LTE Small Cell Optimization

Harri Holma, Antti Toskala and Jussi Reunanen, Nokia (Finland and Thailand).

• Preface xiiiAcknowledgements xvList of Abbreviations xvii1 Introduction 1Harri Holma1.1 Introduction 11.2 LTE Global Deployments and Devices 21.3 Mobile Data Traffic Growth 31.4 LTE Technology Evolution 41.5 LTE Spectrum 51.6 Small Cell Deployments 61.7 Network Optimization 71.8 LTE Evolution Beyond Release 13 81.9 Summary 9References 92 LTE and LTE Advanced in Releases 8–11 11Antti Toskala2.1 Introduction 112.2 Releases 8 and 9 LTE 112.2.1 Releases 8 and 9 Physical Layer 122.2.2 LTE Architecture 172.2.3 LTE Radio Protocols 172.3 LTE Advanced in Releases 10 and 11 192.3.1 Carrier Aggregation 192.3.2 Multiple Input Multiple Output Enhancements 232.3.3 HetNet Enhanced Inter-cell Interference Coordination 232.3.4 Coordinated Multipoint Transmission 252.4 UE Capability in Releases 8–11 262.5 Conclusions 28References 283 LTE-Advanced Evolution in Releases 12–13 29Antti Toskala3.1 Introduction 293.2 Machine-Type Communications 293.3 Enhanced CoMP 343.4 FDD–TDD Carrier Aggregation 353.5 WLAN-Radio Interworking 373.6 Device-to-Device Communication with LTE 393.7 Single Cell Point to Multipoint Transmission 413.8 Release 12 UE Capabilities 423.9 Conclusions 42References 434 Small Cell Enhancements in Release 12/13 45Antti Toskala, Timo Lunttila, Tero Henttonen and Jari Lindholm4.1 Introduction 454.2 Small Cell and Dual Connectivity Principles 454.3 Dual Connectivity Architecture Principle 464.4 Dual Connectivity Protocol Impacts 474.5 Dual Connectivity Physical Layer Impacts and Radio Link Monitoring 494.6 Other Small Cell Physical Layer Enhancement 534.6.1 256QAM for LTE Downlink 534.6.2 Small Cell ON/OFF Switching and Enhanced Discovery 534.6.3 Power Saving with Small Cell ON/OFF 564.6.4 Over the Air Synchronization Between eNodeBs 564.7 Release 13 Enhancements 564.8 Conclusions 57References 575 Small Cell Deployment Options 59Harri Holma and Benny Vejlgaard5.1 Introduction 595.2 Small Cell Motivation 605.3 Network Architecture Options 605.4 Frequency Usage 645.5 Selection of Small Cell Location 655.6 Indoor Small Cells 675.6.1 Distributed Antenna Systems 675.6.2 Wi-Fi and Femto Cells 685.6.3 Femto Cell Architecture 705.6.4 Recommendations 725.7 Cost Aspects 725.7.1 Macro Network Extension 735.7.2 Outdoor Small Cells 735.7.3 Outdoor Pico Cluster 735.7.4 Indoor Offloading 745.8 Summary 74References 756 Small Cell Products 77Harri Holma and Mikko Simanainen6.1 Introduction 776.2 3GPP Base Station Categories 786.3 Micro Base Stations 786.4 Pico Base Stations 806.5 Femtocells 836.6 Low-Power Remote Radio Heads 846.6.1 Alternative Remote Radio Head Designs for Indoor Use 866.7 Distributed Antenna Systems 876.8 Wi-Fi Integration 876.9 Wireless Backhaul Products 896.10 Summary 90Reference 907 Small Cell Interference Management 91Rajeev Agrawal, Anand Bedekar, Harri Holma, Suresh Kalyanasundaram, Klaus Pedersen and Beatriz Soret7.1 Introduction 917.2 Packet Scheduling Solutions 937.3 Enhanced Inter-cell Interference Coordination 977.3.1 Concept Description 977.3.2 Performance and Algorithms 1017.4 Enhanced Coordinated Multipoint (eCoMP) 1107.5 Coordinated Multipoint (CoMP) 1147.6 Summary 119References 1208 Small Cell Optimization 121Harri Holma, Klaus Pedersen, Claudio Rosa, Anand Bedekar and Hua Wang8.1 Introduction 1218.2 HetNet Mobility Optimization 1228.3 Inter-site Carrier Aggregation with Dual Connectivity 1268.3.1 User Data Rates with Inter-site Carrier Aggregation 1268.3.2 Mobility with Dual Connectivity 1318.4 Ultra Dense Network Interference Management 1358.4.1 Ultra Dense Network Characteristics 1358.4.2 Proactive Time-Domain Inter-cell Interference Coordination 1368.4.3 Reactive Carrier-Based Inter-cell Interference Coordination 1388.5 Power Saving with Small Cell On/Off 1398.6 Multivendor Macro Cell and Small Cells 1418.7 Summary 143References 1439 Learnings from Small Cell Deployments 145Brian Olsen and Harri Holma9.1 Introduction 1459.2 Small Cell Motivations by Mobile Operators 1459.3 Small Cell Challenges and Solutions 1469.4 Summary of Learnings from Small Cell Deployments 1479.5 Installation Considerations 1519.6 Example Small Cell Case Study 1529.6.1 Site Solution and Backhaul 1529.6.2 Coverage and User Data Rates 1539.6.3 Macro Cell Offloading and Capacity 1549.6.4 KPIs in Network Statistics 1559.6.5 Mobility Performance 1569.6.6 Parameter and RF Optimization 1579.7 Summary 15810 LTE Unlicensed 159Antti Toskala and Harri Holma10.1 Introduction 15910.2 Unlicensed Spectrum 16010.3 Operation Environment 16110.4 Motivation for the Use of Unlicensed Spectrum with LTE 16210.5 Key Requirements for 5 GHz Band Coexistence 16210.6 LTE Principle on Unlicensed Band 16410.7 LTE Performance on the Unlicensed Band 16510.8 Coexistence Performance 16610.9 Coverage with LTE in 5 GHz Band 17010.10 Standardization 17210.11 Conclusions 172References 17311 LTE Macro Cell Evolution 175Mihai Enescu, Amitava Ghosh, Bishwarup Mondal and Antti Toskala11.1 Introduction 17511.2 Network-Assisted Interference Cancellation 17611.3 Evolution of Antenna Array Technology 18111.4 Deployment Scenarios for Antenna Arrays 18211.5 Massive-MIMO Supported by LTE 18711.5.1 Sectorization (Vertical)-Based Approaches 18711.5.2 Reciprocity-Based Approaches 18811.6 Further LTE Multi-antenna Standardization 18911.7 Release 13 Advanced Receiver Enhancements 19211.8 Conclusions 192References 19312 LTE Key Performance Indicator Optimization 195Jussi Reunanen, Jari Salo and Riku Luostari12.1 Introduction 19512.2 Key Performance Indicators 19612.3 Physical Layer Optimization 19712.4 Call Setup 20012.4.1 Random Access Setup 20212.4.2 RRC Connection Setup 20812.4.3 E-RAB Setup 21512.5 E-RAB Drop 21812.5.1 Handover Performance 21812.5.2 UE-Triggered RRC Connection Re-establishments 22212.5.3 eNodeB-triggered RRC Connection Re-establishments 22612.6 Handover and Mobility Optimization 22812.7 Throughput Optimization 23212.7.1 MIMO Multi-stream Usage Optimization 23412.8 High-Speed Train Optimization 24312.9 Network Density Benchmarking 24612.10 Summary 247References 24813 Capacity Optimization 249Jussi Reunanen, Riku Luostari and Harri Holma13.1 Introduction 24913.2 Traffic Profiles in Mass Events 25113.3 Uplink Interference Management 25513.3.1 PUSCH 25713.3.2 PUCCH 26513.3.3 RACH and RRC Setup Success Rate 26513.3.4 Centralized RAN 26913.4 Downlink Interference Management 27013.4.1 PDSCH 27113.4.2 Physical Downlink Control Channel 27613.5 Signalling Load and Number of Connected Users Dimensioning 27913.5.1 Signalling Load 28013.5.2 RRC-Connected Users 28013.6 Load Balancing 28413.7 Capacity Bottleneck Analysis 28613.8 Summary 291References 29214 VoLTE Optimization 293Riku Luostari, Jari Salo, Jussi Reunanen and Harri Holma14.1 Introduction 29314.2 Voice Options for LTE Smartphones 29314.3 Circuit Switched Fallback 29414.3.1 Basic Concepts 29414.3.2 CSFB Call Setup Time, Transition to Target RAT 29614.3.3 CSFB Call Setup Success Rate 30214.3.4 Return to LTE after CSFB Call 30214.4 Voice over LTE 30714.4.1 Setup Success Rate and Drop Rate 30714.4.2 TTI Bundling and RLC Segmentation 31014.4.3 Semi-persistent Scheduling 31214.4.4 Packet Bundling 31414.4.5 Re-establishment with Radio Preparations 31514.4.6 Voice Quality on VoLTE 31514.5 Single Radio Voice Call Continuity 32214.5.1 Signalling Flows 32214.5.2 Performance 32614.6 Summary 331References 33115 Inter-layer Mobility Optimization 333Jari Salo and Jussi Reunanen15.1 Introduction 33315.2 Inter-layer Idle Mode Mobility and Measurements 33415.2.1 Initial Cell Selection and Minimum Criteria for UE to Camp on a Cell 33415.2.2 Summary of Cell Reselection Rules 33615.2.3 Idle Mode Measurements 33815.3 Inter-layer Connected Mode Measurements 34415.4 Inter-layer Mobility for Coverage-Limited Network 35015.4.1 Basic Concepts 35015.4.2 Mapping Throughput Target to SINR, RSRQ and RSRP 35315.4.3 Inter-layer Mobility Example #1 (Non-equal Priority Non-equal Bandwidth LTE Layers) 36115.4.4 Inter-layer Mobility Example #2 (Equal Priority Equal Bandwidth LTE Layers) 36815.5 Inter-layer Mobility for Capacity-Limited Networks 37015.5.1 Static Load Balancing via Mobility Thresholds 37115.5.2 Dynamic Load Balancing via eNodeB Algorithms 37515.6 Summary 377References 37716 Smartphone Optimization 379Rafael Sanchez-Mejias, Laurent No¨el and Harri Holma16.1 Introduction 37916.2 Smartphone Traffic Analysis in LTE Networks 38016.2.1 Data Volumes and Asymmetry 38016.2.2 Traffic-Related Signalling 38116.2.3 Mobility-Related Signalling 38216.2.4 User Connectivity 38216.3 Smartphone Power Consumption Optimization 38416.3.1 Impact of Downlink Carrier Aggregation 38416.3.2 Impact of Discontinuous Reception 38516.4 Smartphone Operating Systems 39116.5 Messaging Applications 39116.6 Streaming Applications 39316.7 Voice over LTE 39416.7.1 VoLTE System Architecture 39516.7.2 VoLTE Performance Analysis 39616.7.3 Standby Performance 40416.7.4 Impact of Network Loading and Radio Quality 40516.8 Smartphone Battery, Baseband and RF Design Aspects 40616.8.1 Trends in Battery Capacity 40616.8.2 Trends in Cellular Chipset Power Consumption 40916.8.3 Impact of Small Cells on Smartphone Power Consumption 41216.9 Summary 421References 42117 Further Outlook for LTE Evolution and 5G 423Antti Toskala and Karri Ranta-aho17.1 Introduction 42317.2 Further LTE-Advanced Beyond Release 13 42317.3 Towards 5G 42617.4 5G Spectrum 42717.5 Key 5G Radio Technologies 42817.6 Expected 5G Schedule 43017.7 Conclusions 432References 432Index 433