Product name Confidentiality level

WCDMA RNP For internal use only

Product version Total 130 pages

3.2

W-Access Problem Optimization Guide

(For internal use only)

Prepared by Date

Reviewed by Date

Reviewed by Date

Approved by Date

Huawei Technologies Co., Ltd.

All Rights Reserved

Revision Records

Date Version Description Author

2004-08-23 1.00 Outline

2004-11-03 1.00 Initial transmittal

2004-12-20 1.20 Revising according to review

2005-11-21 3.00 According to V3.0 guide requirements, reorganizing and

updating V2.0 guide. The update includes:

� Modifying document structure

� Adding optimization objectives

� Adding delay optimization

� Adding new cases and analysis

� Redrawing analysis flow chats

� Adding appendix which contain the background knowledge

about access.

� Adding analysis of traffic statistics data

2006-05-19 3.10 V3.10 adds analysis of HSDPA with the following content

updated:

� Supplementing admission failure analysis and cases about

RRC connection, RAB assignment process in HSDPA service

� Adding HSDPA-related DT and traffic statistics values

� According to traffic statistics indexes of RNC version

1.6C01B064, adding some traffic statistics indexes

� Updating RRC connection analysis

2006-06-21 3.11 Adding analysis of traffic statistics in paging problems

2006-10-23 3.12 � Adding analysis of reasons for admission rejection

� Adding algorithms of admission rejection in V17

� Adding analysis of dualband access problems

� Adding analysis of impacts brought by dual-carrier direct

retry on the access delay

2007-08-25 3.2 Adding HSUPA analysis, including:

� Introduction to HSUPA load control algorithms

� Description of key parameters in HSUPA load control

� Introduction to indexes of success rate of HSPA RAB setup

� Strategy of HSPA dualband networking

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Contents

1 Introduction.................................................................................................................................. 14

2 Evaluating Access Performance................................................................................................ 15

2.1 Accessibility ................................................................................................................................................... 15

2.2 System Availability ........................................................................................................................................ 16

2.3 Access Delay .................................................................................................................................................. 16

3 Analyzing DT/CQT Data ........................................................................................................... 17

3.1 Data Analysis Software .................................................................................................................................. 17

3.2 Definition of Access Failure ........................................................................................................................... 17

3.2.1 Definition of Call Failure by GENEX Assistant ................................................................................... 17

3.2.2 Definition of Actix Analyzer ................................................................................................................. 19

3.2.3 Definition of TEMS .............................................................................................................................. 19

3.3 Flow and Methods for Analyzing Access Failure Problems ........................................................................... 20

3.3.1 Overall Flow for Analyzing Call Failure Problems............................................................................... 20

3.3.2 Analyzing Paging Problems .................................................................................................................. 21

3.3.3 Analyzing RRC Connection Setup Problems ........................................................................................ 23

3.3.4 Analyzing Authentication Problems ...................................................................................................... 26

3.3.5 Analyzing Security Mode Problems ...................................................................................................... 28

3.3.6 Analyzing PDP Activation Failure Problems ........................................................................................ 29

3.3.7 Analyzing RAB or RB Setup Problems ................................................................................................ 30

3.3.8 Analyzing Access Problems in the Case of Dualband Networking ....................................................... 33

3.4 Processing Access Delay ................................................................................................................................ 36

3.4.1 Configuration of Discontinuous Cyclic Period Duration Factor DRX .................................................. 36

3.4.2 Whether to Disable Authentication and Encryption Flow ..................................................................... 37

3.4.3 Implementing Early or Late Assignment .............................................................................................. 37

3.4.4 Whether the RRC Connection Is Set up on FACH and DCH ............................................................... 38

3.4.5 Impact of Direct Retry on Access Delay ............................................................................................... 38

4 Analyzing Traffic Statistics Data ............................................................................................. 39

4.1 Tool for Analyzing Data ................................................................................................................................. 39

4.2 General Methods for Analyzing Traffic Statistics Data .................................................................................. 39

4.2.1 Flow for Analyzing RNC-level Traffic Statistics Data .......................................................................... 40

4.2.2 Flow for Analyzing Cell-level Traffic Statistics Data ........................................................................... 41

4.3 Accessibility Indexes ...................................................................................................................................... 42

4.3.1 Paging Traffic Statistics Indexes ........................................................................................................... 42

4.3.2 Low Success Rate of RRC Setup .......................................................................................................... 45

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4.3.3 Low Success Rate of CS RAB Setup .................................................................................................... 50

4.3.4 Lower Success Rate of PS RAB Setup ................................................................................................. 53

4.3.5 Low Success Rate of RB Setup ............................................................................................................. 59

4.4 System Availability Index .............................................................................................................................. 61

4.4.1 High Admission Rejection Rate ............................................................................................................ 61

4.4.2 High Paging Congestion Rate ............................................................................................................... 61

4.4.3 High Rate of Congested Cell ................................................................................................................ 61

5 Solving Access Problems ........................................................................................................... 62

5.1 Paging Problems ............................................................................................................................................. 62

5.1.1 Improper Power Configuration of Paging-related Channels ................................................................. 62

5.1.2 Paging Failure due to UE Location Area Update .................................................................................. 62

5.1.3 Paging Failure due Implicit Detach of UE ............................................................................................ 64

5.2 Cell Selection and Reselection Problem......................................................................................................... 65

5.2.1 Repeating to Send the RRC Connection Request Message due to Cell Reselection ............................. 65

5.3 RRC Setup Problems ...................................................................................................................................... 68

5.3.1 Improper Configuration of Parameters of Uplink Access Channel ....................................................... 68

5.3.2 Improper Configuration of AICH Power .............................................................................................. 71

5.3.3 Improper Configuration of FACH Power .............................................................................................. 71

5.3.4 Multiple Times of RRC Connection Request (for Service) and No RAB Assignment Request ........... 74

5.3.5 RRC Connection of HSDPA Subscribers Rejected due to Inadequate Code Resource ......................... 77

5.4 RAB and RB Setup Problems ........................................................................................................................ 79

5.4.1 RAB Setup Failure due to Inadequate Resource ................................................................................... 79

5.4.2 Handover Failure before Completion of Signaling Flow ...................................................................... 80

5.4.3 Admission Failure due to HSDPA Total Bit Rate Threshold Exceeded by HSDPA Bit Rate of Cell .... 82

5.5 Authentication Problems ................................................................................................................................ 83

5.6 Security Mode Problems ................................................................................................................................ 84

5.7 Abnormal Equipment Problems ..................................................................................................................... 86

5.7.1 Abnormal NodeB .................................................................................................................................. 86

5.7.2 Abnormal UE ........................................................................................................................................ 88

6 Summary ....................................................................................................................................... 91

7 Appendix 1: Paging Process ...................................................................................................... 92

7.1 Paging Origination ......................................................................................................................................... 92

7.1.1 Paging by CN ........................................................................................................................................ 92

7.1.2 Paging by UTRAN ................................................................................................................................ 92

7.2 Paging Flow ................................................................................................................................................... 92

7.2.1 Paging Type 1 ........................................................................................................................................ 92

7.2.2 Paging Type 2 ........................................................................................................................................ 94

7.3 Behaviors of UE after Receiving Paging........................................................................................................ 94

7.3.1 UE in Idle Mode .................................................................................................................................... 94

7.3.2 UE in Connected Mode ......................................................................................................................... 95

7.4 DRX Process of UE ....................................................................................................................................... 95

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7.4.1 DRX Cyclic Length and Paging Occasion ............................................................................................ 95

7.4.2 Relationship of PICH and SCCPCH ..................................................................................................... 96

7.4.3 PCH Selection ....................................................................................................................................... 98

7.4.4 DRX Examples of UE ........................................................................................................................... 98

8 Appendix 2: Access Process Analysis .................................................................................... 100

8.1 Cell Search ................................................................................................................................................... 100

8.1.1 Timeslot Synchronization ................................................................................................................... 101

8.1.2 Frame Synchronization and Scramble Group Identification ............................................................... 101

8.1.3 Identification of Cell Primary Scramble ............................................................................................. 101

8.2 Cell Selection and Reselection ..................................................................................................................... 101

8.2.1 Cell Selection ...................................................................................................................................... 101

8.2.2 Judgment Criterion (Criterion S) ........................................................................................................ 102

8.2.3 Cell Reselection .................................................................................................................................. 104

8.3 Random Access ............................................................................................................................................ 110

8.3.1 Random Access Channel ..................................................................................................................... 110

8.3.2 Random Access Process ...................................................................................................................... 113

9 Appendix 3: Authentication Flow .......................................................................................... 116

10 Appendix 4: Description of Access-related Parameters ................................................... 119

10.1 Engineering Parameters .............................................................................................................................. 119

10.2 Cell Parameters .......................................................................................................................................... 119

10.2.1 Transmit Power of FACH.................................................................................................................. 119

10.2.2 Transmit Power of PCH .................................................................................................................... 120

10.2.3 Transmit Power of PICH ................................................................................................................... 120

10.2.4 Cell Reselection Parameter: Measurement Hysteresis 2 (Qhyst2s) .................................................. 120

10.2.5 Cell Reselection Parameter: Reselection Hysteresis Time (Treselections) ....................................... 120

10.2.6 Cell Reselection Parameter: Sintrasearch ......................................................................................... 120

10.2.7 Cell Reselection Parameter: Qoffset2 ............................................................................................... 121

10.2.8 Transmit Power of AICH .................................................................................................................. 121

10.2.9 PRACH-related Parameters .............................................................................................................. 121

11 Appendix 5: HSUPA Load Control ...................................................................................... 122

11.1 Admission Decision in HSUPA Cells ......................................................................................................... 122

11.1.1 Number of Subscribers ...................................................................................................................... 122

11.1.2 lub Transmission Resources and NodeB Credit Resources ............................................................... 122

11.1.3 Power Resources ............................................................................................................................... 126

11.1.4 HSUPA RAB Downlink Admission .................................................................................................. 126

11.1.5 LDR ................................................................................................................................................... 126

11.1.6 OLC ................................................................................................................................................... 127

11.1.7 Description of Parameters ................................................................................................................. 127

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Figures

Figure 3-1 Overall flow for analyzing call failure problems in DT/CQT ............................................................ 20

Figure 3-2 Signaling flow of originated UE in locating paging problems ........................................................... 21

Figure 3-3 Flow for analyzing paging problems ................................................................................................. 22

Figure 3-4 Flow for analyzing RRC connection setup problem .......................................................................... 24

Figure 3-5 Authentication failure due to MAC Failure ....................................................................................... 27

Figure 3-6 Authentication failure due to Synch Failure ...................................................................................... 28

Figure 3-7 Security mode control ........................................................................................................................ 28

Figure 3-8 Security mode reject .......................................................................................................................... 29

Figure 3-9 Dualband scenario 1 (f1: R99; f2: R99+HSPA) ................................................................................. 33

Figure 3-10 Dualband scenario 2 (f1: R99+HSPA; f2: R99+HSPA) ................................................................... 33

Figure 3-11 Functions and process of RRC direct retry and re-direction during setup of the RRC connection .. 34

Figure 3-12 Signaling for service-based direct retry of a HSDPA subscriber ..................................................... 35

Figure 3-13 Signaling for direct retry of a R99 subscriber after admission rejection .......................................... 36

Figure 4-1 Flow for analyzing RNC-level traffic statistics data .......................................................................... 40

Figure 4-2 Flow for analyzing cell-level traffic statistics data ............................................................................ 41

Figure 4-3 Position for counting point by counter for paging loss by idle UE .................................................... 43

Figure 4-4 Position for counting point by counter for paging loss by UE in PCH state ...................................... 44

Figure 4-5 Position for counting point by counter for RRC connection rejection ............................................... 46

Figure 4-6 Position for counting point by counter for CS RAB assignment failure in RNC traffic statistics

starting counting ................................................................................................................................................... 50

Figure 4-7 Position for counting point by counter for PS RAB assignment failure in RNC traffic statistics ...... 54

Figure 4-8 Position for counting point by counter for RB setup failure in traffic statistics ................................. 60

Figure 5-1 Originating signaling flow of paging failure due to UE location area update.................................... 62

Figure 5-2 Content of the Disconnect message in paging failure due to UE location area update ..................... 63

Figure 5-3 Terminating signaling flow of paging failure due to UE location area update................................... 63

Figure 5-4 Signaling of UE ................................................................................................................................. 65

Figure 5-5 Signal quality when the UE sends the RRC connection request message. ........................................ 66

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Figure 5-6 Signal quality when the UE repeats to send the RRC connection request ......................................... 67

Figure 5-7 Signaling of UE in a connection process ........................................................................................... 68

Figure 5-8 Single subscriber tracing signaling on RNC ...................................................................................... 68

Figure 5-9 Quality of downlink signals ............................................................................................................... 69

Figure 5-10 Regular interference in cell 248 ....................................................................................................... 69

Figure 5-11 Part of magnified chart of interference ............................................................................................ 70

Figure 5-12 Signaling upon improper configuration of FACH power ................................................................. 71

Figure 5-13 Signal strength upon the first sending of RRC connection request .................................................. 72

Figure 5-14 Single subscriber tracing signaling by RNC .................................................................................... 72

Figure 5-15 Signaling and signal strength upon the second sending of RRC connection request ....................... 73

Figure 5-16 Traced signaling at UE side ............................................................................................................. 74

Figure 5-17 Traced signaling at RNC side .......................................................................................................... 74

Figure 5-18 BLER statistics at UE side ............................................................................................................... 75

Figure 5-19 BLER and RRC message at UE side ............................................................................................... 76

Figure 5-20 BLER and RRC message at UE side ............................................................................................... 77

Figure 5-21 Assignment of HSDPA code tree ..................................................................................................... 78

Figure 5-22 RNC log for HSDPA admission rejection ........................................................................................ 79

Figure 5-23 Signaling of Disconnect after completion of RB setup ................................................................... 80

Figure 5-24 Signaling of UE upon a connection failure ...................................................................................... 81

Figure 5-25 Single subscriber tracing signaling by RNC .................................................................................... 81

Figure 5-26 Signal strength before release of connection ................................................................................... 82

Figure 5-27 Rejection messages in security mode .............................................................................................. 84

Figure 5-28 Content of the RANAP_SECURITY_MODE_REJECT message .................................................. 84

Figure 5-29 ciphering mode information configured in previous security mode command ................................ 85

Figure 5-30 Security mode message .................................................................................................................... 85

Figure 5-31 Content of the RANAP_SECURITY_MODE_COMMAND message ........................................... 86

Figure 5-32 Signaling of UE upon failure in receiving RRC Connection Setup message................................... 87

Figure 5-33 Single subscriber tracing signaling by RNC .................................................................................... 87

Figure 5-34 Signal strength upon occurrence of problems .................................................................................. 88

Figure 5-35 Signaling of UE ............................................................................................................................... 89

Figure 5-36 Downlink signal quality ................................................................................................................... 89

Figure 7-1 Flow chart of PAGING TYPE 1 message .......................................................................................... 93

Figure 7-2 Flow chart of PAGING TYPE 2 message .......................................................................................... 94

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Figure 7-3 Schematic drawing of UE paging occasion ....................................................................................... 96

Figure 7-4 Frame structure of PICH .................................................................................................................... 97

Figure 7-5 Sequence relationship between PICH and SCCPCH ......................................................................... 98

Figure 8-1 Number and interval of access timeslots of RACH ......................................................................... 111

Figure 8-2 Structure of random access transmission ......................................................................................... 111

Figure 8-3 Timing relation between PRACH and AICH as seen at the UE ....................................................... 112

Figure 8-4 Definition of access timeslot set (taking the uplink and downlink access timeslot fixed difference τp-a

7680 chips as example) ...................................................................................................................................... 115

Figure 9-1 Successful authentication process .................................................................................................... 116

Figure 9-2 Authentication Failure (due to MAC Failure) .................................................................................. 117

Figure 9-3 Authentication failure (due to Synch failure) ................................................................................... 118