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LTE Small Cell Optimization: 3GPP Evolution to Release 13

LTE Small Cell Optimization: 3GPP Evolution to Release 13

Harri Holma (Editor), Antti Toskala (Editor), Jussi Reunanen (Editor)

ISBN: 978-1-118-91256-0

Nov 2015

464 pages

Description

LTE network capabilities are enhanced with small cell deployment, with optimization and with new 3GPP features. LTE networks are getting high loaded which calls for more advanced optimization. Small cells have been discussed in the communications industry for many years, but their true deployment is happening now. New 3GPP features in Release 12 and 13 further push LTE network performance.

This timely book addresses R&D and standardization activities on LTE small cells and network optimization, focusing on 3GPP evolution to Release 13. It covers LTE small cells from specification to products and field results; Latest 3GPP evolution to Release 13; and LTE optimization and learnings from the field.

Preface xiii

Acknowledgements xv

List of Abbreviations xvii

1 Introduction 1
Harri Holma

1.1 Introduction 1

1.2 LTE Global Deployments and Devices 2

1.3 Mobile Data Traffic Growth 3

1.4 LTE Technology Evolution 4

1.5 LTE Spectrum 5

1.6 Small Cell Deployments 6

1.7 Network Optimization 7

1.8 LTE Evolution Beyond Release 13 8

1.9 Summary 9

References 9

2 LTE and LTE Advanced in Releases 8–11 11
Antti Toskala

2.1 Introduction 11

2.2 Releases 8 and 9 LTE 11

2.2.1 Releases 8 and 9 Physical Layer 12

2.2.2 LTE Architecture 17

2.2.3 LTE Radio Protocols 17

2.3 LTE Advanced in Releases 10 and 11 19

2.3.1 Carrier Aggregation 19

2.3.2 Multiple Input Multiple Output Enhancements 23

2.3.3 HetNet Enhanced Inter-cell Interference Coordination 23

2.3.4 Coordinated Multipoint Transmission 25

2.4 UE Capability in Releases 8–11 26

2.5 Conclusions 28

References 28

3 LTE-Advanced Evolution in Releases 12–13 29
Antti Toskala

3.1 Introduction 29

3.2 Machine-Type Communications 29

3.3 Enhanced CoMP 34

3.4 FDD–TDD Carrier Aggregation 35

3.5 WLAN-Radio Interworking 37

3.6 Device-to-Device Communication with LTE 39

3.7 Single Cell Point to Multipoint Transmission 41

3.8 Release 12 UE Capabilities 42

3.9 Conclusions 42

References 43

4 Small Cell Enhancements in Release 12/13 45
Antti Toskala, Timo Lunttila, Tero Henttonen and Jari Lindholm

4.1 Introduction 45

4.2 Small Cell and Dual Connectivity Principles 45

4.3 Dual Connectivity Architecture Principle 46

4.4 Dual Connectivity Protocol Impacts 47

4.5 Dual Connectivity Physical Layer Impacts and Radio Link Monitoring 49

4.6 Other Small Cell Physical Layer Enhancement 53

4.6.1 256QAM for LTE Downlink 53

4.6.2 Small Cell ON/OFF Switching and Enhanced Discovery 53

4.6.3 Power Saving with Small Cell ON/OFF 56

4.6.4 Over the Air Synchronization Between eNodeBs 56

4.7 Release 13 Enhancements 56

4.8 Conclusions 57

References 57

5 Small Cell Deployment Options 59
Harri Holma and Benny Vejlgaard

5.1 Introduction 59

5.2 Small Cell Motivation 60

5.3 Network Architecture Options 60

5.4 Frequency Usage 64

5.5 Selection of Small Cell Location 65

5.6 Indoor Small Cells 67

5.6.1 Distributed Antenna Systems 67

5.6.2 Wi-Fi and Femto Cells 68

5.6.3 Femto Cell Architecture 70

5.6.4 Recommendations 72

5.7 Cost Aspects 72

5.7.1 Macro Network Extension 73

5.7.2 Outdoor Small Cells 73

5.7.3 Outdoor Pico Cluster 73

5.7.4 Indoor Offloading 74

5.8 Summary 74

References 75

6 Small Cell Products 77
Harri Holma and Mikko Simanainen

6.1 Introduction 77

6.2 3GPP Base Station Categories 78

6.3 Micro Base Stations 78

6.4 Pico Base Stations 80

6.5 Femtocells 83

6.6 Low-Power Remote Radio Heads 84

6.6.1 Alternative Remote Radio Head Designs for Indoor Use 86

6.7 Distributed Antenna Systems 87

6.8 Wi-Fi Integration 87

6.9 Wireless Backhaul Products 89

6.10 Summary 90

Reference 90

7 Small Cell Interference Management 91
Rajeev Agrawal, Anand Bedekar, Harri Holma, Suresh Kalyanasundaram, Klaus Pedersen and Beatriz Soret

7.1 Introduction 91

7.2 Packet Scheduling Solutions 93

7.3 Enhanced Inter-cell Interference Coordination 97

7.3.1 Concept Description 97

7.3.2 Performance and Algorithms 101

7.4 Enhanced Coordinated Multipoint (eCoMP) 110

7.5 Coordinated Multipoint (CoMP) 114

7.6 Summary 119

References 120

8 Small Cell Optimization 121
Harri Holma, Klaus Pedersen, Claudio Rosa, Anand Bedekar and Hua Wang

8.1 Introduction 121

8.2 HetNet Mobility Optimization 122

8.3 Inter-site Carrier Aggregation with Dual Connectivity 126

8.3.1 User Data Rates with Inter-site Carrier Aggregation 126

8.3.2 Mobility with Dual Connectivity 131

8.4 Ultra Dense Network Interference Management 135

8.4.1 Ultra Dense Network Characteristics 135

8.4.2 Proactive Time-Domain Inter-cell Interference Coordination 136

8.4.3 Reactive Carrier-Based Inter-cell Interference Coordination 138

8.5 Power Saving with Small Cell On/Off 139

8.6 Multivendor Macro Cell and Small Cells 141

8.7 Summary 143

References 143

9 Learnings from Small Cell Deployments 145
Brian Olsen and Harri Holma

9.1 Introduction 145

9.2 Small Cell Motivations by Mobile Operators 145

9.3 Small Cell Challenges and Solutions 146

9.4 Summary of Learnings from Small Cell Deployments 147

9.5 Installation Considerations 151

9.6 Example Small Cell Case Study 152

9.6.1 Site Solution and Backhaul 152

9.6.2 Coverage and User Data Rates 153

9.6.3 Macro Cell Offloading and Capacity 154

9.6.4 KPIs in Network Statistics 155

9.6.5 Mobility Performance 156

9.6.6 Parameter and RF Optimization 157

9.7 Summary 158

10 LTE Unlicensed 159
Antti Toskala and Harri Holma

10.1 Introduction 159

10.2 Unlicensed Spectrum 160

10.3 Operation Environment 161

10.4 Motivation for the Use of Unlicensed Spectrum with LTE 162

10.5 Key Requirements for 5 GHz Band Coexistence 162

10.6 LTE Principle on Unlicensed Band 164

10.7 LTE Performance on the Unlicensed Band 165

10.8 Coexistence Performance 166

10.9 Coverage with LTE in 5 GHz Band 170

10.10 Standardization 172

10.11 Conclusions 172

References 173

11 LTE Macro Cell Evolution 175
Mihai Enescu, Amitava Ghosh, Bishwarup Mondal and Antti Toskala

11.1 Introduction 175

11.2 Network-Assisted Interference Cancellation 176

11.3 Evolution of Antenna Array Technology 181

11.4 Deployment Scenarios for Antenna Arrays 182

11.5 Massive-MIMO Supported by LTE 187

11.5.1 Sectorization (Vertical)-Based Approaches 187

11.5.2 Reciprocity-Based Approaches 188

11.6 Further LTE Multi-antenna Standardization 189

11.7 Release 13 Advanced Receiver Enhancements 192

11.8 Conclusions 192

References 193

12 LTE Key Performance Indicator Optimization 195
Jussi Reunanen, Jari Salo and Riku Luostari

12.1 Introduction 195

12.2 Key Performance Indicators 196

12.3 Physical Layer Optimization 197

12.4 Call Setup 200

12.4.1 Random Access Setup 202

12.4.2 RRC Connection Setup 208

12.4.3 E-RAB Setup 215

12.5 E-RAB Drop 218

12.5.1 Handover Performance 218

12.5.2 UE-Triggered RRC Connection Re-establishments 222

12.5.3 eNodeB-triggered RRC Connection Re-establishments 226

12.6 Handover and Mobility Optimization 228

12.7 Throughput Optimization 232

12.7.1 MIMO Multi-stream Usage Optimization 234

12.8 High-Speed Train Optimization 243

12.9 Network Density Benchmarking 246

12.10 Summary 247

References 248

13 Capacity Optimization 249
Jussi Reunanen, Riku Luostari and Harri Holma

13.1 Introduction 249

13.2 Traffic Profiles in Mass Events 251

13.3 Uplink Interference Management 255

13.3.1 PUSCH 257

13.3.2 PUCCH 265

13.3.3 RACH and RRC Setup Success Rate 265

13.3.4 Centralized RAN 269

13.4 Downlink Interference Management 270

13.4.1 PDSCH 271

13.4.2 Physical Downlink Control Channel 276

13.5 Signalling Load and Number of Connected Users Dimensioning 279

13.5.1 Signalling Load 280

13.5.2 RRC-Connected Users 280

13.6 Load Balancing 284

13.7 Capacity Bottleneck Analysis 286

13.8 Summary 291

References 292

14 VoLTE Optimization 293
Riku Luostari, Jari Salo, Jussi Reunanen and Harri Holma

14.1 Introduction 293

14.2 Voice Options for LTE Smartphones 293

14.3 Circuit Switched Fallback 294

14.3.1 Basic Concepts 294

14.3.2 CSFB Call Setup Time, Transition to Target RAT 296

14.3.3 CSFB Call Setup Success Rate 302

14.3.4 Return to LTE after CSFB Call 302

14.4 Voice over LTE 307

14.4.1 Setup Success Rate and Drop Rate 307

14.4.2 TTI Bundling and RLC Segmentation 310

14.4.3 Semi-persistent Scheduling 312

14.4.4 Packet Bundling 314

14.4.5 Re-establishment with Radio Preparations 315

14.4.6 Voice Quality on VoLTE 315

14.5 Single Radio Voice Call Continuity 322

14.5.1 Signalling Flows 322

14.5.2 Performance 326

14.6 Summary 331

References 331

15 Inter-layer Mobility Optimization 333
Jari Salo and Jussi Reunanen

15.1 Introduction 333

15.2 Inter-layer Idle Mode Mobility and Measurements 334

15.2.1 Initial Cell Selection and Minimum Criteria for UE to Camp on a Cell 334

15.2.2 Summary of Cell Reselection Rules 336

15.2.3 Idle Mode Measurements 338

15.3 Inter-layer Connected Mode Measurements 344

15.4 Inter-layer Mobility for Coverage-Limited Network 350

15.4.1 Basic Concepts 350

15.4.2 Mapping Throughput Target to SINR, RSRQ and RSRP 353

15.4.3 Inter-layer Mobility Example #1 (Non-equal Priority Non-equal Bandwidth LTE Layers) 361

15.4.4 Inter-layer Mobility Example #2 (Equal Priority Equal Bandwidth LTE Layers) 368

15.5 Inter-layer Mobility for Capacity-Limited Networks 370

15.5.1 Static Load Balancing via Mobility Thresholds 371

15.5.2 Dynamic Load Balancing via eNodeB Algorithms 375

15.6 Summary 377

References 377

16 Smartphone Optimization 379
Rafael Sanchez-Mejias, Laurent No¨el and Harri Holma

16.1 Introduction 379

16.2 Smartphone Traffic Analysis in LTE Networks 380

16.2.1 Data Volumes and Asymmetry 380

16.2.2 Traffic-Related Signalling 381

16.2.3 Mobility-Related Signalling 382

16.2.4 User Connectivity 382

16.3 Smartphone Power Consumption Optimization 384

16.3.1 Impact of Downlink Carrier Aggregation 384

16.3.2 Impact of Discontinuous Reception 385

16.4 Smartphone Operating Systems 391

16.5 Messaging Applications 391

16.6 Streaming Applications 393

16.7 Voice over LTE 394

16.7.1 VoLTE System Architecture 395

16.7.2 VoLTE Performance Analysis 396

16.7.3 Standby Performance 404

16.7.4 Impact of Network Loading and Radio Quality 405

16.8 Smartphone Battery, Baseband and RF Design Aspects 406

16.8.1 Trends in Battery Capacity 406

16.8.2 Trends in Cellular Chipset Power Consumption 409

16.8.3 Impact of Small Cells on Smartphone Power Consumption 412

16.9 Summary 421

References 421

17 Further Outlook for LTE Evolution and 5G 423
Antti Toskala and Karri Ranta-aho

17.1 Introduction 423

17.2 Further LTE-Advanced Beyond Release 13 423

17.3 Towards 5G 426

17.4 5G Spectrum 427

17.5 Key 5G Radio Technologies 428

17.6 Expected 5G Schedule 430

17.7 Conclusions 432

References 432

Index 433