 V100R002 and NodeB V100R003.
Organization
The manual analyzes protocols and signaling of radio access network in UMTS.
There are 7 chapters and 3 appendixes in the manual.
Chapter 1 UTRAN Interface Protocols and Functions profiles the interfaces, functions and the corresponding protocols in the radio access network of UMTS. The user planes of Iub/Iur/Iu interfaces are described in this chapter.
Chapter 2 Transport Network Layer Procedure Analysis analyzes the signalling procedures of transport network layer and describes the functions of entities in the transport network signalling layer.
Chapter 3 Cell Related Procedure Analysis analyzes the cell-related procedures, such as cell setup, common channel setup and a whole cell setup procedure example is presented.
Chapter 4 System Information Procedure Analysis analyzes the system information procedures.
Chapter 5 Call Setup and Release Procedure Analysis mainly analyzed the procedures of RRC connection setup and release, of RAB setup and release.
Chapter 6 Mobility Management Procedure Analysis analyzes the procedures of forward handover, soft handover, hard handover, Inter-Rat handover and SRNS relocation.
Chapter 7 Dynamic Resource Control Procedure Analysis analyzes the procedures of RAB modification and dynamic channel reconfiguration.
Appendix A Tracing Tools introduce the message tracing tools.
Appendix B Call Example presents a whole typical call procedure example.
Appendix C Acronyms and Abbreviations
Intended Audience
The manual is intended for the following readers:
Technical marketing specialists Operation and maintenance personnel
Conventions
The manual uses the following conventions:
I. General conventions
Convention Description
Arial Normal paragraphs are in Arial.
Arial Narrow Warnings, Cautions, Notes and Tips are in Arial Narrow.
Boldface Headings are in Boldface.
Courier New Terminal Display is in Courier New.
II. Symbols
Eye-catching symbols are also used in the manual to highlight the points worthy of special attention during the operation. They are defined as follows:
Caution, Warning, Danger: Means reader be extremely careful during the
operation.
Note, Comment, Tip, Knowhow, Thought: Means a complementary description.
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Table of Contents
i
Table of Contents
Chapter 1 UTRAN Interface Protocols and Functions............................................................... 1-1 1.1 Overview............................................................................................................................ 1-1 1.2 Uu Interface ....................................................................................................................... 1-2
1.2.1 Uu Protocol Structure.............................................................................................. 1-2 1.2.2 RRC Functions........................................................................................................ 1-4 1.2.3 L2 Functions............................................................................................................ 1-5 1.2.4 L1 Functions............................................................................................................ 1-6
1.3 Iub interface ....................................................................................................................... 1-6 1.3.1 Iub Protocol Structure ............................................................................................. 1-6 1.3.2 Functions of NBAP.................................................................................................. 1-8 1.3.3 NBAP Procedures ................................................................................................... 1-8 1.3.4 Iub FP for Common Transport Channel Data Transfer......................................... 1-10 1.3.5 Iub FP for Dedicated Transport Channel Data Transfer ....................................... 1-14
1.4 Iur Interface...................................................................................................................... 1-18 1.4.1 Iur Protocol Structure ............................................................................................ 1-18 1.4.2 Functions of RNSAP ............................................................................................. 1-19 1.4.3 RNSAP Procedures .............................................................................................. 1-20 1.4.4 Iur FP for Transport Channel Data Transfer ......................................................... 1-22
1.5 Iu Interface ....................................................................................................................... 1-22 1.5.1 Iu Protocol Architecture......................................................................................... 1-22 1.5.2 Functions of RANAP ............................................................................................. 1-25 1.5.3 RANAP Procedures .............................................................................................. 1-26 1.5.4 Functions of Iu UP................................................................................................. 1-28 1.5.5 GTP-U ................................................................................................................... 1-33 1.5.6 Functions of SABP ................................................................................................ 1-33
Chapter 2 Transport Network Layer Procedure Analysis ......................................................... 2-1 2.1 Overview............................................................................................................................ 2-1 2.2 SAAL.................................................................................................................................. 2-1
2.2.1 Overview ................................................................................................................. 2-1 2.2.2 SSCOP.................................................................................................................... 2-2 2.2.3 SSCF....................................................................................................................... 2-7 2.2.4 CPCS ...................................................................................................................... 2-8 2.2.5 SAR ......................................................................................................................... 2-8 2.2.6 LM ........................................................................................................................... 2-9 2.2.7 SSCOP Message .................................................................................................. 2-10
2.3 MTP3-B............................................................................................................................ 2-11 2.3.1 Overview ............................................................................................................... 2-11
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Table of Contents
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2.3.2 Function................................................................................................................. 2-12 2.3.3 Message Structure ................................................................................................ 2-14 2.3.4 Changeover/Changeback/ Management prohibit ................................................. 2-19 2.3.5 Signaling Network Management and Status of Signaling Link ............................. 2-20 2.3.6 Signaling Network Management and Signaling Route Status .............................. 2-22 2.3.7 MTP3-B Upper User Message.............................................................................. 2-23 2.3.8 MTP3-B Test Message ......................................................................................... 2-24 2.3.9 MTP3-B Management Message ........................................................................... 2-25
2.4 ALCAP ............................................................................................................................. 2-26 2.4.1 Overview ............................................................................................................... 2-26 2.4.2 Function................................................................................................................. 2-27 2.4.3 Message structure................................................................................................. 2-29 2.4.4 Establish Request Message.................................................................................. 2-30
2.5 SCCP............................................................................................................................... 2-31 2.5.1 Overview ............................................................................................................... 2-31 2.5.2 Function................................................................................................................. 2-32 2.5.3 Message Structure ................................................................................................ 2-33 2.5.4 Connection Request Message.............................................................................. 2-34
Chapter 3 Cell Related Procedure Analysis ............................................................................... 3-1 3.1 Overview............................................................................................................................ 3-1 3.2 Procedures Involved in Cell Setup..................................................................................... 3-1
3.2.1 Resource Status Indication Procedure ................................................................... 3-1 3.2.2 Resource Audit Procedure ...................................................................................... 3-2 3.2.3 Cell Setup Procedure .............................................................................................. 3-3 3.2.4 Common Transport Channel Setup Procedure....................................................... 3-4 3.2.5 Iub Interface User Plane Setup............................................................................... 3-4 3.2.6 System Information Update..................................................................................... 3-5 3.2.7 Common Measurement Initiation Procedure .......................................................... 3-5 3.2.8 Cell Reconfiguration Procedure .............................................................................. 3-6 3.2.9 Cell Deletion Procedure .......................................................................................... 3-7 3.2.10 Resource Status Indication Message ................................................................... 3-7 3.2.11 Audit Response Message ................................................................................... 3-12 3.2.12 Cell Setup Request Message.............................................................................. 3-16 3.2.13 Common Transport Channel Setup Request Message ...................................... 3-20 3.2.14 System Information Update Request Message .................................................. 3-25
3.3 Example of Cell Setup Procedures.................................................................................. 3-28
Chapter 4 System Information Procedure Analysis .................................................................. 4-1 4.1 Overview............................................................................................................................ 4-1
4.1.1 System Information Structure.................................................................................. 4-1 4.1.2 System Information Monitoring Mechanism............................................................ 4-2 4.1.3 Functions of System Information............................................................................. 4-2
4.2 System Information Broadcast and Update....................................................................... 4-3
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Table of Contents
iii
4.2.1 System Information Broadcast ................................................................................ 4-3 4.2.2 System Information Update..................................................................................... 4-3 4.2.3 System Information Message.................................................................................. 4-4
4.3 System Information Modification........................................................................................ 4-6 4.3.1 Modification by a value tag...................................................................................... 4-7 4.3.2 Modification by a timer ............................................................................................ 4-7 4.3.3 Paging Type 1 Message ......................................................................................... 4-7
Chapter 5 Call Setup and Release Procedure Analysis ............................................................ 5-1 5.1 Overview............................................................................................................................ 5-1 5.2 Paging................................................................................................................................ 5-1
5.2.1 Overview ................................................................................................................. 5-1 5.2.2 Paging for UEs in Idle Mode or in PCH State ......................................................... 5-2 5.2.3 Paging for UEs in CELL_DCH or CELL_FACH State............................................. 5-3 5.2.4 Paging Type 1 Message ......................................................................................... 5-3 5.2.5 Paging Type 2 Message ......................................................................................... 5-4
5.3 RRC Connection Setup ..................................................................................................... 5-5 5.3.1 Overview ................................................................................................................. 5-5 5.3.2 RRC Connection Setup on Dedicated Channel ...................................................... 5-6 5.3.3 RRC Connection Setup on Common Channel........................................................ 5-7 5.3.4 RRC Connection Reject .......................................................................................... 5-7 5.3.5 RRC Connection Request Message ....................................................................... 5-8 5.3.6 RRC Connection Setup Message ......................................................................... 5-10 5.3.7 RRC Connection Reject Message ........................................................................ 5-13 5.3.8 Radio Link Setup Request Message..................................................................... 5-14
5.4 Direct Transfer Messages................................................................................................ 5-18 5.4.1 Overview ............................................................................................................... 5-18 5.4.2 Initial Direct Transfer ............................................................................................. 5-18 5.4.3 Uplink Direct Transfer ........................................................................................... 5-19 5.4.4 Downlink Direct Transfer....................................................................................... 5-20 5.4.5 Initial Direct Transfer Message ............................................................................. 5-21 5.4.6 Uplink Direct Transfer Message............................................................................ 5-22 5.4.7 Downlink Direct Transfer Message ....................................................................... 5-23
5.5 UE Capability Information ................................................................................................ 5-24 5.5.1 UE Capability Enquiry ........................................................................................... 5-25 5.5.2 UE Capability Information Update......................................................................... 5-25
5.6 RAB Setup ....................................................................................................................... 5-26 5.6.1 Overview ............................................................................................................... 5-26 5.6.2 DCH-DCH.............................................................................................................. 5-27 5.6.3 CCH-DCH.............................................................................................................. 5-30 5.6.4 CCH-CCH.............................................................................................................. 5-32 5.6.5 RAB Assignment Request Message..................................................................... 5-33 5.6.6 RAB Assignment Response Message .................................................................. 5-36
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Table of Contents
iv
5.6.7 Radio Bearer Setup Message............................................................................... 5-38 5.7 Call Release..................................................................................................................... 5-43
5.7.1 Overview ............................................................................................................... 5-43 5.7.2 Iu Signaling Connection Release.......................................................................... 5-44 5.7.3 RAB Release......................................................................................................... 5-45 5.7.4 Combined Release of CS Domain Iu Signaling Link and RAB............................. 5-47 5.7.5 RRC Connection Release ..................................................................................... 5-48
Chapter 6 Mobility Management Procedure Analysis ............................................................... 6-1 6.1 Overview............................................................................................................................ 6-1 6.2 Forward handover.............................................................................................................. 6-1
6.2.1 Overview ................................................................................................................. 6-1 6.2.2 Cell Update.............................................................................................................. 6-1 6.2.3 URA Update ............................................................................................................ 6-3 6.2.4 Cell Update Message.............................................................................................. 6-4 6.2.5 URA Update Message ............................................................................................ 6-6
6.3 Soft Handover .................................................................................................................... 6-8 6.3.1 Overview ................................................................................................................. 6-8 6.3.2 Radio Link Addition ................................................................................................. 6-9 6.3.3 Radio Link Deletion ............................................................................................... 6-10 6.3.4 Radio Link Addition and Deletion.......................................................................... 6-12 6.3.5 Radio Link Setup Request Message..................................................................... 6-13 6.3.6 Active Set Update Message.................................................................................. 6-13
6.4 Hard Handover................................................................................................................. 6-15 6.4.1 Overview ............................................................................................................... 6-15 6.4.2 Compressed Mode................................................................................................ 6-16 6.4.3 Iur Interface Hard Handover.................................................................................. 6-17 6.4.4 Combined Hard Handover .................................................................................... 6-19 6.4.5 Radio Link Setup Request Message..................................................................... 6-22 6.4.6 Physical Channel Reconfiguration Message ........................................................ 6-22
6.5 Inter-RAT Handover......................................................................................................... 6-24 6.5.1 Overview ............................................................................................................... 6-24 6.5.2 WCDMA->GSM Inter-RAT Handover ................................................................... 6-25 6.5.3 GSM->WCDMA Inter-RAT Handover ................................................................... 6-27 6.5.4 GSM/GPRS->WCDMA Cell Reselection .............................................................. 6-29 6.5.5 WCDMA->GSM/GPRS Cell Reselection .............................................................. 6-29 6.5.6 Handover from UTRAN Command Message........................................................ 6-32 6.5.7 Handover to UTRAN Command Message............................................................ 6-33
6.6 Relocation ........................................................................................................................ 6-35 6.6.1 Overview ............................................................................................................... 6-35 6.6.2 Static Relocation ................................................................................................... 6-35 6.6.3 Relocation with Hard Handover ............................................................................ 6-39 6.6.4 Relocation with Forward Handover....................................................................... 6-41
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Table of Contents
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6.6.5 Relocation Required Message.............................................................................. 6-42 6.6.6 Relocation Request Message ............................................................................... 6-45 6.6.7 Relocation Command Message............................................................................ 6-46 6.6.8 UTRAN Mobility Information Message.................................................................. 6-49 6.6.9 Uplink Signaling Transfer Indication Message...................................................... 6-51
Chapter 7 Dynamic Resource Control Procedure Analysis...................................................... 7-1 7.1 Overview............................................................................................................................ 7-1 7.2 RAB Modification ............................................................................................................... 7-1
7.2.1 Overview ................................................................................................................. 7-1 7.2.2 RAB Modification (DCH-DCH) ................................................................................ 7-1 7.2.3 RAB Assignment Request Message....................................................................... 7-3 7.2.4 Radio Bearer Reconfiguration Message ................................................................. 7-3
7.3 Dynamic Channel Reconfiguration .................................................................................... 7-6 7.3.1 Overview ................................................................................................................. 7-6 7.3.2 RB Reconfiguration ................................................................................................. 7-7 7.3.3 Radio Bearer Reconfiguration Message ................................................................. 7-8
Appendix A Tracing Tools............................................................................................................A-1 A.1 About Tracing Tools ..........................................................................................................A-1
A.1.1 RNC Tracing Tool ...................................................................................................A-1 A.1.2 NodeB Tracing Tool................................................................................................A-1
Appendix B Call Example .............................................................................................................B-1 B.1 Overview............................................................................................................................B-1 B.2 Originating Call Procedure ................................................................................................B-1 B.3 Terminated Call procedure................................................................................................B-4
Appendix C Acronyms and Abbreviations .................................................................................C-1
Index ................................................................................................................................................ i-1
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network
Chapter 1 UTRAN Interface Protocols and Functions
1-1
Chapter 1 UTRAN Interface Protocols and Functions
1.1 Overview
Figure 1-1 UTRAN interfaces
As shown in Figure 1-1, UTRAN interfaces in the UMTS system include Iub, Iur, Iu and Uu interfaces. See Table 1-1 for the description of the interfaces.
Table 1-1 UTRAN interfaces
Interface Description
Uu Logical interface between UTRAN and UE
Iub Logical interface between RNC and NodeB
Iur Logical interface between RNCs
Iu Logical interface between RNC and CN
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network
Chapter 1 UTRAN Interface Protocols and Functions
1-2
Iub, Iur, Iu and Uu interfaces are standard interfaces and can be used to connect different network elements (NEs) from different vendors. Iub, Iur and Iu interfaces are also called as UTRAN terrestrial interfaces.
According to the type of CN entity connected to RNC, the Iu interface can be classified into Iu-CS interface, Iu-PS interface and Iu-BC interface. Iu-CS interface is used to connect RNC and MSC. Iu-PS interface is used to connect RNC and SGSN. The Iu-BC interface is used to connect RNC and CBC.
1.2 Uu Interface
1.2.1 Uu Protocol Structure
Uu interface is the interface between User Equipment (UE) and UMTS Terrestrial Radio Access Network (UTRAN) and it is the most important interface in the UMTS system.
As shown in Figure 1-2, Uu interface includes three protocol layers, physical layer (L1), data link layer (L2) and network layer (L3).
L1 provides the radio physical channels for the transmission of the traffic from upper layers. The functions of L1 are implemented by NodeB.
L2 includes four sublayers, Medium Access Control (MAC), Radio Link Control (RLC), Broadcast/Multicast Control (BMC) and Packet Data Convergence Protocol (PDCP). The functions of L2 are implemented by RNC.
L3 includes the RRC sublayer in the access stratum, the Mobility Management (MM) and Call Control (CC) in the non-access stratum. The RRC functions of L3 are implemented by RNC, and the MM and CC functions of L3 are implemented by CN.
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network
Chapter 1 UTRAN Interface Protocols and Functions
1-3
L3
co
ntr
co
ntr
co
ntr
co
ntr
LogicalChannels
TransportChannels
C-plane signalling U-plane information
PHY
L2/MAC
L1
RLC
DCNtGC
L2/RLC
MAC
RLCRLC
RLCRLC
RLCRLC
RLC
Duplication avoidance
UuS boundary
BMC L2/BMC
control
PDCPPDCP L2/PDCP
DCNtGC
RadioBearers
RRC
Figure 1-2 Uu interface protocol stack
Uu interface specifications are shown in Figure 1-3.
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L3
cont
rol
cont
rol
cont
rol
cont
rol
LogicalChannels
TransportChannels
C-plane signalling U-plane information
TS25.211~TS25.215
L2/MAC
L1
RLC
DCNtGC
L2/RLC
TS25.321
RLCRLC
RLCRLC
RLCRLCTS25.322
Duplication avoidance
UuS boundary
TS25.324 L2/BMC
TS25.331
control
TS25.323 L2/PDCP
DCNtGC
Figure 1-3 Uu interface specifications
1.2.2 RRC Functions
The RRC performs the functions listed below :
Broadcast of information related to the non-access stratum (Core Network); Broadcast of information related to the access stratum; Establishment, maintenance and release of an RRC connection between the UE
and UTRAN; Establishment, reconfiguration and release of Radio Bearers; Assignment, reconfiguration and release of radio resources for the RRC
connection; RRC connection mobility functions; Route selection for the Protocol Data Unit (PDU) of upper layers; Control of requested QoS; UE measurement reporting and control of the reporting; Outer loop power control; Control of ciphering; Paging; Initial cell selection and cell re-selection;
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Arbitration of radio resources on uplink DCH; RRC message integrity protection; CBS control.
1.2.3 L2 Functions
L2 includes four sublayers, Medium Access Control (MAC), Radio Link Control (RLC), Broadcast/Multicast Control (BMC) and Packet Data Convergence Protocol (PDCP).
I. MAC
The functions of MAC include:
Mapping between logical channels and transport channels Selection of appropriate Transport Format for each Transport Channel Priority handling between data flows of one UE Priority handling between UEs by means of dynamic scheduling Priority handling between data flows of several users on FACH Identification of UEs on common transport channels Multiplexing/demultiplexing of upper layer PDUs into/from transport blocks
delivered to/from the physical layer on common transport channels Traffic volume measurement Transport Channel type switching Ciphering for transparent mode RLC Access Service Class selection
II. RLC
The functions of RLC include:
Segmentation and reassembly, concatenation, padding and transfer of user data. Flow control Error correction, in-sequence delivery of upper layer PDUs and duplicate
detection Sequence numbers check Protocol error detection and recovery Ciphering Suspend/resume function
III. PDCP
The functions of PDCP include:
Header compression and decompression of IP data streams at the transmitting and receiving entity respectively.
Transfer of user data
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Forward the PDCP-SDU from non-access stratum to RLC, and multiplex different RBs to the same RLC entity.
IV. BMC
The functions of BMC include:
Storage of Cell Broadcast Messages Traffic volume monitoring and radio resource request for CBS Scheduling of BMC messages Transmission of BMC messages to UE Delivery of Cell Broadcast messages to upper layer (NAS)
1.2.4 L1 Functions
The functions of L1 (physical layer) mainly includes:
Measurements and indication to higher layers (e.g. FER, SIR, interference power, transmission power, etc)
Macro-diversity distribution/combining and soft handover execution; Frequency and time (chip, bit, slot, frame) synchronization; Closed-loop power control; RF processing; Multiplexing of transport channels and demultiplexing of coded composite
transport channels; Mapping of coded composite transport channels on physical channels; Modulation and spreading/demodulation and despreading of physical channels;
The detailed functions and relevant specifications of L1 are involved with the basic principles of W-CMDA which is out of the range of this manual. Refer to relevant protocols for the details.
1.3 Iub interface
1.3.1 Iub Protocol Structure
Iub interface is the logical interface between RNC and NodeB. The protocol stack of Iub interface is illustrated in Figure 1-4.
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Node BApplication Part (NBAP)
TransportLayer
ATM
Physical Layer
Radio NetworkControl Plane
User Plane
Transport Network Control Plane
RadioNetwork
Layer
Q.2630.1
Q.2150.2
ALCAP
SSCF-UNI
SSCOP
AAL Type 5
SSCF-UNI
SSCOP
AAL Type 5 AAL Type 2
PCH
FP
FACH
FPR
ACH
FPD
CH
FP
Figure 1-4 Protocol Stack of Iub interface
Iub interface specifications are shown in Figure 1-5.
NBAPTS 25.433
Transport Layer
Physical Layer TS 25.431
Radio Network Layer
Radio NetworkControl Plane
TransportNetwork
Control Plane
NBAP Transport
TS 25.432
User PlaneDedicatedChannels
TS 25.427
CommonChannels
TS 25.435
DedicatedChannel
Transport
TS 25.426
CommonChannel
Transport
TS 25.434
Transport Signaling
TS 25.426(Dedicated ChannelTransport)
TS 25.434(Common ChannelTransport)
Figure 1-5 Iub interface specifications
In this section, only the functions and procedures of radio network layer are given. For the transport layer, refer to “Chapter 2 Transfer Network Layer Procedure Analysis”.
The radio network user plane of Iub interface is to transfer the data between RNC and NodeB. The plane is implemented by means of Frame Protocol (FP) of transport
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channels. According to the type of transported data, the FP can be classified as FP for common transport channel and FP for Dedicated transport channel.
1.3.2 Functions of NBAP
NBAP is the Radio network control plane of Iub interface, which provides the following functions:
Cell Configuration Management. This function gives the CRNC the possibility to manage the cell configuration information in a NodeB.
Common Transport Channel Management. This function gives the CRNC the possibility to manage the configuration of Common Transport Channels in a NodeB.
System Information Management. This function gives the CRNC the ability to manage the scheduling of System Information to be broadcast in a cell.
Resource Event Management. This function gives the NodeB the ability to inform the CRNC about the status of NodeB resources.
Configuration Alignment. This function gives the CRNC and the NodeB the possibility to verify and enforce that both nodes have the same information on the configuration of the radio resources.
Measurements on Common Resources. This function allows the NodeB to initiate measurements in the NodeB. The function also allows the NodeB to report the result of the measurements.
Radio Link Management. This function allows the CRNC to manage radio links using dedicated resources in a NodeB.
Radio Link Supervision. This function allows the CRNC to report failures and restorations of a Radio Link.
Compressed Mode Control. This function allows the CRNC to control the usage of compressed mode in a NodeB.
Measurements on Dedicated Resources. This function allows the CRNC to initiate measurements in the NodeB. The function also allows the NodeB to report the result of the measurements.
DL Power Drifting Correction. This function allows the CRNC to adjust the DL power level of one or more Radio Links in order to avoid DL power drifting between the Radio Links.
Reporting of General Error Situations. This function allows reporting of general error situations, for which function specific error messages have not been defined.
1.3.3 NBAP Procedures
NBAP procedures are divided into common procedures and dedicated procedures.
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NBAP common procedures are procedures that request initiation of a UE context for a specific UE in NodeB or are not related to a specific UE. NBAP common procedures also incorporate logical O&M procedures.
NBAP dedicated procedures are procedures that are related to a specific UE context in NodeB. This UE context is identified by a UE context identity.
The two types of procedures may be carried on separate signaling links.
I. NBAP Common Procedures
The mapping between the NBAP functions and NBAP elementary procedures is shown in the Table 1-2.
Table 1-2 Mapping between functions and NBAP elementary procedures
Function Elementary Procedure(s)
Cell Configuration Management a) Cell Setup b) Cell Reconfiguration c) Cell Deletion
Common Transport Channel Management a) Common Transport Channel Setup b) Common Transport Channel Reconfiguration c) Common Transport Channel Deletion
System Information Management System Information Update
Resource Event Management a) Block Resource b) Unblock Resource c) Resource Status Indication
Configuration Alignment a) Audit Required b) Audit
c) Reset
Measurements on Common Resources a) Common Measurement Initiation b) Common Measurement Reporting c) Common Measurement Termination d) Common Measurement Failure
Radio Link Management. Radio Link Setup
II. NBAP Dedicated Procedures
The mapping between the NBAP functions and NBAP dedicated procedures is shown in Table 1-3.
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Table 1-3 Mapping between functions and NBAP dedicated procedures
Function Dedicated Procedure(s)
Radio Link Management. a) Radio Link Addition b) Radio Link Deletion c) Unsynchronized Radio Link Reconfiguration d) Synchronized Radio Link Reconfiguration Preparation e) Synchronized Radio Link Reconfiguration Commit f) Synchronized Radio Link Reconfiguration Cancellation
g) Radio Link Pre-emption
Radio Link Supervision. a) Radio Link Failure b) Radio Link Restoration
Compressed Mode Control a) Radio Link Setup b) Radio Link Addition c) Compressed Mode Command d) Unsynchronized Radio Link Reconfiguration e) Synchronized Radio Link Reconfiguration Preparation f) Synchronized Radio Link Reconfiguration Commitg) Synchronized Radio Link Reconfiguration Cancellation
Measurements on Dedicated Resources a) Dedicated Measurement Initiation b) Dedicated Measurement Reporting c) Dedicated Measurement Termination d) Dedicated Measurement Failure
DL Power Drifting Correction Downlink Power Control
Reporting of General Error Situations Error Indication
1.3.4 Iub FP for Common Transport Channel Data Transfer
Iub FP for common transport channel data transfer is the radio network user plane of Iub interface which provides the following services:
Transport of Transport Block Set (TBS) between the NodeB and the CRNC for common transport channels (including RACH, FACH PCH)
Support of transport channel synchronization mechanism Support of Node Synchronization mechanism
I. RACH Data Transfer
RACH Data Transfer procedure is used to transfer data received from Uu interface from NodeB to CRNC.
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The procedure is realized by a transmission of Data Frame from NodeB to CRNC, as shown in Figure 1-6.
RACH Data Frame
NodeB CRNC
Figure 1-6 RACH data transfer procedure
II. FACH Data Transfer
FACH Data Transfer procedure is used to transfer data from CRNC to NodeB.
The procedure is realized by a transmission of Data Frame from CRNC to NodeB, as shown in Figure 1-7.
FACH Data Frame
NodeB CRNC
Figure 1-7 FACH data transfer procedure
III. PCH Data Transfer
PCH Data Transfer procedure is used to transfer data from CRNC to NodeB.
The procedure is realized by a transmission of Data Frame from CRNC to NodeB, as shown in Figure 1-8.
PCH Data Frame
NodeB CRNC
Figure 1-8 PCH data transfer procedure
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IV. Node Synchronization
Node synchronization is to obtain the round trip delay (RTD) of the transmission between information entities over the Iub interface.
In the Node Synchronization procedure, the RNC sends a DL Node Synchronization control frame to NodeB containing the parameter T1. Upon reception of a DL Node Synchronization control frame, the NodeB shall respond with UL Node Synchronization Control Frame, indicating t2 and t3, as well as t1 which was indicated in the initiating DL Node Synchronization control frame, as shown in Figure 1-9.
DL Node Synchronization
NodeB CRNC
UL Node Synchronization
Figure 1-9 Node synchronisation procedure
TheT1, T2, T3 parameters are defined as:
T1: RNC specific frame number (RFN) that indicates the time when RNC sends the frame through the SAP to the transport layer.
T2: NodeB specific frame number (BFN) that indicates the time when NodeB receives the correspondent DL Node synchronization frame through the SAP from the transport layer.
T3: NodeB specific frame number (BFN) that indicates the time when NodeB sends the frame through the SAP to the transport layer.
V. DL Transport Channels Synchronization
DL transport channel synchronization procedure is used to synchronize the transport channel after the transport channel has been set up or used to maintain the synchronization of the transport channel when there is no DL data frame.
In the DL transport channel synchronization procedure, CRNC sends a DL Synchronization control Frame to NodeB. This message indicates the target CFN. Upon reception of control message, NodeB shall immediately respond with UL Synchronization Control Frame indicating the Time of Arrival (ToA) for the DL Synchronization frame and the CFN indicated in the received message, as shown in Figure 1-10.
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DL Synchronization
NodeB CRNC
UL Synchronization
Figure 1-10 FACH and PCH transport channels synchronization procedure
VI. DL Timing Adjustment
Timing Adjustment procedure is used for NodeB to indicate the CRNC the incorrect arrival time of downlink data to the NodeB.
Timing adjustment procedure is initiated by the NodeB if a DL frame arrives outside of the defined arrival window. If the DL frame has arrived before the ToAWS or after the ToAWE, NodeB will include the ToA and the target CFN in the Timing Adjustment Control Frame, as shown in Figure 1-11.
Timing Adjustment
NodeB CRNC
.
Figure 1-11 FACH and PCH Timing Adjustment procedure
The arrival window and the time of arrival are defined as follows:
Time of Arrival Window Endpoint (ToAWE): ToAWE represents the time point by which the DL data shall arrive to the NodeB from Iub. The ToAWE is defined as the amount of milliseconds before the last time point from which a timely DL transmission for the identified CFN would still be possible taking into account the NodeB internal delays. ToAWE is set via control plane. If data does not arrive before ToAWE a Timing Adjustment Control Frame shall be sent by NodeB.
Time of Arrival Window Startpoint (ToAWS): ToAWS represents the time after which the DL data shall arrive to the NodeB from Iub. The ToAWS is defined as the amount of milliseconds from the ToAWE. ToAWS is set via control plane. If data arrives before ToAWS a Timing Adjustment Control Frame shall be sent by NodeB.
Time of Arrival (ToA): ToA is the time difference between the end point of the DL arrival window (ToAWE) and the actual arrival time of DL frame for a specific CFN. A positive ToA means that the frame is received before the ToAWE, a negative ToA means that the frame is received after the ToAWE.
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1.3.5 Iub FP for Dedicated Transport Channel Data Transfer
Iub FP for dedicated transport channel data transfer is the radio network user plane of Iub interface which provides the following services:
Transport of TBS between SRNC and NodeB Transport of outer loop power control information between the SRNC and the
NodeB Support of transport channel synchronization mechanism Support of Node Synchronization mechanism Transfer of radio interface parameters from the SRNC to the NodeB
I. Uplink Data Transfer
UL Data Frame
NodeB SRNC
Figure 1-12 Uplink data transfer procedure
Uplink Data Transfer procedure is used to transfer data from NodeB to SRNC.
The procedure is realized by a transmission of UL Data Frame from NodeB to SRNC, as shown in Figure 1-12.
Two modes can be used for the UL transmission: normal mode and silent mode. The mode is selected by the SRNC when the transport bearer is set up and signalled to the NodeB with the relevant control plane procedure.
In normal mode, the NodeB shall always send an UL Data Frame to the RNC for all the DCHs in a set of coordinated DCHs regardless of the number of Transport Blocks of the DCHs.
In silent mode and in case only one transport channel is transported on a transport bearer, the NodeB shall not send an UL Data Frame to the RNC when it has received a TFI indicating “number of TB equal to 0” for the transport channel during a TTI.
In silent mode and in case of coordinated DCHs, when the NodeB receives a TFI indicating “number of TB equal to 0” for all the DCHs in a set of coordinated DCHs, the NodeB shall not send an UL data frame to the RNC for this set of coordinated DCHs.
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II. Downlink Data Transfer
DL Data Frame
NodeB SRNC
Figure 1-13 Downlink data transfer procedure
Downlink Data Transfer procedure is used to transfer data from SRNC to NodeB.
The procedure is realized by a transmission of DL Data Frame from SRNC to NodeB, as shown in Figure 1-13.
The NodeB shall consider a transport bearer synchronized only after it has received at least one data frame on this transport bearer before the latest time of arrival (LTOA).
The NodeB shall consider the DL user plane for a certain RL synchronized if all transport bearers established for carrying DL DCH data frames for this RL are synchronized.
Only when the DL user plane is considered synchronized, the NodeB shall transmit the data on the DL DPDCH.
When the DL user plane is considered synchronized and the NodeB does not receive a valid DL Data Frame in a TTI, it assumes that there is no data to be transmitted in that TTI for this transport channel, and shall act as one of the following cases:
If the NodeB is aware of a TFI value corresponding to zero bits for this transport channel, this TFI is assumed. When combining the TFI’s of the different transport channels, a valid TFCI might result and in this case data shall be transmitted on Uu.
If the NodeB is not aware of a TFI value corresponding to zero bits for this transport channel or if combining the TFI corresponding to zero bits with other TFI’s, results in an unknown TFI combination, the handling will be different. In the former case, at each radio frame, the NodeB shall build the TFCI value of each CCTrCH, according to the TFI of the DCH data frames multiplexed on this CCTrCH. In the latter case, NodeB shall transmit only the DPCCH without TFCI bits.
III. Outer Loop Power Control Information Transfer
Outer loop power control information transfer procedure is used to transfer power control information from SRNC to NodeB.
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The procedure is realized by a transmission of Outer Loop PC control frame from SRNC to NodeB, as shown in Figure 1-14. The Outer Loop PC control frame can be sent via any of the transport bearers dedicated to one UE.
Based, for example, on the CRC Indicator (CRCI) values and on the quality estimate in the UL frames, SRNC modifies the SIR target used by the UL Inner Loop Power Control by including the absolute value of the new SIR target in the Outer Loop PC control frame sent to the NodeB's. At the reception of the Outer Loop PC control frame, the NodeB shall immediately update the SIR target used for the inner loop power control with the specified value.
Outer Loop PC
NodeB SRNC
Figure 1-14 Outer loop power control information transfer procedure
IV. Radio Interface Parameter Update
Radio interface parameter update procedure is used to update radio interface parameters which are applicable to all RL’s for the concerning UE. Both synchronized and unsynchronized parameter updates are supported.
The procedure is realized by a transmission of Radio Interface Parameter Update control frame SRNC to the NodeB, as shown in Figure 1-15
Radio Interface Parameter Update
NodeB SRNC
Figure 1-15 Radio interface parameter update procedure
V. Node Synchronization
Node synchronization procedure is to obtain the round trip delay (RTD) of the transmission between information entities over the Iub interface.
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In the Node Synchronization procedure, the SRNC sends a DL Node Synchronization control frame to NodeB containing the parameter T1. Upon reception of a DL Node Synchronization control frame, the NodeB shall respond with UL Node Synchronization control frame, indicating t2 and t3, as well as t1 which was indicated in the initiating DL Node Synchronization control frame, as shown in Figure 1-16.
DL Node Synchronization
NodeB SRNC
UL Node Synchronization
Figure 1-16 Node synchronization procedure
The T1, T2, T3 parameters are defined as:
T1: RNC specific frame number (RFN) that indicates the time when RNC sends the frame through the SAP to the transport layer.
T2: NodeB specific frame number (BFN) that indicates the time when NodeB receives the correspondent DL synchronization frame through the SAP from the transport layer.
T3: NodeB specific frame number (BFN) that indicates the time when NodeB sends the frame through the SAP to the transport layer.
VI. Downlink Transport Channel Sychronization
Downlink transport channel synchronization procedure is used to achieve or restore the synchronization of the DCH data stream in DL direction, and as a keep-alive procedure in order to maintain activity on the Iur/Iub transport bearer.
In the downlink transport channel synchronization procedure, CRNC sends a DL Synchronization control frame to NodeB. This message indicates the target CFN. Upon reception of control message, NodeB shall immediately respond with UL Synchronization control frame indicating the Time of Arrival (ToA) for the DL Synchronization frame and the CFN indicated in the received message, as shown in Figure 1-17.
UL Synchronization control frame shall always be sent, even if the DL Synchronization control frame is received by the NodeB within the arrival window.
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DL Synchronization
NodeB SRNC
UL Synchronization
Figure 1-17 DCH synchronization procedure
VII. Downlink Timing Adjustment
The timing adjustment procedure is used to keep the synchronization of the DCH data stream in DL direction.
Timing adjustment procedure is initiated by the NodeB if a DL frame arrives outside of the defined arrival window. If the DL frame has arrived before the ToAWS or after the ToAWE, NodeB will include the ToA and the target CFN in the Timing Adjustment control frame, as shown in Figure 1-18.
Timing Adjustment
NodeB SRNC
Figure 1-18 Timing adjustment procedure
1.4 Iur Interface
1.4.1 Iur Protocol Structure
Iur interface is the interface between RNCs, The protocol stack of Iur interface is illustrated in Figure 1-19.
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Iur DataStream(s)
ALCAP(Q.2630.1)TransportNetwork
Layer
ATM
SSCOP
Physical Layer
SCCP
TransportUser
NetworkPlane
Control Plane User Plane
TransportUser
NetworkPlane
STC (Q.2150.1)
Transport NetworkControl Plane
RadioNetwork
Layer RNSAP
MTP3-BSSCF-NNI
SSCOPAAL5
MTP3-BSSCF-NNI
AAL5 AAL2
Figure 1-19 Protocol stack of Iur interface
Iur interface specifications are shown in Figure 1-20.
RNSAP
TS 25.423
TransportLayer
Physical Layer TS 25.421
RadioNetworkLayer
Radio NetworkControl Plane
TransportNetwork
Control Plane
SignallingTransport
TS 25.422
User PlaneDedicatedChannels
TS 25.427
CommonChannels
TS 25.425
DedicatedChannel
Transport
TS 25.426
CommonChannel
Transport
TS 25.424
Transport Signaling
TS 25.426(Dedicated Channel
Transport)
TS 25.424(Common Channel
Transport)
Figure 1-20 Iur interface specifications
1.4.2 Functions of RNSAP
RNSAP is the Radio network control plane of Iur interface, which provides the following functions:
Radio Link Management. This function allows the SRNC to manage radio links using dedicated resources in a DRNS;
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Physical Channel Reconfiguration. This function allows the DRNC to reallocate the physical channel resources for a Radio Link;
Radio Link Supervision. This function allows the DRNC to report failures and restorations of a Radio Link;
Compressed Mode Control. This function allows the SRNC to control the usage of compressed mode within a DRNS;
Measurements on Dedicated Resources. This function allows the SRNC to initiate measurements on dedicated resources in the DRNS. The function also allows the DRNC to report the result of the measurements;
DL Power Drifting Correction. This function allows the SRNC to adjust the DL power level of one or more Radio Links in order to avoid DL power drifting between the Radio Links;
CCCH Signaling Transfer. This function allows the SRNC and DRNC to pass information between the UE and the SRNC on a CCCH controlled by the DRNS;
Paging. This function allows the SRNC to page a UE in a URA or a cell in the DRNS;
Relocation Execution. This function allows the SRNC to finalise a Relocation previously prepared via other interfaces;
Reporting of General Error Situations. This function allows reporting of general error situations, for which function specific error messages have not been defined.
1.4.3 RNSAP Procedures
RNSAP procedures can be classified into class 1 and class2.
The procedures of class 1 have response message including successful or unsuccessful outcome, as shown in Table 1-4
The procedures of class 2 have no response message. The message is always assumed successful, as shown in Table 1-5.
Table 1-4 Class 1 Elementary Procedures
Response message Elementary Procedure Initiating Message
Successful Outcome Unsuccessful Outcome
Radio Link Setup RADIO LINK SETUP REQUEST
RADIO LINK SETUP RESPONSE
RADIO LINK SETUP FAILURE
Radio Link Addition RADIO LINK ADDITION REQUEST
RADIO LINK ADDITION RESPONSE
RADIO LINK ADDITION FAILURE
Radio Link Deletion RADIO LINK DELETION REQUEST
RADIO LINK DELETION RESPONSE
Synchronised Radio Link Reconfiguration Preparation
RADIO LINK RECONFIGURATION PREPARE
RADIO LINK RECONFIGURATION READY
RADIO LINK RECONFIGURATION FAILURE
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Response message Elementary Procedure Initiating Message
Successful Outcome Unsuccessful Outcome
Unsynchronised Radio Link Reconfiguration
RADIO LINK RECONFIGURATION REQUEST
RADIO LINK RECONFIGURATION RESPONSE
RADIO LINK RECONFIGURATION FAILURE
Physical Channel Reconfiguration
PHYSICAL CHANNEL RECONFIGURATION REQUEST
PHYSICAL CHANNEL RECONFIGURATION COMMAND
PHYSICAL CHANNEL RECONFIGURATION FAILURE
Dedicated Measurement Initiation
DEDICATED MEASUREMENT INITIATION REQUEST
DEDICATED MEASUREMENT INITIATION RESPONSE
DEDICATED MEASUREMENT INITIATION FAILURE
Common Transport Channel Resources Initialisation
COMMON TRANSPORT CHANNEL RESOURCES REQUEST
COMMON TRANSPORT CHANNEL RESOURCES RESPONSE
COMMON TRANSPORT CHANNEL RESOURCES FAILURE
Table 1-5 Class 2 Elementary Procedures
Elementary Procedure Initiating Message
Uplink Signalling Transfer UPLINK SIGNALLING TRANSFER INDICATION
Downlink Signalling Transfer DOWNLINK SIGNALLING TRANSFER REQUEST
Relocation Commit RELOCATION COMMIT
Paging PAGING REQUEST
Synchronised Radio Link Reconfiguration Commit RADIO LINK RECONFIGURATION COMMIT
Synchronised Radio Link Reconfiguration Cancellation RADIO LINK RECONFIGURATION CANCEL
Radio Link Failure RADIO LINK FAILURE INDICATION
Radio Link Restoration RADIO LINK RESTORE INDICATION
Dedicated Measurement Reporting DEDICATED MEASUREMENT REPORT
Dedicated Measurement Termination DEDICATED MEASUREMENT TERMINATION REQUEST
Dedicated Measurement Failure DEDICATED MEASUREMENT FAILURE INDICATION
Downlink Power Control DL POWER CONTROL REQUEST
Compressed Mode Command COMPRESSED MODE COMMAND
Common Transport Channel Resources Release COMMON TRANSPORT CHANNEL RESOURCES RELEASE REQUEST
Error Indication ERROR INDICATION
Radio Link Pre-emption RADIO LINK PREEMPTION REQUIRED INDICATION
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1.4.4 Iur FP for Transport Channel Data Transfer
Iur FP is the radio network layer protocol of Iur interface user plane. It includes Iur FP for common transport channel data transfer and Iur FP for dedicated transport channel data transfer.
Iur FP for common transport channel data transfer and Iub FP for common transport channel data transfer are both specified in 3GPP TS25.425 protocol. Refer to “1.3.4 Iub FP for Common Transport Channel Data Transfer” for the Iur FP for transport channel data transfer.
Iur FP for dedicated transport channel data transfer and Iub FP for dedicated transport channel data transfer are both specified in 3GPP TS25.427 protocol. Refer to “1.3.5 Iub FP for dedicated Transport Channel Data Transfer” for the Iur FP for dedicated transport channel data transfer.
1.5 Iu Interface
1.5.1 Iu Protocol Architecture
Iu interface is the interface between UTRAN and CN.
The Iu interface that connects with CS domain of CN is called as Iu-CS whose protocol stack is shown in Figure 1-21 ;
The Iu interface that connects with PS domain of CN is called as Iu-PS whose protocol stack is shown in Figure 1-22;
The Iu interface that connects with BC domain of CN is called as Iu-BC whose protocol stack is shown in Figure 1-23.
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Iu UP Protocol Layer
Q.2630.1TransportNetwork
Layer
ATM
SSCOP
Physical Layer
SCCP
TransportUser
NetworkPlane
Control Plane User Plane
TransportUser
NetworkPlane
Q.2150.1
Transport NetworkControl Plane
RadioNetwork
Layer RANAP
MTP3-B
SSCF-NNISSCOP
AAL5
MTP3-B
SSCF-NNI
AAL5 AAL2
Figure 1-21 Protocol stack of Iu-CS interface
Iu UP Protocol Layer
TransportNetwork
Layer
ATM
SSCOP
Physical Layer
SCCP
TransportUser
NetworkPlane
Control Plane User Plane
TransportUser
NetworkPlane
Transport NetworkControl Plane
RadioNetwork
Layer RANAP
MTP3-B
AAL5 AAL5
ATM
Physical Layer
IP
GTP-UUDPSSCF-NNI
Figure 1-22 Protocol stack of Iu-PS interface
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TransportNetwork
Layer
RadioNetwork
Layer SABP Protocol Layer
SA Broadcast Plane
TransportUser
NetworkPlane
AAL5
IP
TCP
Physical Layer
ATM
Figure 1-23 Protocol stack of Iu-BC interface
Iu interface technical specifications are given in Figure 1-24.
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25.413 25.415
TransportNetwork
Layer
25.411
TransportUser
NetworkPlane
Control Plane User Plane
TransportUser
NetworkPlane
Transport NetworkControl Plane
RadioNetwork
Layer
25.412 25.414
25.419
SA Broadcast Plane
TransportUser
NetworkPlane
Figure 1-24 Iu interface specifications
1.5.2 Functions of RANAP
RANAP is the Radio network control plane of Iu interface, which provides the following functions:
Relocating serving RNC (SRNC). This function enables to change the serving RNC functionality as well as the related Iu resources (RAB(s) and Signalling connection) from one RNC to another.
Overall RAB management. This function is responsible for setting up, modifying and releasing RABs.
Queuing the setup of RAB. The purpose of this function is to allow placing some requested RABs into a queue, and indicate the peer entity about the queuing.
Requesting RAB release. While the overall RAB management is a function of the CN, the RNC has the capability to request the release of RAB.
Release of all Iu connection resources. This function is used to explicitly release all resources related to one Iu connection.
Requesting the release of all Iu connection resources. While the Iu release is managed from the CN, the RNC has the capability to request the release of all Iu connection resources from the corresponding Iu connection.
SRNS context forwarding function. This function is responsible for transferring SRNS context from the RNC to the CN for intersystem forward handover in case of packet forwarding.
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Controlling overload in the Iu interface. This function allows adjusting the load in the Iu interface.
Resetting the Iu. This function is used for resetting an Iu interface. Sending the UE Common ID (permanent NAS UE identity) to the RNC. This
function makes the RNC aware of the UE's Common ID. Paging the user. This function provides the CN for capability to page the UE. Controlling the tracing of the UE activity. This function allows setting the trace
mode for a given UE. This function also allows the deactivation of a previously established trace.
Transport of NAS information between UE and CN. This function has two sub-classes:
Sub-class1: Transport of the initial NAS signalling message from the UE to CN. This function transfers transparently the NAS information. As a consequence also the Iu signalling connection is set up.
Sub-class2: Transport of NAS signalling messages between UE and CN, This function transfers transparently the NAS signalling messages on the existing Iu signalling connection. It also includes a specific service to handle signalling messages differently.
Controlling the security mode in the UTRAN. This function is used to send the security keys (ciphering and integrity protection) to the UTRAN, and setting the operation mode for security functions.
Controlling location reporting. This function allows the CN to operate the mode in which the UTRAN reports the location of the UE.
Location reporting. This function is used for transferring the actual location information from RNC to the CN.
Data volume reporting function. This function is responsible for reporting unsuccessfully transmitted DL data volume over UTRAN for specific RABs.
Reporting general error situations.
1.5.3 RANAP Procedures
RANAP procedures can be classified into class 1, class 2 and class 3.
The procedures of class 1 have response message including successful or unsuccessful outcome, as shown in Table 1-6.
The procedures of class 2 have no response message. The message is always considered successful, as shown in Table 1-7.
The procedures of class 3 may have one or several response messages reporting both successful, unsuccessful outcome of the requests and temporary status information about the requests, as shown in Table 1-8. This type of EP only terminates through response(s) or EP timer expiry.
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Table 1-6 Class 1 elementary procedures
Response message Elementary Procedure Initiating Message
Successful Outcome Unsuccessful Outcome
Iu Release IU RELEASE COMMAND
IU RELEASE COMPLETE
Relocation Preparation RELOCATION REQUIRED
RELOCATION COMMAND RELOCATION PREPARATION FAILURE
Relocation Resource Allocation
RELOCATION REQUEST
RELOCATION REQUEST ACKNOWLEDGE
RELOCATION FAILURE
Relocation Cancel RELOCATION CANCEL
RELOCATION CANCEL ACKNOWLEDGE
SRNS Context Transfer SRNS CONTEXT REQUEST
SRNS CONTEXT RESPONSE
Security Mode Control SECURITY MODE COMMAND
SECURITY MODE COMPLETE SECURITY MODE REJECT
Data Volume Report DATA VOLUME REPORT REQUEST
DATA VOLUME REPORT
Reset RESET RESET ACKNOWLEDGE
Reset Resource RESET RESOURCE RESET RESOURCE ACKNOWLEDGE
Table 1-7 Class 2 elementary procedures
Elementary Procedure Message
RAB Release Request RAB RELEASE REQUEST
Iu Release Request IU RELEASE REQUEST
Relocation Detect RELOCATION DETECT
Relocation Complete RELOCATION COMPLETE
SRNS Data Forwarding Initiation SRNS DATA FORWARD COMMAND
SRNS Context Forwarding from Source RNC to CN FORWARD SRNS CONTEXT
SRNS Context Forwarding to Target RNC from CN FORWARD SRNS CONTEXT
Paging PAGING
Common ID COMMON ID
CN Invoke Trace CN INVOKE TRACE
CN Deactivate Trace CN DEACTIVATE TRACE
Location Reporting Control LOCATION REPORTING CONTROL
Location Report LOCATION REPORT
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Elementary Procedure Message
Initial UE Message INITIAL UE MESSAGE
Direct Transfer DIRECT TRANSFER
Overload Control OVERLOAD
Error Indication ERROR INDICATION
Table 1-8 Class 3 elementary procedures
Elementary Procedure Initiating Message Response Message
RAB Assignment RAB ASSIGNMENT REQUEST RAB ASSIGNMENT RESPONSE x N (N>=1)
1.5.4 Functions of Iu UP
Iu UP is located in the User plane of the Radio Network layer over the Iu interface and used to convey user data associated to Radio Access Bearers. One Iu UP protocol instance is associated to one RAB only.
Iu UP protocol instances exist at Iu access point i.e. at CN and UTRAN. Whenever a RAB requires transfer of user data in the Iu UP, an Iu UP protocol instance exists at each Iu interface access points. These Iu UP protocol instances are established, relocated and released together with the associated RAB procedures.
The Iu UP includes two modes of operation: Transparent Mode (TrM) and Support Mode for predefined SDU size (SMpSDU).
Transparent mode (TrM)
The transparent mode is intended for those RABs that do not require any particular feature from the Iu UP protocol other than transfer of user data. Figure 1-25 illustrates the transparent mode of Iu UP protocol layer.
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Iu UP layer(transparent mode)
TNL-SAP
RNL-SAP
TNL-SAP
CNUTRAN
R
adio
Inte
rface
P
roto
cols
Non AccessStratum
Access Stratum
Iu
Iu UP layer(transparent mode)
Figure 1-25 Transparent mode of Iu UP
In this mode, the Iu UP protocol instance does not perform any Iu UP protocol information exchange with its peer over the Iu interface. The Iu UP protocol layer is used for PDUs transfer between upper layers and transport network layer. For instance, Iu UP of Iu-PS adopts transparent mode.
Support mode
The support modes are intended for those RABs that require particular features from the Iu UP protocol in addition to transfer of user data. When operating in a support mode, the peer Iu UP protocol instances exchange Iu UP frames. Figure 1-26 illustrates the support mode of Iu UP protocol layer.
TNL-SAP
Iu
TNL-SAP
Iu UP layer(support mode)
CNUTRAN
Rad
io In
terfa
cePr
otoc
ols
RNL-SAPNon Access
Stratum Access Stratum
Transfer of IuUP protocol
frames
Support ModeFunctions
Iu UP layer(support mode)
Support ModeFunctions
Figure 1-26 Support mode of Iu UP
The only support mode which has been defined is the Support mode for predefined SDU size (SMpSDU). For instance, the transfer of AMR speech PDUs would utilize SMpSDU.
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I. User Data Transfer
User data transfer procedure is to transfer Iu UP frames between the two Iu UP protocol layers of the Iu interface. Since an Iu UP instance is associated to a RAB and a RAB only, the user data being transferred only relate to the associated RAB.
As shown in Figure 1-27, the transfer of user data procedure is invoked whenever user data for that particular RAB needs to be sent across the Iu interface.
In SRNC, the upper layers may deliver frame quality classification information together with the RFCI.
CN/ RNC
RNC/ CN Transfer of User Data
(RFCI, payload)
Figure 1-27 Transfers of user data
II. Initialisation Procedure
Initialization procedure is to configure both termination points of the Iu UP with the RFCIs and associated RAB Sub Flows SDU sizes necessary during the transfer of user data phase. This procedure is mandatory for RABs using the support mode for predefined SDU size.
RNC send initialization frame to CN, indicating the RFCIs and their corresponding RAB subflow SDU size, as shown in Figure 1-28.
If CN receives the initialization frame and accepts the parameters, it will respond with Initialization ACK frame, otherwise it will respond with Initialization NACK frame.
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*
Transfer Of User Data
Initialisation
((RFCI, SDU sizes ) m )
Initialisation ACK
* it can repeated n times
RNC CN/other
Figure 1-28 Initialization of Iu UP for m RFCIs
III. Iu Rate Control
Iu rate control procedure is to signal to the peer Iu UP protocol layer the permitted rate(s) over Iu in the reverse direction of the sent rate control frame.
The Iu rate control procedure is invoked whenever the SRNC/CN decides that the set of downlink/uplink permitted rates over Iu shall be modified, as shown in Figure 1-29. The permitted rate is given as RFCI indicators.
Rate Control(RFCI indicators,
[Downlink send intervals*])
* Optional
RNC/CN CN/RNC
Figure 1-29 Rate control
IV. Time Alignment Procedure
Time alignment procedure is to minimize the buffer delay in RNC by controlling the transmission timing in the peer Iu UP protocol layer entity.
The time alignment procedure is invoked whenever the SRNC detects the reception of Iu UP PDU at an inappropriate timing that leads to an unnecessary buffer delay as shown in Figure 1-30. The Iu UP protocol layer entity in SRNC indicates the peer entity the necessary amount of the delay or advance adjustment in the number of 500 µs steps.
A supervision timer TTA is started after sending the Iu UP time alignment frame. This timer supervises the reception of the time alignment acknowledgement frame.
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The requested Iu UP protocol layer entity in the peer node adjusts the transmission timing by the amount as indicated by SRNC. If the time alignment frame is correctly formatted and treated by the receiving Iu UP protocol layer and the time alignment is treated correctly by the upper layers, this latter sends a time alignment acknowledgement frame.
Upon reception of a time alignment acknowledgement frame, the Iu UP protocol layer in the SRNC stops the supervision timer TTA.
If CN can not handle the time alignment frame, it will send NACK frame to RNC, indicating the causes. The RNC will decide to send the time alignment frame or not according to the causes and stop the timer TTA.
Time Alignment
ACK
User data with bad timing
User data with adjusted timing
RNC CN
Figure 1-30 Time alignment
V. Error Event
Error event procedure is to handle the error reporting.
Over the Iu UP protocol the error reports are made with Error event frames as shown in in Figure 1-31,The Error event procedure in the Iu UP can be triggered by:
An error detected by the Iu UP functions A request by the upper layers
When an Error event is reported by an Error event frame the following information shall be included:
A cause value Error distance (=0 if Iu UP function detected, =1 if requested by upper layers).
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CN or other/RNC
RNC/CN or other
Error event(Cause value,
Error distance)
Figure 1-31 Error event
VI. Frame Quality Classification
Frame quality classification (FQC) is used to classify the Iu UP frames depending on whether errors have occurred in the frame or not.
The FQC information is exchanged between RNC and CN through user data transfer procedure, as shown in Figure 1-32.
Transfer of User Data(FQC, RFCI, payload )
Transfer of User Data(FQC, RFCI, payload )
CN/RNCRNC/CN
Figure 1-32 Transfers of user data with FQC information
1.5.5 GTP-U
The function of GTP-U (GPRS Tunnel Protocol User Plane) is to transfer Iu-PS user data through tunnel protocol. In addition, it also includes the user plane auxiliary signaling such as error indication of data transferring, handshaking message and supported extension head list.
1.5.6 Functions of SABP
SABP is the radio network layer of Iu-BC interface, which provides the following functions:
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Message Handling. This function is responsible for the broadcast of new messages, amend existing broadcasted messages and to stop the broadcasting of specific messages.
Load Handling. This function is responsible for determining the loading of the broadcast channels at any particular point in time.
Reset. This function permits the CBC to end broadcasting in one or more Service Areas.
Error Handling. This function allows the reporting of general error situations, for which function specific error messages have not been defined.
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Chapter 2 Transport Network Layer Procedure Analysis
2.1 Overview
In UTRAN, the transport network layer adopts an adaptation and message transfer mechanism to provide transport service for the radio network layer message. In this way, the radio network layer can evolve without too much consideration for the transport technology.
The transport network logical entities adopted in UTRAN include SAAL, MTP3-B, ALCAP, and SCCP and so on. In this chapter, we will discuss the architecture and function of each entity.
2.2 SAAL
2.2.1 Overview
Signaling adaptation is required for the transmission of signaling messages in the ATM network, that is, signaling messages in various formats in the upper layer shall be converted into the messages of format that can be transmitted in the ATM network. These functions can be accomplished by the SAAL layer.
NBAP STC
SSCF AT UNI SSCF AT NNI
SSCOP
MTP3-B
CPCS
SAR
LM
SAALSSCS
CP
Figure 2-1 SAAL Structure
The structure of SAAL in BSC6800 is illustrated in Figure 2-1. The SAAL comprises the following parts:
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Service Specification Convergence Sublayer (SSCS), which includes SSCF (Service Specific Coordination Function), SSCOP (Service Specific Connection Oriented Protocol).
Common Part (CP). CP adopts AAL type 5 as adaptation layer and comprises two parts: CPCS and SAR.
Layer Management (LM).
Note:
For details about SSCF, refer to ITU-T Q.2140. For details about SSCOP, refer to ITU-T Q.2110. For details about LM, refer to ITU-T Q.2144.
2.2.2 SSCOP
I. Overview
SSCOP provides the transmission of information and control information between two peer to peer entities.
II. Function
The SSCOP performs the following functions.
Sequence Integrity. This function preserves the order of SSCOP SDUs that were submitted for transfer by SSCOP.
Error Correction by Selective Retransmission. Through a sequencing mechanism, the receiving SSCOP entity can detect missing SSCOP SDUs. This function corrects sequence errors through retransmission.
Flow Control. This function allows an SSCOP receiver to control the rate at which the peer SSCOP transmitter entity may send information.
Error Reporting to Layer Management. This function indicates to layer management errors which have occurred.
Keep Alive. This function verifies that the two peer SSCOP entities participating in a connection are remaining in a link connection established state even in the case of a prolonged absence of data transfer.
Local Data Retrieval. This function allows the local SSCOP user to retrieve in-sequence SDUs which have not yet been released by the SSCOP entity.
Connection Control. This function performs the establishment, release, and resynchronization of an SSCOP connection. It also allows the transmission of variable length user-to-user information without a guarantee of delivery.
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Transfer of User-Data. This function is used for the conveyance of user data between users of the SSCOP. SSCOP supports both assured and unassured data transfer.
Protocol Error Detection and Recovery. This function detects and recovers from errors in the operation of the protocol.
Status Reporting. This function allows the transmitter and receiver peer entities to exchange status information.
SSCOP data units are the message units transmitted between SSCOP peer layers for connection setup and release, and for message reliable transmission. They include the following basic message units.
BGN PDU (Begin), used to set up connection between two peer SSCOP entities. It requests the peer SSCOP to clear data in the transmitter and receiver buffers, to perform initialization of state variables and receiving/sending counters.
BGAK PDU (Begin Acknowledge), used to acknowledge the connection request from the peer end.
BGREJ PDU (Begin Reject), used to reject the connection request from the peer SSCOP entity.
END PDU (End), used to release the connection between the two ends in communication.
ENDAK PDU (End Acknowledge), used to acknowledge the release action. RS PDU (Resynchronization), used to resynchronize the buffers and data transfer
state variables. RSAK PDU (Resynchronization Acknowledge), used to acknowledge the
resynchronization request originated from the peer entity. ER PDU (Error Recovery), used to recover errors in connection action. ERAK PDU (Error Recovery Acknowledge), used to acknowledge the recovery
request. SD PDU (Sequenced Data), used to send user service data to the peer entity
after SSCOP connection has been set up. POLL PDU (Status Request), used to request status information of the peer
SSCOP after SSCOP connection setup. STAT PDU (Solicited Status Response), used as the response for POLL PDU. It
is used to notify which SD PDUs have been received and which have not. It is also used to update the location of sending window so as to control the sending sequence No. of the max. SD PDU. The STAT PDU also includes the sending SN of the POLL PDU(N(PS)), which is used as the response to the POLL PDU.
USTAT PDU (Unsolicited Status Response). It is sent by the receiving end to inform the peer end resending the lost SD PDUs when the receiving end detects loss of SD PDUs after comparing the receiving SN of SD PDU. The USTAT PDU also contains data for updating sending window of the peer end, but contains no N(PS) segment.
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Unnumbered Data (UD). UD are transmitted between peer SSCOP users. The in-progress connection oriented sequencing will not be affected, no counter or status between the two entities will be altered, and no data will be retransmitted if they get lost.
Management Data (MD). Unnumbered MD is transmitted between two SSCOP management entities. Similar to UD PDUs, no reliable receiving of the peer end is guaranteed.
III. SSCOP Operation State
The states of SSCOP entities reflect the states of information exchange between the SSCOP and its user and the states of the PDUs transmitted between peer entities. It includes the following basic states.
State 1 - Idle, the initial state of SSCOP. Each SSCOP entity turns to idle state after initialization and connection release.
State 2 - Outgoing Connection Pending, the state when the local SSCOP entity has sent connection setup request and has not received acknowledgement from the peer end.
State 3 - Incoming Connection Pending, the state when the local SSCOP has received a connection setup request from the peer end and is waiting for the response from the local end user.
State 4 - Outgoing Disconnection Pending, the state after the local SSCOP entity requests to release the connection with the peer end and before the local end receives the connection release acknowledgement message.
State 5-Outgoing Resynchronization Pending, the state when the local end is waiting for the acknowledgement from the peer end for its connection resynchronization request.
State 6-Incoming Resynchronization Pending, the state when the local end has received the resynchronization request from the peer end and is waiting for the response from its user.
State 7-Outgoing Recovery Pending, the state when the local end has sent request to the peer end for connection recovery and is waiting for recovery acknowledgement.
State 8-Recovery Response Pending, the state when the SSCOP entity has recovered the connection and notified the user and is waiting for response from the user.
State 9-Incoming Recovery Pending, the state when the SSCOP entity has received the connection recovery request from the peer end and is waiting for response from its user.
State 10-Data Transfer Ready: the state when the connection setup, resynchronization or error recovery program has been successfully accomplished and the two SSCOP entities are ready for reliable data transmission.
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IV. SSCOP Connection Setup
To set up connection between two peer SSCOP entities, the SSCF sends to SSCOP entities an AA-ESTABLISH.req primitive, as is shown in Figure 2-2. The primitive includes the SSCOP-UU that is used by the SSCOP entities to generate BGN message and BR parameter. The BGN message is sent to the receiving SSCOP entity, where it is decoded, processed and mapped to AA-ESTABLISH.ind signal. The AA-ESTABLISH.ind signal is sent to the SSCF of the receiving entity, which responds to the SSCOP with AA-ESTABLISH.rsp primitive. The AA-ESTABLISH.rsp primitive also includes SSCOP-UU and BR parameter. Then the receiving SSCOP sends BGAK message to the originated SSCOP, where the BGAK message is decoded, processed and sent to the SSCF of the originated SSCOP. Now connection is set up between the two SAAL entities of two wideband signaling switches.
SSCOP A SSCOP B
AA-ESTABLISH.req PDU BGNAA-ESTABLISH.ind.
AA-ESTABLISH.rsp.PDU BGAK
AA-ESTABLISH.con.
Figure 2-2 SSCOP connection setup
V. SSCOP Connection Release
When SSCOPA receives AA-RELEASE.request, it sends END PDU to SSCOP B as is shown in Figure 2-3. After SSCOP B receives the END PDU, it sends AA-RELEASE.indication to the user. When the connection is released, the SSCOP B sends ENDAK PDU to SSCOP A. When SSCOP A receives the ENDAK PDU, it sends AA-RELEASE.confirm to the SSCF to release the connection.
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SSCOP A SSCOP B
END
ENDAK
AA-RELEASE.request
AA-RELEASE. confirm
AA-RELEASE.indication
Figure 2-3 SSCOP connection release
VI. SSCOP Data Transmission and Error Recovery
In this section, we will introduce the SSCOP data transmission and error recovery mechanism through an example as shown in Figure 2-4.
1) SSCOP A sends 4 SD PDUs to SSCOP B, with their N(S) numbered from 0 to 3. Only PDU1 and PDU2 properly reach SSCOP B. SSCOP B delivers PDU1 and PDU2 to the user.
2) SSCOP A then sends a POLL PDU, which contains a N(S) =5 representing the N(S) value of the next new SD PDU (the SD PDU to be transferred the next time). The POLL PDU also contains a N(PS)=1, the sequence No. of the POLL PDU.
3) SSCOP B uses STAT PDU as the response to the POLL PDU. The N(R) in the STAT PDU is coded 3 for acknowledging PDU1 and PDU2 and for indicating its expectation of the next PDU, that is, PDU3. The N (PS) segment in the STAT PDU is the same as that in the corresponding POLL PDU. The list element in the STAT PDU is set as (3, 5), which tells the SSCOP A: To resend PDU3 and PDU4; To release PDU1 and PDU2 from the buffer; To preserve PDU3 and PDU4, because there is still no sufficient information about the final results of PDU3 and PDU4.
Note:
The odd element (the value is 3) represents a PDU within a certain loss interval, while the even element represents the first PDU in the next sequence properly received.
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1 (0) 2 (0) 3 (0) 4 (0)
1 2XX
X X
5 (1) 6 (1) 7 (1)
X X 7Free 1, 2
POLL(5,1)
STAT(3, 1, N(MR), {3, 5})
Action DeliveredTx Rx
Figure 2-4 SSCOP data transmission
2.2.3 SSCF
I. Overview
As shown in Figure 2-1, the SSCF functions as the adaptation layer of the SSCOP and the upper layer applications. Upper layer applications include NBAP, MTP3-B and Signal Transport Convert (STC).
The MTP3-B is used for Network to network interface (NNI), which has higher link quality. SAAL is required to support link quality check and to help the MTP3-B with link switchover.
However, NBAP is used for User to Network Interface (UNI), which has poorer link quality and greater delay. Therefore, SSCF is divided into SSCF-NNI and SSCF-UNI to cater to different upper layer applications.
SSCF-NNI is used for adapting SSCOP and upper layer MTP3-B. It maps the primitive from MTP3-B to SSCOP signal as required, or reversely. SSCF-NNI acts as a medium for signal transferring between SSCOP and MTP3-B. SSCF does not send PDUs to the peer SSCF of the receiver. It transfers its information through the SSCOP PDU. Besides primitive mapping, SSCF-NNI also implements local data retrieval, link state maintenance and link quality check functions. It reports link information to layer management.
SSCF-UNI is used for adapting SSCOP or upper layer NBAP or STC. It implements error-free sequential data transmission by use of SSCOP. Similar to SSCF-NNI, it maps the primitive from NBAP/STC to SSCOP signal as required. It differs from SSCF-NNI in that it does not implement link alignment and data retrieval functions. SSCF-UNI accomplishes primitive mapping, SAAL link setup and release, and data transmission acknowledgement.
II. Function
The SSCF performs the following functions.
Primitive mapping. SSCF maps the primitive from MTP3-B to SSCOP signals as required, or reversely.
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Local data retrieval. SSCF retrieves data that have not been sent in the links when the links get faulty or switched over, and sends the data to other links for transmission.
Flow control. SSCF reports to the user the congestion level (or no congestion) to prevent the loss of cells. It also adjusts certain PDU flow to the lower layer to prevent congestion of the peer end.
Link state maintenance. According to the primitive received from MTP3-B and SSCOP, SSCF maintains information about link states, such as Out Of Service and In Service. Using the information, it can provide primitives/signals to MTP3-B and SSCOP to help with link management.
Layer management report. SCCF sends MAAL primitive to LM, for example, SSCF reports link fault to LM when one link gets faulty. It monitors errors with the help of LM.
Link alignment.
2.2.4 CPCS
0~47bytes 8 bits 8 bits 16 bits 32 bits
CPCS-PDU Tail
CPCS-PDUPayload PAD UU CPI LI CRC
Figure 2-5 CPCS-PDU format
CPCS-PDU format is shown in Figure 2-5, including three parts, CPCS-PDU payload, PAD and PCS-PDU tail.
The length of CPCS-PDU payload is variable within 1~65535 bytes.
PAD filling-in bits makes the length of CPCS-PDU the integer times of 48 bytes. The length of CPCS-PDU tail is 8 bytes, including the following parts:
User-to-User Indication (UUI), used for the transparent transmission of information between CPCS users.
CPCS Part Indication (CPI), used to make the length of CPCS-PDU tail as 8 bytes.
Length Indication (LI), used to indicate the length of CPCS-PDU payload. Cyclic Redundancy Check (CRC), used to check the content of CPCS-PDU,
including CPCS-PDU payload area, PAD, UU, CP and LI and so on.
2.2.5 SAR
The Segment And Reassemble (SAR) sublayer in the AAL5 segments the CPCS-PDU into 48-byte SAR-PDU without any overheads. Reassembly function is achieved during SDU receiving.
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2.2.6 LM
I. Overview
LM interacts directly with SAAL sublayers to accomplish Operation And Maintenance (OAM) functions. No interactions are defined in CPCS and SAR, because CPCS and SAR are accomplished by the hardware. SSCS LM is responsible for the following tasks.
Determine whether a link shall exit service or enter service. As a component for accomplishing operations, links must be monitored so as to prevent great delay in transmission. To prevent useless link change, LM allows certain amount of errors on the links.
Conduct periodical measurement; for example, record the service life of each links with counters, the fault frequency, congestion frequency, number of congestions and other information.
LM can be in any of the following states:
Out Of Service Alignment Proving Aligned Ready In Service
II. Function
LM provides three algorithms for error monitoring. These algorithms can detect bursting errors lasting more than 400ms.
Algorithm 1 is mainly used when the load is heavy. If the data volume to be sent is too large, the receiving end does not have enough time to process them so that data in the buffer cannot be released on time and the sending queue keeps increasing. When the sending queue is increased to a certain value, links will get released.
Algorithm 2 is mainly for medium load. Algorithm 2 monitors the number of data retransmissions. Within a certain period, if the number of data retransmissions exceeds the threshold, the link quality must be very poor. When the transmission delay cannot be tolerated by the system, links will get released.
Algorithm 3 is mainly used for low load. When the load is low, the difference between the number of POLL PDUs sent and the number of STAT PDUs received, that is, the number of STAT PDUs lost, exceeds a certain value within a certain period, it means the link quality is very poor and links will get released.
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2.2.7 SSCOP Message
I. Message Parameters
Parameters Comments
N(S) VT(S) is mapped to N(S) whenever a new SD or POLL PDU is generated.
Information field The information field of an SD, MD, or UD PDU is mapped from the “Message unit” parameter of an AA-DATA, MAA-UNITDATA, or AA-UNITDATA request, respectively. It is mapped to a “Message unit” parameter of an AA-DATA, MAA-UNITDATA, or AA-UNITDATA indication, respectively.
N(PS) VT(PS) (after VT(PS) has been incremented) is mapped to N(PS) whenever a POLL PDU is generated. The receiver of a POLL PDU maps the received POLL.N(PS) into the field STAT.N(PS). In addition, to facilitate error recovery procedures, the current value of VT(PS) is mapped into N(PS) and stored in the transmitter buffer with the corresponding SD PDU whenever a SD PDU is sent.
N(R) VR(R) is mapped to N(R) whenever a STAT or USTAT PDU is generated.
N(MR) VR(MR) is mapped to N(MR) whenever a STAT, USTAT, RS, RSAK, ER, ERAK, BGN, or BGAK PDU is generated. This is the basis for credit granting by the receiver.
SSCOP-UU The SSCOP-UU in a BGN, BGAK, BGREJ, END or RS PDU is mapped to and from the “SSCOP-UU” parameter of the corresponding SSCOP signal.
Source (S) bit In an END PDU this bit conveys whether the originator of the release was the SSCOP or the SSCOP user. When the transmission of an END PDU is stimulated by the user, this bit is set to 0. When the transmission of an END PDU is stimulated by the SSCOP, this bit is set to 1. This bit is mapped into the “Source” field of an AA-RELEASE.indication
N(SQ) This field carries the connection sequence value. VT(SQ) is mapped to N(SQ) whenever a new BGN, RS, or ER PDU is transmitted. This field is used by the receiver together with VR(SQ) to identify retransmitted BGN, RS, and ER PDUs
PDU Type field The type field codings.
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II. Example
2.3 MTP3-B
2.3.1 Overview
Based on Message Transfer Part Layer 3 (MTP3), MTP3-B is the protocol specification aiming at ATM features. It performs message exchange through the services provided by SAAL.
MTP3-B module performs MTP3-B protocol functions, including signaling message handling and signaling network management, as shown in Figure 2-6.
The signaling message handling part provides the following functions: Guaranteeing the signaling message generated at the user part of a signaling point (SP) can be transmitted to the corresponding user part of the destination
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specified by the related field in Message signaling unit (MSU). There are only two user parts at Iu/Iur interface, that is, SCCP and Signal Transport Convert (STC). Functionally this part may be further subdivided into message discrimination, message routing and message distribution.
The signaling network management part provides the following functions: Performing re-networking for a signaling network that gets faulty (e.g., a signaling link or a signaling transfer point is congested) during its running. With the increase of signaling network traffics and of loads over signaling links, the signaling network might be congested. Therefore, this part also performs congestion control function. The signaling network management function can be classified into signaling traffic management, signaling link management and signaling route management.
Figure 2-6 Protocol structure of MTP3-B
2.3.2 Function
I. Message Discrimination
Message discrimination function is used to identify the signaling message destination and to direct the signaling message.
Message discrimination is implemented by analyzing the destination signaling point code (DPC) in the signaling message routing label.
When a signaling message is transmitted from Level 2 (SAAL) arrives at Level 3 (MTP3-B) , message discrimination will firstly process it and determine its next handling procedure. If the local signaling point is the destination of the message, the message will be handed over to the message distribution function for subsequent
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handling. If the local signaling point is not the destination and is capable of transferring, the message routing function will be enabled, so as to transfer the message through message routing. If the local signaling point does not have the transferring capability, the signaling network management function will be informed to handle the message as an illegal one.
II. Message Distribution
Message distribution function distributes signaling messages to corresponding users of the local signaling point. As the MTP-B of the signaling point has to serve multiple users, to decide to which user a signaling message will be distributed is implemented by analyzing the service indicator (SI) in the service information octet (SIO) of the signaling message.
When the SI field equals 0000 or 0001 (i.e., the message to be distributed is a signaling network management message or maintenance and test message), the codes of the herder, H0 and H1, will be analyzed so as to specify by which signaling network management part the message is to be handled
III. Message Routing
The message routing function selects a proper route for the message according to the header information. It processes the messages as follows.
For the message sent from the upper layer, the message routing has to find an available route to send it unless such route does not exist.
For the message sent from another SP, it will be sent out if the SP receiving it has the signaling transfer function and the Destination Signaling Point (DSP) of this message exists in the DSP table of this SP.
For the message that does not belong to a SP, it will be discarded if this SP has the signaling transfer function but the DSP of this message does not exist in the DSP table of this SP.
IV. Signaling Traffic Management
The signaling traffic management transfers signaling traffics over signaling links or over routes or temporarily reduces traffics in case of congestion. Signaling traffic management covers the following procedures:
In case a signaling link gets unavailable (for example, faulty, disconnected or inhibited), the traffics over the signaling link will be changed over to another one or more links.
When the link becomes available (reconnected or uninhibited), the traffics will be changed back to this link.
In case a signaling route gets unavailable, the traffics over this route will be changed over to the substitute route by means of forced rerouting.
When the route becomes available, the traffics will be changed back to this route by using the controlled rerouting program.
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In case a signaling route is restricted, the traffics over this route will be changed over to the substitute route by using the controlled rerouting program.
To limit the traffics of signaling sources in case of congestion, the signaling traffic flow control program is used to control these traffics.
V. Signaling Route Management
Signaling route management aims at ensuring reliable interchange of signaling route availability information among signaling points.
VI. Signaling Link Management
Signaling link management serves to stop using the unavailable or unreliable link and repeatedly restarts it for the purpose of making it available. Besides, it also provides the link test function to periodically test links for confirmation of the usability of these links.
2.3.3 Message Structure
The structure of MTP3-B is the same as that of MTP3. Service Information Octet (SIO) and Service Information Field (SIF) are also included in Its MSU.
I. Service Information Octet(SIO)
SIO comprises Service Indicator (SI) and Sub-Service Field (SSF), as shown in Figure 2-7. The length of SIO is eight bits, among which SI and SSF occupy four bits respectively.
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Figure 2-7 Format and codes of SIO
Service Indicator (SI)
SI is used to indicate to which specified user part the transmitted messages belong. In the Message Transfer Part of the signaling network, signaling message handling function distributes the message to the specified user part according to the indication of SI.
The code of SI is illustrated in Figure 2-7. The capacity of SI can be used to indicate 16 different user parts. The figure only shows several of them.
Sub-Service Field (SSF)
It is made up of 4 bits, of which the higher two bits act as the network indicator, and the lower two bits, coded 00, are reserved presently.
The network indicator serves to distinguish the network attribute of the transmitted message, that is, to distinguish between an international signaling network message and a national signaling network message, as shown in Figure 2-7.
II. Signaling Information Field (SIF)
SIF includes two parts addressing Label and signaling message, as shown in Figure 2-8.
1) Label
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Label includes the necessary information needed to send the message to its destination. The length of standard routing label is 32 bits, it locates in the beginnig of the SIF. Label includes Destination Point Code (DPC), Originating signaling Point Code (OPC) and Signaling Link Selection Code (SLS).
DPC is digital address, which is the code used to identify each signaling point uniquely in the SS7. When the DPC of the message represents the accepting signaling point, the message is sent to the corresponding user part that the service indicator of the SIO indicates (for instance, the SCCP).
SLS is used to:
Guarantee the message order. Any two messages with the same SLS reaches their destination with the same order they are sent.
Allow all the available links to share the traffic load equally. If a user part sends message periodically, and distributes the SLS in a cyclic way, then all the service level at the destination shall be the same.
Signaling message SLS
OPC
DPC
SIF SIO First bit transmitted
Figure 2-8 Format of SIF
2) Signaling message
Signaling message part is also called as service information part. This part can be further divided into several sub-fields. These sub-fields can be mandatory or optional. The length of them can be fixed or flexible to meet the demand of various functions or expansion. This enables the signaling message unit to meet different user messages. It also makes it possible to transmit different user messages in the common channel.
The most important signaling message of MTP layer is the signaling network management message. In the following, we will focus on it.
III. Format of Signaling Network Management Message
Signaling network management messages, originating from Level 3 (opposite or local end), mainly apply to signaling traffic management, signaling link management and signaling route management.
A signaling network management message is identified, in a signaling network, by the SI of the SIO in the signal message unit, where SI equals to 0000.
Sigaling network management message is composed of n X 8 (nú0) bits. It may contain one or more signaling or indicators, yet with a total length of integer number of octets.
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Being one of MSUs, the signaling information of signaling network management messages is transmitted in the SIF, with the structure illustrated in Figure 2-9.
Management information
H 1
8n
(n= 0)
4
H 0
4 4
SLC
4
OPC
24/14
DPC
24/14
First bit transmitted
Figure 2-9 General format of a signaling network management message
1) Label
Composed of DPC, OPC and SLC, as stated before
2) Heading code
The heading code is made up of two 4 bits: H0 and H1.
H0 identifies the management message group, and H1 determines the messages in a message group. H0 and H1 occupy 4 bits respectively and their total capacity of representing messages is up to 265 kinds, i.e., there are 16 message groups and each of them has 16 types of message.
Table 2-1 The allocation of heading code H0
H0 Description
0000 Reserved
0001 Changeover and changeback messages (CHM)
0010 Emergency changeover message (ECM)
0011 Transfer controlled and signaling route set congestion messages (FCM)
0100 Transfer-prohibited-allowed-restricted messages (TFM)
0101 Signaling-route-set-test messages (RSM)
0110 Management inhibit messages (MIM)
0111 Traffic restart allowed message (TRM)
1001 Spare
1010 User part flow control messages (UFC)
1011–1111 Spare
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Signaling network management message and its heading code allocation are described in Table 2-2 in details.
Table 2-2 Messages of SS7 the third function level network management
Message Group
H1
H0 0000
0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111
0000
CHM 0001 XCO XCA CBD CBA
ECM 0010 ECO ECA
FCM 0011 RCT TFC
TFM 0100 TFP TFR TFA
RSM 0101 RST RSR
MIM 0110 LIN LUN LIA LUA LID LFU LLT(LRT)
TRM 0111 (TRA)
DLM 1000
1001
UFC 1010 (UPU)
1011
1100
1101
1110
1111
CBA: Changeback-acknowledgement signal
CBD: Changeback-declaration signal
XCA: Extended Changeover Acknowledgement
XCO: Extended Changeover Order
ECA: Emergency-changeover-acknowledgement signal
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ECO: Emergency-changeover-order signal
RCT: Signaling-route-set-congestion-test signal
RSR: Signaling-route-set-test signal for restricted destination (national option),
RST: Signaling-route-set-test signal for prohibited destination
TFR: Transfer-restricted signal (national option)
TFA: Transfer-allowed signal
TFC: Transfer-controlled signal
TRA: Traffic-restart-allowed signal
TFP: Transfer-prohibited signal
LID: Link inhibit denied signal
LFU: Link forced uninhibit signal
LIN: Link inhibit signal
LIA: Link inhibit acknowledgement signal
LUA: Link uninhibit acknowledgement signal
LUN: Link uninhibit signal
LLT: Link local inhibit test signal
LRT: Link remote inhibit test signal
UPU: User Part Unavailable signal
2.3.4 Changeover/Changeback/ Management prohibit
I. Changeover
Changeover refers to the signaling traffic management process which shifts the signaling traffic from a signaling link, when it turns from normal operation into unavailable (such as signaling link fault, blocking or out of service), to one or more alternative signaling links.
II. Changback
Generally, signaling traffic in the signaling network are carried on normal signaling links, while alternative signaling links only take over the signaling traffic from the signaling links that are "temporarily" faulty. Therefore signaling traffic must be changed back to normal signaling links once the “temporarily” faulty links are available again.
III. Management Prohibit
Management prohibit is a signaling traffic management function, which is used to maintain and test the signaling network.
Signaling link prohibit can be started by the management function of the signaling link terminal. During the blocked period, the link status of the second function level does
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not change. However, the signaling link is marked as “blocked”, the signaling traffic of the blocked link is stopped temporarily. You can carry out test periodically.
If necessary, the blocked link can be unblocked by the MML command. Signaling route control function can also start the unblocking management prohibit procedure.
2.3.5 Signaling Network Management and Status of Signaling Link
MTP3-B Level 3 usually regards a signaling link as either available or unavailable. A signaling link can only transmit signaling traffic when it is available.
There are the following three causes for a signal link to become unavailable:
Link fault or not working. Link blocking. Link fault or not working and blocking.
In the signaling network, the status of signaling link may change as a result of the following:
Signaling link fault Signaling link restoration Signaling link disconnection Signaling link connected Signaling link blocking or unblocking.
If a signal link is identified as "Faulty" , "Disconnected" , or "Blocked" , it will become unavailable. If the signaling link is identified as "Restored" , "Connected” or "Unblocked" , it will again become available.
1) Signaling link fault
In any of the following cases, the signaling link is deemed faulty and unavailable:
SAAL gives the fault indications “Out of Service” Receives request from the management system. Receives changeover command from the opposite end, requesting to change
over the signaling traffic of the signaling link to another signaling link. 2) Signaling link restoration
The process to remove signaling link fault and make the signaling ready for transmitting signaling traffic is referred to as signaling link restoration. When the fault is removed and initial alignment is successfully completed at both ends of the once faulty signaling link, the signaling link becomes available again.
3) Disconnection of signaling link
The process to stop traffic of a signaling link set or a signaling link is defined as signaling link disconnection.
Signaling link may be disconnected upon the request by the maintenance and management system, or performed by the signaling link management function as well.
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4) Signaling link connecting
The process to make the signaling link ready for signaling traffic transmission is defined as connection of a signaling link.
When a disconnected signaling link has its signaling data link or signaling terminal connected again and the initial alignment is completed successfully, the once disconnected signaling link is regarded as being connected.
Table 2-3 shows general management process of signaling network upon change of signaling link status.
Table 2-3 General management process of signaling network upon change of signaling link status
Signaling network management Signaling link status Signaling traffic management Signaling link management
Signaling route management
When a signaling link is faulty (becomes unavailable)
starts the changeover procedure (or emergency changeover procedure when necessary) to transfer the signaling traffic on the unavailable signaling link to one or more alternative signaling links. The process above mentioned includes specifying the alternative signaling link, recovering the sent yet not acknowledged messages.
when a signaling link is faulty, signaling link management function will, according to the status of the signaling link set, connect another signaling link in the signaling link set, and then prepare for the restoration of the faulty signaling link and its signaling transmission
signaling route function is not enabled if the signaling link fault does not result in any changes of signaling route set status. However, if the fault affects the status of route sets, the transfer forbidden process or transfer restricted process has to be started.
When a signaling link is restored
the changeback process, when necessary, is activated to change the signaling traffic from the one or more alternative signaling links back to the link which recovers to be available. It includes the process to specify the signaling traffic that can be changed back and to maintain correct message sequence.
if another signaling link in the same link set is connected during the signaling link fault, then the stop process is used to change the signaling link set status back to that before the fault occurs, and to disconnect the operating link connected during the signaling link fault, regarding it unable to transmit signaling.
signaling route function is not enabled if the signaling link fault does not result in any changes of signaling route set status. Otherwise, the transfer allowed process has to be started.
When a signaling link
Normally, when a signaling link is to be disconnected, the
When one signaling link is disconnected, if the number of
the same procedure as that of signaling link
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Signaling network management Signaling link status Signaling traffic management Signaling link management
Signaling route management
is disconnected
signaling traffic has already been transferred. If it is not yet transferred, the signaling traffic changeover process shall be executed.
signaling links operating in the link set is less than the necessary number, another link will be connected.
fault handling.
When a signaling link is connected
the same procedure as that of signaling link restoration
When the signaling link is connected, if the number of connected signaling links in the link set is greater than the necessary number, another link will be disconnected.
the same procedure as that of signaling link restoration.
When a signaling link is blocked
the same procedure as that of signaling link fault handling.
None
If a signaling route set becomes unavailable or restricted, due to blocking, it can not perform transfer prohibited process on the STP which can select route for relevant messages.
When a signaling link is unblocked
the same procedure as that of signaling link restoration.
None
When a signaling route set becomes available again due to unblocking of the link, the transfer allowed process will be employed.
2.3.6 Signaling Network Management and Signaling Route Status
For the signaling traffic of a destination, the signaling route may be in one of these two states: available, unavailable.
When a transfer prohibited message is received, indicating that the signaling traffic to a destination can no longer be transmitted via the STP which sends out relevant message, the signaling route will become unavailable.
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When a transfer allowed message is received, indicating that the signaling traffic to a destination can be transmitted via the STP sending out transfer allowed message, the signaling route will again become available.
shows the process involved in signaling route status changing
Table 2-4 The process involved in signaling route status changing
Signaling network management Signaling route status Signaling traffic management Signaling route management
When a signaling route turns unavailable
the forced rerouting process is performed so that the signaling traffic to a destination is changed over from the link set which includes the unavailable route to the alternative route connecting another STP.
when a signaling route becomes unavailable, the transfer prohibited process will be started, informing one or multiple adjacent signaling points that it can no longer transmit messages via this STP. In the meantime, the route set testing process or the route set congestion testing process will be started accordingly.
When a signaling route becomes available
the controlled rerouting process is performed so that the signaling traffic to a destination is changed back from the signaling link set which includes the alternative signaling route to the signaling link set which includes the recovered route once in faulty.
the transfer allowed process will be started, informing one or multiple adjacent signaling points that it can transmit messages again via this STP. In the meantime, the route set testing process or route set congestion testing process will be stopped
2.3.7 MTP3-B Upper User Message
I. Message Structrue
Refer to “2.3.3 Message Structure”.
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II. Example
2.3.8 MTP3-B Test Message
I. Message Structue
Refer to “2.3.3 Message Structure”.
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II. Example
2.3.9 MTP3-B Management Message
I. Message Structue
Refer to “2.3.3 Message Structure”.
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II. Example
2.4 ALCAP
2.4.1 Overview
Q. AAL2
SAAL STC
SAAL UNI
MTP3-B STC
MTP3-B
ALCAP
Figure 2-10 ALCAP structure in the BSC6800 system
Access Link Control Application Part (ALCAP), also called Q.AAL2 protocol, is the control plane of the Iub/Iur/Iu-CS transport network layer with the signaling bearers of SAAL UNI type and MTP3-B type.
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As is shown in Figure 2-10, ALCAP consists of a Q.AAL2 protocol processing layer and two STC adaptation layers the former of which performs all protocol functions while the latter one adapts primitives and shield bottom-layer differences (SAAL, MTP3-B).
The basic function of ALCAP is establishing and releasing AAL2 connection between two SPs. Besides, it also maintains and manages such resources as path and micro channel.
The ALCAP of BSC6800 complies with ITU-T Q.2630.1.
2.4.2 Function
ALCAP performs the processes of AAL2 connection establishment and release, of AAL2 PATH block and unblock, of AAL2 connection reset.
I. Establishment and release of AAL2 Connection
The establishment and release of an AAL2 connection is initiated by the ALCAP at the RNC, as shown in Figure 2-11.
Figure 2-11 Establishment and release of AAL2 connection
The procedures to establish AAL2 connection are as follows:
1) ALCAP at RNC sends ESTABLISH REQUEST message to the ALCAP of the peer end.
2) Upon receiving an ESTABLISH request sent by the ALCAP of the peer end, the ALCAP sends an ESTABLISH indication primitive to the service layer after resource allocation and activates the wait timer.
3) After receiving an ESTABLISH response from the service layer before the time expires, it sends an ESTABLISH confirm to the RNC ALCAP.
The release procedures are similar with the establish procedures.
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II. Blocking and unblocking of AAL2 path
To prevent a new connection being established over an AAL2 path, a blocking can be initiated from the O&M system for the path.
When a path is unblocked, the originating end is in a locally blocked state and the peer end in a remotely blocked state. If the peer end also initiates a blocking, both ends of the path are in a locally blocked state. The test connection can be set up over the path in a blocked state.
The blocked AAL2 path may be unblocked through an unblocking procedure. The unblocking procedure can be initiated by local end or remote end.
The message procedure of blocking and unblocking a path is shown in Figure 2-12.
BLOCK REQUEST
RNC ALCAP ALCAPO&M
BLOCK CONFIRM
BLOCK REQUEST
UNBLOCK CONFIRM
UNBLOCK REQUEST
BLOCK CONFIRM
UNBLOCK REQUEST
UNBLOCK CONFIRM
Figure 2-12 Blocking and unblocking of a path
The procedures to block a path are as follows:
1) O&M at RNC initiates BLOCK REQUEST to ALCAP at RNC. 2) ALCAP at RNC sends BLOCK REQUEST to ALCAP at the peer end. 3) After analyzing the message, ALCAP at the peer end set the path as blocked and
generates a BLOCK confirm message. 4) After receiving the BLOCK CONFIRM message, RNC ALCAP sends back the
message to O&M.
The unblocking procedures are similar with the blocking procedures.
III. Reset
Reset can help to release AAL2 connection or AAL2 PATH in a confused state. There are three types of resets: reset of an AAL2 connection, reset of an AAL2 PATH and reset of all AAL2 PATHs between two SPs.
The message procedures for a reset are shown in Figure 2-13.
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RESET REQUEST
RNC ALCAP ALCAPO&M
RESET CONFIRM
RESET REQUEST
RESET CONFIRM
Service
RELEASE INDICATION
Figure 2-13 Reset procedures
This procedures to reset are as follows:
1) O&M at RNC initiates RESET REQUEST to ALCAP at RNC. 2) ALCAP at RNC sends RESET REQUEST to ALCAP at the peer end. 3) After analyzing the message, ALCAP at the peer end set the path as blocked and
generates a RESET confirm message. If there is any connection in the micro path or tunnel, the connection will be released and a RELEASE INDICATION will be reported to service layer.
4) After receiving the RESET CONFIRM message, RNC ALCAP feeds back the message to O&M.
2.4.3 Message structure
The length of the ALCAP message is variable and the message header is 6 bytes long fixedly. The parameter in the message is classified into mandatory parameter that may be further divided into fixed-length parameter and variable-length parameter and optional parameter. The first byte of the variable-length field in the variable-length parameter should indicate the length of the field. The architecture is shown in Figure 2-14.
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Signaling related ID
Message ID
Message compatability field
Message length
ID of parameter A
Compatability field for parameter A
Length of parameter A
Field a in parameter A
Field b in parameter A
Length of field c in parameter A
Field c in parameter A
Parameter B
M
Figure 2-14 ALCAP message structure
2.4.4 Establish Request Message
I. Message Structure
Refer to “2.4.3 Message Structure”.
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II. Example
2.5 SCCP
2.5.1 Overview
Signaling Connection Control Part (SCCP) is used to enhance the functions of Message Transfer Part (MTP). The addressing function of MTP only can be used to transmit messages to nodes, providing only the connectionless message transfer. While SCCP is able to provide a type of addressing function to identify each SCCP user in a node using DPC and subsystem number (SSN).
The SCCP in the BSC6800 system complies with ITU-T Q711-716.
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2.5.2 Function
The SCCP performs network service, routing and management functions.
I. Network service function
The SCCP provides three classes of service:
Class 0: Basic connectionless class Class 1: In sequence delivery connectionless class Class 2: Basic connection-oriented class
Class 0 and class 1 protocols are used in connectionless-oriented services, while class-2 protocol is used in connection-oriented services.
1) Connectionless services
Connectionless services are implemented in the case that the user directly transmits data information in the signaling network by means of SCCP and MTP route functions without prior establishment of signaling connections, featuring flexibility and simpleness and applicable for the transmission of small quantities of data. Among them, class-0 service does not ensure the messages can be transmitted in sequence but class-1 service is able to do that depending on the cooperation of the signaling link selection code (SLS) and MTP.
Connectionless services implement user data transmission using Unit Data (UDT) and Enhanced Unit Data (XUDT) messages. The UDT message is not able to segment/reassemble data and the maximum length of the user data that can be transmitted via this message is 255 octets. The XUDT message is capable of segmenting/reassembling data and transmitting the user data of with the maximum length of 2k octets.
2) Connection-oriented services
Connection-oriented services are implemented only after the user establishes signaling connections (virtual connections) between OSPs and DSPs by means of answer mode before transmitting signaling messages. In this way, data can be transmitted via the established signaling connection instead of the route selected via the SCCP routing function. Upon the completion of the data transmission, the user can release the connection with the primitive N_DISCONNECT_REQ. Connection-oriented services are applicable for the transmission of large quantities of data. The DSP is confirmed to be able to receive data prior to data transmission; therefore invalid transmission of large quantities of data can be avoided. Furthermore, the pre-established connection makes the SCCP routing function unnecessary for the subsequent transmissions, thus effectively reducing the batch transmission delay.
The implementation procedure of connection-oriented services includes connection establishment, data transmission and connection release. Capable of setting up coupling connections, the BSC6800 system provides the local reference function of
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freezing the local node to prevent disordered connections when releasing the local connection reference source.
II. Routing function
The routing function of the BSC6800 system is used to implement the addressing for DPC+SSN address information.
The SCCP routing function implements the addressing for SCCP address information more universal than DPC.
SCCP address information covers:
1) DPC 2) DPC+SSN
In which DPC is the one adopted by MTP while SSN is used to identify different SCCP users (for example, ISUP, MAP, TCAP. and so on) so as to compensate for shortage of MTP users and broaden the addressing scope, thus to be applicable for new services in the future. The routing function of the BSC6800 system can translate the following types of address information as per the actual requirements: DPC+SSN and DPC.
Upon receiving a message from MTP, the SCCP route control part of a node analyzes its called address. If this node is the destination of this message, it will distribute the message to the destination user. Otherwise it will translate the address of the message to form a new route flag and potential new called address and then send them to MTP.
Upon receiving a message from the connection-oriented control part or the connectionless control part, SCCP performs route analysis to it and then send it to the MTP part, the connection-oriented control part or the connectionless control part for processing.
III. Management function
The SCCP management function implements network maintenance by rerouting or adjusting traffic volume in case of network fault or congestion. This function is realized via the transmission of the SCCP management message and primitive where class-0 UDT serves as the management message. The SCCP management includes SP management, subsystem management, harmonization between active/standby subsystems, broadcast of status information and status test of faulty subsystem.
2.5.3 Message Structure
If the SI of a MSU equals to 0011, it means the message is SCCP message. The content of the SCCP message is located in the SIF of the MSU, as shown in Figure 2-15. The route flags of SCCP also includes DPC, OPC and SLS.
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Figure 2-15 SCCP message structure
2.5.4 Connection Request Message
I. Message Structure
Refer to “2.5.3 Message Structure”
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II. Example
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Chapter 3 Cell Related Procedure Analysis
3.1 Overview
Successful cell setup is prerequisite to normal communication of the WCDMA system. The BSC6800 can implement cell setup in two ways.
Cell setup via O&M system
This procedure is directly initiated by an RNC and involves such procedures as cell setup, common transport channel setup, Iub interface data transport bearer setup, system information update, common measurement initiation, and so on.
Cell setup triggered by resource audit response from NodeB
RNC initiates resource audit procedure towards NodeB. NodeB responses to RNC, and then RNC initiate the cell setup procedure. The procedures thereafter are similar to those involved in the cell setup through O&M system.
This chapter includes the following contents:
1) Description of each procedure of cell setup. 2) One example of the procedures to set up a cell.
3.2 Procedures Involved in Cell Setup
3.2.1 Resource Status Indication Procedure
RESOURCE STATUS INDICATION
NodeB CRNC
Figure 3-1 Resource status indication
NodeB uses resource status indication to report its physical resources to RNC. In the following cases, NodeB will trigger the resource status indication procedures:
When a Local Cell becomes existing at the NodeB. When a Local Cell is to be deleted in NodeB, that is, the status becomes Not
existing. When the capabilities of the Local Cell changes at the NodeB.
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When a cell has changed its capability and/or its resource operational state at NodeB.
When common physical channels and/or common transport channels have changed their capabilities at a NodeB.
When a communication control port changed its resource operational state at the NodeB.
When a Local Cell Group has changed its resource capability at the NodeB.
The NodeB initiates a RESOURCE STATUS INDICATION message to the CRNC in each of the above cases and the RESOURCE STATUS INDICATION message may contain the trigger cause and the associated logical resource contents, as shown in Figure 3-1.
3.2.2 Resource Audit Procedure
The resource audit procedure is executed by the CRNC to perform an audit of the configuration and status of the logical resources in the NodeB. A complete audit of a NodeB is performed by one or more Audit procedures and each procedure carries an audit sequence number. The audit may cause the CRNC to re-sync the NodeB to the status of logical resources known by the CRNC.
The procedure is initiated with an AUDIT REQUEST message sent from the CRNC to the NodeB, as shown in Figure 3-2.
If the Start of Audit Sequence information element (IE) in the AUDIT REQUEST message is set to “start of audit sequence”, a new audit sequence is started, any ongoing audit sequence shall be aborted and the NodeB shall provide (part of the) audit information.
If the Start of Audit Sequence IE is set to” not start of audit sequence”, the NodeB shall provide (part of) the remaining audit information not already provided during this audit sequence.
AUDIT REQUEST
NodeB CRNC
AUDIT RESPONSE
Figure 3-2 Resource audit procedure
The NodeB responds to the resource audit request of the RNC by an AUDIT RESPONSE message. AUDIT RESPONSE message includes information about physical common channel of logical cell, CCP, local cell, local group cell. Among which the local cell and the local cell group information is the abstraction of the NodeB’s
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physical resources. In this way, RNC can distribute the logical resources of the cell according to the abstract data.
If the information provided in the AUDIT RESPONSE message completes the audit sequence, the NodeB shall set the End of Audit Sequence Indicator IE in the AUDIT RESPONSE message to “End of Audit Sequence”.
If not all audit information has been provided yet as part of the ongoing audit sequence, the NodeB shall set the End of Audit Sequence Indicator IE in the AUDIT RESPONSE message to “Not End of Audit Sequence”.
3.2.3 Cell Setup Procedure
CELL SETUP REQUEST
NodeB CRNC
CELL SETUP RESPONSE
Figure 3-3 Cell setup procedure
After receiving the AUDIT RESPONSE from the NodeB, the CRNC sends a CELL SETUP REQUEST message to the NodeB if the conditions of cell setup are satisfied. The NodeB shall set up a new cell according to the parameters included in that message, as shown in Figure 3-3.
If the CELL SETUP REQUEST message includes one or more Secondary CPICH Information IE(s), the NodeB shall configure and activate the Secondary CPICH(s) (SCPICH(s)) in the cell according to received configuration data.
The Maximum Transmission Power IE value shall be stored in the NodeB and at any instance of time the total maximum output power in the cell shall not be bigger than this value.
If the CELL SETUP REQUEST message includes one or more Closed Loop Timing Adjustment Mode IE(s), the value(s) shall be stored in the NodeB and applied when closed loop Feed-Back mode diversity is used on DPCH.
When the cell is successfully configured, the NodeB shall store the Configuration Generation ID IE value and send a CELL SETUP RESPONSE message as a response.
When the cell is successfully configured, CPICH(s), Primary SCH (PSCH), Secondary SCH (SSCH), Primary CCPCH (PCCPCH) and BCH exist. The cell and the channels shall be set to Enabled state. When the cell is not successfully configured, the CELL SETUP FAILURE message shall be sent to CRNC.
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3.2.4 Common Transport Channel Setup Procedure
The common transport channel setup procedure is used for establishing the following channels: Secondary CCPCH (SCCPCH), FACH, PCH, PICH, PRACH, RACH, AICH.
COMMON TRANSPORT CHANNEL SETUPREQUEST
NodeB CRNC
COMMON TRANSPORT CHANNEL SETUPRESPONSE
Figure 3-4 Common transport channel setup procedure
The procedure is initiated with a COMMON TRANSPORT CHANNEL SETUP REQUEST message sent from the CRNC to the NodeB. One message can configure only one of the following combinations:
One SCCPCH, and FACHs, PCH and PICH related to that SCCPCH One PRACH, one RACH and one AICH related to that PRACH
If successfully set up the common transport channel, NodeB responds with a COMMON TRANSPORT CHANNEL SETUP RESPONSE message to the CRNC. If fails to set up the common transport channel, NodeB responds with a COMMON TRANSPORT CHANNEL SETUP FAILURE message.
Note:
The transport channel synchronization procedure in user plane follows the establishment of downlink common transport channel. After the PCH is established successfully, the node synchronization procedure in user plane may follow.
3.2.5 Iub Interface User Plane Setup
The CRNC sends an ALCAP message Q.AAL2 ESTABLISH REQUEST to the NodeB, requesting for Iub interface user plane establishment. After a successful establishment, NodeB responds with an ALCAP message Q.AAL2 ESTABLISH CONFIRM to the CRNC, indicating the Iub interface user plane has been established.
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3.2.6 System Information Update
SYSTEM INFORMATION UPDATEREQUEST
NodeB CRNC
SYSTEM INFORMATION UPDATERESPONSE
Figure 3-5 System information update
After all common transport channels are set up, the CRNC sends a SYSTEM INFORMATION UPDATE REQUEST message to the NodeB, as shown in Figure 3-5. That message includes the contents of the system information segments broadcast on the BCCH and the segment scheduling information.
When the NodeB successfully completes the updating of the broadcast channel scheduling cycle according to the parameters given in the SYSTEM INFORMATION UPDATE REQUEST message, it responds to the CRNC with a SYSTEM INFORMATION UPDATE RESPONSE message. When the NodeB does not successfully complete the updating, it responds with a SYSTEM INFORMATION UPDATE FAILURE message.
3.2.7 Common Measurement Initiation Procedure
COMMON MEASUREMENT INITIATIONREQUEST
NodeB CRNC
COMMON MEASUREMENT INITIATIONRESPONSE
Figure 3-6 Common measurement initiation procedure
The procedure is initiated with a COMMON MEASUREMENT INITIATION REQUEST message sent from the CRNC to the NodeB using the NodeB control port, as shown in Figure 3-6. That message includes the measurement object type (cell, RACH, and so on), common measurement type (Tx carrier power, total Rx broadband power, and so on) and report characteristics (On-Demand report, periodic report, event report, and so on). Upon receipt of the message, the NodeB initiates the requested measurement according to the parameters given in the request.
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If the NodeB is able to initiate the measurement requested by the CRNC, it responds with the COMMON MEASUREMENT INITIATION RESPONSE message sent over the NodeB control port. If the initiation fails, it responds the COMMON MEASUREMENT INITIATION FAILURE message.
3.2.8 Cell Reconfiguration Procedure
The cell reconfiguration procedure is used for an RNC to reconfigure a cell in NodeB when the cell parameters need to be modified, as illustrated in Figure 3-7.
CELL RECONFIGURATION REQUEST
NodeB CRNC
CELL RECONFIGURATION RESPONSE
Figure 3-7 Cell reconfiguration
The CRNC sends a CELL RECONFIGURATION REQUEST message to the NodeB. Upon reception, the NodeB reconfigures the cell according to the parameter included in the message.
If the CELL RECONFIGURATION REQUEST message includes the Primary SCH Information IE, the NodeB reconfigures Primary SCH power in the cell according to Primary SCH Power IE value.
If the CELL RECONFIGURATION REQUEST message includes the Secondary SCH Information IE, the NodeB reconfigures Secondary SCH power in the cell according to the Secondary SCH Power IE value.
If the CELL RECONFIGURATION REQUEST message includes the Primary CPICH Information IE, the NodeB reconfigures Primary CPICH power in the cell according to the Primary CPICH Power IE value. NodeB adjusts all the transmitted power levels relative to the Primary CPICH power according to the new value.
If the CELL RECONFIGURATION REQUEST message includes one or more Secondary CPICH Information IE, the NodeB reconfigures the power for each Secondary CPICH in the cell according to their Secondary CPICH Power IE value.
If the CELL RECONFIGURATION REQUEST message includes the Primary CCPCH Information IE, the NodeB reconfigures BCH power in the cell according to the BCH Power IE value.
If the CELL RECONFIGURATION REQUEST message includes the Maximum Transmission Power IE, the value shall be stored in the NodeB and at any
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instance of time the total maximum output power in the cell shall not be bigger than this value.
If reconfigure the cell successfully, NodeB stores the new Configuration Generation ID IE value and sends a CELL RECONFIGURATION RESPONSE message as a response. If fail to reconfigure the cell, NodeB sends a CELL RECONFIGURATION FAILURE message.
If the CELL RECONFIGURATION REQUEST message includes the Synchronization Configuration IE, NodeB reconfigures the indicated parameters in the cell according to the IE value. When the parameters in the Synchronization Configuration IE affect the thresholds applied to a radio link set, NodeB immediately applies the new thresholds.
3.2.9 Cell Deletion Procedure
The cell deletion procedure is used to delete a cell from NodeB, as illustrated in Figure 3-8.
CELL DELETION REQUEST
NodeB CRNC
CELL DELETION RESPONSE
Figure 3-8 Cell deletion
1) The CRNC sends a CELL DELETION REQUEST message to NodeB. Upon reception, NodeB deletes the cell and any remaining common and dedicated channels within the cell. The states for the cell and the deleted common channels shall be set as Not Existing. The NodeB deletes all radio links and all NodeB Communication Context within the cell. NodeB also initiates releasing of the user plane transport bearers for the deleted common and dedicated channels.
2) After delete the cell, NodeB return a CELL DELETION RESPONSE message as a response.
3.2.10 Resource Status Indication Message
I. Message Structure
IE/Group Name Presence Semantics description
Message Discriminator M –
Message Type M –
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IE/Group Name Presence Semantics description
Transaction ID M –
Indication Type M –
CHOICE Indication Type M –
>No Failure –
>>Local Cell Information –
>>>Local Cell ID M –
>>>Add/Delete Indicator M –
>>>DL or Global Capacity Credit C-add –
>>>UL Capacity Credit O –
>>>Common Channels Capacity Consumption Law
C-add –
>>>Dedicated Channels Capacity Consumption Law
C-add –
>>>Maximum DL Power Capability C-add –
>>>Minimum Spreading Factor C-add –
>>>Minimum DL Power Capability C-add –
>>>Local Cell Group ID O –
>>Local Cell Group Information –
>>>Local Cell Group ID M –
>>>DL or Global Capacity Credit M –
>>>UL Capacity Credit O –
>>>Common Channels Capacity Consumption Law
M –
>>>Dedicated Channels Capacity Consumption Law
M –
>Service Impacting –
>>Local Cell Information –
>>>Local Cell ID M –
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IE/Group Name Presence Semantics description
>>>DL or Global Capacity Credit O –
>>>UL Capacity Credit O –
>>>Common Channels Capacity Consumption Law
O –
>>>Dedicated Channels Capacity Consumption Law
O –
>>>Maximum DL Power Capability O –
>>>Minimum Spreading Factor O –
>>>Minimum DL Power Capability O –
>>Local Cell Group Information –
>>>Local Cell Group ID M –
>>>DL or Global Capacity Credit O –
>>>UL Capacity Credit O –
>>>Common Channels Capacity Consumption Law
O –
>>>Dedicated Channels Capacity Consumption Law
O –
>>Communication Control Port Information
–
>>>Communication Control Port ID M –
>>>Resource Operational State M –
>>>Availability Status M –
>>Cell Information –
>>>C-ID M –
>>>Resource Operational State O –
>>>Availability Status O –
>>>Primary SCH Information O –
>>>Secondary SCH Information O –
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IE/Group Name Presence Semantics description
>>>Primary CPICH Information O –
>>>Secondary CPICH Information –
>>>>Secondary CPICH Individual Information
M –
>>>Primary CCPCH Information O –
>>>BCH Information O –
>>>Secondary CCPCH Information –
>>>>Secondary CCPCH Individual Information
M –
>>>PCH Information O –
>>>PICH Information O –
>>>FACH Information –
>>>>FACH Individual Information M –
>>>PRACH Information –
>>>>PRACH Individual Information M –
>>>RACH Information –
>>>>RACH Individual Information M –
>>>AICH Information –
>>>>AICH Individual Information M –
>>>PCPCH Information –
>>>>PCPCH Individual Information M –
>>>CPCH Information –
>>>>CPCH Individual Information M –
>>>AP-AICH Information –
>>>>AP-AICH Individual Information M –
>>>CD/CA-ICH Information –
>>>>CD/CA-ICH Individual Information M –
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IE/Group Name Presence Semantics description
>>>SCH Information O –
Cause O –
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II. Examples
3.2.11 Audit Response Message
I. Message Structure
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IE/Group Name Presence Semantics description
Message Discriminator M –
Message Type M –
Transaction ID M –
End Of Audit Sequence Indicator M –
Cell Information –
>C-ID M –
>Configuration Generation ID M –
>Resource Operational State M –
>Availability Status M –
>Local Cell ID M –
>Primary SCH Information O –
>Secondary SCH Information O –
>Primary CPICH Information O –
>Secondary CPICH Information –
>>Secondary CPICH Individual Information M –
>Primary CCPCH Information O –
>BCH Information O –
>Secondary CCPCH Information –
>>Secondary CCPCH Individual Information
M –
>PCH Information O –
>PICH Information O –
>FACH Information –
>>FACH Individual Information M –
>PRACH Information –
>>PRACH Individual Information M –
>RACH Information –
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IE/Group Name Presence Semantics description
>>RACH Individual Information M –
>AICH Information –
>>AICH Individual Information M –
>PCPCH Information –
>>PCPCH Individual Information M –
>CPCH Information –
>>CPCH Individual Information M –
>AP-AICH Information –
>>AP-AICH Individual Information M –
>CD/CA-ICH Information –
>>CD/CA-ICH Individual Information M –
>SCH Information O –
Communication Control Port Information
–
>Communication Control Port ID M –
>Resource Operational State M –
>Availability Status M –
Local Cell Information –
>Local Cell ID M –
>DL or Global Capacity Credit M –
>UL Capacity Credit O –
>Common Channels Capacity Consumption Law
M –
>Dedicated Channels Capacity Consumption Law
M –
>Maximum DL Power Capability O –
>Minimum Spreading Factor O –
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IE/Group Name Presence Semantics description
>Minimum DL Power Capability O –
>Local Cell Group ID O –
Local Cell Group Information –
>Local Cell Group ID M –
>DL or Global Capacity Credit M –
>UL Capacity Credit O –
>Common Channels Capacity Consumption Law
M –
>Dedicated Channels Capacity Consumption Law
M –
Criticality Diagnostics O –
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II. Examples
3.2.12 Cell Setup Request Message
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I. Message Structure
IE/Group Name Presence Semantics description
Message Discriminator M –
Message Type M –
Transaction ID M –
Local Cell ID M –
C-ID M Cell ID
Configuration Generation ID M –
T_Cell M Offset of T_cell against BFN
UARFCN M –
UARFCN M –
Maximum Transmission Power M Maximum transmission power
Closed Loop Timing Adjustment Mode O –
Primary Scrambling Code M Primary scrambling code of cell
Synchronization Configuration –
>N_INSYNC_IND M –
>N_OUTSYNC_IND M –
>T_RLFAILURE M –
DL TPC pattern 01 count M –
Primary SCH Information –
>Common Physical Channel ID M –
>Primary SCH Power M –
>TSTD Indicator M –
Secondary SCH Information –
>Common Physical Channel ID M –
>Secondary SCH power M –
>TSTD Indicator M –
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IE/Group Name Presence Semantics description
Primary CPICH Information –
>Common Physical Channel ID M –
>Primary CPICH power M –
>Transmit Diversity Indicator M –
Secondary CPICH Information –
>Common Physical Channel ID M –
>DL Scrambling code M –
>FDD DL Channelisation Code Number M –
>Secondary CPICH Power M –
>Transmit Diversity Indicator M –
Primary CCPCH Information –
>Common Physical Channel ID M –
>BCH Information –
>>Common Transport Channel ID M –
>>BCH Power M PCPICH transmission power
>STTD Indicator M –
Limited power increase information –
>Power_Raise_Limit M –
>DL_power_averaging_window_size M –
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II. Example
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3.2.13 Common Transport Channel Setup Request Message
I. Message Structure
IE/Group Name Presence Semantics description
Message Discriminator M
Message Type M
Transaction ID M
C-ID M Cell ID
Configuration Generation ID M
CHOICE common physical channel to be configured
M
>Secondary CCPCH Situation when the SCCPCH established
>>Secondary CCPCH
>>>Common Physical Channel ID M
>>>FDD SCCPCH Offset M SCCPCH timing offset
>>>DL Scrambling Code C-PCH
>>>FDD DL Channelisation Code Number M
>>>TFCS M –
>>>Secondary CCPCH Slot Format M –
>>>TFCI Presence C – SlotFormat
–
>>>Multiplexing Position M –
>>>Power Offset Information Power offset
>>>>PO1 M TFCI bit power offset
>>>>PO3 M Preamble bit power offset
>>>STTD Indicator M –
>>>FACH Parameters –
>>>>Common Transport Channel ID M –
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IE/Group Name Presence Semantics description
>>>>Transport Format Set M –
>>>>ToAWS M –
>>>>ToAWE M –
>>>>Max FACH Power M –
>>>PCH Parameters
>>>>Common Transport Channel ID M –
>>>>Transport Format Set M –.
>>>>ToAWS M –
>>>>ToAWE M –.
>>>>PCH Power M –
>>>>PICH Parameters
>>>>>Common Physical Channel ID M –
>>>>>FDD DL Channelisation Code Number
M –.
>>>>>PICH Power M –
>>>>>PICH Mode M –.
>>>>>STTD Indicator M –
>PRACH Situation when PRACH established
>>PRACH
>>>Common Physical Channel ID M
>>>Scrambling Code Number M
>>>TFCS M –.
>>>Preamble Signatures M
>>>Allowed Slot Format Information
>>>>RACH Slot Format M
>>>RACH Sub Channel Numbers M
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IE/Group Name Presence Semantics description
>>>Puncture Limit M
>>>Preamble Threshold M
>>>RACH Parameters –
>>>>Common Transport Channel ID M –
>>>>Transport Format Set M –
>>AICH Parameters –
>>>Common Physical Channel ID M –
>>>AICH Transmission Timing M –
>>>FDD DL Channelisation Code Number M –
>>>AICH Power M –
>>>STTD Indicator M –
>PCPCHes Situation when PCPCH established
>>CPCH Parameters –
>>>Common Transport Channel ID M –
>>>Transport Format Set M –
>>>AP Preamble Scrambling Code M –
>>>CD Preamble Scrambling Code M –
>>>TFCS M –
>>>CD Signatures O –
>>>CD Sub Channel Numbers –
>>>Puncture Limit M –
>>>CPCH UL DPCCH Slot Format M –
>>>UL SIR M –
>>>Initial DL transmission Power M –
>>>Maximum DL Power M –
>>>Minimum DL Power M –
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IE/Group Name Presence Semantics description
>>>PO2 M –
>>>PO3 M –
>>>FDD TPC DL Step Size M –
>>>N_Start_Message M –
>>>N_EOT M –
>>>Channel Assignment Indication M –
>>>CPCH Allowed Total Rate M –
>>>PCPCH Channel Information –
>>>>Common Physical Channel ID M –
>>>>CPCH Scrambling Code Number M –
>>>>DL Scrambling Code M –
>>>>FDD DL Channelisation Code Number
M –
>>>>PCP Length M –
>>>>UCSM Information C-NCA –
>>>>>Min UL Channelisation Code Length M –
>>>>>NF_max M –
>>>>>Channel Request Parameters –
>>>>>>AP Preamble Signature M –
>>>>>AP Sub Channel Number O –
>>>VCAM Mapping Information C-CA –
>>>>Min UL Channelisation Code Length M –
>>>>NF_max M –
>>>>Max Number of PCPCHes M –
>>>>SF Request Parameters –
>>>>>AP Preamble Signature M –
>>>>>AP Sub Channel Number O –
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IE/Group Name Presence Semantics description
>>>AP-AICH Parameters –
>>>>Common Physical Channel ID M –
>>>>FDD DL Channelisation Code Number
M –
>>>>AP-AICH Power M –
>>>>CSICH Power M –
>>>>STTD Indicator M –
>>>CD/CA-ICH Parameters –
>>>>Common Physical Channel ID M –
>>>>FDD DL Channelisation Code Number
M –
>>>>CD/CA-ICH Power M –
>>>>STTD Indicator M –
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II. Example
3.2.14 System Information Update Request Message
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I. Message Structure
IE/Group Name Presence Semantics description
Message Discriminator M –
Message Type M –
Transaction ID M –
C-ID M –
BCCH Modification Time O –
MIB/SB/SIBInformation –
>IB Type M –
>IB OC ID M –
>CHOICE IB DeletionIndicator M –
>>NoDeletion –
>>>SIB Originator C-SIB –
>>>IB SG REP O –
>>>Segment Information –
>>>>IB SG POS O –
>>>>Segment type C – CRNCOrigination
–
>>>>IB SG DATA C – CRNCOrigination
–
>>Deletion –
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II. Example
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3.3 Example of Cell Setup Procedures
This section describes an example of cell setup triggered by the resource status indication procedure, as illustrated in Figure 3-9.
In this example, Two SCCPCHs and one PRACH are setup in the cell. One SCCPCH bears two FACHs and the other SCCPCH bears two FACHs and one PCH. The PRACH bears one RACH.
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Node B
13.ALCAP:QAAL2 ESTABLISH CONFIRM
2. NCP: AUDIT REQUEST
1.NCP:RESOURCE STATUS INDICATION
3.NCP: AUDIT RESPONSE
4.NCP: CELL SETUP REQUEST
5.NCP: CELL SETUP RESPONSE
6.NCP: COMMON TRANSPORT CHANNEL SETUP REQUEST
7.NCP: COMMON TRANSPORT CHANNEL SETUP RESPONSE
12.ALCAP:QAAL2 ESTABLISH REQUEST
8.ALCAP:QAAL2 ESTABLISH REQUEST
9.ALCAP:QAAL2 ESTABLISH CONFIRM
10.NCP: COMMON TRANSPORT CHANNEL SETUP REQUEST
11.NCP: COMMON TRANSPORT CHANNEL SETUP RESPONSE
RNC
15.ALCAP:QAAL2 ESTABLISH CONFIRM
14.ALCAP:QAAL2 ESTABLISH REQUEST
17.ALCAP:QAAL2 ESTABLISH CONFIRM
16.ALCAP:QAAL2 ESTABLISH REQUEST
18.NCP:COMMON TRANSPORT CHANNEL SETUP REQUEST
19.NCP:COMMON TRANSPORT CHANNEL SETUP RESPONSE
20. ALCAP: QAAL2 ESTABLISH REQUEST
21. ALCAP: QAAL2 ESTABLISH CONFIRM
22. ALCAP: QAAL2 ESTABLISH REQUEST
23. ALCAP: QAAL2 ESTABLISH CONFIRM
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Figure 3-9 Cell setup procedures
Each step is explained as follows:
1) NodeB sends a RESOURCE STATUS INDICATION message to the CRNC. The message may contain the trigger cause and the associated logical resource contents.
2) The CRNC sends an AUDIT REQUEST message to the NodeB to initiate the resource audit procedure.
3) The CRNC performs an audit of the configuration and status of the logical resources in the NodeB. It may also re-synchronize the NodeB and the CRNC. After the audit, the NodeB returns an AUDIT RESPONSE message to the CRNC.
4) The CRNC sends a CELL SETUP REQUEST message to the NodeB to initiate a cell setup procedure.
5) The NodeB stores the necessary resources and configures a new cell according to the parameters given in the CELL SETUP REQUEST message. After the cell setup, the NodeB returns a CELL SETUP RESPONSE message to the CRNC, confirming that the cell is successfully set up.
NodeB
RNC
32. NCP: MEASUREMENT REPORT
33. NCP: MEASUREMENT REPORT
30. NCP: COMMON MEASUREMENT INITIATION REQUEST
31. NCP: COMMON MEASUREMENT INITIATION RESPONSE
28. NCP: COMMON MEASUREMENT INITIATION REQUEST
29. NCP: COMMON MEASUREMENT INITIATION RESPONSE
34. NCP: MEASUREMENT REPORT
26. NCP: COMMON MEASUREMENT INITIATION REQUEST
27. NCP: COMMON MEASUREMENT INITIATION RESPONSE
24. NCP: SYSTEM INFORMATION UPDATE REQUEST
NCP: SYSTEM INFORMATION UPDATE RESPONSE25
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6) The CRNC sends a COMMON TRANSPORT CHANNEL SETUP REQUEST message to the NodeB, requesting the NodeB to set up a PRACH.
7) The NodeB returns a COMMON TRANSPORT CHANNEL SETUP RESPONSE, confirming that the common transport channel is successfully set up.
8) The CRNC sends a QAAL2 ESTABLISH REQUEST message to the NodeB using ALCAP protocol to initiate an Iub interface data transport bearer establishment procedure. The message contains an AAL2 binding identity to bind the Iub interface data transport bearer to the RACH.
9) The NodeB returns a QAAL2 ESTABLISH CONFIRM message to the CRNC as a response.
10) The CRNC sends a COMMON TRANSPORT CHANNEL SETUP REQUEST to the NodeB, requesting the NodeB to set up an SCCPCH. Here, the SCCPCH bears two FACHs and one PCH.
11) The NodeB returns a COMMON TRANSPORT CHANNEL SETUP RESPONSE message, confirming that the common transport channel is successfully set up.
12) 14) 16) The CRNC sends a QAAL2 ESTABLISH REQUEST message to the NodeB to initiate an Iub interface data transport bearer establishment procedure. This procedure is implemented for three times to set up three Iub interface data transport bearers. Each QAAL2 ESTABLISH REQUEST message contains an AAL2 binding identity to bind the corresponding Iub interface data transport bearer to the two FACHs and one PCH.
13) 15) 17) The NodeB returns a QAAL2 ESTABLISH CONFIRM message to the CRNC as a response. Corresponding to the three QAAL2 ESTABLISH REQUEST messages, the NodeB returns three QAAL2 ESTABLISH CONFIRM messages to the CRNC.
14) The CRNC sends a COMMON TRANSPORT CHANNEL SEUTP REQUEST message to the NodeB, requesting the NodeB to set up a SCCPCH. This SCCPCH bears two FACHs.
15) The NodeB returns a COMMON TRANSPORT CHANNEL SETUP RESPONSE message, confirming the successful setup of the common transport channel.
16) 22) The CRNC sends an ALCAP message QAAL2 ESTABLISH REQUEST to the NodeB to initiate an Iub interface data transport bearer establishment procedure. This procedure is implemented for two times to set up two Iub interface data transport bearers. Each QAAL2 ESTABLISH REQUEST message contains an AAL2 binding identity to bind the corresponding Iub interface data transport bearer to the two FACHs.
17) 23) The NodeB returns a QAAL2 ESTABLISH CONFIRM message to the CRNC as a response. Corresponding to the two QAAL2 ESTABLISH REQUEST messages, the NodeB returns two QAAL2 ESTABLISH CONFIRM messages to the CRNC.
18) The CRNC sends a SYSTEM INFORMATION UPDATE REQUEST message to the NodeB.
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19) The NodeB returns a SYSTEM INFORMATION UPDATE RESPONSE message, confirming the successful update of the system information.
20) 28) 30) The RNC sends a COMMON MEASUREMENT INITIATION REQUEST message to the NodeB. The message is sent for three times, requesting for three types of common measurements: Tx carrier power measurement in the form of periodic report, RTWP measurement in the form of periodic report and Tx carrier power measurement in the form of event-E report.
21) 29) 31) Corresponding to the three COMMON MEASUREMENT INITIATION REQUEST messages, the NodeB returns three COMMON MEASUREMENT INITIATION RESPONSE messages, confirming the successful initiation of the common measurement.
22) According to the RNC request, the NodeB periodically sends the Tx carrier power MEASUREMENT REPORT.
23) According to the RNC request, the NodeB periodically sends the RTWP MEASUREMENT REPORT.
24) According the RNC request, the NodeB sends the Tx carrier power MEASUREMENT REPORT only when the event E occurs.
So far, the setup of the cell has completed and UE can access to the network.
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Chapter 4 System Information Procedure Analysis
4.1 Overview
System information is broadcasted to the UEs within a cell or the whole PLMN. Its purpose is to tell UE the common information of the access stratum and the non-access stratum. In this way, it helps the UE to know the network configuration before initiate a call, thus to choose a proper way to initiate the call.
Information on the non-access stratum includes operator’s information, CN domain information and so on; Information on the access stratum includes URA information, cell information, channel information, cell selection/re-selection information and so on.
4.1.1 System Information Structure
System information includes MIB (Master Information Block), SB (Scheduling Block) and SIB (System Information Block).
MIB
SIB
SB
SIB
SIB
SIB
Figure 4-1 System information structure
The three types of system information blocks are organized as a tree as shown in Figure 4-1. Their features and main contents are as follows:
A MIB bears scheduling information to a number of SIBs or SBs in a cell. A MIB can also contain the PLMN Type (GSM and/or ANSI-41) supported by the cell and the PLMN ID. MIBs are regularly broadcast on a BCH on fixed occasions. Because BCH is mapped to the PCCPCH, UE within the cell can read the content of MIB to know if it is necessary of update or store the system information.
A SB bears additional scheduling information for SIBs. The SB is applied when the scheduling resources of the MIB are insufficient.
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SIB bears the actual system information, including 18 type of SIB. The scheduling information of SIB is borne by MIB or SB.
4.1.2 System Information Monitoring Mechanism
A SIB groups together system information elements of the same nature. Dynamic parameters (i.e., system parameters changing frequently) and static parameters (i.e., system parameters less or never changing) are borne in different SIBs.
For a SIB containing dynamic parameters (SIB7, SIB8, SIB9, SIB14, SIB17,), the scheduling occasion information is described in the scheduling information included in MIB or SB. The UE regularly reads the SIB at repetition periods.
A SIB containing static parameters (SIB1-SIB6, SIB10-SIB3, SIB15, SIB16 and SIB18) is identified using a value tag. A value tag is included in MIB or SB as a part of the scheduling information. The UE checks whether the value tag for a SIB is different compared to the value tag for the SIB the UE last read. If so, the UE shall re-read the SIB. Therefore, the UE can know by monitoring the MIB whether a SIB containing static parameters is updated.
4.1.3 Functions of System Information
The functions of each SIB type are described as follows:
SIB1: include NAS system information (such as CN information) and UE Timers and constants in idle mode or in connected mode. The scope is PLMN.
SIB2: include URA information.
SIB3: include cell selection and re-selection parameters.
SIB4: include cell selection and re-selection parameters of UE in connected mode.
SIB5: include the configuration parameter of cell common physical channel.
SIB6: include the configuration parameter of cell common physical channel and shared physical channel when UE is in connected mode.
SIB7: include rapid changed parameters (UL interference and Dynamic persistence level).
SIB8: include static CPCH information of cell. Only used in FDD.
SIB9: include CPCH information of cell. Only used in FDD.
SIB10: include the UE’s DCH information controlled by DRAC process. Only used in FDD.
SIB11: include measurement control information of cell.
SIB12: include UE measurement control information under connected mode.
SIB13: include ANSI-41 relevant information.
SIB14: include UL outer loop control parameters of common and dedicated physical channel. Only used in TDD.
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SIB15: include information on UE-based or UE-assisted positioning method
SIB 16: include parameters of radio bearing, transport channel and physical channel. These parameters are stored in UE (either in idle mode or in connected mode). It is used when UE switched to UTRAN. The scope is PLMN.
SIB17: include the rapid changed parameters used to configure the shared physical channel under connected mode. Only used in TDD.
SIB18: include PLMN identity of neighbor cell.
4.2 System Information Broadcast and Update
4.2.1 System Information Broadcast
The signaling flow of system information broadcast is illustrated as Figure 4-2.
UE UTRAN
SYSTEM INFORMATION
Figure 4-2 System information broadcast
UTRAN sends a SYSTEM INFORMATION message to the UE. The message contains the scheduling information, area scope, system information contents, and so on.
The RRC layer in UTRAN performs segmentation and concatenation of encoded system information blocks. If the encoded system information block is larger than the size of a SYSTEM INFORMATION message, it will be segmented and transmitted in several messages. If the encoded system information block is smaller than a SYSTEM INFORMATION message, UTRAN may concatenate several system information blocks, or the first segment or the last segment into the same message.
The UE shall read SYSTEM INFORMATION messages broadcast on a BCH transport channel in idle mode and in states CELL_PCH, CELL_FACH and URA_PCH. In idle mode and connected mode different combinations of SIBs are valid. The UE shall acquire the needed system information blocks. The UE may store SIBs for different cells and different PLMNs, to be used if the UE returns to these cells or PLMNs.
4.2.2 System Information Update
This section describes a complete system information update signaling procedure, as illustrated in Figure 4-3.
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3. BCCH: SYSTEM INFORMATION
1.SYSTEM INFORMATION UPDATE REQUEST
UE NodeB CRNC
NBAPNBAP
RRCRRC
4. BCCH: SYSTEM INFORMATIONRRCRRC
5. BCCH: SYSTEM INFORMATIONRRCRRC
2.SYSTEM INFORMATION UPDATE RESPONSE NBAPNBAP
3. BCCH: SYSTEM INFORMATION
1.SYSTEM INFORMATION UPDATE REQUEST
UE NodeB CRNC
NBAPNBAP
RRCRRC
4. BCCH: SYSTEM INFORMATIONRRCRRC
5. BCCH: SYSTEM INFORMATIONRRCRRC
2.SYSTEM INFORMATION UPDATE RESPONSE NBAPNBAP
Figure 4-3 System information update
Each step is explained in the following list:
1) The RNC sends a NBAP SYSTEM INFORMATION UPDATE REQUEST message to the associated NodeB, requesting for system information broadcast.
2) The NodeB returns a NBAP message SYSTEM INFORMATION UPDATE RESPONSE to the RNC, confirming the system information broadcast.
3) ~ 5), the NodeB sends SYSTEM INFORMATION messages on the air interface.
4.2.3 System Information Message
I. Message Structure
Information Element/Group name Need Type and reference
Message type OP –
SFNprime CV-channel –
CHOICE Segment combination MP –
>Combination 1 –
>Combination 2 –
>>First Segment MP –
>Combination 3 –
>>Subsequent Segment MP –
>Combination 4 –
>>Last segment MP –
>Combination 5 –
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Information Element/Group name Need Type and reference
>>Last segment MP –
>>First Segment MP –
>Combination 6 –
>>Last Segment MP –
>>Complete list MP –
>>>Complete MP –
>Combination 7 –
>>Last Segment MP –
>>Complete list MP –
>>>Complete MP –
>>First Segment MP –
>Combination 8 –
>>Complete list MP –
>>>Complete MP –
>Combination 9 –
>>Complete list MP –
>>>Complete MP –
>>First Segment MP –
>Combination 10 –
>>>Complete SIB of size 215 to 226 MP –
>Combination 11 –
>>Last segment of size 215 to 222 MP –
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II. Example
4.3 System Information Modification
System information is modified in two ways: by a value tag and by a timer.
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4.3.1 Modification by a value tag
Upon modifications of SIBs using value tags, UTRAN should notify the new value tag for the MIB to the UE.
To notify UEs in idle mode, CELL_PCH state or URA_PCH state, UTRAN sends a PAGING TYPE 1 message on the PCCH on all paging occasions in the cell to transmit the new MIB value tag.
To notify UEs in CELL_FACH state, UTRAN sends a SYSTEM INFORMATION CHANGE INDICATION message on the BCCH to transmit the new MIB value tag.
Upon reception of a PAGING TYPE 1 message or a SYSTEM INFORMATION CHANGE INDICATION message from UTRAN, the UE shall read the changed system information according to the new MIB value tag.
UE UTRAN
PAGING TYPE 1
Figure 4-4 System information modification (in idle mode and in state CELL_PCH or URA_PCH)
UE UTRAN
SYSTEM INFORMATION CHANGE INDICATION
Figure 4-5 System information modification procedure (in state CELL_FACH)
4.3.2 Modification by a timer
Other types of SIBs have timers respectively. The UE shall consider the stored system information content invalid, start and re-acquire the content of the new SIB when the expiry timer of a SIB expires.
The UE may postpone reading the SIB until the content is needed.
4.3.3 Paging Type 1 Message
Refer to “5.2.4 Paging Type 1 Message”.
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Chapter 5 Call Setup and Release Procedure Analysis
5.1 Overview
When UE searches a cell and reads the system information of the cell, it can obtain the configured parameter of the system and thus access to the network.
There are two types of call setup procedures. One is implemented when the UE acts as a caller and the other when the UE acts as a callee. The difference between the two procedures is that different parties initiate the call setup request.
Either the UE is the caller or is a callee, the call setup/release includes the following procedures:
1) UE initiates the RRC connection setup procedure to set up a signaling connection to the UTRAN.
2) Through Direct Transfer Messages, The RNC sets up a signaling connection to the CN
3) UE capacity information 4) RAB setup 5) RAB release and Iu signaling connection release 6) RRC connection release
5.2 Paging
5.2.1 Overview
Paging includes CN originated paging and UTRAN originated paging.
The CN originated paging procedure is used to establish a signaling connection. It is divided into co-ordination paging and non co-ordination paging. The CN indicates in the RANAP PAGING message whether the RNC shall perform the UTRAN coordination paging.
In the case of co-ordination paging, the RNC shall check whether the UE has other CN domain signaling connections besides the paging domain connection. If so and the UE is in CELL_DCH or CELL_FACH state, the paging message shall be transmitted on the already connected DCCH on the radio interface. If so and the UE is in CELL_FACH or URA_PCH state, the paging message shall be transmitted on the PCCH on the radio interface. If no, the paging message shall be transmitted on the PCCH.
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In the case of non co-ordination paging, the RNC need not check whether the UE has other CN domain signaling connections besides the paging domain connection but directly transmit the paging message on the PCCH in the CN specified paging area.
UTRAN may initiate paging for UEs in CELL_PCH or URA_PCH state to trigger a cell update procedure to CELL_FACH state. In addition, UTRAN may initiate paging for UEs to trigger reading of updated system information.
For UEs in idle mode or in CELL_PCH or URA_PCH state, RNC initiates the paging procedure by transmitting a PAGING TYPE 1 message on the PCCH.
For UEs in CELL_FACH or CELL_DCH state, RNC initiates the paging procedure by transmitting a PAGING TYPE 2 message on the DCCH.
5.2.2 Paging for UEs in Idle Mode or in PCH State
UTRAN usually pages UEs in idle mode or in CELL_PCH or URA_PCH state by transmitting a PAGING TYPE 1 message on the PCCH.
Such paging procedure generally occurs on the following occasions:
When the upper layer in the network initiates paging to set up a call or a signaling connection;
When UTRAN initiates paging for UEs in CELL_PCH or URA_PCH state to trigger a cell update procedure to CELL_FACH state;
When UTRAN initiates paging for UEs to trigger reading of updated system information. In this case, the value tag of the MIB is included in the “BCCH modification info” IE in the PAGING TYPE 1 message.
Figure 5-1 illustrates the paging procedure.
UE UTRAN
PAGING TYPE 1
Figure 5-1 Paging procedure for UEs in idle mode or in PCH state
UTRAN initiates the paging procedure by transmitting a PAGING TYPE 1 message on an appropriate paging occasion on the PCCH. UTRAN may repeat transmission of a PAGING TYPE 1 message to a UE on several paging occasions to increase the probability of proper reception of a page.
UEs in idle mode and in PCH state receive the paging information from the network layer for all its monitored paging occasions. The paging procedure ends.
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5.2.3 Paging for UEs in CELL_DCH or CELL_FACH State
UTRAN usually pages UEs in CELL_DCH or CELL_FACH state by transmitting a PAGING TYPE 2 message on the DCCH.
Figure 5-2 illustrates the signaling procedure.
UE UTRAN
PAGING TYPE 2
Figure 5-2 Paging for UEs in CELL_DCH or CELL_FACH state
UTRAN initiates the paging procedure by transmitting a PAGING TYPE 2 message on the DCCH. Such paging procedure is also called dedicated paging procedure. The UE receives and reads the PAGING TYPE 2 message and forwards the Paging cause IE and the Paging record type identifier IE to NAS in it. The paging procedure ends. This procedure shall not affect the state of any other ongoing RRC procedures at the UE.
If the UE receives a PAGING TYPE 2 message which contains a protocol error, the UE shall discard that paging message and transmit an RRC STATUS message on the uplink DCCH using AM RLC.
5.2.4 Paging Type 1 Message
I. Message Structure
Information Element/Group name Need Type and reference
Message Type MP –
UE Information elements –
Paging record list OP –
>Paging record MP –
Other information elements –
BCCH modification info OP –
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II. Example
5.2.5 Paging Type 2 Message
I. Message Structure
Information Element/Group name Need Type and reference
Message Type MP –
UE information elements –
RRC transaction identifier MP –
Integrity check info CH –
Paging cause MP –
CN Information elements –
CN domain identity MP –
Paging Record Type Identifier MP –
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II. Example
5.3 RRC Connection Setup
5.3.1 Overview
The UE shall initiate the RRC connection setup procedure when the NAS in the UE requests the establishment of a signaling connection and the UE is in idle mode.
After receiving the RRC CONNECTION REQUEST message from the UE, the RNC shall determine according to a specific algorithm whether to accept or reject the RRC connection request. If accepting the request, the RNC shall then determine whether to set up the RRC connection on a dedicated channel (DCH) or on a common channel (CCH). On different channels, the RRC connection setup procedures are different.
Note:
RRC connection setup is always initiated by the UE and RRC connection release by the RNC. Each UE has at most one RRC connection.
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5.3.2 RRC Connection Setup on Dedicated Channel
The RNC shall allocate dedicated radio resources to the UE and set up a radio link and an Iub interface ALCAP user plane transport bearer for the radio link when an RRC connection is set up on a dedicated channel.
Figure 5-3 illustrates the RRC connection setup signaling procedure on a dedicated channel.
UE RNC
NBAP
6.CCCH
NodeB
NBAP
RRCRRC
RRCRRC
1.CCCH:: RRC CONNECTION REQUESTRRCRRC
NBAP NBAP
7.DCCH: RRC CONNECTION SETUP COMPLETE
3. RADIO LINK SETUP REQUEST
4. RADIO LINK SETUP RESPONSE
2.Allocate parameters such asRNTI、L1、L2
5.ALCAP Setup and synchronization
: RRC CONNECTION SETUP
Figure 5-3 RRC connection setup procedure (on dedicated channel)
Each step is explained in the following list:
1) The UE sends an RRC CONNECTION REQUEST message on the uplink CCCH, requesting for the establishment of an RRC connection.
2) The RNC determines, according to the cause in the RRC connection request and the system resource status, to set up the RRC connection on a dedicated channel and allocates the RNTI, radio resources and other resources (L1 and L2 resources).
3) The RNC sends a RADIO LINK SETUP REQUEST message to the NodeB, requesting the NodeB to allocate the specific radio link resources required for an RRC connection.
4) The NodeB responds with a RADIO LINK SETUP RESPONSE message to the RNC after successfully preparing the resources.
5) The RNC sets up the Iub interface user plane transport bearer using ALCAP and performs the NodeB synchronization procedure.
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6) The RNC sends an RRC CONNECTION SETUP message to the UE on the downlink CCCH. The message contains the information about the dedicated channel allocated by the RNC.
7) The UE sends an RRC CONNECTION SETUP COMPLETE message on the just established uplink DCCH after confirming that the RRC connection is successfully set up. The RRC connection setup procedure ends.
5.3.3 RRC Connection Setup on Common Channel
Since the UE uses the common resources already established in a cell when the RRC connection is set up on a common channel, the UE need only map its logical channel onto a common channel in the cell rather than set up a radio link and a user plane data transport bearer. Other procedures are similar to those used for RRC connection setup on a dedicated channel.
Figure 5-4 illustrates the RRC connection setup signaling procedure on a common channel.
UE RNC
4.CCCH
NodeB
RRCRRC
RRCRRC
1.CCCH : RRC CONNECTION REQUESTRRCRRC
5.DCCH: RRC CONNECTION SETUP COMPLETE
2.Allocate parameterssuch as RNTI、L1、L2
: :RRC CONNECTION SETUP
3.Map the logical channels used by UE to the common channels
Figure 5-4 RRC connection setup procedure (on common channel)
5.3.4 RRC Connection Reject
If RNC judges that the RRC connection request can not be set up (for instance, insufficient resources), RNC directly sends a RRC CONNECTION REJECT message to UE, and indicates the reject reason in the message as well.
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UE RNC
CCCH:RRC CONNECTION REQUEST
CCCH:RRC CONNECTION REJECT
Figure 5-5 RRC connection reject
5.3.5 RRC Connection Request Message
I. Message Structure
Information Element/Group name Need Comments
Message Type MP –
UE information elements –
Initial UE identity MP Initial UE identity , such as IMSI(P-TMSI), LAI,RAI
Establishment cause MP RRC establishment cause, including:
Originating Conversational Call,
Originating Streaming Call,
Originating Interactive Call,
Originating Background Call,
Originating Subscribed traffic Call,
Terminating Conversational Call,
Terminating Streaming Call,
Terminating Interactive Call,
Terminating Background Call,
Emergency Call,
Inter-RAT cell re-selection,
Inter-RAT cell change order,
Registration, Detach,
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Information Element/Group name Need Comments
Originating High Priority Signalling,
Originating Low Priority Signalling,
Call re-establishment,
Terminating High Priority Signalling,
Terminating Low Priority Signalling,
Terminating – cause unknown
Protocol error indicator MD –
Measurement information elements –
Measured results on RACH OP –
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II. Example
5.3.6 RRC Connection Setup Message
I. Message Structure
Information Element/Group name Need Comments
Message Type MP –
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Information Element/Group name Need Comments
UE Information Elements –
Initial UE identity MP Initial UE identity, such as IMSI(P-TMSI), LAI and RAI
RRC transaction identifier MP
Activation time MD Activation time defines the exact starting time point of the operation caused by the message. The range is 0–255 (CFN)
New U-RNTI MP –
New C-RNTI OP –
RRC State Indicator MP RRC state indicator: CELL_DCH, CELL_FACH, CELL_PCH, URA_PCH
UTRAN DRX cycle length coefficient MP –
Capability update requirement MD –
RB Information Elements –
Signaling RB information to setup list MP –
>Signaling RB information to setup MP SRB information, including SRB identity, RB mapping information and so on
TrCH Information Elements –
Uplink transport channels –
UL Transport channel information common for all transport channels
OP Including the messages like TFC message and so on
Added or Reconfigured TrCH information list
MP –
>Added or Reconfigured UL TrCH information
MP –
Downlink transport channels –
DL Transport channel information common for all transport channels
OP –
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Information Element/Group name Need Comments
Added or Reconfigured TrCH information list
MP –
>Added or Reconfigured DL TrCH information
MP –
PhyCH information elements –
Frequency info MD –
Uplink radio resources –
Maximum allowed UL TX power MD –
CHOICE channel requirement OP –
>Uplink DPCH info –
>CPCH SET Info –
Downlink radio resources –
Downlink information common for all radio links
OP –
Downlink information per radio link list OP –
>Downlink information for each radio link
MP –
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5.3.7 RRC Connection Reject Message
I. Message Structure
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Information Element/Group name Need Comments
Message Type MP –
UE information elements –
RRC transaction identifier MP –
Initial UE identity MP –
Rejection cause MP RRC Rejection cause, including congestion or unspecified
Wait time MP Indicate the time that the UE needs to wait to re-send the RRC connection request
Redirection info OP Indicate the UE initiates the connection request in other frequencies or systems.
II. Example
None
5.3.8 Radio Link Setup Request Message
I. Message Structure
IE/Group Name Presence IE type and reference
Message Discriminator M –
Message Type M –
CRNC Communication Context ID M –
Transaction ID M –
UL DPCH Information –
>UL Scrambling Code M UL scrambling code of UE
>Min UL Channelisation Code length M –
>Max Number of UL DPDCHs C –
CodeLen
–
>puncture Limit M –
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IE/Group Name Presence IE type and reference
>TFCS M –
>UL DPCCH Slot Format M –
> UL SIR Target M –
>Diversity mode M –
>SSDT cell ID Length O –
>S Field Length C-FBI –
DL DPCH Information –
>TFCS M –
>DL DPCH Slot Format M –
>TFCI signalling mode M –
>TFCI presence C-SlotFormat –
>Multiplexing Position M –
>PDSCH RL ID C-DSCH –
>PDSCH code mapping C-DSCH –
>Power Offset Information –
>>PO1 M –
>>PO2 M –
>>PO3 M –
>FDD TPC DL Step Size M –
>Limited Power Increase M –
>Inner Loop DL PC Status M –
DCH Information M –
DSCH Information O –
TFCI2 bearer information –
>ToAWS M –
>ToAWE M –
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IE/Group Name Presence IE type and reference
RL Information –
>RL ID M –
>C-ID M –
>First RLS Indicator M –
>Frame Offset M –
>Chip Offset M –
>Propagation Delay O –
>Diversity Control Field C –
NotFirstRL
–
>DL Code Information M –
>Initial DL transmission Power M –
>Maximum DL power M –
>Minimum DL power M –
>SSDT Cell Identity O –
>Transmit Diversity Indicator C –
Diversity mode
–
Transmission Gap Pattern Sequence Information
O –
Active Pattern Sequence Information O –
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5.4 Direct Transfer Messages
5.4.1 Overview
Direct transfer messages used to exchange the NAS information between the UE and the CN, for instance, authentication, service request, connection setup and so on. Such information is transparently transported in the RNC, and is therefore called direct transfer message.
The RRC connection is only a signaling connection between the UE and the RNC. A signaling connection shall also be set up between the UE and the CN to transport direct transfer messages. The RNC shall set up the signaling connection to the CN on the SCCP when it receives the first direct transfer message, that is, INITIAL DIRECT TRANSFER message.
When the signaling connection is successfully set up, the message from the UE to the CN shall be sent in the following way: the UE sends an UPLINK DIRECT TRANSFER message to the RNC and the RNC converts the message to a DIRECT TRANSFER message and forwards it to the CN. The message from the CN to the UE shall be sent in the following way: the CN sends a DIRECT TRANSFER message to the RNC and the RNC converts the message to a DOWNLINK DIRECT TRANSFER message and forwards it to the UE.
5.4.2 Initial Direct Transfer
The initial direct transfer procedure is used to establish a signaling connection. It is also used to carry an initial NAS message from UE to CN. The NAS content is not interpreted in RNC and is transferred to CN directly.
Note:
Upon initiation of the initial direct transfer procedure when the UE is in CELL_PCH or URA_PCH state, the UE shall perform a cell update procedure using the cause "uplink data transmission" to transfer the UE to the CELL_FACH state. When the cell update procedure completed successfully, the UE shall continue with the initial direct transfer procedure.
Figure 5-6 illustrates the initial direct transfer signaling procedure.
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UE CNSRNC
SCCP SCCP
1. INITIAL DIRECT TRANSFERRRCRRC
RANAP2.INITIAL UE MESSAGE
RANAP
SCCP SCCP
3.CONNECITON CONFIRM(SUCCESS)
4.CONNECTION REFUSE(FAILURE)
Figure 5-6 Initial direct transfer procedure
Each step is explained in the following list:
1) After the RRC connection is set up, the UE sends an INITIAL DIRECT TRANSFER message to the RNC. The message shall contain the initial NAS message and CN domain identity the UE wants to send to the CN.
2) After receiving the INITIAL DIRECT TRANSFER message from the UE, the RNC sends an INITIAL UE MESSAGE to the CN on the Iu interface as a Connection Request (CR) for SCCP connection establishment. The message shall contain the message the UE sends to the CN.
3) The CN shall return a CONNECTION CONFIRM message to the RNC if it determines to accept the connection request and the SCCP connection is successfully set up. Upon reception of the message, the RNC confirms that the connection is successfully set up.
4) The CN shall return a CONNECTION REFUSE message to the RNC if it determines to refuse the connection request and the SCCP connection setup fails. Upon reception of the message, the RNC confirms that the connection setup fails and initiates an RRC release procedure. The initial direct transfer procedure ends.
For the NAS message contained in INITIAL DIRECT TRANSFER and INITIAL UE MESSAGE from UE to CN, the acceptance or reject information is forwarded from CN to UE by the downlink transfer procedure.
5.4.3 Uplink Direct Transfer
The UE shall initiate an uplink direct transfer procedure when it need send NAS messages to the CN on an already existing signaling connection.
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Note:
Upon initiation of the uplink direct transfer procedure in CELL_PCH or URA_PCH state, the UE shall perform a cell update procedure using the cause "uplink data transmission" to transfer the UE to the CELL_FACH state. When the cell update procedure completed successfully, the UE shall continue with the uplink direct transfer procedure.
Figure 5-7 illustrates the uplink direct transfer signaling procedure.
UE CNSRNC
1. UPLINK DIRECT TRANSFERRRCRRC
RANAP2.DIRECT TRANSFER
RANAP
Figure 5-7 Uplink direct transfer procedure
Each step is explained in the following list:
1) The UE sends an UPLINK DIRECT TRANSFER message to the RNC to initiate an uplink direct transfer procedure. The message shall contain the NAS messages and CN domain identity.
2) On reception of the UPLINK DIRECT TRANSFER message, the RNC shall send a DIRECT TRANSFER message on the Iu interface to the CN according to the CN domain identity so as to route the NAS messages to the CN.
Note:
If the UPLINK DIRECT TRANSFER message includes the “Measured results on RACH IE” information unit, it indicates the message carries a measurement report. UTRAN should extract the contents to be used for radio resource control. The rest of the message continues to be sent to the CN.
5.4.4 Downlink Direct Transfer
The CN shall initiate a downlink direct transfer procedure when it need send NAS messages to the UE on an already existing signaling connection.
Figure 5-8 illustrates the downlink direct transfer signaling procedure.
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UE CNSRNC
2. DOWNLINK DIRECT TRANSFERRRCRRC
RANAP1.DIRECT TRANSFER
RANAP
Figure 5-8 Downlink direct transfer procedure
Each step is explained in the following list:
1) The CN sends a DIRECT TRANSFER message to the RNC to initiate a downlink direct transfer procedure. The message shall contain the NAS messages.
2) UTRAN sends a DOWNLINK DIRECT TRANSFER message on the downlink DCCH using AM RLC. The message shall contain the NAS messages and CN domain identity the CN wants to send to the US.
The UE receives and reads the NAS messages contained in the DOWNLINK DIRECT TRANSFER message. If the UE receives a DOWNLINK DIRECT TRANSFER message which contains a protocol error, the UE shall transmit an RRC STATUS message on the uplink DCCH using AM RLC. The downlink direct transfer procedure ends.
5.4.5 Initial Direct Transfer Message
I. Message Structure
Information Element/Group name Need Type and reference
Message Type MP –
UE information elements –
Integrity check info CH –
CN information elements
CN domain identity MP –
Intra Domain NAS Node Selector MP –
NAS message MP –
Measurement information elements
Measured results on RACH OP –
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II. Example
5.4.6 Uplink Direct Transfer Message
I. Message Structure
Information Element/Group name Need Semantics description
Message Type MP –
UE information elements –
Integrity check info CH –
CN information elements –
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Information Element/Group name Need Semantics description
CN domain identity MP –
NAS message MP –
Measurement information elements –
Measured results on RACH OP –
II. Example
5.4.7 Downlink Direct Transfer Message
I. Message Structure
Information Element/Group name Need Type and reference
Message Type MP –
UE information elements –
RRC transaction identifier MP –
Integrity check info CH –
CN information elements –
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Information Element/Group name Need Type and reference
CN Domain Identity MP –
NAS message MP –
II. Example
5.5 UE Capability Information
The UE capability information includes the information and extensions about the access stratum (AS) in the UE like security capability, location capability, measurement capability, physical channel, transport channel capability, etc.
Because UEs have different capabilities due to manufacturer and specification differences, a UE shall transmit the UE capability information to UTRAN after the RRC connection setup for the network to perform configuration for the UE according to the supported capability parameters.
Transmission of UE capability information may be implemented in the following three ways.
When the RRC connection is successfully set up, the UE capability information is transmitted to the RNC through an RRC CONNECTION SETUP COMPLETE message.
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When the RRC connection is successfully set up, the RNC sends a UE CAPABILITY ENQUIRY message to the UE if it finds the capability information about the corresponding UE does not exist. UE returns a UE CAPABILITY INFORMATION message to the RNC which contains the UE capability information.
When the UE capability information changes during the RRC connection setup procedure, the UE transmits the updated UE capability to the RNC through a UE CAPABILITY INFORMATION message.
5.5.1 UE Capability Enquiry
UTRAN may request the UE to initiate a UE capability update procedure by transmitting a UE CAPABILITY ENQUIRY message to the UE, as illustrated in Figure 5-9.
UE UTRAN
UE CAPABILITY ENQUIRY
Figure 5-9 UE capability enquiry procedure
The UE capability enquiry procedure is initiated by UTRAN by transmitting a UE CAPABILITY ENQUIRY message on the downlink DCCH using AM RLC.
5.5.2 UE Capability Information Update
When UTRAN initiates a UE capability enquiry procedure or when the UE capability information changes during the RRC connection setup procedure, the UE shall initiate a UE capability information update procedure. The UE capability information update procedure is used to convey the radio network related capability information the UE can support to UTRAN, as illustrated in Figure 5-10.
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Figure 5-10 UE capability information update
1) The UE sends a UE CAPABILITY INFORMATION message on the uplink DCCH using AM or UM RLC. The message shall contain the UE capability information.
2) UTRAN reads the UE capability information and returns a UE CAPABILITY INFORMATION CONFIRM message on the downlink DCCH using AM or UM RLC. The UE capability information update procedure ends.
5.6 RAB Setup
5.6.1 Overview
Radio access bearer (RAB) is a user plane bearer. It is used to convey the service information like speech, data and multimedia between the UE and the CN. The RAB setup procedure shall only be implemented after the signaling connection is successfully set up between the UE and the CN. This procedure is initiated by the CN and implemented by UTRAN.
RAB setup procedures are as follows: CN initiates RAB ASSIGNMENT REQUEST; RNC configures the relevant radio network parameters according to the QoS parameter in the RAB ASSIGNMENT REQUEST, and then informs the setup result to CN through the RAB ASSIGNMENT RESPONSE message.
Note:
RAB ASSIGNMENT REQUEST is initiated by CN; each UE can have one RAB or several RABs.
The RAB setup procedure can be classified into the following three kinds according to the RRC connection status before and after the RAB setup:
DCH-DCH: The RRC connection is on a DCH before the RAB setup and also on a DCH after the RAB setup.
CCH-DCH: The RRC connection is on a CCH before the RAB setup and on a DCH after the RAB setup.
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CCH-CCH: The RRC connection is on a CCH before the RAB setup and also on a CCH after the RAB setup.
5.6.2 DCH-DCH
When the current RRC status of the UE is DCH, the assigned RAB can only be set up on a DCH. The RAB setup procedure can be further classified into the following two kinds according to the radio link reconfiguration situation:
Synchronized radio link reconfiguration Unsynchronized radio link reconfiguration
The difference is that in the former kind of procedure the NodeB and UE cannot invoke the reconfiguration parameters immediately after they receive the configuration messages from the Serving Radio Network Controller (SRNC) while in the latter they can.
I. Synchronized radio link reconfiguration
In this case, the SRNC, NodeB and UE shall synchronously perform radio link reconfiguration. The synchronization procedure is given below:
The NodeB shall not invoke the reconfiguration parameters immediately after it receives a RADIO LINK RECONFIGURATION PREPARE message but prepare for the radio resources required. Then it shall wait till it receives a RADIO LINK RECONFIGURATION COMMIT message from the SRNC and obtains the synchronization time specified by the SRNC in the message.
The UE shall also not invoke the reconfiguration parameters immediately after it receives a RADIO BEARER SETUP message but obtain the synchronization time specified by the SRNC in the message.
The NodeB and UE shall invoke the reconfiguration parameters at the synchronization time specified by the SRNC.
Figure 5-11 illustrates the DCH-DCH RAB setup procedure in the case of synchronized radio link reconfiguration.
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UE SRNC
NBAP
6.
NodeB
NBAP
RRCRRC
RRCRRC
NBAP NBAP
8.RADIO BEARER SETUP COMPLETE
3. RADIO LINK RECONFIGURATIONPREPARE (Synchronised)
4. RADIO LINK RECONFIGURATION READY (Synchronised)
5.ALCAP Setup and synchronization
RADIO BEARER SETUP
CN
RANAPRANAP1. RAB ASSIGNMENT REQUEST
2.ALCAP setup
RANAPRANAP
9. RAB ASSIGNMENT RESPONSE
NBAP NBAP
7. RADIO LINK RECONFIGURATION COMMIT (Synchronised)
Figure 5-11 RAB setup procedure (DCH-DCH, synchronous)
Each step is explained in the following list:
1) The CN sends an RAB ASSIGNMENT REQUEST message to UTRAN to initiate an RAB setup procedure.
2) Upon reception of the RAB ASSIGNMENT REQUEST message, the SRNC shall map the QoS parameter for the RAB to the AAL2 link characteristic parameter and radio resource characteristic parameter. The ALCAP on the Iu interface shall initiate an Iu interface user plane transport bearer setup procedure according to the AAL2 link characteristic parameter (as for PS domain, the ALCAP step does not exist).
3) The SRNC sends a RADIO LINK RECONFIGURATION PREPARE message to the controlled NodeB to request the NodeB to prepare to add one (or several) DCH(s) to the existing radio link for bearing the RAB.
4) The NodeB allocates the corresponding resources and returns a RADIO LINK RECONFIGURATION READY message to the SRNC which it belongs to, informing it that the radio link reconfiguration is ready.
5) The ALCAP on the Iub interface at the SRNC initiates an Iub interface user plane transport bearer setup procedure. The NodeB and the SRNC perform synchronization by exchanging the uplink & downlink synchronization frame in the DCH frame protocol.
6) The SRNC sends an RRC message RADIO BEARER SETUP to the UE. 7) The SRNC sends a RADIO LINK RECONFIGURATION COMMIT message to the
controlled NodeB.
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8) After performing radio bearer setup, the UE sends a RADIO BEARER SETUP COMPLETE message to the SRNC.
9) Upon reception of the RADIO BEARER SETUP COMPLETE message, the SRNC sends an RAB ASSIGNMENT RESPONSE message to the CN. The RAB setup procedure ends.
II. Unsynchronized radio link reconfiguration
In this case, the SRNC, NodeB and UE need not synchronously perform radio link reconfiguration. The NodeB and UE shall invoke the reconfiguration parameters immediately after they receive the configuration messages from the SRNC.
Figure 5-12 illustrates the DCH-DCH RAB setup procedure in the case of unsynchronized radio link reconfiguration.
UE SRNC
NBAP
6.
NodeB
NBAP
RRCRRC
RRCRRC
NBAP NBAP
7. RADIO BEARER SETUP COMPLETE
3. RADIO LINK RECONFIGURATION REQUEST
4. RADIO LINK RECONFIGURATIONRESPONSE
5.ALCAP Setup and synchronization
RADIO BEARER SETUP
CN
RANAPRANAP1. RAB ASSIGNMENT REQUEST
2.ALCAP setup
RANAPRANAP8. RAB ASSIGNMENT RESPONSE
Figure 5-12 RAB setup procedure (DCH-DCH, asynchronous)
Each step is explained in the following list:
1) The CN sends a RANAP message RAB ASSIGNMENT REQUEST to the SRNC to initiate an RAB setup procedure.
2) Upon reception of the RAB ASSIGNMENT REQUEST message, the SRNC shall map the QoS parameter for the RAB to the AAL2 link characteristic parameter and radio resource characteristic parameter. The ALCAP on the Iu interface shall initiate an Iu interface user plane transport bearer setup procedure according to the AAL2 link characteristic parameter (as for PS domain, the ALCAP step does not exist).
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3) In the unsynchronized situation, the radio link reconfiguration need not be implemented synchronously. The SRNC sends a NBAP message RADIO LINK RECONFIGURATION REQUEST to the controlled NodeB, requesting the NodeB to reconfigure the DCH in the existing radio link.
4) Upon reception of the RADIO LINK RECONFIGURATION REQUEST message, the NodeB allocates the corresponding resources and returns a RADIO LINK RECONFIGURATION RESPONSE message to the SRNC which it belongs to, informing the SRNC that it finishes radio link reconfiguration.
5) The ALCAP on the Iub interface at the SRNC initiates an Iub interface user plane transport bearer setup procedure. The NodeB and the SRNC perform synchronization by exchanging the uplink & downlink synchronization frame in the DCH frame protocol.
6) The SRNC sends an RRC message RADIO BEARER SETUP to the UE. 7) After performing radio bearer setup, the UE sends a RADIO BEARER SETUP
COMPLETE message to the SRNC 8) Upon reception of the RADIO BEARER SETUP COMPLETE message, the
SRNC sends an RAB ASSIGNMENT RESPONSE message to the CN. The RAB setup procedure ends.
5.6.3 CCH-DCH
When the RRC connection is on a CCH, the RNC can set up the assigned RAB on a DCH according to the QoS parameter in the RAB ASSIGNMENT REQUEST message. The RRC status shall be transferred from the CCH to the DCH.
Figure 5-13 illustrates the CCH-DCH RAB setup procedure.
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UE SRNC
NBAP
6.
NodeB
NBAP
RRCRRC
RRCRRC
NBAP NBAP
7. RADIO BEARER SETUP COMPLETE
3.
4.
5.ALCAP Setup and synchronization
RADIO BEARER SETUP
CN
RANAPRANAP1. RABASSIGNMENT REQUEST
2. ALCAP setup
RANAPRANAP8. RAB ASSIGNMENT RESPONSE
RADIO LINK SETUP REQUEST
RADIO LINK SETUP RESPONSE
Figure 5-13 RAB setup procedure (CCH-DCH)
Each step is explained in the following list:
1) The CN sends a RANAP message RAB ASSIGNMENT REQUEST to the SRNC to initiate an RAB setup procedure.
2) Upon reception of the RAB ASSIGNMENT REQUEST message, the SRNC shall map the QoS parameter for the RAB to the AAL2 link characteristic parameter and radio resource characteristic parameter. The ALCAP on the Iu interface shall initiate an Iu interface user plane transport bearer setup procedure according to the AAL2 link characteristic parameter (as for PS domain, the ALCAP step does not exist).
3) The SRNC initiates an Iub interface radio link setup procedure by sending a RADIO LINK SETUP REQUEST message to the controlled NodeB to request the NodeB to allocate the specific radio link resources required for the RRC connection.
4) After preparing the resources, the NodeB returns a RADIO LINK SETUP RESPONSE message to the RNC.
5) The RNC sets up an Iub interface user plane transport bearer using ALCAP and performs the NodeB synchronization procedure.
6) The SRNC sends an RRC message RADIO BEARER SETUP to the UE. 7) After performing radio bearer setup, the UE sends a RADIO BEARER SETUP
COMPLETE message to the SRNC. 8) Upon reception of the RADIO BEARER SETUP COMPLETE message, the
SRNC sends an RAB ASSIGNMENT RESPONSE message to the CN. The RAB setup procedure ends.
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5.6.4 CCH-CCH
When the RRC connection is on a CCH, the RNC can set up the assigned RAB on a CCH according to the QoS parameter in the RAB ASSIGNMENT REQUEST message.
Figure 5-14 illustrates the CCH-CCH RAB setup procedure.
UE SRNC
3.
NodeB
RRCRRC
RRCRRC4. RADIO BEARER SETUP COMPLETE
RADIO BEARER SETUP
CN
RANAPRANAP1. RAB ASSIGNMENT REQUEST
2. ALCAP setup
RANAPRANAP5. RAB ASSIGNMENT RESPONSE
Figure 5-14 RAB setup procedure (CCH-CCH)
Each step is explained in the following list:
1) The CN sends a RANAP message RAB ASSIGNMENT REQUEST to UTRAN to initiate an RAB setup procedure.
2) Upon reception of the RAB ASSIGNMENT REQUEST message, the SRNC shall map the QoS parameter for the RAB to the AAL2 link characteristic parameter and radio resource characteristic parameter. The ALCAP on the Iu interface shall initiate an Iu interface user plane transport bearer setup procedure according to the AAL2 link characteristic parameter (as for PS domain, the ALCAP step does not exist).
3) The SRNC sends an RRC message RADIO BEARER SETUP to the UE. 4) After performing radio bearer setup, the UE sends a RADIO BEARER SETUP
COMPLETE message to the SRNC. 5) Upon reception of the RADIO BEARER SETUP COMPLETE message, the
SRNC sends an RAB ASSIGNMENT RESPONSE message to the CN. The RAB setup procedure ends.
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5.6.5 RAB Assignment Request Message
I. Message Structure
IE/Group Name Presence Comments
Message Type M –
RABs To Be Setup Or Modified List C – ifNoOtherGroup –
>RABs To Be Setup Or Modified Item IEs –
>>First Setup Or Modify Item M –
>>>RAB ID M –
>>>NAS Synchronisation Indicator C-ifModifandNASInfoProvided
–
>>>RAB Parameters C - ifSetuporNewValues
–
>>>User Plane Information C - ifSetuporNewValues
–
>>>>User Plane Mode M –
>>>>UP Mode Versions M –
>>>Transport Layer Information C- ifNot OnlyNSI –
>>>>Transport Layer Address M –
>>>>Iu Transport Association M –
>>>Service Handover O –
>>Second Setup Or Modify Item M –
>>> PDP Type Information C – ifPSandSetup –
>>>Data Volume Reporting Indication
C – ifPSandSetup –
>>>DL GTP-PDU Sequence Number C- ifAvailPSandSetup –
>>>UL GTP-PDU Sequence Number C- ifAvailPSandSetup –
>>>DL N-PDU Sequence Number C- ifAvailPSandSetup –
>>>UL N-PDU Sequence Number C- ifAvailPSandSetup –
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IE/Group Name Presence Comments
RABs To Be Released List C – ifNoOtherGroup –
>RABs To Be Released Item IEs –
>>RAB ID M –
>>Cause M Release cause
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5.6.6 RAB Assignment Response Message
I. Message Structure
IE/Group Name Presence Comments
Message Type M –
RABs Setup Or Modified LIST C - ifNoOtherGroup –
>RABs Setup Or Modified Item IEs –
>>RAB ID M –
>>Transport Layer Address C - ifPS –
>>Iu Transport Association C - ifPS –
>>DL Data Volumes C – ifModReqPS –
>>>Data Volume List –
>>>>Unsuccessfully Transmitted DL Data Volume
M –
>>>>Data Volume Reference O –
RABs Released List C – ifNoOtherGroup –
>RABs Released Item IEs –
>>RAB ID M –
>>DL Data Volumes C – ifReqPS –
>>>Data Volume List –
>>>>Unsuccessfully Transmitted DL Data Volume
M –
>>>>Data Volume Reference O –
>>DL GTP-PDU Sequence Number C-ifAvailUiPS –
>>UL GTP-PDU Sequence Number C-ifAvailUiPS –
RABs Queued List C – ifNoOtherGroup –
>RABs Queued Item IEs –
>>RAB ID M –
RABs Failed To Setup Or Modify List C – ifNoOtherGroup –
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IE/Group Name Presence Comments
>RABs Failed To Setup Or Modify Item IEs –
>>RAB ID M –
>>Cause M –
RABs Failed To Release List C – ifNoOtherGroup –
>RABs Failed To Release Item IEs –
>>RAB ID M –
>>Cause M –
Criticality Diagnostics O –
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II. Example
5.6.7 Radio Bearer Setup Message
I. Message Structure
Information Element/Group name Need Type and reference
Message Type MP –
UE Information Elements –
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Information Element/Group name Need Type and reference
RRC transaction identifier MP –
Integrity check info CH –
Integrity protection mode info OP –
Ciphering mode info OP –
Activation time MD –
New U-RNTI OP –
New C-RNTI OP –
RRC State Indicator MP –
UTRAN DRX cycle length coefficient MD –
CN Information Elements –
CN Information info OP –
UTRAN mobility information elements –
URA identity OP –
RB Information Elements –
Signaling RB information to setup list OP –
>Signaling RB information to setup MP –
RAB information to setup list OP –
>RAB information for setup MP –
RB information to be affected list OP –
>RB information to be affected MP –
Downlink counter synchronisation info OP –
>RB with PDCP information list OP –
>>RB with PDCP information MP –
TrCH Information Elements –
Uplink transport channels –
UL Transport channel information common for all transport channels
OP –
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Information Element/Group name Need Type and reference
Deleted TrCH information list OP –
>Deleted UL TrCH information MP –
Added or Reconfigured TrCH information list
OP –
>Added or Reconfigured UL TrCH information MP –
CHOICE mode OP –
>FDD –
>>CPCH set ID OP –
>>Added or Reconfigured TrCH information for DRAC list
OP –
>>>DRAC static information MP –
>TDD –
Downlink transport channels –
DL Transport channel information common for all transport channels
OP –
Deleted TrCH information list OP –
>Deleted DL TrCH information MP –
Added or Reconfigured TrCH information list
OP –
>Added or Reconfigured DL TrCH information MP –
PhyCH information elements –
Frequency info MD –
Uplink radio resources –
Maximum allowed UL TX power MD –
CHOICE channel requirement OP –
>Uplink DPCH info –
>CPCH SET Info –
Downlink radio resources –
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Information Element/Group name Need Type and reference
CHOICE mode MP –
>FDD –
>>Downlink PDSCH information OP –
>TDD –
Downlink information common for all radio links OP –
Downlink information per radio link list OP –
>Downlink information for each radio link MP –
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5.7 Call Release
5.7.1 Overview
There are two types of call release procedures. One is implemented when the UE initiates an upper layer call release request and the other when the CN initiates an upper layer call release request. The resource release procedures in the two cases are both initiated by the CN.
For a UE, there may have the following situations: one RRC connects with several RAB (for instance, it connects with VP service and Web Browse service at the same time), both CS domain and PS domain corresponds to one Iu signaling link respectively.
The call release can be classified as follows:
I. CS Domain Service Release
When UE releases the CS domain service:
If CS domain sets up only one RAB, then CN initiates the IU RELEASE COMMAND message. After RNC receives the message, it automatically releases the Iu signaling link and RAB. Refer to 5.7.4 Combined Release of CS Domain Iu Signaling Link and RAB for details. After the service release completes, SRNC checks if the RRC connection still has corresponding Iu signaling link (PS domain). If NO, it starts the RRC connection release procedure.
If CS domain sets up several RABs, CN initiates the RAB release only for the RAB(s) that need(s) to be released. It does not release the Iu signaling link. Refer to 5.7.3 RAB Release for details.
II. PS Domain Service Release
When UE releases the PS domain service:
If PS domain sets up only one RAB, CN first sends RAB release procedure to this RAB. Then it sends the IU RELEASE COMMAND message to release the Iu signaling link of Iu-PS interface. Refer to 5.7.3 RAB Release and 5.7.2 Iu Signaling Connection Release for details. After the service release completes, SRNC checks if the RRC connection still has corresponding Iu signaling link (CS domain). If NO, it starts the RRC connection release procedure.
If PS domain sets up several RABs, CN initiates the RAB release only for the RAB(s) that need(s) to be released. It does not release the Iu signaling link. Refer to 5.7.3 RAB Release for details.
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5.7.2 Iu Signaling Connection Release
I. Signaling Connection Release Request Procedure
The Iu signaling connection release request procedure is used by UTRAN to request the CN to initiate an Iu signaling connection release procedure. The Iu signaling connection release procedure is directly initiated by the CN generally. UTRAN may also request the CN to initiate the procedure. This procedure is a connection-oriented procedure. Figure 5-15 illustrates the Iu signaling connection release request procedure.
RNC CN
IU RELEASE REQUEST
Figure 5-15 Iu signaling connection release request procedure
The SRNC sends an IU RELEASE REQUEST message to the CN domain to initiate an Iu interface release request procedure. The message shall contain the cause for the Iu connection release request. The CN determines how to respond to the Iu release request. For example, the CN may initiate an Iu release procedure if it determines to release the Iu connection.
II. Signaling connection release procedure
The Iu signaling connection release procedure is used by the CN to release an Iu connection. All UTRAN resources associated with the specific Iu connection shall be released. This procedure is also a connection-oriented procedure. Figure 5-16 illustrates the Iu signaling connection release procedure.
RNC CN
1.IU RELEASE COMMAND
2.IU RELEASE COMPLETE
Figure 5-16 Iu signaling connection release procedure
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1) The CN sends an IU RELEASE COMMAND to UTRAN to initiate a signaling connection release procedure. The message shall contain the cause for the signaling connection release e.g., "Successful Relocation", "Normal Release", "Release due to UTRAN Generated Reason", "Relocation Cancelled" and "No Remaining RAB". After sending the message, the CN shall no more send any connection-oriented RANAP message on that connection.
2) Upon reception of the IU RELEASE COMMAND message, the RNC shall clear the related resources in UTRAN. The RNC returns an IU RELEASE COMPLETE message to the CN. The Iu signaling connection release procedure ends.
5.7.3 RAB Release
The RAB release procedure is also initiated by the CN and implemented by UTRAN. The RAB release procedure can also be classified into the following three kinds:
DCH-DCH: The RRC connection is on a DCH before the RAB release and also on a DCH after the RAB release.
CCH-CCH: The RRC connection is on a CCH before the RAB release and also on a CCH after the RAB release.
DCH-CCH: The RRC connection is on a DCH before the RAB release and on a CCH after the RAB release.
This section describes only the DCH-DCH RAB release procedure. Other kinds of procedures may be known on the analogy of this procedure. Similar to the RAB setup procedure, the DCH-DCH RAB release procedure on the radio interface can also be further classified into the following two kinds:
Synchronized radio link reconfiguration Unsynchronized radio link reconfiguration
This section describes only the RAB release procedure in the case of synchronized radio link reconfiguration. The RAB release procedure in the case of unsynchronized radio link reconfiguration may be known on the analogy of the Iub interface unsynchronized radio link reconfiguration procedure. Figure 5-17 illustrates the DCH-DCH RAB release procedure in the case of synchronized radio link reconfiguration.
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UE NodeBServing RNS
ServingRNC
CN
RRCRRC 6.DCCH : RADIO BEARER RELEASE COMPLETE
NBAPNBAP3.RADIO LINK RECONFIGURATION
READY
NBAPNBAP
5.RADIO LINK RECONFIGURATION COMMIT
RRCRRC
DCCH
4:RADIO BEARER RELEASE
Apply new transport format set
7.ALCAP Iub Data Transport Bearer Release
RANAP RANAP1 RAB ASSIGNMENT REQUEST
[Release]
NBAPNBAP
2RADIO LINK RECONFIGURATION PRPARE
[DCH Deletion]
RANAP RANAP9. RAB ASSIGNMENT RESPONSE
8. ALCAP Iu Data TransportBearer Release
not required towards PS domain
UE NodeBServing RNS
ServingRNC
CN
RRCRRC 6.DCCH : RADIO BEARER RELEASE COMPLETE
NBAPNBAP3.RADIO LINK RECONFIGURATION
READY
NBAPNBAP
5.RADIO LINK RECONFIGURATION COMMIT
RRCRRC
DCCH
4:RADIO BEARER RELEASE
Apply new transport format set
7.ALCAP Iub Data Transport Bearer Release
RANAP RANAP1 RAB ASSIGNMENT REQUEST
[Release]
NBAPNBAP
2RADIO LINK RECONFIGURATION PRPARE
[DCH Deletion]
RANAP RANAP9. RAB ASSIGNMENT RESPONSE
8. ALCAP Iu Data TransportBearer Release
not required towards PS domain
Figure 5-17 RAB release procedure (DCH-DCH, synchronous)
Each step is explained in the following list:
1) The CN sends an RAB ASSIGNMENT REQUEST (release) message to initiate an RAB release procedure. The message shall indicate the ID of the RAB to be released.
2) The SRNC sends a RADIO LINK RECONFIGURATION PREPARE message to the NodeB, requesting the NodeB to prepare to release the DCH bearing the RAB.
3) The NodeB returns a RADIO LINK RECONFIGURATION READY message to the SRNC, informing it that the release is ready.
4) The SRNC sends a RADIO BEARER RELEASE message to the UE to initiate the bearer release procedure.
5) The SRNC sends a RADIO LINK RECONFIGURATION COMMIT message to the NodeB.
6) The SRNC receives a RADIO BEARER RELEASE COMPLETE message from the UE.
7) The SRNC initiates an Iub interface user plane transport bearer release procedure using ALCAP.
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8) If it is an AAL2 bearer, the SRNC uses an ALCAP AAL2 release message to initiate the Iu interface data transport bearer release from the CN (this step is not required towards PS domain).
9) The SRNC sends a RANAP message RAB ASSIGNMENT RESPONSE to the CN. The RAB release procedure ends.
Note:
In the case of user plane exception at RNC, the RNCAP shall send an RAB RELEASE REQUEST message to the CN, requesting the CN to release the affected RAB, as illustrated in Figure 5-18.
RNC CN
RAB RELEASE REQUEST
Figure 5-18 RAB release request
5.7.4 Combined Release of CS Domain Iu Signaling Link and RAB
If CS domain sets up only one RAB, then MSC sends IU RELEASE COMMAND message to RNC during the service release. When RNC receives this message, it will release the Iu signaling connection of Iu-CS interface and RAB.
Figure 5-19 shows the combined release of CS domain Iu signaling link and RAB (DCH-DCH)
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UE NodeBServing RNS
ServingRNC
CN
RRCRRC 6.DCCH : RADIO BEARER RELEASE COMPLETE
NBAPNBAP3.RADIO LINK RECONFIGURATION
READY
NBAPNBAP
5.RADIO LINK RECONFIGURATIONCOMMIT
RRCRRC
DCCH
4:RADIO BEARER RELEASE
Apply new transport format set
7.ALCAP Iub Data Transport Bearer Release
RANAP RANAP1
NBAPNBAP
2 RADIO LINK RECONFIGURATIONPRPARE
[DCH Deletion]
RANAP RANAP9. IU RELEASE COMPLETE
8. ALCAP Iu Data TransportBearer Release
UE NodeBServing RNS
ServingRNC
CN
RRCRRC 6.DCCH : RADIO BEARER RELEASE COMPLETE
NBAPNBAP3.RADIO LINK RECONFIGURATION
READY
NBAPNBAP
5.RADIO LINK RECONFIGURATIONCOMMIT
RRCRRC
DCCH
4:RADIO BEARER RELEASE
Apply new transport format set
7.ALCAP Iub Data Transport Bearer Release
RANAP RANAP1 IU RELEASE COMMAND
NBAPNBAP
2PRPARE
[DCH Deletion]
RANAP RANAP9.
8. ALCAP Iu Data TransportBearer Release
Figure 5-19 Combined release of CS domain Iu signaling link and RAB (DCH-DCH)
1) CN sends IU RELEASE COMMAND message to SRNC. 2) SRNC sends RADIO LINK RECONFIGURATION PREPARE message to NodeB,
requesting NodeB to prepare for the release of DCH that bears the RAB. 3) NodeB sends RADIO LINK RECONFIGURATION READY to SRNC, informing
SRNC that the release is ready. 4) SRNC sends RADIO BEARER RELEASE to UE, starting the bearer release
procedure. 5) SRNC sends RADIO LINK RECONFIGURATION COMMIT to NodeB. 6) SRNC receives the RADIO BEARER RELEASE COMPLETE message of UE. 7) RNC releases the data transfer bearer of Iub interface through ALCAP protocol. 8) SRNC uses ALCAP protocol. If it is AAL2 bearer, it uses AAL2 release message
to start the release of Iu data transfer bearer between CN. 9) SRNC sends IU RELEASE COMPLETE message to CN.
5.7.5 RRC Connection Release
I. Overview
After the RAB release, the SRNC shall check whether the same RRC bears other RABs. If no, the SRNC shall release that RRC connection.
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The RRC connection release procedure is used to release the RRC connection including all radio bearers between the UE and the UTRAN. By doing so, all established signaling connections will be released.
The RRC connection release procedure can be divided into two kinds according to the RRC status i.e., RRC release on a DCH and RRC release on a CCH.
Only when the UE is in CELL_DCH or CELL_FACH state, can RRC connection release be implemented. If the RRC is currently in CELL_PCH or URA_PCH state, UTRAN shall initiate a paging procedure to transfer the UE to CELL_FACH state before it performs the release.
The RNC shall send an RRC CONNECTION RELEASE message on the downlink DCCH or CCCH using UM RLC.
UTRAN sends RRC CONNECTION RELEASE message using DCCH channel if DCCH is available. Otherwise, UTRAN sends the message using CCCH.
II. RRC Connection Release on DCH
Figure 5-20 illustrates the signaling procedure for RRC connection release on a DCH.
UE SRNCNodeB
NBAPNBAP
NBAPNBAP
1.RRC CONNECTION RELEASE
3.
RADIO LINK DELETION REQUEST
RRCRRC
2.RRC CONNECTION RELEASE COMPLETERRCRRC
4. RADIO LINK DELETION RESPONSE
5.ALCAP Release
Figure 5-20 RRC connection release procedure (on DCH)
Each step is explained in the following list:
1) The SRNC sends the RRC CONNECTION RELEASE message to the UE on the DCCH. It may transmit several RRC CONNECTION RELEASE messages to increase the probability of proper reception of the message by the UE
2) The UE returns an RRC CONNECTION RELEASE COMPLETE message to the SRNC.
3) The SRNC sends a RADIO LINK DELETION REQUEST message to the NodeB to delete the radio link resources in the NodeB.
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4) After releasing the resources, the NodeB returns a RADIO LINK DELETION RESPONSE message to the SRNC.
5) The RNC initiates an Iub interface user plane transport bearer release procedure using ALCAP. The RRC connection release procedure ends.
III. RRC Connection Release on CCH
Figure 5-21 illustrates the signaling procedure for RRC connection release on a CCH.
UE SRNCNodeB
RRC CONNECTION RELEASERRCRRC
Figure 5-21 RRC connection release procedure (on CCH)
The SRNC sends the RRC CONNECTION RELEASE message to the UE on the CCCH to initiate an RRC connection release procedure. The UE shall release the resources.
In the case of RRC connection release on a CCH, the RRC CONNECTION RELEASE COMPLETE is not required. UTRAN shall release only the UE rather than the NodeB resources and data transport bearer, for the UE uses only the cell common resources.
Note:
UTRAN may transmit several RRC CONNECTION RELEASE messages to increase the probability of proper reception of the message by the UE. The RRC message sequence number (RRC SN) for these messages is the same. The number of repetitions and the repetition period are controlled by the network
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Chapter 6 Mobility Management Procedure Analysis
6.1 Overview
The handover procedures are an important feature of mobile communication. UMTS includes the following mobility management:
Forward handover (cell update and URA update) Soft handover Hard handover, Inter-RAT handover Relocation
6.2 Forward handover
6.2.1 Overview
The forward handover procedure is divided into cell and URA update procedures. The procedures are used to update the UE information in UTRAN after UE location change. In addition, they are also used to supervise the RRC connection, transit the RRC connection status, report an error and transmit information.
Both cell and URA update procedures are initiated by a UE.
6.2.2 Cell Update
The Cell Update procedure is possible for UEs in the connected mode (URA_PCH, CELL_PCH, CELL_FACH and CELL_DCH).
The UE shall initiate the cell update procedure in the following cases:
Cell reselection Re-entering service area Periodical cell update Radio link failure Paging response Uplink data transmission RLC unrecoverable error
Figure 6-1 illustrates a basic cell update procedure.
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UE UTRAN
1.CELL UPDATE
2.CELL UPDATE CONFIRM
Figure 6-1 Basic cell update procedure
Each step is explained in the following list:
1) The UE sends a CELL UPDATE message to the RNC to initiate a cell update procedure. The message shall contain the cell update cause, U-RNTI and so on.
2) The RNC returns a CELL UPDATE CONFIRM message to the UE. The message may contain the transport channel information elements, physical channel information elements, radio bearer information elements, U-RNTI and so on.
Upon reception of the CELL UPDATE CONFIRM message, the UE shall invoke information elements in the message and performs corresponding status transition. Depending on the different information elements included in the CELL UPDATE CONFIRM message, the UE may return different messages or no message to the RNC.
The messages the UE may return are given below:
RADIO BEARER RELEASE COMPLETE RADIO BEARER RECONFIGURATION COMPLETE TRANSPORT CHANNEL RECONFIGURATION COMPLETE PHYSICAL CHANNEL RECONFIGURATION COMPLETE UTRAN MOBILITY INFORMATION CONFIRM
The cell update procedure ends.
This section describes a cell update instance in which the UE returns a PHYSICAL CHANNEL RECONFIGURATION COMPLETE message on the radio interface, as illustrated in Figure 6-2.
UE RNCNodeB
RRCRRC
RRCRRC
1.CELL UPDATERRCRRC
3.PHYSICAL CHANNEL RECONFIGURATION COMPLETE
2.CELL UPDATE CONFIRM
Figure 6-2 Cell update procedure
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The CELL UPDATE CONFIRM message contains the C-RNTI and U-RNTI the network allocates to the UE. After invoking the new parameters, the UE sends a PHYSICAL CHANNEL RECONFIGURATION COMPLETE message to the RNC. The cell update procedure ends.
6.2.3 URA Update
For the UE in URA_PCH state, the URA update procedure is actually a procedure the UE initiates to update the URA information at the network side when an RRC connection exists and the position of the UE is known on URA level in the UTRAN.
The UE shall initiate the URA update procedure in the following cases:
URA reselection Periodic URA update
Figure 6-3 illustrates the basic URA update procedure.
UE UTRAN
URA UPDATE
URA UPDATE CONFIRM
Figure 6-3 Basic URA update procedure
Each step is explained in the following list:
1) The UE sends a URA UPDATE message to the RNC to initiate a URA update procedure. The message shall contain the URA update cause, U-RNTI and so on.
2) The RNC returns a URA UPDATE CONFIRM message to the UE. The message may contain the new C-RNTI, U-RNTI, ciphering mode info, integrity protection mode info and so on.
Upon reception of the URA UPDATE CONFIRM message, the UE shall invoke information elements in the message and send a PHYSICAL CHANNEL RECONGURITION COMPLETE message or no message to the RNC depending on the different information elements included in the URA UPDATE CONFIRM message.
This section describes a URA update instance in which a PHYSICAL CHANNEL RECONGURITION COMPLETE message is sent, as illustrated in Figure 6-4.
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UE RNCNodeB
RRCRRC
RRCRRC
1.URA UPDATERRCRRC
3.PHYSICAL CHANNEL RECONFIGURATION COMPLETE
2.URA UPDATE CONFIRM
Figure 6-4 URA update procedure
The URA UPDATE CONFIRM message contains RRC Transaction Identity and RRC State Indicator, and may contain the CN information elements, integrity protection mode info, ciphering mode info, new C-RNTI and U-RNTI. After invoking the new parameters, the UE sends a PHYSICAL CHANNEL RECONFIGURATION COMPLETE message to the RNC. The URA update procedure ends.
6.2.4 Cell Update Message
I. Message Structure
Information Element/Group name Need Type and reference
Message Type MP –
UE information elements –
U-RNTI MP –
RRC transaction identifier CV-Failure –
Integrity check info CH –
START list MP –
>CN domain identity MP –
>START MP –
AM_RLC error indication(RB2 or RB3) MP –
AM_RLC error indication(RB>3) MP –
Cell update cause MP Includes: cell reselection, periodical cell update, uplink data transmission, paging response,
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Information Element/Group name Need Type and reference
re-entered service area, radio link failure,
RLC unrecoverable error
Failure cause OP –
RB timer indicator MP –
Measurement information elements –
Measured results on RACH OP –
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II. Example
6.2.5 URA Update Message
I. Message Structure
Information Element/Group name Need Type and reference
Message Type MP –
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Information Element/Group name Need Type and reference
UE information elements –
U-RNTI MP –
RRC transaction identifier CV- ProtErr –
Integrity check info CH –
URA update cause MP Includes: change of URA, periodic URA update, re-entered service area
Protocol error indicator MD –
Other information elements –
Protocol error information CV-ProtErr –
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II. Example
6.3 Soft Handover
6.3.1 Overview
Because there may be intra-frequency neighboring cells in the WCDMA system, a UE can communicate with the network through multiple radio links. The multiple radio links are combined on a macro-diversity basis by the selection or maximum ratio to optimize the communication QoS.
By making a soft handover, a UE can be smoothly handed from one cell over to another without affecting the previous communication. The soft handover procedure is only used in FDD mode.
The soft handover procedure is divided into the following three kinds according to the resource usage situation:
Radio link addition Radio link deletion Radio link addition/deletion
A soft handover generally includes the following steps:
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1) The UE performs measurements for the intra-frequency neighboring cells according to the measurement control information from the RNC. The measurement results are reported to the RNC after a certain processing.
2) The RNC compares the measurement results with the set thresholds to determine which cell shall be added or deleted.
3) The RNC requests the NodeB to prepare if it determines to add a cell. 4) The RNC requests the UE to add and/or delete a cell through an ACTIVE SET
UPDATE procedure. 5) The UE successfully performs the active set update. RNC shall request the
NodeB to release the corresponding RL resources if it deletes a cell.
6.3.2 Radio Link Addition
This section describes the soft handover procedure (radio link addition) implemented by the NodeB under DRNC, as illustrated in Figure 6-5.
UE DRNC
NBAP
7.
NodeBDRNS
NBAP
RRCRRC
RRCRRC
NBAP NBAP
8. ACTIVE SET UPDATE COMPLETE
2.
3.
4.ALCAP Iub Bearer setup
ACTIVE SET UPDATE
SRNC
RNSAPRNSAP1. RADIO LINK SETUP REQUEST
RNSAPRNSAP5. RADIO LINK SETUP RESPONSE
RADIO LINK SETUP REQUEST
RADIO LINK SETUP RESPONSE
Decision to setupnew RL
Start RXdescription
6.ALCAP Iur Bearer setup
Start TXdescription
[RADIO LINK ADDITION]
Figure 6-5 Soft handover procedure (radio link addition)
Each step is explained in the following list:
1) According to the resource usage situation, the SRNC decides to set up a radio link in the new cell in DRNC. It sends a RNSAP message RADIO LINK SETUP
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REQUEST to the DRNC, requesting for radio resources. If this is the first radio link between the DRNC and the UE, a signaling connection shall also be established on the Iur interface for bearing the RNSAP signaling associated with the UE.
2) After confirming that the resources requested by the SRNC are available, the DRNC sends a NBAP message RADIO LINK SETUP REQUEST to the target NodeB. The NodeB starts uplink receiving.
3) After successfully allocating the resources requested by the SRNC, the NodeB sends a NBAP message RADIO LINK SETUP RESPONSE to the DRNC, reporting the allocation result.
4) The DRNC initiates an Iub interface transport bearer setup procedure using ALCAP.
5) The DRNC sends a RNSAP message RADIO LINK SETUP RESPONSE to the SRNC.
6) The SRNC initiates an Iur interface transport bearer setup procedure using ALCAP.
7) The SRNC transmits the ACTIVE SET UPDATE (Radio Link Addition) message to the UE on the DCCH. The message shall contain the information about the radio link to be added.
8) The UE adds the corresponding radio link information to the active set and returns an RRC message ACTIVE SET UPDATE COMPLETE message to the SRNC. The soft handover procedure (radio link addition) ends.
6.3.3 Radio Link Deletion
This section describes the soft handover procedure (radio link deletion) implemented by the NodeB under control of DRNC, as illustrated in Figure 6-6.
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UE DRNC
NBAP
1.
NodeBDRNS
NBAP
NBAP NBAP
2.ACTIVE SET UPDATE COMPLETE
4.
5.
6.ALCAPIub Bearer release
ACTIVE SET UPDATE
SRNC
RNSAPRNSAP3. RADIO LINK DELETION REQUEST
RNSAPRNSAP7. RADIO LINK DELETION RESPONSE
RADIO LINK DELETION REQUEST
RADIO LINK DELETION RESPONSE
Decision to deleteold RL
Stop RX and TX
8.ALCAP Iur Bearer release
RADIO LINK DELETIONRRCRRC
RRCRRC
Figure 6-6 Soft handover procedure (radio link deletion)
Each step is explained in the following list:
1) According to the resource usage situation, the SRNC decides to delete a radio link from the DRNC. It transmits the RRC message ACTIVE SET UPDATE (Radio Link Deletion) to the UE on the DCCH. The message shall contain the information about the radio link to be deleted.
2) The UE stops downlink receiving on the radio link and deletes that radio link. Then it sends an RRC message ACTIVE SET UPDATE COMPLETE to the SRNC.
3) After confirming that the deleted radio link is in the DRNC, the SRNC sends a RNSAP message RADIO LINK DELETION REQUEST to the DRNC, requesting the DRNC to release the allocated radio resources.
4) The DRNC sends a NBAP message RADIO LINK DELETION REQUEST to the NodeB, requesting the NodeB to release the allocated radio resources.
5) After successfully releasing the radio resources, the NodeB returns a NBAP message RADIO LINK DELETION RESPONSE to the DRNC, reporting the release result.
6) The DRNC initiates an Iub interface data transport bearer release procedure using ALCAP.
7) The DRNC sends a RNSAP message RADIO LINK DELETION RESPONSE to the SRNC.
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8) The SRNC initiates an Iur interface data transport bearer release procedure using ALCAP. The soft handover procedure (radio link deletion) ends.
6.3.4 Radio Link Addition and Deletion
The soft handover procedure (radio link addition and deletion) is implemented when the number of radio links of the UE reaches the maximum number of macro–diversity tributaries allowed. This section describes the soft handover procedure (radio link addition and deletion) implemented by the NodeB under DRNC, as illustrated in Figure 6-7.
UE NodeBSRNS
NBAP
7.
NodeBDRNS
NBAP
RRCRRC
RRCRRC8. ACTIVE SET UPDATE COMPLETE
2.
ACTIVE SET UPDATE
SRNC
1. RADIO LINK SETUP REQUEST
RADIO LINK SETUP REQUEST
DRNC
Decision to setupnew RL and
release old RL
RNSAP RNSAP
Start RXdescription
NBAPNBAP3. RADIO LINK SETUP RESPONSE
RNSAPRNSAP
4. ALCAP Iub Data Transport Bearer Setup
5.RADIO LINK SETUP RESPONSE
[Radio Link Addition & Deletion]
NBAP NBAP
NBAPNBAP
Stop RX and TX
11. ALCAP Iub Data Transport Bearer Release
6.ALCAP Iur Bearer Setup
9.RADIO LINK DELETION REQUEST
10.RADIO LINK DELETION RESPONSE
Figure 6-7 Soft handover procedure (radio link addition and deletion)
Each step is explained in the following list:
1)– 6) These steps are the same as the steps 1) – 6) in the "soft handover procedure (radio link addition)" (see Figure 6-5). Through these steps, a radio link is added to the NodeB under control of DRNC.
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7) The SRNC transmits the RRC message ACTIVE SET UPDATE (Radio Link Addition & Deletion) message to the UE on the DCCH. The message shall contain the information about the radio links to be added & deleted.
8) After successfully adding & deleting the corresponding radio links, the UE sends an RRC message ACTIVE SET UPDATE COMPLETE to the NodeB.
9) –11) These steps are similar to the steps 3)–7) in the "soft handover procedure (radio link deletion)" (see Figure 6-6). The difference is that the radio link is deleted from the NodeB under control of SRNC in this case. Therefore, no radio link deletion through Iur interface is implemented.
6.3.5 Radio Link Setup Request Message
Refer to “5.3.8 Radio Link Setup Request Message” for details.
6.3.6 Active Set Update Message
I. Message Structure
Information Element/Group name Need Type and reference
Message Type MP –
UE information elements –
RRC transaction identifier MP –
Integrity check info CH –
Integrity protection mode info OP –
Ciphering mode info OP –
Activation time MD –
New U-RNTI OP –
CN information elements –
CN Information info OP –
RB information elements –
Downlink counter synchronisation info OP –
>RB with PDCP information list OP –
>>RB with PDCP information MP –
Phy CH information elements –
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Information Element/Group name Need Type and reference
Uplink radio resources –
Maximum allowed UL TX power MD –
Downlink radio resources –
Radio link addition information OP –
>Radio link addition information MP –
Radio link removal information OP –
>Radio link removal information MP –
TX Diversity Mode MD –
SSDT information OP –
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II. Example
6.4 Hard Handover
6.4.1 Overview
The hard handover procedure is a procedure in which the UE stops communication with the previous cell before it accesses a new cell. The procedure can be divided into
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intra-frequency hard handover and inter-frequency hard handover according to the comparison of working frequencies before and after the hard handover.
Since the hard handover’s performance is worse than the soft handover’s, the hard handover procedure is generally not adopted unless the soft handover procedure cannot be implemented.
Relocation shall be triggered along with hard handover when the UE performs the hard handover between different RNCs. Such relocation is generally called relocation with hard handover.
The hard handover procedure may be performed by using one of the following five procedures on the Uu interface:
Physical channel reconfiguration Transport channel reconfiguration Radio bearer setup Radio bearer release Radio bearer reconfiguration
In the following, we will introduce the compressed mode and then introduce the hard handover of Iur interface and the CN combined hard handover to demonstrate the hard handover procedures.
6.4.2 Compressed Mode
The UE may directly implement hard handover without performing measurements for the target cell, as is not allowed in the soft handover procedure. Such hard handover has great possibility of failure, and therefore shall be applied in only emergency circumstances. In more cases of hard handover, the UE shall perform measurements for the target cell. The UE is generally configured with one decoder and cannot simultaneously decode the signals at two frequencies. In order that the UE can perform inter-frequency and inter-RAT measurements, the compressed mode is introduced to the WCDMA system. Figure 6-8 illustrates the principle of compressed mode.
One frame(10 ms) Idle period available for
inter-frequency measurements
Figure 6-8 Principle of compressed mode
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The fundamental principle of compressed mode is given below:
When in compressed mode, the UE transmits a radio frame compressed in time instead of a full radio frame so that the decoder can switch to another frequency or mode to perform inter-frequency and inter-RAT measurements during the transmission gap. The transmission time reduction can be achieved by puncturing or by SF/2.
Puncturing is a method in which bits of a coded radio frame on a radio channel are regularly stopped to create a transmission gap.
SF/2 is a method in which the spreading factor is halved to increase the transmission rate of data bits. That is, this method is used to transmit the bits originally transmitted in one radio frame in a shorter period so as to create a transmission gap.
When the UE performs inter-frequency hard handover measurements, the NodeB shall also be in the compressed mode to ensure that the UE can receive messages from the RNC. Whether to use the compressed mode is determined by the RNC.
6.4.3 Iur Interface Hard Handover
Figure 6-9 illustrates the hard handover signaling procedure which the UE in CELL_DCH state implements on the Iur interface.
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RNSAPRNSAP
1. RADIO LINKSETUP REQUEST
UE NodeBSource
NodeBTarget
RNCSource
RNCtarget SRNC
RRC RRC
10. PHYSICAL CHANNEL RECONFIGURATION COMPLETE
RRC7. PHYSICALl CHANNEL RECONFIGURATION
RRC
6. ALCAP Iur Data Transport Bearer Setup
NBAP NBAP2. RADIO LINK SETUP REQUEST
NBAP NBAP3. RADIO LINK SETUP RESPONSE
NBAP NBAP12. RADIO LINK DELETION REQUEST
NBAP NBAP13. RADIO LINK DELETION RESPONSE
4. ALCAP Iub Data Transport Bearer Setup
14. ALCAP Iub Data Transport Bearer Release
RNSAP RNSAP15. RADIO LINK DELETION RESPONSE
16. ALCAP Iur Data Transport Bearer Release
RNSAP
5. RADIO LINK SETUPRESPONSE
RNSAP
RNSAP
11. RADIO LINK DELETION REQUEST
RNSAP
NBAP NBAP
8. RADIO LINK FAILURE INDICATION
RNSAP RNSAP
9. RADIO LINK FAILURE INDICATION
Figure 6-9 Hard handover (UE in DCH) on Iur interface
Each step is explained in the following list:
1) The SRNC sends a RADIO LINK SETUP REQUEST message to the target RNC on the Iur interface.
2) The target RNC allocates the RNTI and radio resources and sends a RADIO LINK SETUP REQUEST message to the target NodeB on the Iub interface.
3) The target NodeB allocates the resources starts physical layer receiving and returns a RADIO LINK SETUP RESPONSE message to the target RNC.
4) The target RNC initiates an Iub interface data transport bearer setup procedure using ALCAP.
5) The target RNC sends a RADIO LINK SETUP RESPONSE message to the SRNC on the Iur interface.
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6) The SRNC initiates an Iur interface data transport bearer setup procedure using ALCAP.
7) The SRNC sends a PHYSICAL CHANNEL RECONFIGURATION message to the UE on the Uu interface.
8) The UE clears the previous radio links and access the network on the new radio links. The NodeB detects the radio link failure and sends a RADIO LINK FALURE INDICATION message to the CRNC on the Iub interface.
9) The source RNC sends a RADIO LINK FAILURE INDICATION message to the SRNC on the Iur interface.
10) After setting up a radio connection to the target RNC and allocating the necessary radio resources, the UE sends a PHYSICAL CHANNEL RECONFIGURATION COMPLETE message to the SRNC on the Uu interface.
11) The SRNC sends a RADIO LINK DELETION REQUEST message to the source RNC on the Iur interface.
12) The source RNC sends a RADIO LINK DELETION REQUEST message to the source NodeB on the Iub interface.
13) After successfully releasing the radio resources, the source NodeB returns a RADIO LINK DELETION RESPONSE message.
14) The source RNC initiates an Iub interface data transport bearer release procedure using ALCAP.
15) After successful release, the source RNC sends a RADIO LINK DELETION RESPONSE message to the SRNC.
16) The SRNC initiates an Iur interface data transport bearer release procedure using ALCAP. The hard handover procedure implemented on the Iur interface ends.
6.4.4 Combined Hard Handover
The UE in CELL_DCH state has simultaneously connections to two CN domains. It can implement combined hard handover via the CN domain between different RNCs, as illustrated in Figure 6-10, accompanying a SRNC relocation signaling procedure.
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2. RELOCATION REQUIREDRANAP RANAP
RANAP RANAP
4. RELOCATION REQUEST
RANAP RANAP
9. RELOCATION REQUESTACKNOWLEDGE
RANAP RANAP1. RELOCATION REQUIRED
UE RNCSource
RNCTarget MSC
RANAP RANAP3. RELOCATION REQUEST
RANAP RANAP
10. RELOCATION REQUESTACKNOWLEDGE
RANAP RANAP11. RELOCATION COMMAND
RANAP12. RELOCATION COMMAND
RANAP
RANAP RANAP15. RELOCATION
DETECT
RRC13. PHYSICAL CHANNEL RECONFIGURATION
RRC
5. ALCAP Iu DataTransport Bearer Setup
NodeBSource
NodeBTarget
NBAP NBAP6. RADIO LINK SETUP REQUEST
NBAP NBAP7. RADIO LINK SETUP RESPONSE
8. ALCAP Iub Data Transport Bearer Setup
RANAP RANAP19. RELOCATION
COMPLETE
RRC RRC18. PHYSICAL CHANNEL RECONFIGURATION COMPLETE
RANAPRANAP16. RELOCATION DETECT
RANAP RANAP20. RELOCATION COMPLETE
RANAP21. IU RELEASE COMMAND
RANAP
NBAP NBAP17. RADIO LINK FAILURE INDICATION
RANAP 22. IU RELEASE COMMAND RANAP
23. ALCAP IU DATA TRANSPORT BEARERRELEASE
RANAP24. IU RELEASE COMPLETE
RANAP
RANAP25. IU RELEASE COMPLETE
RANAP
SGSN
NBAP NBAP14. RADIO LINK RESTORE INDICAITON
Figure 6-10 Combined hard handover (through CN domain)
Each step is explained in the following list:
1)–2): The source RNC decides to perform relocation with hard handover. The combined hard handover procedure starts. The source RNC sends two RELOCATION
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REQUIRED messages respectively to two CN nodes. Upon reception of the RELOCATION REQUIRED message, the two CN nodes respectively make preparation for the handover procedure.
3)–4): After successful preparation, the two CN nodes respectively send a RELOCATION REQUEST message to the target RNC, requesting the target RNC to allocate resources. The target RNC configures the necessary resources for the radio links to be set up during the hard handover procedure.
5): The target RNC and the MSC set up a new Iu interface transport bearer for the RAB associated with that MSC.
6): The target RNC allocates the RNTI and radio resources to the RRC connection and radio links and sends a RADIO LINK SETUP REQUEST message to the target NodeB.
7) The target NodeB allocates the resources starts physical layer receiving and sends a RADIO LINK SETUP RESPONSE message to the target RNC.
8): The target RNC initiates an Iub interface data transport bearer set up procedure using ALCAP.
9)–10): After successful preparation, the target RNC sends two RELOCATION REQUEST ACKNOWLEDGE messages respectively to the two CN nodes.
11)–12): After successful preparation for SRNC relocation, the two CN nodes respectively send a RELOCATION COMMAND message to the source RNC.
13): The source RNC sends a PHYSICAL CHANNEL RECONFIGURATION message to the UE, informing it of the new physical channel parameters.
14)–16): The target NodeB detects the radio link synchronization on the air interface and sends a RADIO LINK RESTORE INDICATION message to the target RNC, causing the target RNC to send RELOCATION DETECT messages respectively to the MSC and the SGSN.
17): When the UE is handed from the previous radio links over to the new ones, the NodeB detects the asynchronization of the previous radio links and sends a RADIO LINK FAILURE INDICATION message to the target RNC.
18)–20): After successfully physical channel reconfiguration, the UE sends a PHYSICAL CHANNEL RECONFIGURATION COMPLETE message to the target RNC, causing the target RNC to send RELOCATION COMPLETE messages respectively to the MSC and the SGSN.
21)–22): The MSC and the SGSN respectively send an IU RELEASE COMMAND message to the source RNC to initiate an Iu connection release procedure.
23)–25): Upon reception of the IU RELEASE COMMAND messages from the two CN nodes, the source RNC returns two IU RELEASE COMPLETE messages respectively to the CN node and releases all visible UTRAN resources associated with the RRC connection.
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6.4.5 Radio Link Setup Request Message
Refer to “5.3.8 Radio Link Setup Request Message” for details.
6.4.6 Physical Channel Reconfiguration Message
I. Message Structure
Information Element/Group name Need Type and reference
Message Type MP –
UE Information Elements –
RRC transaction identifier MP –
Integrity check info CH –
Integrity protection mode info OP –
Ciphering mode info OP –
Activation time MD –
New U-RNTI OP –
New C-RNTI OP –
RRC State Indicator MP –
UTRAN DRX cycle length coefficient MD –
CN Information Elements –
CN Information info OP –
UTRAN mobility information elements –
URA identity OP –
RB information elements –
Downlink counter synchronisation info OP –
>RB with PDCP information list OP –
>>RB with PDCP information MP –
PhyCH information elements –
Frequency info MD –
Uplink radio resources –
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Information Element/Group name Need Type and reference
Maximum allowed UL TX power MD –
CHOICE channel requirement OP –
>Uplink DPCH info –
>CPCH SET Info –
>CPCH set ID –
Downlink radio resources –
CHOICE mode MP –
>FDD –
>>Downlink PDSCH information OP –
>TDD –
Downlink information common for all radio links OP –
Downlink information per radio link list OP –
>Downlink information for each radio link MP –
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II. Example
6.5 Inter-RAT Handover
6.5.1 Overview
The inter-RAT handover procedure is a handover between the WCDMA system and the GSM/GPRS system and can be divided into:
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1) WCDMA->GSM inter-RAT handover: This procedure is used to hand the UE in CELL_DCH state that sets up CS domain service in the WCDMA system over to the GSM system.
2) GSM->WCDMA inter-RAT handover: This procedure is used to hand the UE in connection mode that sets up CS domain service in the GSM system over to the WCDMA system.
3) GSM/GPRS->WCDMA cell reselection 4) WCDMA->GSM/GPRS cell reselection
Note:
This manual only introduces the signaling procedures of UTRAN. The signaling procedures of CN and GSM/BSS are not included. This section describes equipment in the format of ABC/abc to distinguish equipment that may exist in UMTS, GSM and GPRS systems. For example, GSM/MSC denotes the MSC in GSM.
6.5.2 WCDMA->GSM Inter-RAT Handover
This section describes the basic WCDMA->GSM inter-RAT handover procedure, as illustrated in Figure 6-11.
Note:
The signaling procedures between the UMTS/CN and the GSM/MSC and between the GSM/MSC and the GSM/BSC are outside the scope of this manual and are only schematically mentioned here.
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MAP/E MAP/E
2. PREPARE HANDOVER
BSSMAP BSSMAP
4. HANDOVER REQUEST ACK
RANAP RANAP
13. IU RELEASE COMPLETE
BSSMAP BSSMAP
3. HANDOVER REQUEST
MAP/E MAP/E
5. PREPARE HANDOVERRESPONSE
RANAP RANAP
6. RELOCATION COMMAND
BSSMAP BSSMAP8. HANDOVER
DETECT
BSSMAP BSSMAP
10. HANDOVER COMPLETE
MAP/E MAP/E
11. SEND END SIGNALREQUEST
MAP/E MAP/E
14. SEND END SIGNAL
RANAP RANAP
1. RELOCATION REQUIRED
UE NodeB SRNC CN GSM/MSC GSM/BSC
RRC
7.DCCH : HANDOVER FROM UTRAN COMMAND
RRC[Hard Handover]
RR9. HANDOVER COMPLETE
RR
RANAP RANAP
12. IU RELEASE COMMAND
RESPONSE
Figure 6-11 Inter-RAT handover procedure (WCDMA->GSM)
Each step is explained in the following list:
1) The SRNC decides to perform inter-RAT handover to the GSM system and sends a RELOCATION REQUIRED message to the CN on the Iu interface.
2) The CN sends a MAP message PREPARE HANDOVER to the GSM/MSC.
3) –4) these two steps indicate the signaling procedures in GSM and are only schematically mentioned here.
5) The GSM/MSC and the GSM/BSS perform the initialization procedure and return a MAP/E message PREPARE HANDOVER RESPONSE to the CN.
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6) The CN sends a RANAP message RELOCATION COMMAND to the SRNC as a response to the RELOCATION REQUIRED message.
7) The SRNC sends a HANDOVER FROM UTRAN COMMAND message to the UE on the existing RRC connection, commanding the UE to perform inter-RAT handover.
8) This step indicates a signaling procedure in GSM and is only schematically mentioned here.
9)–10) The UE accesses the network via the GSM/BSS and sends a HANDOVER COMPLETE message.
11) The GSM/MSC detects the UE in the GSM coverage and sends a MAP/E message SEND END SIGNAL REQUEST to the CN.
12) The CN sends an IU RELEASE COMMAND message to initiate a release procedure for the SRNC allocated resources.
13) The UMTS releases the bearer resources and returns an IU RELEASE COMPLETE message to the CN on the Iu interface.
14) Upon completion of the call, the CN sends a MAP/E message SEND END SIGNAL RESPONSE to the GSM/MSC.
6.5.3 GSM->WCDMA Inter-RAT Handover
This section describes the basic GSM->WCDMA inter-RAT handover procedure, as illustrated in Figure 6-12
Note:
The signaling procedures between the CN and the GSM/MSC and between the GSM/MSC and the GSM/BSC are outside the scope of this manual and are only schematically mentioned here.
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RANAP RANAP
3. RELOCATION REQUEST
BSSMAP BSSMAP
1. HANDOVER REQUIRED
RANAP RANAP
4. RELOCATION REQUEST ACK
MAP/E MAP/E
5. PREPARE HANDOVERRESPONSE
MAP/E MAP/E
2. PREPARE HANDOVER
BSSMAP BSSMAP
6. HANDOVER COMMAND
MAP/E MAP/E
11. SEND END SIGNALREQUEST
BSSMAP BSSMAP
12. CLEAR COMMAND
BSSMAP BSSMAP
13. CLEAR COMPLETE
RANAP RANAP10. RELOCATION COMPLETE
UE NodeB RNCTarget CN MSC BSC
MAP/E MAP/E
14. SEND END SIGNALRESPONSE
RRC9. DCCH: : HANDOVER TO UTRAN COMPLETE RRC
RR7. HANDOVER COMMAND
RR
RANAP RANAP8. RELOCATION DETECT
Figure 6-12 Inter-RAT handover procedure (GSM->WCDMA)
Each step is explained in the following list:
1) The GSM/BSC sends a HANDOVER REQUIRED message to the GSM/MSC. 2) The GSM/MSC sends a MAP/E message PREPARE HANDOVER to the CN. 3) The CN sends a RELOCATION REQUEST message to the target RNC on the Iu
interface. 4) The target RNC returns a RELOCATION REQUEST ACKNOWLEDGE message
to the CN. 5) The CN sends a MAP/E message PREPARE HANDOVER RESPONSE to the
GSM/MSC. 6) The GSM/MSC sends a HANDOVER COMMAND message to the GSM/BSC.
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7) The GSM/BSC sends a HANDOVER COMMAND message to the UE, commanding the UE to access the network via the target RNC in UMTS.
8) The target RNC detects the UE and sends a RELOCATION DETECT message to the CN node.
9) The UE sets up an RRC connection to the target RNC. After allocating the necessary radio resources, the UE sends a HANDOVER TO UTRAN COMPLETE message to the target RNC.
10) The target RNC sends a RANAP message RELOCATION COMPLETE to the CN.
11) The CN sends a MAP/E message SEND END SIGNAL REQUEST to the GSM/MSC.
12) The GSM/MSC sends a CLEAR COMMAND message to the GSM/BSC. 13) The GSM/BSC returns a CLEAR COMPLETE message to the GSM/MSC. 14) The GSM/MSC sends a MAP/E message SEND END SIGNAL RESPONSE to
the CN.
6.5.4 GSM/GPRS->WCDMA Cell Reselection
The GSM/GPRS->WCDMA cell reselection procedure is given below:
1) The UE camps on a GSM/GPRS cell and obtains the information (downlink frequency, primary scramble and so on.) about adjacent WCDMA cells and the cell reselection parameters from the system information broadcast in the cell. Depending on the information and parameters, the UE determines whether to perform cell reselection to the WCDMA cell.
2) The UE performs cell reselection to the WCDMA cell by reading the system information and making registration in the WCDMA system. This procedure is the same as the location update procedure and is not included in this section.
6.5.5 WCDMA->GSM/GPRS Cell Reselection
I. Overview
WCDMA->GSM/GPRS cell reselection includes the following cases:
1) WCDMA->GSM/GPRS cell reselection implemented by the UE in IDLE mode in the WCDMA system
2) WCDMA->GPRS cell reselection initiated by the UE in CELL_FACH, CELL_PCH or URA_PCH state that sets up PS domain service in the WCDMA system
3) WCDMA->GPRS cell reselection initiated by the network for the UE in CELL_DCH or CELL_FACH state that sets up PS domain service in the WCDMA system
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II. UE in IDLE Mode
1) The UE camps on a WCDMA cell and obtains the information about adjacent GSM/GPRS cells and cell reselection parameters from the system information broadcast in the cell. Depending on the information and parameters, the UE determines whether to perform cell reselection to the GSM/GPRS cell.
2) The UE selects a GSM/GPRS cell, reads the system information and initiates a registration procedure.
This procedure is the same as the registration procedure in GSM/GPRS and is not included in this section.
III. UE in CELL_FACH, CELL_PCH or URA_PCH state
The UE in CELL_FACH, CELL_PCH or URA_PCH state that sets up PS domain service in the WCDMA system can initiate a WCDMA->GPRS cell reselection signaling procedure, as illustrated in Figure 6-13.
UE CN
1. Cell Reselection
triggered
ServingRNC
RANAP RANAP2. IU RELEASE COMMAND
RANAP RANAP
3. IU RELEASE COMPLETE
Figure 6-13 Cell reselection procedure (UMTS->GPRS initiated by UE)
1) The UE selects a GPRS cell, reads the system information of the cell and initiates a UE-GPRS signaling connection setup procedure.
2) After necessary CN-GPRS preparation (e.g., UE context information retrieval), the CN sends an IU RELEASE COMMAND message to the SRNC to initiate an Iu connection release procedure.
3) After successful release, the SRNC returns an IU RELEASE COMPLETE message to the CN. The WCDMA->GPRS cell reselection procedure initiated by the UE ends.
IV. UE in CELL_DCH or CELL_FACH state
When the UE in in CELL_DCH or CELL_FACH state that sets up PS domain service in the WCDMA system detects the signal of a GPRS cell and reports an inter-RAT
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measurement report, the network can initiate a WCDMA->GPRS cell reselection signaling procedure, as illustrated in Figure 6-14.
Note:
The UMTS->GPRS cell reselection procedure can be initiated by the network only when the RNC can generate GSM messages.
UE CNServing
RNC
RANAP RANAP
2. IU RELEASE COMMAND
RANAP RANAP3. IU RELEASE COMPLETE
RRC RRC
1. CELL CHANGE ORDER FROM UTRAN
Figure 6-14 Cell reselection procedure (UMTS->GPRS initiated by network)
Each step is explained in the following list:
1) The SRNC decides to perform handover to GPRS for the UE based on the measurement results from the UE and sends a CELL CHANGE ORDER FROM UTRAN message to the UE. Upon reception of the message, the UE performs a UE-GPRS connection setup procedure.
2) After necessary CN-GPRS preparation (e.g., UE context information retrieval), the CN sends an IU RELEASE COMMAND message to the SRNC to initiate an RRC connection release procedure on the Iu interface.
3) After successfully releasing all resources reserved for the UE, the SRNC returns an IU RELEASE COMPLETE message to the CN. The WCDMA->GPRS cell reselection procedure initiated by the network ends.
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6.5.6 Handover from UTRAN Command Message
I. Message Structure
Information Element/Group name Need Type and reference
Message Type MP –
UE information elements –
RRC transaction identifier MP –
Integrity check info CH –
Activation time MD –
RB information elements –
RAB information list OP –
>RAB info MP –
Other information elements –
CHOICE System type MP –
>GSM –
>>Frequency band MP –
>>GSM message –
>>>Single GSM message MP –
>>>GSM message List MP –
>cdma2000 –
>>cdma2000MessageList MP –
>>>MSG_TYPE(s) MP –
>>>cdma2000Messagepayload(s) MP –
II. Example
None
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6.5.7 Handover to UTRAN Command Message
I. Message Structure
Information Element/Group name Need Type and reference
New U-RNTI MP –
Ciphering algorithm OP –
CHOICE specification mode MP –
>Complete specification –
RB information elements –
>>Signaling RB information to setup list MP –
>>>Signaling RB information to setup MP –
>>RAB information to setup list OP –
>>>RAB information for setup MP –
Uplink transport channels –
>>UL Transport channel information common for all transport channels
MP –
>>Added or Reconfigured TrCH information MP –
>>>Added or Reconfigured UL TrCH information MP –
Downlink transport channels –
>>DL Transport channel information common for all transport channels
MP –
>>Added or Reconfigured TrCH information MP –
>>>Added or Reconfigured DL TrCH information MP –
Uplink radio resources –
>>Uplink DPCH info MP –
>>CHOICE mode MP –
>>>FDD –
>>>>CPCH SET Info OP –
Downlink radio resources –
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Information Element/Group name Need Type and reference
>>>>Downlink PDSCH information OP –
>>>TDD –
>>Downlink information common for all radio links MP –
>>Downlink information per radio link MP –
>>>Downlink information for each radio link MP –
>Preconfiguration –
>>CHOICE Preconfiguration mode MP –
>>>Predefined configuration MP –
>>>Default configuration –
>>>>Default configuration mode MP –
>>>>Default configuration identity MP –
>>RAB info OP –
>>Uplink DPCH info MP –
Downlink radio resources –
>>Downlink information common for all radio links MP –
>>Downlink information per radio link MP –
>>>Downlink information for each radio link MP –
>>CHOICE mode MP –
>>>FDD –
>>>TDD –
>>>>Primary CCPCH Tx Power MP –
Frequency info MP –
Maximum allowed UL TX power MP –
II. Example
None
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6.6 Relocation
6.6.1 Overview
The RNC relocation procedure is a procedure in which the SRNC of the UE changes from one RNC to another.
According to whether the connection between UE and DRNC is set up during the relocation procedure, the procedure is divided into two kinds i.e., UE NOT INVOLVED relocation and UE INVOLVED relocation.
According to the triggering cause, the relocation procedure can also be divided into the following four kinds:
Static relocation: A relocation procedure occurring after a radio link is added to the DRNC. The UE has set up a radio link in the DRNC and established a connection to the DRNC before the static relocation procedure; therefore, this relocation is a kind of UE NOT INVOLVED relocation.
Relocation with hard handover: A relocation procedure occurring with inter-RNC hard handover. The UE removes the connection with the SRNC and establishes a connection to the DRNC during the relocation with hard handover; therefore, this relocation is a kind of UE INVOLVED relocation.
Relocation with forward handover: A relocation procedure occurring when the UE with RRC connection to the SRNC enters into a DRNC cell and initiates a forward handover (cell update or URA update) procedure. The UE has entered into the DRNC and sent a CELL UPDATE or URA UPDATE message before the relocation with forward handover; therefore, this relocation is a kind of UE NOT INVOLVED relocation.
Inter-RAT handover: The UE removes the connection with the SRNC and establishes a connection to the GSM system during the inter-RAT handover procedure; therefore, inter-RAT handover is a kind of UE INVOLVED relocation.
This section describes the former three kinds of relocation procedures. Refer to 6.5 Inter-RAT Handover for the details about the inter-RAT handover procedure.
6.6.2 Static Relocation
When the UE has a radio link connection only to the DRNC, the Iur interface transport resources between the SRNC and the DRNC shall be occupied. The static relocation procedure is implemented in this case. Through the relocation procedure, the Iur interface connection and the Iu interface connection between the SRNC and the CN are released and an Iu interface connection is set up between the DRNC and the CN. After relocation, the original DRNC becomes the SRNC, as illustrated in Static relocation.
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CN
SRNC
NodeBCELL CELL
UE
DRNC
NodeBCELL CELL
NodeBCELL CELL
UE
SRNC
NodeBCELL CELL
Orig. SRNC
CN
Figure 6-15 Static relocation
Note:
If the UE has connections to two CN domains in the WCDMA system before the relocation procedure, the two CN domains must be relocated together.
Figure 6-16 illustrates the static relocation signaling procedure.
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UE DRNC
13.
SRNC
RRCRRC
5.ALCAP SETUP
UTRAN MOBILITY INFORMATION
MSC
RANAP1. RELOCATION REQUIRED
SGSN
RANAP
RANAP
RANAP RANAP2. RELOCATION REQUIRED
RANAP
RANAP
RANAP
RANAP3. RELOCATION REQUEST
4. RELOCATION REQUEST
RANAPRANAP6. RELOCATION REQUEST ACKNOWLEDGE
RANAPRANAP
7. RELOCATION REQUEST ACKNOWLEDGE
RANAP8. RELOCATION COMMAND
RANAP
RANAP RANAP9. RELOCATION COMMAND
RNSAP RNSAP10. RELOCATION COMMIT
RANAP RANAP11. RELOCATION DETECT
RANAP12. RELOCATION DETECT
14.RRCRRC
UTRAN MOBILITY INFORMATION CONFIRM
RANAP
RANAP RANAP15. RELOCATION COMPLETE
RANAP16. RELOCATION COMPLETE
RANAP17. IU RELEASE COMMAND
RANAP
RANAP RANAP18. IU RELEASE COMMAND
19.ALCAP release
RANAP21. IU RELEASE COMPLETE
RANAP
RANAP RANAP20. IU RELEASE COMPLETE
Figure 6-16 Static relocation procedure
Each step is explained in the following list:
1) The SRNC sends a RELOCATION REQUIRED message to the SGSN (CN in PS domain).
2) The SRNC sends a RELOCATION REQUIRED message to the MSC (CN in CS domain).
3) The SGSN sends a RELOCATION REQUEST message to the DRNC, requesting the DRNC to make resource preparation for the relocation.
4) The MSC sends a RELOCATION REQUEST message to the DRNC, requesting the DRNC to make resource preparation for the relocation.
5) The DRNC initiates an Iu interface user plane bearer setup procedure using ALCAP.
6) The DRNC sends a RELOCATION REQUEST ACKNOWLEDGE message to the SGSN, informing it that the resource preparation is ready.
7) The DRNC sends a RELOCATION REQUEST ACKNOWLEDGE message to the MSC, informing it that the resource preparation is ready.
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8) The SGSN sends a RELOCATION COMMAND message to the SRNC, informing it that the relocation may start.
9) The MSC sends a RELOCATION COMMAND message to the SRNC, informing it that the relocation may start.
10) The SRNC sends a RELOCATION COMMIT message to the DRNC on the Iur interface. If an RAB supporting lossless relocation exists, the message shall contain the PDCP and GTP-U sequence numbers required for context transfer. Then the SRNC starts context transfer. After receiving the RELOCATION COMMIT message, the DRNC becomes the SRNC.
11) The DRNC sends a RELOCATION DETECT message to the SGSN, informing the SGSN that it detects the relocation triggering.
12) The DRNC sends a RELOCATION DETECT message to the MSC, informing the MSC that it detects the relocation triggering.
13) The DRNC sends a UTRAN MOBILITY INFORMATION message to the UE. The message shall contain the new U-RNTI and so on.
14) The UE returns a UTRAN MOBILITY INFORMATION CONFIRM message to the DRNC.
15) The DRNC sends a RELOCATION COMPLETE message to the SGSN, informing it that the relocation ends successfully.
16) The DRNC sends a RELOCATION COMPLETE message to the MSC, informing it that the relocation ends successfully.
17) The SGSN sends an IU RELEASE COMMAND message to the original SRNC, requesting it to release the Iu connection in the PS domain.
18) The MSC sends an IU RELEASE COMMAND message to the original SRNC, requesting it to release the Iu connection in the CS domain.
19) The original SRNC initiates an Iu interface user plane bearer release procedure using ALCAP.
20) After successful release, the SRNC returns an IU RELEASE COMPLETE message to the MSC.
21) The SRNC returns an IU RELEASE COMPLETE message to the SGSN. The static relocation procedure ends.
Note:
When two Iu connections are handed over, the relocation messages for the CS and PS domains are not transmitted in the precedence order. Take the RELOCATION REQUIRED message for example. The SRNC may either first send the RELOCATION REQUIRED message to the MSC or first send the RELOCATION REQUIRED message to the SGSN. The same applies below.
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6.6.3 Relocation with Hard Handover
The relocation procedure with hard handover is a procedure in which the UE performs hard handover to the target RNC and the Iu interface connection changes. Figure 6-17 illustrates the relocation signaling procedure with hard handover.
UE TRNCSRNC
5.ALCAP setup
MSC
RANAP1. RELOCATION REQUIRED
SGSN
RANAP
RANAP RANAP2. RELOCATION REQUIRED
RANAP
RANAP
RANAP
RANAP3. RELOCATION REQUEST
4. RELOCATION REQUEST
RANAPRANAP6. RELOCATION REQUEST ACKNOWLEDGE
RANAPRANAP
7. RELOCATION REQUEST ACKNOWLEDGE
RANAP8. RELOCATION COMMAND
RANAP
RANAP RANAP9. RELOCATION COMMAND
RANAP RANAP10*. FORWARD SRNS CONTEXT
RANAP RANAP11*. FORWARD SRNS CONTEXT
RANAP
RANAP RANAP14. RELOCATION COMPLETE
RANAP15. RELOCATION COMPLETE
RANAP16. IU RELEASE COMMAND
RANAP
RANAP RANAP17. IU RELEASE COMMAND
18.ALCAP release
RRCRRC13. PHYSICAL CHANNEL RECONFIGURATION COMPLETE
RRC RRC
12. PHYSICAL CHANNEL RECONFIGURATION
RANAP19. IU RELEASE COMPLETE
RANAP
RANAP RANAP20. IU RELEASE COMPLETE
Figure 6-17 Relocation procedure with hard handover
Each step is explained in the following list:
1) The SRNC sends a RELOCATION REQUIRED message to the SGSN. 2) The SRNC sends a RELOCATION REQUIRED message to the MSC. 3) The SGSN sends a RELOCATION REQUEST message to the DRNC, requesting
the DRNC to make resource preparation for the relocation. 4) The MSC sends a RELOCATION REQUEST message to the DRNC, requesting
the DRNC to make resource preparation for the relocation. 5) The DRNC initiates an Iu interface user plane bearer setup procedure using
ALCAP.
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6) The DRNC sends a RELOCATION REQUEST ACKNOWLEDGE message to the SGSN, informing it that the resource preparation is ready. The message shall contain the reconfiguration information, indicating which of the radio bearer setup, radio bearer release, radio bearer reconfiguration, transport channel reconfiguration and physical channel reconfiguration procedures the SRNC shall use to perform the relocation.
7) The DRNC sends a RELOCATION REQUEST ACKNOWLEDGE message to the MSC, informing it that the resource preparation is ready. The message shall contain the reconfiguration information, indicating which of the radio bearer setup, radio bearer release, radio bearer reconfiguration, transport channel reconfiguration and physical channel reconfiguration procedures the SRNC shall use to perform the relocation.
8) The SGSN sends a RELOCATION COMMAND message to the SRNC, informing it that the relocation may start.
9) The MSC sends a RELOCATION COMMAND message to the SRNC, informing it that the relocation may start.
10) Optional. If an RAB supporting lossless relocation exists, the SRNC shall send a FORWARD SRNS CONTEXT message to the SGSN, requesting the SGSN to send the PDCP and GTP-U sequence numbers required for context transfer to the target RNC. Then the system goes to step 11). Otherwise, the system skips to step 12).
11) Optional. If it receives a FORWARD SRNS CONTEXT message from the SRNC, the SGSN shall forward the message to the target RNC. The message shall contain the PDCP and GTP-U sequence numbers required for context transfer.
12) The SRNC sends a PHYSICAL CHANNEL RECONFIGURATION message to the UE, informing it of the new physical channel parameters. The specific message type sent at this step is determined by the target RNC during resource preparation and the SRNC is informed of that message type through steps 6), 7), 8) and 9).
13) After successfully accessing the target RNC, the UE sends a PHYSICAL CHANNEL RECONFIGURATION COMPLETE message to the target RNC. The handover procedure succeeds and the target RNC becomes the new SRNC of the UE.
14) The target RNC sends a RELOCATION COMPLETE message to the SGSN, informing it that the relocation ends successfully.
15) The target RNC sends a RELOCATION COMPLETE message to the MSC, informing it that the relocation ends successfully.
16) The SGSN sends an IU RELEASE COMMAND message to the original SRNC, requesting it to release the Iu connection in the PS domain.
17) The MSC sends an IU RELEASE COMMAND message to the original SRNC, requesting it to release the Iu connection in the CS domain.
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18) The original SRNC initiates an Iu interface (including Iu-CS interface and Iu-PS interface) user plane bearer release procedure using ALCAP.
19) The original SRNC returns an IU RELEASE COMPLETE message to the SGSN, indicating that the IU release completes.
20) The original SRNC returns an IU RELEASE COMPLETE message to the MSC, indicating that the IU release completes.
6.6.4 Relocation with Forward Handover
Relocation may occur when the UE performs forward handover between different RNCs. Such relocation is called relocation with forward handover. This section describes the relocation signaling procedure with forward handover, as illustrated in Figure 6-18, with relocation with cell update as an example.
UE SRNC DRNC
RRCRRC
RANAP
3. RELOCATION REQUIRED
SGSN
RANAP
RANAP
RANAPRANAP4. RELOCATION REQUEST
RANAPRANAP
5. RELOCATION REQUEST ACKNOWLEDGERANAP
6. RELOCATION COMMAND
RANAP
RNSAPRNSAP
RANAP8.RELOCATION DETECT
10.PHYSICAL CHANNEL RECONFIGURATION COMPLETE
RANAPRANAP
11.RELOCATION COMPLETE
RANAP RANAP
RRCRRC1.CELL UPDATE
RNSAP RNSAP2.UPLINK SIGNALLING TRANSFER INDICATION
7.RELOCATION COMMIT
RRCRRC
9.CELL UPDATE CONFIRM
12.IU RELEASE COMMAND
RANAP RANAP13.IU RELEASE COMPLETE
Figure 6-18 Relocation procedure with cell update
Each step is explained in the following list:
1) The UE sends a CELL UPDATE message to the DRNC. The message shall contain the S-RNTI, SRNC ID and so on.
2) The DRNC gets the SRNC ID of the UE from the URNTI information element in the CELL UPDATE message. Then the DRNC sends an UPLINK SIGNALING TRANSFER INDICATION message to the SRNC, informing it that the UE requests for cell update.
3) The SRNC sends a RELOCATION REQUIRED message to the SGSN.
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4) The SGSN sends a RELOCATION REQUEST message to the DRNC, requesting the DRNC to make resource preparation for the relocation.
5) The DRNC returns a RELOCATION REQUEST ACKNOWLEDGE message to the SGSN, informing it that the resource preparation is ready.
6) The SGSN sends a RELOCATION COMMAND message to the SRNC, informing it that the relocation may start.
7) The SRNC sends a RELOCATION COMMIT message to the DRNC on the Iur interface. If an RAB supporting lossless relocation exists, the message shall contain the PDCP and GTP-U sequence numbers required for data transfer. Then the SRNC starts data transfer.
8) The DRNC sends a RELOCATION DETECT message to the SGSN, informing the SGSN that it detects the relocation triggering.
9) The DRNC sends a CELL UPDATE CONFIRM message to the UE. The message may contain the transport channel information element, physical channel information element, radio bearer information element, U-RNTI and so on.
10) The UE sends a PHYSICAL CHANNEL RECONFIGURATION COMPLETE message to the DRNC.
11) The DRNC sends a RELOCATION COMPLETE message to the SGSN, informing it that the relocation ends successfully. The DRNC becomes the SRNC.
12) The SGSN sends an IU RELEASE COMMAND message to the original SRNC, requesting it to release the Iu connection in the PS domain.
13) After successfully releasing the Iu connection in the PS domain, the original SRNC returns an IU RELEASE COMPLETE message to the SGSN, indicating that the Iu connection release in the PS domain completes. The relocation procedure with cell update ends.
6.6.5 Relocation Required Message
I. Message Structure
IE/Group Name Presence IE type and reference
Message Type M –
Relocation Type M –
Cause M –
Source ID M –
Target ID M –
MS Classmark 2 C – ifGSMtarget –
MS Classmark 3 C – ifGSMtarget –
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IE/Group Name Presence IE type and reference
Source RNC To Target RNC Transparent Container
C – ifUMTStarget –
Old BSS To New BSS Information C – ifGSMtarget –
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II. Example
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6.6.6 Relocation Request Message
I. Message Structure
IE/Group Name Presence IE type and reference
Message Type M –
Permanent NAS UE Identity C – ifAvail –
Cause M –
CN Domain Indicator M –
Source RNC To Target RNC Transparent Container
M –
RABs To Be Setup List O –
>RABs To Be Setup Item IEs –
>>RAB ID M –
>>NAS Synchronisation Indicator C – ifNASInfoProvided
–
>>RAB Parameters M –
>>Data Volume Reporting Indication
C – ifPS –
>> PDP Type Information C – ifPS –
>>User Plane Information M –
>>>User Plane Mode M –
>>>UP Mode Versions M –
>>Transport Layer Address M –
>>Iu Transport Association M –
>>Service Handover O –
Integrity Protection Information C – ifAvail –
Encryption Information O –
Iu Signalling Connection Identifier M –
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II. Example
6.6.7 Relocation Command Message
I. Messaage Structure
IE/Group Name Presence IE type and reference
Message Type M –
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IE/Group Name Presence IE type and reference
Target RNC To Source RNC Transparent Container
C - ifRecdFromRelocTarget
–
L3 Information C - ifRecdFromRelocTarget
–
RABs To Be Released List O –
>RABs To Be Released Item IEs –
>>RAB ID M –
RABs Subject To Data Forwarding List C - ifPS –
>RABs Subject To Data Forwarding Item IEs
–
>>RAB ID M –
>>Transport Layer Address M –
>>Iu Transport Association M –
Criticality Diagnostics O –
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II. Example
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6.6.8 UTRAN Mobility Information Message
I. Message Structure
Information Element/Group name Need Type and reference
Message Type MP –
UE Information Elements –
Integrity check info CH –
RRC transaction identifier MP –
Integrity protection mode info OP –
Ciphering mode info OP –
New U-RNTI OP –
New C-RNTI OP –
UE Timers and constants in connected mode
OP –
CN Information Elements –
CN Information info OP –
UTRAN Information Elements –
URA identity OP –
RB Information elements –
Downlink counter synchronisation info OP –
>RB with PDCP information list OP –
>>RB with PDCP information MP –
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6.6.9 Uplink Signaling Transfer Indication Message
I. Message Structure
IE/Group Name Presence IE type and reference
Message Type M
Transaction ID M
UC-Id M
SAI M
Cell GAI O
C-RNTI M
S-RNTI M
D-RNTI O
Propagation Delay M
STTD Support Indicator M
Closed Loop Mode1 Support Indicator M
Closed Loop Mode2 Support Indicator M
L3 Information M
CN PS Domain Identifier O
CN CS Domain Identifier O
URA Information O
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II. Example
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Chapter 7 Dynamic Resource Control Procedure Analysis
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Chapter 7 Dynamic Resource Control Procedure Analysis
7.1 Overview
Dynamic resource control is the process to control the radio resources through such means as the channel reconfiguration, radio bear reconfiguration (RB reconfiguration) and so on. In this way, it can achieve reasonable distribution and efficient utilization of the resources.
In this chapter, we will describe the dynamic resource control process through examples, including:
RAB modification Dynamic channel reconfiguration
7.2 RAB Modification
7.2.1 Overview
When the service parameters change, the RAB modification procedure shall be initiated by the CN to reconfigure the RAB as adapted to the QoS change. This procedure is initiated by the CN and implemented by UTRAN.
Corresponding to the RAB setup and release procedures, the RAB modification procedure can be classified into the following four kinds according to the RRC connection status before and after the RAB modification:
DCH-DCH: The RRC connection is in CELL_DCH state before the RAB modification and also in CELL_DCH state after the RAB modification.
CCH-CCH: The RRC connection is in CELL_FACH state before the RAB modification and also in CELL_FACH state after the RAB modification.
CCH-DCH: The RRC connection is in CELL_FACH state before the RAB modification and in CELL_DCH state after the RAB modification.
DCH-CCH: The RRC connection is in CELL_DCH state before the RAB modification and in CELL_FACH state after the RAB modification.
This section describes only the DCH-DCH RAB modification procedure. Other kinds of procedures may be known on the analogy of this procedure.
7.2.2 RAB Modification (DCH-DCH)
Similar to the RAB setup procedure, the DCH-DCH RAB modification procedure can also be further classified into the following two kinds:
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Synchronized radio link reconfiguration Unsynchronized radio link reconfiguration
This section describes only the RAB modification procedure in the case of synchronized radio link reconfiguration. Figure 7-1 illustrates the DCH-DCH RAB modification procedure in the case of synchronized radio link reconfiguration.
NBAP
UE NodeBServing RNS
ServingRNC CN
RRCRRC
NBAPNBAP 5.RADIO LINK RECONFIGURATION READY
NBAP7.RADIO LINK ECONFIGURATION COMMIT
RRCRRC
Iu Data
RANAP RANAP9. RAB ASSIGNMENT RESPONSE
RANAP RANAP1. RAB ASSIGNMENT REQUEST
NBAPNBAP 4.RADIO LINK RECONFIGURATION PREPARE
2. Select L1, L2 and Transport Bearer parameters
e.g. for Radio Bearerreconfiguration.)
3. ALCAP Iu Data Transport Bearer Modify
[Modify]
ALCAP Iub Data Transport Bearer Modify
Actualizing Radio Bearer modification (e.g. Apply new transport format set)
6.DCCH: RADIO BEARER RECONFIGURATION
8 .DCCH: RADIO BEARER RECONFIGURATION COMPLETE
Figure 7-1 RAB modification procedure (DCH-DCH, synchronized)
Each step is explained in the following list:
1) The CN sends a RAB ASSIGNMENT REQUEST (modify) message to initiate an RAB modification procedure. The message shall indicate the RAB ID, modified RAB information, user plane information, transport network layer information, etc.
2) The SRNC selects the corresponding parameters for the corresponding reconfiguration procedure.
3) The SRNC modifies the channel characteristics of the Iu interface data transport bearer using ALCAP if the Iu interface user plane is borne on an AAL2 link.
4) The SRNC sends a RADIO LINK RECONFIGURATION PREPARE message to the NodeB on the Iub interface to initiate a radio link reconfiguration procedure.
5) The NodeB returns a RADIO LINK RECONFIGURATION READY message to the SRNC on the Iub interface.
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6) After the Iu interface transport control plane is successfully modified and the NodeB successfully modifies the radio link, the SRNC sends a RADIO BEARER RECONFIGURATION message to the UE on the DCCH. The message shall contain the RAB information, RAB ID, etc.
7) The SRNC sends a RADIO LINK RECONFIGURATION COMMIT message to the NodeB. The message shall contain the CFN information element. When the next CFN indicated by the information element is received, the NodeB shall use the prepared new configuration.
8) The UE returns a RADIO BEARER SETUP COMPLETE message to the SRNC. 9) The SRNC sends a RANAP message RADIO BEARER ASSIGNMENT
RESPONSE to the CN, confirming that the RAB modification procedure succeeds. The RAB modification procedure ends.
7.2.3 RAB Assignment Request Message
Refer to “5.6.5 RAB Assignment Request Message”.
7.2.4 Radio Bearer Reconfiguration Message
I. Message Structure
Information Element/Group name Need Type and reference
Message Type MP –
UE Information elements –
RRC transaction identifier MP –
Integrity check info CH –
Integrity protection mode info OP –
Ciphering mode info OP –
Activation time MD –
New U-RNTI OP –
New C-RNTI OP –
RRC State Indicator MP –
UTRAN DRX cycle length coefficient MD –
CN information elements –
CN Information info OP –
UTRAN mobility information elements –
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Information Element/Group name Need Type and reference
URA identity OP –
RB information elements –
RAB information to reconfigure list OP –
>RAB information to reconfigure MP –
RB information to reconfigure list MP –
>RB information to reconfigure MP –
RB information to be affected list OP –
>RB information to be affected MP –
TrCH Information Elements –
Uplink transport channels –
UL Transport channel information common for all transport channels
OP –
Deleted TrCH information list OP
–
>Deleted UL TrCH information MP –
Added or Reconfigured TrCH information list
OP
–
>Added or Reconfigured UL TrCH information MP –
CHOICE mode OP –
>FDD –
>>CPCH set ID OP –
>>Added or Reconfigured TrCH information for DRAC list
OP
–
>>>DRAC static information MP –
>TDD –
Downlink transport channels –
DL Transport channel information common for all OP –
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Information Element/Group name Need Type and reference
transport channels
Deleted TrCH information list OP
–
>Deleted DL TrCH information MP –
Added or Reconfigured TrCH information list
OP
–
>Added or Reconfigured DL TrCH information MP –
PhyCH information elements –
Frequency info MD –
Uplink radio resources –
Maximum allowed UL TX power MD –
CHOICE channel requirement OP –
>Uplink DPCH info –
>CPCH SET Info –
Downlink radio resources –
CHOICE mode MP –
>FDD –
>>Downlink PDSCH information OP –
>TDD –
Downlink information common for all radio links OP –
Downlink information per radio link list MP
–
>Downlink information for each radio link MP –
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II. Example
7.3 Dynamic Channel Reconfiguration
7.3.1 Overview
When the UE initiates a service request, the RNC shall allocate appropriate service bandwidth as per the requested QoS. The RNC keeps monitoring the traffic
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measurement, downlink code transmit power, etc. during the service process. When the rate of service origin or quality of air interface changes, the RNC adjusts the channel bandwidth to satisfy the new requirement of the service origin. This procedure is called dynamic channel reconfiguration.
The RNC informs the UE of the new radio link parameters through the procedure of radio bearer reconfiguration.
7.3.2 RB Reconfiguration
The radio bearer reconfiguration procedure is used to reconfigure a radio bearer. This section describes the dynamic channel reconfiguration procedure, as illustrated in Figure 7-2, with radio bearer reconfiguration as an example. The RRC connection of the UE is in CELL_FACH state before the radio bearer reconfiguration and in CELL_DCH state after the radio bearer reconfiguration.
UE
RRCRRC
CRNC
3. ALCAP Data Transport Bearer setup
NBAPNBAP1. RADIO LINK SETUP REQUEST
NBAPNBAP2. RADIO LINK SETUP RESPONSE
4.RADIO BEARER RECONFIGURATION
RRCRRC5. RADIO BEARER RECONFIGURATION COMPLETE
NodeB
NBAPNBAP6. RADIO LINK RESTORE
Figure 7-2 Radio bearer reconfiguration procedure (CCH-DCH)
Each step is explained in the following list:
1) The CRNC sends a RADIO LINK SETUP REQUEST message to the NodeB where the target cell belongs to initiate a radio link setup procedure.
2) The NodeB where the target cell belongs returns a RADIO LINK SETUP RESPONSE message to the CRNC.
3) The CRNC sets up an Iub interface transport bearer between the CRNC and the NodeB using ALCAP and implements synchronization using FP.
4) The CRNC sends a RADIO BEARER RECONFIGURATION message to the UE on the downlink DCCH. The message shall contain the target cell information and the target RRC connection status of the UE.
5) After successfully handed over to the target cell, the UE sends a RADIO BEARER RECONFIGURATION COMPLETE message to the CRNC on the DCCH.
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6) After detecting the uplink synchronization of the new radio link, the NodeB sends a RADIO LINK RESTORE INDICATION message to the CRNC. The message shall contain the information about the radio link detected as synchronized. The radio bearer reconfiguration procedure ends.
7.3.3 Radio Bearer Reconfiguration Message
Refer to 7.2.4 Radio Bearer Reconfiguration.
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Appendix A Tracing Tools
A-1
Appendix A Tracing Tools
A.1 About Tracing Tools
You can browse the signaling procedures and the content of each message described in this manual through the message trace tools integrated in LMT of Huawei RNC and NodeB.
A.1.1 RNC Tracing Tool
Refer to “Chapter 7 Tracing Management” of “HUAWEI BSC6800 WCDMA Radio Network Controller Operation Manual – Routine Operation” for the details of how to use the tracing tool.
A.1.2 NodeB Tracing Tool
Refer to “Chapter 3 Tracing Management” of “WCDMA NodeB Operation Manual – Routine Operation” for the details of how to use the tracing tool.
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Appendix B Call Example
B-1
Appendix B Call Example
B.1 Overview
In the chapter, we will introduce a typical call process in UTRAN through an example of originating calling procedure and an example of terminated call procedure.
B.2 Originating Call Procedure
Originating call procedure is a procedure in which a UE calls other subscribers e.g., PSTN subscriber.
Figure B.1 illustrates a specific calling procedure. The calling procedure generally consists of the following procedures:
1) RRC connection setup
To successfully make a call, the UE initiates the RRC connection setup procedure to set up a signaling connection to the RNC. For details, see Section “5.3 RRC Connection Setup”.
2) Signaling connection setup
The RNC sets up a signaling connection to the CN. For details, see Section “5.4 Direct Transfer Messages”.
3) RAB setup
The CN responds to the service request from the UE and requests the RNC to set up the corresponding RAB. After successful RAB setup, the called party answers the call and the call is set up. For details, see Section “5.6 RAB Setup”.
4) Signaling connection release
Upon completion of the call, the signaling connection between the RNC and the CN shall be released. For details, see Section “5.7 Call Release”.
5) RAB release
The RAB shall be released through the RAB release procedure. For details, see Section “5.7 Call Release”.
6) RRC connection release
The RRC connection between the UE and the RNC shall be released through the RRC connection release procedure if the RRC bears no other RABs. For details, see Section “5.7 Call Release”.
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Appendix B Call Example
B-2
NodeBSRNS
SRNC
RRCRRC CCCH : RRC CONNECTION REQUEST
NBAP RADIO LINK SETUP RESPONSE
NBAP
NBAP RADIO LINK SETUP REQUEST
CCCH : RRC CONNECTION SETUP
Start RX
Start TX
RRC
RRCDCCH : RRC CONNECTION SETUP COMPLETE
NBAP
RRC
RANAPRANAPINNTIAL UE MESSAGE
RANAPRANAP
DCCH
DIRECT TRANSFER
RANAPRANAP DIRECT TRANSFER
:
DIRECT TRANSFER
DCCH: DIRECT TRANSFER
DCCH:
:
RRCDOWNLINK
RRC
RRC
RRC
UPLINK
RRC
RRC
RRC
RRC
(CM Service Request)
(CM Service Accept)
(Setup)
DCCH:
DCCH:
DOWNLINK
UPLINK
DIRECT TRANSFER
DIRECT TRANSFERRRC
RRC
RRC
RRC
RANAPRANAPDIRECT TRANSFER (Call Proceeding)
RAB ASSIGNMENT REQUESTRANAPRANAP (Establishment)
NBAPPREPARE
NBAP
RADIO LINK RECONFIGURATION
NBAP
RADIO LINK RECONFIGURATION
NBAPREADY
INITAL DIRECT TRANSFER
UE CN
ALCAP Iub Data Transport Bearer Setup
ALCAP Iur Data Transport Bearer Setup
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Appendix B Call Example
B-3
UE NodeBSRNS
SRNC CN
RRC
DCCH : RADIO BEARER SETUP
DCCH : RADIO BEARER SETUP COMPLETE
RADIO LINK RECONFIGURATION NBAP NBAP
Apply new transport format set
RRC
RRC
RRC
RRC
RANAPRANAP DIRECT TRANSFER
RRC
RANAPRANAP DIRECT TRANSFER
(Alerting)
(Connect)
RRC
RRC
RANAPRANAP DIRECT TRANSFER
(Connect Acknowledge)
RRC
RANAPRANAP DIRECT TRANSFER(Release Complete)
RANAPRANAP DIRECT TRANSFER(Release)
RANAPRANAP DIRECT TRANSFER(Disconnect)
RRC
RANAPRANAP
RANAPRANAP
IU RELEASE COMMANDE
IU RELEASE COMPLETE
DCCH:
DCCH::
DOWNLINK
UPLINK
DIRECT TRANSFER
DIRECT TRANSFER
RRC
RRC
DCCH:DOWNLINK
DCCH: DOWNLINK
DIRECT TRANSFERRRC
DCCH: UPLINKRRC DIRECT TRANSFER
DIRECT TRANSFERRRC
DCCH: UPLINK DIRECT TRANSFERRRC
COMMIT
DCCH : RRC CONNECTION
DCCH : RRC CONNECTION
RELEASE
RELEASE COMPLETE
NBAP RADIO LINK DELETION
NBAP RADIO LINK DELETION
NBAP
NBAPCOMPLETE
RRC RRC
RRC RRC
RAB ASSIGNMENT RESPONSERANAP RANAP(Establish)
ALCAP Iub Data Transport Bearer Setup
ALCAP Iu Data Transport Bearer Release
ALCAP Iub Data Transport Bearer Release
Figure B-1 Calling procedure
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Appendix B Call Example
B-4
B.3 Terminated Call procedure
Terminated call procedure is a procedure in which the network pages a UE and the UE responds to the paging. Upon reception of a Paging message, the UE shall initiate an RRC connection setup procedure. The terminated procedure generally consists of the following procedures:
1) Paging
The network pages the UE. For details, see Section “5.2 Paging”.
2) RRC connection setup
The UE answers the call and initiates an RRC connection setup procedure to set up a connection to the RNC. For details, see Section “5.3 RRC Connection Setup”.
3) Signaling connection setup and direct transfer
The RNC sets up a signaling connection to the CN. For details, see Section “5.4 Direct Transfer Messages”.
4) RAB setup
The CN requests the RNC to set up the corresponding RAB. After successful RAB setup, the UE exchanges signaling messages with the CN and answers the call to enter into a conversation. For details, see Section “5.6 RAB Setup”.
5) Signaling connection release
Upon completion of the call, the signaling connection between the RNC and the CN shall be released. For details, see Section “5.7 Call release”.
6) RAB release
The RAB shall be released through the RAB release procedure. For details, see Section “5.7 Call release”.
7) RRC release
The RRC connection between the UE and the RNC shall be released through the RRC connection release procedure if the RRC bears no other RABs. For details, see Section “5.7 Call release”.
Figure Figure B-2 illustrates a specific terminated procedure.
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Appendix B Call Example
B-5
UENodeBSRNS
SRNC
RRCRRC
CCCH: RRC CONNECTION REQUEST
NBAP RADIO LINK
SETUP RESPONSE NBAP
NBAP RADIO LINK SETUP REQUEST
CCCH : RRC CONNECTION SETUP
Start RX
Start TX
RRC
DCCH : RRC CONNECTION SETUP COMPLETE
NBAP
INITAL DIRECT TRANSFER
RRC
RANAPRANAP
CN
INITIAL UE MESSAGE
RANAP
DCCH
DIRECT TRANSFER
DIRECT TRANSFER
:
DIRECT TRANSFER DCCH:::
DIRECT TRANSFERDCCH ::
RRCDOWNLINK
RRC
RRC
RRC
UPLINK
RRC
RRC
RRC
(Paging Response)
(Set Up)
RAB ASSIGNRMENT REQUEST
(Establishment)
NBAPPREPARE
NBAPRAKIO LINK RECONFIGURATION
NBAPRADIO LINK RECONFIGURATION
NBAPREADY
RANAPRANAPPAGING
PAGING TYPE 1
(Call Confirm)
RANAP
RANAPRANAP
RANAP RANAP
RRC
RRC
RRCRRC
ALCAP Iub Data Transport Bearer Setup
ALCAP Iu Data Transport Bearer Setup
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Appendix B Call Example
B-6
UENodeBSRNS SRNC CN
RRC
DCCH : RADIO BEARER SETUP
DCCH : RADIO BEARER SETUP COMPLETE
RADIO LINK RECONFIGURATION NBAP NBAP
Apply new transport format set
RRC
RRC
RRC
RRC
RANAPRANAP DIRECT TRANSFER
RANAPRANAP DIRECT TRANSFER
(Alerting)
(Connect)
RRC
RANAPRANAP DIRECT TRANSFER(Connect Acknowledge)
RRC
RANAPRANAP DIRECT TRANSFER (Release Complete)
RANAPRANAP DIRECT TRANSFER
(Release)
RANAPRANAP DIRECT TRANSFER(Disconnect)
RRC
RANAPRANAP IU RELEASE COMMAND
DIRECT TRANSFER DCCH:
DIRECT TRANSFER
DCCH:
UPLINKRRC RRC
UPLINK DIRECT TRANSFER RRC
DCCH:DOWNLINKRRC DIRECT TRANSFER
DCCH:DOWNLINKRRC DIRECT TRANSFER
DIRECT TRANSFERDCCH:DOWNLINKRRC RRC
DCCH:UPLINKRRC
COMMIT
RANAPRANAPIU RELEASE COMPLETE
DCCH:RRC CONNECTION
DCCH:RRC CONNECTION
RELEASE
RELEASE COMPLETE
NBAP RADIO LINK DELETION
NBAP RADIO LINK DELETION
NBAP
NBAP
RRC
RRC
COMPLETE
RRC
RRC
RAB ASSIGNMENT RESPONSERANAP RANAP
(Establishment)
ALCAP Iub Data Transport Bearer Setup
ALCAP Iu Data Transport Bearer Release
ALCAP Iub Data Transport Bearer Release
Figure B-2 Terminated procedure
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Appendix C Acronyms and Abbreviations
C-1
Appendix C Acronyms and Abbreviations
A
AAL ATM Adaptation Layer
AAL2 ATM Adaptation Layer type 2
AAL5 ATM Adaptation Layer Type 5
AICH Acquisition Indicator Channel
ALCAP Access Link Control Application Part
AMR Adaptive Multi-Rate
ATM Asynchronous Transfer Mode
B
BCCH Broadcast Control CHannel
BCH Broadcast Channel
BFN NodeB Frame Number Counter
BMC Broadcast/Multicast Control protocol
BSC Base Station Controller
BSC6800 Huawei RNC Model
BSS Base Station Subsystem
C
CA-ICH Channel assignment indication channel
CBC Cell Broadcast Center
CBS Cell Broadcast Service
CC Call Control
CCCH Common Control Channel
CCH Common transport channel
CCTrcH Coded Composite Transport Channel
CFN Connection Frame Number
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Appendix C Acronyms and Abbreviations
C-2
CN Core Network
CPCH Common Packet Channel
CPCS Common Part Convergence Sublayer
CPICH Common Pilot Channel
CRC Cyclic Redundancy Check
CRNC Controlling RNC
C-RNTI Cell Radio Network Temporary Identifier
CS Circuit-Switched
CSICH CPCH status indication channel
D
DCCH Dedicated Control CHannel
DCH Dedicated CHannel
DPC Destination (Signaling)Point Code
DPCCH Dedicated Physical Control Channel
DPCH Dedicated Physical Channel
DPDCH Dedicated Physical Data Channel
DRNC Drift RNC
DRNS Drift RNS
DRX Discontinuous Reception
DSCH Downlink Shared Channel
F
FACH Forward Access Channel
FDD Frequency Division Duplex
FER Frame Error Rate
G
GPRS General Packet Radio Service
GSM Global System for Mobile Communications
GTP-U User plane part of GPRS tunneling protocol
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Appendix C Acronyms and Abbreviations
C-3
I
IE Information Element
IMSI International Mobile Station Identity
IP Internet Protocol
ISUP Integrated Services Digital Network User Part/ISDN User Part
ITU-T International Telecommunication Union - Telecommunication Standardization Sector
IU Iu Interface
IUR Iur Interface
L
LAI Location Area Identity
M
MAC Medium Access Control
MIB Master Information Block
MM Mobility Management
MS Mobile Station
MSC Mobile Switching Center
MSU Message Signalling Unit
MTP Message Transfer Part
MTP3 Message Transfer Part Layer 3
N
NAS Non-Access Stratum
NBAP NodeB Application Part
NNI Network Node Interface (Network-to-Network)
NodeB WCDMA Base Station
O
OAM Operation Administration and Maintenance
OPC Originating Point Code
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Appendix C Acronyms and Abbreviations
C-4
P
PCCH Paging Channel (logical Channel)
PCCPCH Primary Common Control Physical Channel
PCH Paging Channel
PCP Power Control Preamble
PCPCH Physical Common Packet Channel
PCPICH Primary Common Pilot Channel
PDCP Packet Data Convergence Protocol
PDP Packet Data Protocol
PDSCH Physical Downlink Shared Channel
PICH Paging Indicator Channel
PLMN Public Land Mobile Network
PRACH Packet Random Access Channel
PS Packet Switched
PSCH Physical shared channel
PSTN Public Switched Telephone Network
Q
QoS Quality of Service
R
RAB Radio Access Bearer
RACH Random Access CHannel
RANAP Radio Access Network Application Part
RB Radio Bearer
RFN RNC Frame Number counter
RNC Radio Network Controller
RNS Radio Network Subsystem
RNSAP Radio Network Subsystem Application Part
RNTI Radio Network Temporary Identity
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Appendix C Acronyms and Abbreviations
C-5
RRC Radio Resource Control
RTWP Receive Total Widthband Power
S
SAAL Signaling ATM Adaptation Layer
SABP Service Area Broadcast Protocol
SAR Segmentation And Reassembly
SCCP Signaling Connection and Control Part
SCCPCH Secondary Common Control Physical Channel
SCH Synchronization CHannel
SCPICH Secondary Common Pilot Channel
SDU Service Data Unit
SGSN Serving GPRS Support Node
SI Service Indicator
SIB System Information Block
SIF Signaling Information Field
SIO Service Information Octet
SIR Signal-Interference Ratio
SLS Signaling Link Selection
SRB Signalling radio bearer
SRNC Serving RNC
SRNS Serving RNS
SS7 Signaling System Number 7
SSCF Service Specific Coordination Function
SSCH Secondary Synchronization CHannel
SSCOP Service Specific Connection Oriented Protocol
SSCS Service Special Convergence Sublayer
SSN Sub-System Number
STC Signaling Transport Converter
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Appendix C Acronyms and Abbreviations
C-6
STTD Space Time Transmit Diversity
T
TB Transport Block
TBS Transport Block Set
TDD Time Division Duplex
TFC Transport Format Combination
TFCI Transmit Format Combined Indicator
TFI Transport Format Indicator
ToA Time of Arrival
ToAWE Time of Arrival Window Endpoint
ToAWS Time of Arrival Window Startpoint
TPC Transmit Power Control
TTI Transmission Time Interval
U
UE User Equipment
UMTS Universal mobile telecommunication services/Universal Mobile Telecommunications System
UNI Logical User-Network Interface
UP User Plane
URA UTRAN Registration Area
U-RNTI UTRAN Radio Network Temporary Identifier
UTRAN UMTS Terrestrial Radio Access Network
UU Uu Interface
V–W
VP Video Phone
WCDMA Wideband CDMA
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Index
i-1
Index
A active set update message, 6-13
ALCAP, 2-26
audit response message, 3-12
B blocking of AAL2 path, 2-28
BMC, 1-6
C call example, B-1
call release, 5-43
call setup and release procedure analysis, 5-1
CCH-CCH, 5-32
CCH-DCH, 5-30
cell deletion procedure, 3-7
cell reconfiguration procedure, 3-6
cell related procedure analysis, 3-1
cell setup procedure, 3-3
cell setup request message, 3-16
cell update, 6-1
cell update message, 6-4
changback, 2-19
changeover, 2-19
class 1 elementary procedure, 1-20, 1-27
class 2 elementary procedure, 1-21, 1-27
class 3 elementary procedure, 1-28
combined hard handover, 6-19
combined release, 5-47
common measurement initiation procedure, 3-5
common transport Channel setup procedure, 3-4
common transport channel setup request, 3-20
compressed mode, 6-16
connection request message, 2-34
CPCS, 2-8
CS domain service release, 5-43
D DCH-DCH, 5-27
direct transfer message, 5-18
disconnection of signaling link, 2-20
DL timing adjustment, 1-13
DL transport channel synchronization, 1-12
downlink data transfer, 1-15
downlink direct transfer, 5-20
downlink direct transfer message, 5-23
downlink timing adjustment, 1-18
downlink transport channel sychronization, 1-17
dynamic channel reconfiguration, 7-6
dynamic resource control procedure analysis, 7-1
E error event, 1-32
establish request message, 2-30
establishment of AAL2 connection, 2-27
example of cell setup procedure, 3-28
F FACH data transfer, 1-11
forward handover, 6-1
frame quality classification, 1-33
function of Iu UP, 1-28
function of NBAP, 1-8
function of RANAP, 1-25
function of RNSAP, 1-19
function of SABP, 1-33
function of system information, 4-2
G GSM/GPRS->WCDMA cell reselection, 6-29
GSM->WCDMA inter-RAT handover, 6-27
GTP-U, 1-33
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Index
i-2
H handover from UTRAN command message, 6-32
handover to UTRAN command message, 6-33
hard handover, 6-15
heading code, 2-17
I initial direct transfer, 5-18
initial direct transfer message, 5-21
initialisation procedure, 1-30
Inter-RAT handover, 6-24
Iu interface, 1-22
Iu interface specification, 1-25
Iu protocol architecture, 1-22
Iu rate control, 1-31
Iu signaling connection release, 5-44
Iub FP
common transport channel data transfer, 1-10
dedicated transport channel data transfer, 1-14
Iub interface, 1-6
Iub interface specification, 1-7
Iub interface user plane setup, 3-4
Iub protocol structure, 1-6
Iur FP
transport channel data transfer, 1-22
Iur interface, 1-18
Iur interface hard handover, 6-17
Iur interface specification, 1-19
Iur protocol structure, 1-18
L L1 function, 1-6
L2 function, 1-5
LM, 2-9
M MAC, 1-5
management prohibit, 2-19
message
active set update, 6-13
audit response, 3-12
cell setup request, 3-16
cell update, 6-4
common transport channel setup request, 3-20
connection request, 2-34
downlink direct transfer, 5-23
establish request, 2-30
handover from UTRAN command, 6-32
handover to UTRAN command, 6-33
initial direct transfer, 5-21
MTP3-B management, 2-25
MTP3-B test, 2-24
MTP3-B upper user, 2-23
paging type 1, 5-3
paging type 2, 5-4
physical channel reconfiguration, 6-22
RAB assignment request, 5-33
RAB assignment response, 5-36
radio bearer reconfiguration, 7-3
radio bearer setup, 5-38
radio link setup request, 5-14
relocation command, 6-46
relocation request, 6-45
relocation required, 6-42
resource status indication, 3-7
RRC connection reject, 5-13
RRC connection request, 5-8
RRC connection setup, 5-10
SSCOP, 2-10
system information, 4-4
system information update request, 3-25
uplink direct transfer, 5-22
uplink signaling transfer indication, 6-51
URA update, 6-6
UTRAN mobility information, 6-49
message discrimination, 2-12
message distribution, 2-13
message routing, 2-13
message structure, 2-14, 2-29, 2-33
mobility management procedure analysis, 6-1
modification by a timer, 4-7
modification by a value tag, 4-7
MTP3-B, 2-11
MTP3-B management message, 2-25
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Index
i-3
MTP3-B test message, 2-24
MTP3-B upper user message, 2-23
N NBAP common procedure, 1-9
NBAP dedicated procedure, 1-9
NBAP procedure, 1-8
Node synchronization, 1-12, 1-16
NodeB tracing tool, A-1
O originating call procedure, B-1
outer loop power control transfer, 1-15
P paging, 5-1
UE in CELL_DCH state, 5-3
UE in CELL_FACH state, 5-3
UE in idle mode, 5-2
UE in PCH state, 5-2
paging type 1 message, 5-3
paging type 2 message, 5-4
PCH data transfer, 1-11
PDCP, 1-5
physical channel reconfiguration message, 6-22
procedure
ALCAP, 2-26
call release, 5-43
cell setup, 3-1
direct transfer message, 5-18
dynamic channel reconfiguration, 7-6
forward handover, 6-1
hard handover, 6-15
inter-RAT handover, 6-24
MTP3-B, 2-11
paging, 5-1
RAB modification, 7-1
RAB setup, 5-26
relocation, 6-35
RRC connection setup, 5-5
SAAL, 2-1
SCCP, 2-31
soft handover, 6-8
system information broadcast and update, 4-3
system information modification, 4-6
UE capability information, 5-24
procedure Involved in cell setup, 3-1
Protocol stack of Iub interface, 1-7
protocol stack of Iu-BC interface, 1-24
protocol stack of Iu-CS interface, 1-23
protocol stack of Iu-PS interface, 1-23
protocol stack of Iur interface, 1-19
protocol structure of MTP3-B, 2-12
PS domain service release, 5-43
R RAB assignment request message, 5-33
RAB assignment response message, 5-36
RAB modification, 7-1
RAB modification (DCH-DCH), 7-1
RAB release, 5-45
RAB setup, 5-26
RACH data transfer, 1-10
radio bearer reconfiguration message, 7-3
radio bearer setup message, 5-38
radio interface parameter update, 1-16
radio link addition, 6-9
radio link addition and deletion, 6-12
radio link deletion, 6-10
radio link setup request message, 5-14
RANAP procedure, 1-26
release of AAL2 connection, 2-27
relocation, 6-35
relocation command message, 6-46
relocation request message, 6-45
relocation required message, 6-42
relocation with forward handover, 6-41
relocation with hard handover, 6-39
reset, 2-28
resource audit procedure, 3-2
resource status indication message, 3-7
resource status indication procedure, 3-1
RLC, 1-5
RNC tracing tool, A-1
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Index
i-4
RNSAP procedure, 1-20
RRC connection reject, 5-7
RRC connection reject message, 5-13
RRC connection release, 5-48
on CCH, 5-50
on DCH, 5-49
RRC connection request message, 5-8
RRC connection setup, 5-5
on common channel, 5-7
on dedicated channel, 5-6
RRC connection setup message, 5-10
RRC function, 1-4
S SAAL, 2-1
SAAL Structure, 2-1
SAR, 2-8
SCCP, 2-31
service indicator (SI), 2-15
service information octet(SIO), 2-14
signaling connection release, 5-44
signaling connection release request, 5-44
signaling information field (SIF), 2-15
signaling link connecting, 2-21
signaling link fault, 2-20
signaling link management, 2-14
signaling link restoration, 2-20
signaling network management message, 2-16
signaling route management, 2-14
signaling traffic management, 2-13
soft handover, 6-8
SSCF, 2-7
SSCOP, 2-2
SSCOP connection release, 2-5
SSCOP connection setup, 2-5
SSCOP data transmission, 2-6
SSCOP error recovery, 2-6
SSCOP message, 2-10
SSCOP operation state, 2-4
static relocation, 6-35
synchronized radio link reconfiguration, 5-27
system information broadcast, 4-3
system information broadcast and update, 4-3
system information message, 4-4
system information modification, 4-6
system information monitoring mechanism, 4-2
system information procedure analysis, 4-1
system information structure, 4-1
system information update, 3-5, 4-3
system information update request message, 3-25
T terminated call procedure, B-4
time alignment procedure, 1-31
ToA, 1-13
ToAWE, 1-13
ToAWS, 1-13
tool
NodeB message tracing, A-1
RNC message tracing, A-1
transport network layer procedure analysis, 2-1
U UE capability enquiry, 5-25
UE capability information, 5-24
UE capability information update, 5-25
unblocking of AAL2 path, 2-28
unsynchronized radio link reconfiguration, 5-29
uplink data transfer, 1-14
uplink direct transfer, 5-19
uplink direct transfer message, 5-22
uplink signaling transfer indication message, 6-51
URA update, 6-3
URA update message, 6-6
user data transfer, 1-30
UTRAN interface function, 1-1
UTRAN interface protocol, 1-1
UTRAN interface protocol and function, 1-1
UTRAN interfaces, 1-1
UTRAN mobility information message, 6-49
Uu interface, 1-2
Uu protocol structure, 1-2
Protocols and Signalling Analysis HUAWEI UMTS Radio Access Network Index
i-5
W WCDMA->GSM inter-RAT handover, 6-25
WCDMA->GSM/GPRS cell reselection, 6-29
i.