Introduction to LTE

Christopher Cox is a professional technical trainer and consultant in mobile telecommunications. He is an expert in the technical and radio network planning aspects of LTE and UMTS, and regularly delivers training courses about them to audiences drawn from equipment manufacturers, network operators and consultancies worldwide. He has a degree in Physics and a PhD in Radio Astronomy from the University of Cambridge and 20 years’ experience in scientific and technical consultancy, telecommunications and training.

• Preface xxi Acknowledgements xxiiiList of Abbreviations xxv1 Introduction 11.1 Architectural Review of UMTS and GSM 11.1.1 High-Level Architecture 11.1.2 Architecture of the Radio Access Network 21.1.3 Architecture of the Core Network 41.1.4 Communication Protocols 51.2 History of Mobile Telecommunication Systems 61.2.1 From 1G to 3G 61.2.2 Third Generation Systems 71.3 The Need for LTE 81.3.1 The Growth of Mobile Data 81.3.2 Capacity of a Mobile Telecommunication System 91.3.3 Increasing the System Capacity 101.3.4 Additional Motivations 111.4 From UMTS to LTE 111.4.1 High-Level Architecture of LTE 111.4.2 Long-Term Evolution 121.4.3 System Architecture Evolution 131.4.4 LTE Voice Calls 141.4.5 The Growth of LTE 151.5 From LTE to LTE-Advanced 161.5.1 The ITU Requirements for 4G 161.5.2 Requirements of LTE-Advanced 161.5.3 4G Communication Systems 161.5.4 The Meaning of 4G 171.6 The 3GPP Specifications for LTE 17References 192 System Architecture Evolution 212.1 High-Level Architecture of LTE 212.2 User Equipment 212.2.1 Architecture of the UE 212.2.2 UE Capabilities 222.3 Evolved UMTS Terrestrial Radio Access Network 232.3.1 Architecture of the E-UTRAN 232.3.2 Transport Network 242.3.3 Small Cells and the Home eNB 252.4 Evolved Packet Core 252.4.1 Architecture of the EPC 252.4.2 Roaming Architecture 272.4.3 Network Areas 282.4.4 Numbering, Addressing and Identification 282.5 Communication Protocols 302.5.1 Protocol Model 302.5.2 Air Interface Transport Protocols 312.5.3 Fixed Network Transport Protocols 312.5.4 User Plane Protocols 322.5.5 Signalling Protocols 332.6 Example Signalling Flows 342.6.1 Access Stratum Signalling 342.6.2 Non-Access Stratum Signalling 352.7 Bearer Management 362.7.1 The EPS Bearer 362.7.2 Default and Dedicated Bearers 372.7.3 Bearer Implementation Using GTP 382.7.4 Bearer Implementation Using GRE and PMIP 392.7.5 Signalling Radio Bearers 392.8 State Diagrams 402.8.1 EPS Mobility Management 402.8.2 EPS Connection Management 402.8.3 Radio Resource Control 412.9 Spectrum Allocation 43References 453 Digital Wireless Communications 493.1 Radio Transmission and Reception 493.1.1 Carrier Signal 493.1.2 Modulation Techniques 503.1.3 The Modulation Process 513.1.4 The Demodulation Process 533.1.5 Channel Estimation 553.1.6 Bandwidth of the Modulated Signal 553.2 Radio Transmission in a Mobile Cellular Network 563.2.1 Multiple Access Techniques 563.2.2 FDD and TDD Modes 563.3 Impairments to the Received Signal 583.3.1 Propagation Loss 583.3.2 Noise and Interference 583.3.3 Multipath and Fading 583.3.4 Inter-symbol Interference 603.4 Error Management 613.4.1 Forward Error Correction 613.4.2 Automatic Repeat Request 623.4.3 Hybrid ARQ 63References 654 Orthogonal Frequency Division Multiple Access 674.1 Principles of OFDMA 674.1.1 Sub-carriers 674.1.2 The OFDM Transmitter 684.1.3 The OFDM Receiver 704.1.4 The Fast Fourier Transform 724.1.5 Block Diagram of OFDMA 724.1.6 Details of the Fourier Transform 734.2 Benefits and Additional Features of OFDMA 754.2.1 Orthogonal Sub-carriers 754.2.2 Choice of Sub-carrier Spacing 754.2.3 Frequency-Specific Scheduling 774.2.4 Reduction of Inter-symbol Interference 784.2.5 Cyclic Prefix Insertion 794.2.6 Choice of Symbol Duration 804.2.7 Fractional Frequency Re-use 814.3 Single Carrier Frequency Division Multiple Access 824.3.1 Power Variations From OFDMA 824.3.2 Block Diagram of SC-FDMA 83References 855 Multiple Antenna Techniques 875.1 Diversity Processing 875.1.1 Receive Diversity 875.1.2 Closed Loop Transmit Diversity 885.1.3 Open Loop Transmit Diversity 895.2 Spatial Multiplexing 905.2.1 Principles of Operation 905.2.2 Open Loop Spatial Multiplexing 925.2.3 Closed Loop Spatial Multiplexing 945.2.4 Matrix Representation 965.2.5 Implementation Issues 995.2.6 Multiple User MIMO 995.3 Beamforming 1015.3.1 Principles of Operation 1015.3.2 Beam Steering 1025.3.3 Downlink Multiple User MIMO Revisited 103References 1046 Architecture of the LTE Air Interface 1056.1 Air Interface Protocol Stack 1056.2 Logical, Transport and Physical Channels 1076.2.1 Logical Channels 1076.2.2 Transport Channels 1076.2.3 Physical Data Channels 1086.2.4 Control Information 1096.2.5 Physical Control Channels 1106.2.6 Physical Signals 1116.2.7 Information Flows 1116.3 The Resource Grid 1116.3.1 Slot Structure 1116.3.2 Frame Structure 1136.3.3 Uplink Timing Advance 1156.3.4 Resource Grid Structure 1166.3.5 Bandwidth Options 1176.4 Multiple Antenna Transmission 1186.4.1 Downlink Antenna Ports 1186.4.2 Downlink Transmission Modes 1196.5 Resource Element Mapping 1196.5.1 Downlink Resource Element Mapping 1196.5.2 Uplink Resource Element Mapping 121References 1237 Cell Acquisition 1257.1 Acquisition Procedure 1257.2 Synchronization Signals 1267.2.1 Physical Cell Identity 1267.2.2 Primary Synchronization Signal 1277.2.3 Secondary Synchronization Signal 1287.3 Downlink Reference Signals 1287.4 Physical Broadcast Channel 1297.5 Physical Control Format Indicator Channel 1307.6 System Information 1317.6.1 Organization of the System Information 1317.6.2 Transmission and Reception of the System Information 1337.7 Procedures after Acquisition 133References 1348 Data Transmission and Reception 1358.1 Data Transmission Procedures 1358.1.1 Downlink Transmission and Reception 1358.1.2 Uplink Transmission and Reception 1378.1.3 Semi Persistent Scheduling 1398.2 Transmission of Scheduling Messages on the PDCCH 1398.2.1 Downlink Control Information 1398.2.2 Resource Allocation 1408.2.3 Example: DCI Format 1 1418.2.4 Radio Network Temporary Identifiers 1428.2.5 Transmission and Reception of the PDCCH 1438.3 Data Transmission on the PDSCH and PUSCH 1448.3.1 Transport Channel Processing 1448.3.2 Physical Channel Processing 1468.4 Transmission of Hybrid ARQ Indicators on the PHICH 1488.4.1 Introduction 1488.4.2 Resource Element Mapping of the PHICH 1488.4.3 Physical Channel Processing of the PHICH 1498.5 Uplink Control Information 1498.5.1 Hybrid ARQ Acknowledgements 1498.5.2 Channel Quality Indicator 1508.5.3 Rank Indication 1518.5.4 Precoding Matrix Indicator 1518.5.5 Channel State Reporting Mechanisms 1518.5.6 Scheduling Requests 1528.6 Transmission of Uplink Control Information on the PUCCH 1538.6.1 PUCCH Formats 1538.6.2 PUCCH Resources 1548.6.3 Physical Channel Processing of the PUCCH 1558.7 Uplink Reference Signals 1558.7.1 Demodulation Reference Signal 1558.7.2 Sounding Reference Signal 1568.8 Power Control 1578.8.1 Uplink Power Calculation 1578.8.2 Uplink Power Control Commands 1588.8.3 Downlink Power Control 1598.9 Discontinuous Reception 1598.9.1 Discontinuous Reception and Paging in RRC_IDLE 1598.9.2 Discontinuous Reception in RRC_CONNECTED 159References 1619 Random Access 1639.1 Transmission of Random Access Preambles on the PRACH 1639.1.1 Resource Element Mapping 1639.1.2 Preamble Sequence Generation 1659.1.3 Signal Transmission 1659.2 Non-Contention-Based Procedure 1669.3 Contention-Based Procedure 167References 16910 Air Interface Layer 2 17110.1 Medium Access Control Protocol 17110.1.1 Protocol Architecture 17110.1.2 Timing Advance Commands 17310.1.3 Buffer Status Reporting 17310.1.4 Power Headroom Reporting 17310.1.5 Multiplexing and De-multiplexing 17410.1.6 Logical Channel Prioritization 17410.1.7 Scheduling of Transmissions on the Air Interface 17510.2 Radio Link Control Protocol 17610.2.1 Protocol Architecture 17610.2.2 Transparent Mode 17710.2.3 Unacknowledged Mode 17710.2.4 Acknowledged Mode 17810.3 Packet Data Convergence Protocol 18010.3.1 Protocol Architecture 18010.3.2 Header Compression 18010.3.3 Prevention of Packet Loss during Handover 182References 18311 Power-On and Power-Off Procedures 18511.1 Power-On Sequence 18511.2 Network and Cell Selection 18711.2.1 Network Selection 18711.2.2 Closed Subscriber Group Selection 18711.2.3 Cell Selection 18811.3 RRC Connection Establishment 18911.3.1 Basic Procedure 18911.3.2 Relationship with Other Procedures 19011.4 Attach Procedure 19111.4.1 IP Address Allocation 19111.4.2 Overview of the Attach Procedure 19211.4.3 Attach Request 19211.4.4 Identification and Security Procedures 19411.4.5 Location Update 19511.4.6 Default Bearer Creation 19611.4.7 Attach Accept 19711.4.8 Default Bearer Update 19811.5 Detach Procedure 199References 20012 Security Procedures 20312.1 Network Access Security 20312.1.1 Security Architecture 20312.1.2 Key Hierarchy 20412.1.3 Authentication and Key Agreement 20512.1.4 Security Activation 20712.1.5 Ciphering 20812.1.6 Integrity Protection 20912.2 Network Domain Security 21012.2.1 Security Protocols 21012.2.2 Security in the Evolved Packet Core 21012.2.3 Security in the Radio Access Network 211References 21213 Quality of Service, Policy and Charging 21513.1 Policy and Charging Control 21513.1.1 Quality of Service Parameters 21513.1.2 Service Data Flows 21713.1.3 Charging Parameters 21813.1.4 Policy and Charging Control Rules 21913.2 Policy and Charging Control Architecture 21913.2.1 Basic PCC Architecture 21913.2.2 Local Breakout Architecture 22013.2.3 Architecture Using a PMIP Based S5/S8 22013.2.4 Software Protocols 22113.3 Session Management Procedures 22213.3.1 IP-CAN Session Establishment 22213.3.2 Mobile Originated SDF Establishment 22313.3.3 Server Originated SDF Establishment 22413.3.4 Dedicated Bearer Establishment 22513.3.5 PDN Connectivity Establishment 22613.3.6 Other Session Management Procedures 22813.4 Data Transport in the Evolved Packet Core 22813.4.1 Packet Handling at the PDN Gateway 22813.4.2 Data Transport Using GTP 22913.4.3 Differentiated Services 23013.4.4 Multiprotocol Label Switching 23113.4.5 Data Transport Using GRE and PMIP 23113.5 Charging and Billing 23113.5.1 High Level Architecture 23113.5.2 Offline Charging 23213.5.3 Online Charging 233References 23414 Mobility Management 23714.1 Transitions between Mobility Management States 23714.1.1 S1 Release Procedure 23714.1.2 Paging Procedure 23914.1.3 Service Request Procedure 23914.2 Cell Reselection in RRC_IDLE 24114.2.1 Objectives 24114.2.2 Measurement Triggering on the Same LTE Frequency 24114.2.3 Cell Reselection to the Same LTE Frequency 24214.2.4 Measurement Triggering on a Different LTE Frequency 24314.2.5 Cell Reselection to a Different LTE Frequency 24414.2.6 Fast Moving Mobiles 24414.2.7 Tracking Area Update Procedure 24514.2.8 Network Reselection 24614.3 Measurements in RRC_CONNECTED 24714.3.1 Objectives 24714.3.2 Measurement Procedure 24714.3.3 Measurement Reporting 24814.3.4 Measurement Gaps 24914.4 Handover in RRC_CONNECTED 25014.4.1 X2 Based Handover Procedure 25014.4.2 Handover Variations 252References 25315 Inter-operation with UMTS and GSM 25515.1 System Architecture 25515.1.1 Architecture of the 2G/3G Packet Switched Domain 25515.1.2 S3/S4-Based Inter-operation Architecture 25715.1.3 Gn/Gp-Based Inter-operation Architecture 25815.2 Power-On Procedures 25915.3 Mobility Management in RRC_IDLE 25915.3.1 Cell Reselection 25915.3.2 Routing Area Update Procedure 26015.3.3 Idle Mode Signalling Reduction 26215.4 Mobility Management in RRC_CONNECTED 26215.4.1 RRC Connection Release with Redirection 26215.4.2 Measurement Procedures 26415.4.3 Optimized Handover 265References 26816 Inter-operation with Non-3GPP Technologies 27116.1 Generic System Architecture 27116.1.1 Network-Based Mobility Architecture 27116.1.2 Host-Based Mobility Architecture 27316.1.3 Access Network Discovery and Selection Function 27416.2 Generic Signalling Procedures 27516.2.1 Overview of the Attach Procedure 27516.2.2 Authentication and Key Agreement 27616.2.3 PDN Connectivity Establishment 27816.2.4 Radio Access Network Reselection 28016.3 Inter-Operation with cdma2000 HRPD 28016.3.1 System Architecture 28016.3.2 Preregistration with cdma2000 28116.3.3 Cell Reselection in RRC_IDLE 28216.3.4 Measurements and Handover in RRC_CONNECTED 283References 28617 Self-Optimizing Networks 28917.1 Self-Configuration of an eNB 28917.1.1 Automatic Configuration of the Physical Cell Identity 28917.1.2 Automatic Neighbour Relations 29017.1.3 Random Access Channel Optimization 29117.2 Inter-Cell Interference Coordination 29217.3 Mobility Management 29217.3.1 Mobility Load Balancing 29217.3.2 Mobility Robustness Optimization 29317.3.3 Energy Saving 29517.4 Radio Access Network Information Management 29517.4.1 Introduction 29517.4.2 Transfer of System Information 29617.4.3 Transfer of Self-Optimization Data 29717.5 Drive Test Minimization 297References 29818 Enhancements in Release 9 30118.1 Multimedia Broadcast/Multicast Service 30118.1.1 Introduction 30118.1.2 Multicast/Broadcast over a Single Frequency Network 30218.1.3 Implementation of MBSFN in LTE 30218.1.4 Architecture of MBMS 30418.1.5 Operation of MBMS 30518.2 Location Services 30618.2.1 Introduction 30618.2.2 Positioning Techniques 30618.2.3 Location Service Architecture 30718.2.4 Location Service Procedures 30818.3 Other Enhancements in Release 9 30918.3.1 Dual Layer Beamforming 30918.3.2 Commercial Mobile Alert System 310References 31019 LTE-Advanced and Release 10 31319.1 Carrier Aggregation 31319.1.1 Principles of Operation 31319.1.2 UE Capabilities 31419.1.3 Scheduling 31619.1.4 Data Transmission and Reception 31619.1.5 Uplink and Downlink Feedback 31719.1.6 Other Physical Layer and MAC Procedures 31719.1.7 RRC Procedures 31719.2 Enhanced Downlink MIMO 31819.2.1 Objectives 31819.2.2 Downlink Reference Signals 31819.2.3 Downlink Transmission and Feedback 32019.3 Enhanced Uplink MIMO 32119.3.1 Objectives 32119.3.2 Implementation 32119.4 Relays 32219.4.1 Principles of Operation 32219.4.2 Relaying Architecture 32319.4.3 Enhancements to the Air Interface 32419.5 Heterogeneous Networks 32419.5.1 Introduction 32419.5.2 Enhanced Inter-Cell Interference Coordination 32519.5.3 Enhancements to Self-Optimizing Networks 32619.6 Traffic Offload Techniques 32619.6.1 Local IP Access 32619.6.2 Selective IP Traffic Offload 32719.6.3 Multi-Access PDN Connectivity 32719.6.4 IP Flow Mobility 32919.7 Overload Control for Machine-Type Communications 330References 33120 Releases 11 and 12 33320.1 Coordinated Multipoint Transmission and Reception 33320.1.1 Objectives 33320.1.2 Scenarios 33420.1.3 CoMP Techniques 33520.1.4 Standardization 33620.1.5 Performance 33720.2 Enhanced Physical Downlink Control Channel 33720.3 Interference Avoidance for in Device Coexistence 33820.4 Machine-Type Communications 33920.4.1 Device Triggering 33920.4.2 Numbering, Addressing and Identification 34020.5 Mobile Data Applications 34020.6 New Features in Release 12 34120.6.1 Proximity Services and Device to Device Communications 34120.6.2 Dynamic Adaptation of the TDD Configuration 34220.6.3 Enhancements for Machine-Type Communications and Mobile Data 34420.6.4 Traffic Offloading Enhancements 34420.7 Release 12 Studies 34520.7.1 Enhancements to Small Cells and Heterogeneous Networks 34520.7.2 Elevation Beamforming and Full Dimension MIMO 346References 34621 Circuit Switched Fallback 34921.1 Delivery of Voice and Text Messages over LTE 34921.1.1 The Market for Voice and SMS 34921.1.2 Third Party Voice over IP 35021.1.3 The IP Multimedia Subsystem 35121.1.4 VoLGA 35121.1.5 Dual Radio Devices 35221.1.6 Circuit Switched Fallback 35321.2 System Architecture 35321.2.1 Architecture of the 2G/3G Circuit Switched Domain 35321.2.2 Circuit Switched Fallback Architecture 35421.3 Attach Procedure 35521.3.1 Combined EPS/IMSI Attach Procedure 35521.3.2 Voice Domain Preference and UE Usage Setting 35621.4 Mobility Management 35721.4.1 Combined Tracking Area/Location Area Update Procedure 35721.4.2 Alignment of Tracking Areas and Location Areas 35721.4.3 Cell Reselection to UMTS or GSM 35821.5 Call Setup 35921.5.1 Mobile-Originated Call Setup using RRC Connection Release 35921.5.2 Mobile Originated Call Setup using Handover 36121.5.3 Signalling Messages in the Circuit Switched Domain 36221.5.4 Mobile-Terminated Call Setup 36321.5.5 Returning to LTE 36421.6 SMS over SGs 36521.6.1 System Architecture 36521.6.2 SMS Delivery 36521.7 Circuit Switched Fallback to cdma2000 1xRTT 36621.8 Performance of Circuit Switched Fallback 367References 36822 VoLTE and the IP Multimedia Subsystem 37122.1 Introduction 37122.1.1 The IP Multimedia Subsystem 37122.1.2 VoLTE 37222.1.3 Rich Communication Services 37222.2 Hardware Architecture of the IMS 37322.2.1 High-Level Architecture 37322.2.2 Call Session Control Functions 37422.2.3 Application Servers 37522.2.4 Home Subscriber Server 37522.2.5 User Equipment 37522.2.6 Relationship with LTE 37622.2.7 Border Control Functions 37722.2.8 Media Gateway Functions 37822.2.9 Multimedia Resource Functions 37922.2.10 Security Architecture 38022.2.11 Charging Architecture 38022.3 Signalling Protocols 38122.3.1 Session Initiation Protocol 38122.3.2 Session Description Protocol 38222.3.3 Other Signalling Protocols 38222.4 Service Provision in the IMS 38222.4.1 Service Profiles 38222.4.2 Media Feature Tags 38322.4.3 The Multimedia Telephony Service for IMS 38322.5 VoLTE Registration Procedure 38422.5.1 Introduction 38422.5.2 LTE Procedures 38422.5.3 Contents of the REGISTER Request 38522.5.4 IMS Registration Procedure 38722.5.5 Routing of SIP Requests and Responses 38822.5.6 Third-Party Registration with Application Servers 38922.5.7 Subscription for Network-Initiated Deregistration 38922.6 Call Setup and Release 39022.6.1 Contents of the INVITE Request 39022.6.2 Initial INVITE Request and Response 39122.6.3 Acceptance of the Initial INVITE 39322.6.4 Establishment of a Call to a Circuit Switched Network 39622.6.5 Call Release 39622.7 Access Domain Selection 39722.7.1 Mobile-Originated Calls 39722.7.2 Mobile-Terminated Calls 39822.8 Single Radio Voice Call Continuity 39822.8.1 Introduction 39822.8.2 SRVCC Architecture 39922.8.3 Attach, Registration and Call Setup Procedures 40022.8.4 Handover Preparation 40022.8.5 Updating the Remote Leg 40122.8.6 Releasing the Source Leg 40322.8.7 Handover Execution and Completion 40322.8.8 Evolution of SRVCC 40422.9 IMS Centralized Services 40522.10 IMS Emergency Calls 40622.10.1 Emergency Call Architecture 40622.10.2 Emergency Call Setup Procedure 40722.11 Delivery of SMS Messages over the IMS 40822.11.1 SMS Architecture 40822.11.2 Access Domain Selection 409References 41023 Performance of LTE and LTE-Advanced 41323.1 Peak Data Rates of LTE and LTE-Advanced 41323.1.1 Increase of the Peak Data Rate 41323.1.2 Limitations on the Peak Data Rate 41523.2 Coverage of an LTE Cell 41623.2.1 Uplink Link Budget 41623.2.2 Downlink Link Budget 41823.2.3 Propagation Modelling 41923.2.4 Coverage Estimation 42023.3 Capacity of an LTE Cell 42123.3.1 Capacity Estimation 42123.3.2 Cell Capacity Simulations 42223.4 Performance of Voice over IP 42423.4.1 AMR Codec Modes 42423.4.2 Transmission of AMR Frames on the Air Interface 42523.4.3 Transmission of AMR Frames in the Fixed Network 426References 427Bibliography 429Index 431