LTE Self–Organising Networks (SON) – Network Management Automation for Operational Efficiency

Covering the key functional areas of LTE Self-Organising Networks (SON), this book introduces the topic at an advanced level before examining the state-of-the-art concepts. The required background on LTE network scenarios, technologies and general SON concepts is first given to allow readers with basic knowledge of mobile networks to understand the detailed discussion of key SON functional areas (self-configuration, -optimisation, -healing). Later, the book provides details and references for advanced readers familiar with LTE and SON, including the latest status of 3GPP standardisation. Based on the defined next generation mobile networks (NGMN) and 3GPP SON use cases, the book elaborates to give the full picture of a SON-enabled system including its enabling technologies, architecture and operation. "Heterogeneous networks" including different cell hierarchy levels and multiple radio access technologies as a new driver for SON are also discussed.* Introduces the functional areas of LTE SON (self-optimisation, -configuration and -healing) and its standardisation, also giving NGMN and 3GPP use cases* Explains the drivers, requirements, challenges, enabling technologies and architectures for a SON-enabled system* Covers multi-technology (2G/3G) aspects as well as core network and end-to-end operational aspects* Written by experts who have been contributing to the development and standardisation of the LTE self-organising networks concept since its inception* Examines the impact of new network architectures ("Heterogeneous Networks") to network operation, for example multiple cell layers and radio access technologies

Table of Contents:
Foreword xiii Preface xv List of Contributors xix Acknowledgements xxi List of Abbreviations xxiii 1. Introduction 1 1.1 Self-Organising Networks (SON) 3 1.2 The Transition from Conventional Network Operation to SON 6 1.2.1 Automation of the Network Rollout 9 1.2.2 Automation of Network Optimisation and Troubleshooting 10 1.2.3 SON Characteristics and Challenges 11 References 12 2. LTE Overview 13 2.1 Introduction to LTE and SAE 13 2.1.1 3GPP Structure, Timeline and LTE Specifications 14 2.1.2 LTE Requirements 16 2.1.3 System Architecture Overview 16 2.1.4 Evolved UTRAN 18 2.1.5 E-UTRAN Functional Elements 19 2.1.6 Evolved Packet Core 21 2.1.7 Voice over LTE (VoLTE) 24 2.1.8 LTE-Advanced 24 2.1.9 Network Management 30 2.2 LTE Radio Access Network Scenarios and Their Evolution 33 2.2.1 LTE Radio Coverage Scenario 33 2.2.2 LTE for Capacity Enhancement in Existing GERAN/UTRAN 34 2.2.3 Enhancing LTE Capacity, the Multi-Layer LTE 34 2.2.4 Data Offloading, LIPA-SIPTO 35 2.2.5 Multi-Radio Access Network Scenarios or non-GPP 36 References 37 3. Self-Organising Networks (SON) 39 3.1 Vision 39 3.2 NGMN Operator Use Cases and 3GPP SON Use Cases 42 3.2.1 Operational Use Cases 42 3.2.2 NGMN SON Use Cases and Requirements 47 3.2.3 SON Use Cases in 3GPP 50 3.3 Foundations for SON 52 3.3.1 Control Engineering: Feedback Loops 53 3.3.2 Autonomic Computing and Autonomic Management 55 3.3.3 SON Research Projects 57 3.4 Architecture 60 3.4.1 Use-Case Related Criteria 62 3.4.2 System-Level Criteria 64 3.5 Business Value 65 3.5.1 The Economics of eNB Sites 65 3.5.2 General Mode of Operation of SON 68 3.5.3 Installation and Planning 71 3.5.4 Network Optimisation 72 3.5.5 Fault Management 73 3.5.6 Conclusions 74 3.6 SON Operational and Technical Challenges 75 3.6.1 Transition of Operational Processes to SON 75 3.6.2 Technical (Engineering) Challenges 78 References 80 4. Self-Configuration ('Plug-and-Play') 81 4.1 Auto-Connectivity and -Commissioning 82 4.1.1 Preparation 85 4.1.2 Connectivity Setup, Site-Identification and Auto-Commissioning 87 4.1.3 LTE-A Relay Auto-Connectivity 93 4.1.4 Conclusions 100 4.2 Dynamic Radio Configuration 100 4.2.1 Generation of Initial Transmission Parameters 106 4.2.2 Physical Cell-ID Allocation 111 4.2.3 Automatic Neighbour Relationship Setup (ANR) 118 4.2.4 DRC Architecture 130 4.2.5 Conclusions 132 References 133 5. Self-Optimisation 135 5.1 Mobility Robustness Optimisation 136 5.1.1 Goals of MRO 136 5.1.2 Cell Changes and Interference Challenges 137 5.1.3 MRO Relevant Parameters 140 5.1.4 Causes for Mobility Problems 144 5.1.5 MRO Solutions 146 5.1.6 MRO Time Scales 151 5.1.7 MRO Performance 152 5.2 Mobility Load Balancing and Traffic Steering 157 5.2.1 Introduction to Traffic Steering 157 5.2.2 SON Policies for Mobility Load Balancing 159 5.2.3 A Theoretical View of Load Balancing 160 5.2.4 Standardised Features and Procedures to Direct UEs to the Desired Layer 166 5.2.5 Exemplary Results of MLB 182 5.2.6 Uplink Load Balancing 189 5.2.7 Interactions Between TS/MLB and MRO 190 5.3 Energy Saving 193 5.3.1 Introduction 193 5.3.2 Requirements 195 5.3.3 Energy Saving Management 195 5.3.4 eNB Overlaid Scenario 196 5.3.5 Capacity-Limited Network 198 5.3.6 Equipment/Local ES 200 5.3.7 Example Scenarios and Expected Gains 201 5.3.8 Summary 204 5.4 Coverage and Capacity Optimisation 204 5.4.1 CCO with Adaptive Antennas 205 5.4.2 Performance Analysis for Antenna Parameter Optimisation Based CCO 208 5.4.3 CCO with TX Power 216 5.5 RACH Optimisation 217 5.5.1 General 217 5.5.2 PRACH Configuration 218 5.5.3 RACH Configuration 219 5.5.4 RACH/PRACH Configuration Example 221 5.5.5 RA Performance 222 5.5.6 Self-Optimisation Framework 223 5.5.7 UE Reporting 223 5.5.8 Inter-eNB Communication 225 5.6 RRM and SON (Interference Coordination, P0 Optimisation) 226 5.6.1 Interference Coordination 226 5.6.2 P0 Optimisation 230 References 232 6. Self-Healing 235 6.1 Introduction 236 6.1.1 3GPP Use Cases 236 6.1.2 3GPP Self-Healing Process and its Management 237 6.1.3 Cell Degradation Management 238 6.2 Cell Degradation Detection 242 6.3 Cell Degradation Diagnosis and Prediction 248 6.3.1 Rule Based Systems 250 6.3.2 Bayesian Networks 251 6.3.3 Case Based Reasoning 253 6.3.4 Neural Networks 255 6.3.5 Active Measurements 256 6.3.6 Prediction 257 6.4 Cell Outage Compensation 259 6.4.1 Activation of Cell Outage Compensation 260 6.4.2 Means of Cell Outage Compensation 260 6.4.3 Interaction between Cell Outage Compensation and Self-Configuration Functions 263 References 264 7. Supporting Function: Minimisation of Drive Tests (MDT) 267 7.1 Introduction 267 7.1.1 General 267 7.1.2 History and Background 269 7.2 Relation to SON 272 7.3 Requirements 273 7.4 Use Cases 275 7.4.1 Operator Scenarios 276 7.4.2 Coverage Optimisation 277 7.4.3 Mobility Optimisation 281 7.4.4 Capacity Optimisation 281 7.4.5 Parameterisation for Common Channels 282 7.4.6 QoS Verification 282 7.5 Overall Architecture 283 7.6 Managing MDT 285 7.6.1 Subscriber and Equipment Trace 285 7.6.2 MDT Configuration Parameters 285 7.6.3 Subscription Based MDT 287 7.6.4 Area Based MDT 292 7.6.5 Supporting Functionality in the Management System 293 7.6.6 MDT Reporting 293 7.7 MDT Radio Interface Procedures 295 7.7.1 Immediate MDT 296 7.7.2 Logged MDT 298 7.7.3 RLF Reporting 303 7.7.4 Measurement Parameters 305 7.7.5 Location Information 308 7.8 Conclusion 309 References 310 8. SON for Core Networks 311 8.1 Introduction 311 8.2 SON for Packet Core Networks 311 8.2.1 Packet Core Element Auto-Configuration 311 8.2.2 Automatic Neighbour Relation 313 8.2.3 S1 Flex (MME Pooling) 314 8.2.4 Signalling Optimisation 315 8.2.5 Latency Optimisation 317 8.2.6 Fast Gateway Convergence with Bidirectional Forward Detection 318 8.2.7 Dynamic IP Pool Allocation 318 8.2.8 Energy Saving 319 8.3 SON for Voice Core Networks 319 8.3.1 Voice Over IP Quality Monitoring and Management 319 8.3.2 Resource Optimisation in Voice Core Network 320 References 321 9. SON Operation 322 9.1 SON Function Interactions 323 9.1.1 Spatial Characteristic 324 9.1.2 Temporal Characteristic 324 9.1.3 Categories of SON Conflicts 326 9.1.4 Network Parameters Related to SON Functions 329 9.1.5 Examples for Conflicts between SON Functions 330 9.2 Coordination of SON Functions 334 9.2.1 Basic Options for SON Coordination 334 9.2.2 Goals of SON Function Coordination 338 9.2.3 SON Coordination Function Concept 340 9.2.4 Coordination Schemes 346 9.2.5 Related Work 352 9.2.6 SON Function Coordination Example 352 9.3 Conclusions 355 References 356 10. SON for Heterogeneous Networks (HetNet) 357 10.1 Introduction 357 10.2 Standardisation and Network Architecture 359 10.2.1 Network Architecture for HetNet 361 10.3 Self-Configuration 362 10.3.1 Auto-Connectivity and -Commissioning 363 10.3.2 Automatic Site Identification and Hardware-to-Site Mapping 364 10.3.3 Automatic Neighbour Relations (ANR) 365 10.4 Self-Optimisation: Interference Management 365 10.4.1 Interference Characteristics in HetNet Scenarios 365 10.4.2 Basic Interference Management Techniques 366 10.4.3 Scenarios with Macro eNBs and Micro/Pico eNBs 369 10.4.4 Enhanced Time-Domain Interference Management: eICIC 370 10.4.5 Outlook on Further Interference Management Innovations 374 10.5 Self-Optimisation: Mobility Aspects; MRO and Traffic Steering 375 10.5.1 Mobility Robustness Optimisation 375 10.5.2 Multi-Layer Traffic Steering and Load Balancing 377 10.5.3 IEEE 802.11 (WiFi) Integration 378 References 378 11. Future Research Topics 379 11.1 Future Mobile Network Scenarios 379 11.1.1 Heterogeneous Networks 379 11.1.2 Cloud RAN 380 11.1.3 Requirements for Future OAM Systems 381 11.2 Cognitive Radio Networks (CRN) 381 11.2.1 From SON to CRN 381 11.2.2 Definitions 382 11.2.3 Framework 383 11.2.4 Artificial Intelligence 385 11.3 Applications 387 11.3.1 Self-Configuration 387 11.3.2 Self-Optimisation 387 11.3.3 Self-Healing 388 11.3.4 Operation 388 11.4 Conclusion 389 References 389 Index 391

About the Author :
Seppo Hamalainen Seppo Hamalainen is research manager at Nokia Siemens Networks. He received an MSc degree in Electrical Engineering from the Department of Information Technology at Lappeenranta University of Technology in 1994 and a PhD degree in Electrical Engineering from the Department of Information technology at Jyvaskyla University in 2003. He joined Nokia Research Center in 1993, where he worked in various research and research management positions until the end of 2005. From 2002 to 2005 he led Nokia Research Center's office in China and at the beginning of 2006 he joined Nokia Networks, where he was director of Network Systems Research. He is now working with Nokia Siemens Networks. His research interests cover 3G and beyond 3G radio network performance and radio resource management issues and self-organizing networks. He is author or co-author of 50 scientific journal and conference papers and book chapters, and 18 independent patents. Henning Sanneck Dr. Henning Sanneck studied Electrical Engineering at the University of Erlangen-Nuremberg, Germany. After receiving his Diploma in 1995, he joined GMD Fokus (now part of Fraunhofer) in Berlin. At Fokus, he worked as a Researcher in the area of Quality-of-Service (QoS) support for Real-Time Services in IP-based networks. He received his Dr.-Ing. (PhD) degree in Electrical Engineering from the Technical University of Berlin with a thesis on Voice over IP QoS in 2000. In 2001 he joined Siemens - Mobile Networks in Munich, working as a Senior Research Engineer on cross-layer design for IP-based Radio Access Networks (RANs), Software Technologies for Mobile Networks and Technology Management. He became a Project Manager for technology innovation projects in the area of Network Management for 3G and beyond RANs in 2003, working on Basestation Auto-Configuration and Real-Time Performance Management concepts and their realisation as product features. Since the formation of Nokia Siemens Networks in 2007 he has been a Research Manager heading the "Network Management Automation" team. Dr. Sanneck has published 40 papers in refereed conferences and journals and has more than 15 patents granted or pending. Cinzia Sartori Cinzia Sartori is Research Area Manager at Nokia Siemens Networks. After graduating in Electronic Engineer at the University of Pavia in Italy, she was based at GTE in SW Research & Development and transferred for 18 months to Phoenix (Arizona, USA). In the early 1990s she joined Siemens - Mobile Networks R&D- for the development of the "BSC-Base Station Controller" leading a SW team for SS7 and Radio Resource Management development; later she moved to "RAN System Engineering and Tests". At the establishment of Nokia Siemens Networks in 2007, she lead the Network Telecom team in RAN System Architecture, dealing with 2G, 3G, WiMax and LTE call processing. Since November 2009 she has worked at the Radio Research unit of Nokia Siemens Networks and is responsible for the Self Organizing Networks (SON) research field. She participated in 3GPP standardization in SA2 working group and currently she leads the Nokia- NSN team responsible for defining the SON strategy in 3GPP RAN standardization.