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UMTS Performance Measurement: A Practical Guide to KPIs for the UTRAN Environment

UMTS Performance Measurement: A Practical Guide to KPIs for the UTRAN Environment

Ralf Kreher

ISBN: 978-0-470-03486-6

Nov 2006

226 pages


UMTS Performance Measurement is a practical guide that explains how to identify and measure the main problems seen in today's UMTS live networks and will make performance measurement results gathered in the UTRAN environment understandable for the reader.  It provides a fundamental background for daily work in the field or lab, covering a wide range of performance measurements that help to troubleshoot and optimize the UTRAN environment.

The content goes far beyond what has been defined by international standard bodies like 3GPP and closes the gap between international standards and definitions of network equipment manufacturers (NEM) and network operators.  The emphasis is on definition of Key Performance Indicators (KPIs) and measurements that are not described in 3GPP standard documents, such as throughput measurements and the success/failure analysis of all possible handover types.

  • Includes clear coverage of the fundamentals of performance measurement software architecture and ways to collect and present statistical data
  • Contains numerous call flow diagrams, conversion tables, protocol message examples and sample measurement results that can be used as reference for daily work in the field or lab
  • Explains measurement limitations and how tolerances provide valuable information for validation and evaluation of measurement results
  • Provides an overview of how performance measurement software works as well as information on how data streams are captured and analyzed, and how analysis results are aggregated and presented in graphic user interfaces and reports

Providing a gateway into the world of UMTS-specific measurement scenarios and a general overview of what can be defined and measured at an in-depth technical level, this book will appeal to those involved in network operation, planning, configuration and deployment, as well as consulting and training companies, students, technical journalists and measurement equipment manufacturers.

Preface ix

Acknowledgements xi

1 Basics of Performance Measurement in UMTS Terrestrial Radio Access Network (UTRAN) 1

1.1 General Ideas of Performance Measurement 2

1.1.1 What is a KPI? 4

1.1.2 KPI Aggregation Levels and Correlations 6

1.1.3 Basic Approach to Capture and Filter Performance-Related Data in UTRAN 7

1.1.4 Performance Measurement Definitions of 3GPP 13

1.1.5 User Experience vs. 3GPP Performance Measurement Definitions 16 Problems with Registration and Call Setup 17 Dropped Calls 19 Poor Transmission Speed 20 Corrupted Data 25

1.1.6 Basics of PS Call Analysis in UTRAN 27

1.2 Basic Architectural Concept of Performance Measurement Equipment Based on Protocol Analysis 34

1.2.1 Protocol Decoding and Protocol Stacks 37

1.2.2 Diversity Combining and Filtering 39

1.2.3 State Transition Analysis 44

1.3 Aggregation Levels/Dimensions 47

1.3.1 SGSN Dimension 47

1.3.2 MSC Dimension 48

1.3.3 SRNC Dimension 48

1.3.4 DRNC Dimension 48

1.3.5 CRNC Dimension 48

1.3.6 Node B Dimension 49

1.3.7 Cell Dimension 49

1.3.8 Call/Connection Dimension 51

1.3.9 UE Dimensions 51

1.3.10 Radio Bearer/Radio Access Bearer Type Dimensions 52

1.4 Statistics Calculation and Presentation 54

1.4.1 Sampling Period 54

1.4.2 Bins 56

1.4.3 The 95th Percentile 57

1.4.4 Gauges and Distribution Functions 58

2 Selected UMTS Key Performance Parameters 61

2.1 Block Error Rate (BLER) Measurements 61

2.1.1 Uplink Block Error Rate (UL BLER) 62 Uplink Transport Channel BLER 62 UL BLER per Call 65 UL BLER per Call Type 65

2.1.2 Downlink Block Error Rate (DL BLER) 65 DL BLER per Call or Service 68

2.1.3 Correlation of BLER and Other Measurements 69

2.2 Radio-Related Measurements 71

2.2.1 Radio Link Quality Parameters and Flow Control in Lub Frame Protocol (FP) 71

2.2.2 NBAP Common Measurements 74 Transmitted Carrier Power 76 NBAP Common Measurement Enhancements in Release 5 77 Received Total Wideband Power 78

2.2.3 NBAP Dedicated Measurements 81 Signal-to-Interference Ratio (SIR) 82 Signal-to-Interference Ratio Error (SIR Error) 83 Uplink SIR Target 85 Transmitted Code Power 86 Round Trip Time (RTT) 87

2.2.4 RRC Measurements and UE Measurement Abilities 87

2.3 Throughput Measurements 100

2.3.1 RLC Throughput 101

2.3.2 Transport Channel Throughput 102

2.3.3 Packet Switched User Perceived Throughput 112

2.3.4 Application Throughput 114

2.4 Transport Channel Usage Ratio 115

2.5 Primary and Secondary Traffic 118

2.6 Active Set Size Distribution 122

2.7 Soft Handover Success and Failure Analysis 127

2.8 Inter-Frequency Hard Handover Success and Failure Rates 132

2.9 Core Network Hard Handover Success and Failure Rates 137

2.9.1 Intra-MSC and Inter-MSC Hard Handover (3G-3G) 138

2.9.2 3G-2G Inter-RAT Handover for CS and PS Services 143 CS 3G-2G Inter-RAT Handover 144 PS 3G-2G Inter-RAT Handover 146

2.10 State Transitions and Channel Type Switching 147

2.11 Call Establish Success and Failure Rates 151

2.11.1 RRC Connection Establishment 152

2.11.2 Radio Bearer and Radio Access Bearer Establishment and Release 155

2.12 Call Drop Rates 160

2.13 NBAP Radio Link Failure Analysis and RRC Re-Establishment Success Rate 165

2.14 Cell Matrices 171

2.15 Miscellaneous Protocol Procedures and Events that Indicate Abnormal Behaviour of Protocol Entities on Different Layers 174

2.15.1 Miscellaneous RRC Failure Indications and Ratio KPIs 175 RRC UTRAN Mobility Information Failure 175 RRC Measurement Control Failure 175 RRC Status 175 RRC Security Mode Failure 176 RRC Transport Format Combination Control Failure 176 RRC Paging Response 176

2.15.2 SCCP Failure Analysis 177 Connection Refused (CREF) 177 Inactivity Check Failure 178

2.15.3 RANAP Failure Analysis 178 RANAP Reset Resource 178 RANAP Reset 178 RANAP Overload 178

2.15.4 NBAP Failure Analysis 178

2.15.5 RLC Acknowledge Mode Retransmission Rate 180

3 Call Establishment and Handover Procedures of PS Calls using HSDPA 181

3.1 HSDPA Cell Set Up 181

3.2 HSDPA Basic Call 182

3.2.1 Call Set Up and Measurement Initialisations 182

3.2.2 Call Release 187

3.3 Mobility Management and Handover Procedures in HSDPA 188

3.3.1 Serving HS-DSCH Cell Change without Change of Active Set 189

3.3.2 Inter-Node B Serving HS-DSCH Cell Change 191

3.3.3 HSDPA Cell Change After Soft Handover 193

Glossary 197

References 205

Index 207