An Introduction to 5G

Preface xxi Acknowledgements xxiii List of Abbreviations xxv 1 Introduction 1 1.1 Architecture of a Mobile Telecommunication System 1 1.1.1 High-level Architecture 1 1.1.2 Internal Architecture of the Mobile 2 1.1.3 Architecture of the Radio Access Network 2 1.1.4 Coverage and Capacity 3 1.1.5 Architecture of the Core Network 4 1.1.6 Communication Protocols 4 1.2 History of Mobile Telecommunications 5 1.2.1 Introduction 5 1.2.2 Global System for Mobile Communications (GSM) 6 1.2.3 Universal Mobile Telecommunication System (UMTS) 6 1.2.4 Long-term Evolution (LTE) 7 1.2.5 LTE-Advanced 8 1.2.6 LTE-Advanced Pro 8 1.2.7 Other Mobile Communication Systems 9 1.3 The Mobile Telecommunication Market 9 1.3.1 Traffic Levels 9 1.3.2 Numbers of Subscriptions 10 1.3.3 Operator Revenue 10 1.4 Use Cases and Markets for 5G 11 1.4.1 5G Research Projects 11 1.4.2 Enhanced Mobile Broadband 11 1.4.3 Massive Machine-type Communications 12 1.4.4 Ultra-reliable Low-latency Communication 13 1.4.5 Vehicle-to-everything Communication 14 1.4.6 Network Operation 15 1.5 Technical Performance Requirements 15 1.6 Technologies for 5G 16 1.6.1 Network Function Virtualization 16 1.6.2 Software-defined Networking 17 1.6.3 Network Slicing 18 1.6.4 Technologies for the Air Interface 19 1.7 The 3GPP Specifications for 5G 19 1.8 Architecture of 5G 21 1.8.1 High-level Architecture 21 1.8.2 Architectural Options 22 References 25 2 Architecture of the Core Network 29 2.1 The Evolved Packet Core 29 2.1.1 Release 8 Architecture 29 2.1.2 Control and User Plane Separation 30 2.2 The 5G Core Network 31 2.2.1 Representation Using Reference Points 31 2.2.2 Representation Using Service-based Interfaces 32 2.2.3 Data Transport 33 2.2.4 Roaming Architectures 34 2.2.5 Data Storage Architectures 35 2.2.6 Non-3GPP Access to the 5G Core 37 2.3 Network Areas, Slices and Identities 37 2.3.1 Network Identities 37 2.3.2 Network Slices 38 2.3.3 AMF Areas and Identities 39 2.3.4 UE Identities 39 2.3.5 UE Registration Areas 39 2.4 State Diagrams 40 2.4.1 Registration Management 40 2.4.2 Connection Management 41 2.4.3 Non-3GPP Access 41 2.5 Signalling Protocols 41 2.5.1 Signalling Protocol Architecture 41 2.5.2 Example Signalling Procedures 42 2.6 The Hypertext Transfer Protocol 43 2.6.1 HTTP/1.1 and HTTP/2 43 2.6.2 Representational State Transfer 44 2.6.3 The HTTP/2 Data Layer 45 2.6.4 JavaScript Object Notation (JSON) 46 2.7 Example Network Function Services 47 2.7.1 Network Function Service Registration 47 2.7.2 Network Function Service Discovery 48 2.7.3 Network Function Service Subscription and Notification 49 References 50 3 Architecture of the Radio Access Network 55 3.1 The Evolved UMTS Terrestrial Radio Access Network 55 3.1.1 Release 8 Architecture 55 3.1.2 Carrier Aggregation 56 3.1.3 Dual Connectivity 57 3.2 The Next-generation Node B 58 3.2.1 High Level Architecture 58 3.2.2 Internal Architecture 58 3.2.3 Deployment Options 59 3.3 Architectural Options 61 3.3.1 Multi-radio Dual Connectivity 61 3.3.2 Options 1 and 3 – EPC, E-UTRAN and MeNB 61 3.3.3 Options 5 and 7 – 5GC, NG-RAN and MeNB 62 3.3.4 Options 2 and 4 – 5GC, NG-RAN and MgNB 62 3.3.5 Data Transport 63 3.4 Network Areas and Identities 64 3.4.1 Tracking Areas 64 3.4.2 RAN Areas 65 3.4.3 Cell Identities 65 3.5 RRC State Diagram 65 3.5.1 5G State Diagram 65 3.5.2 Interworking with 4G 66 3.6 Signalling Protocols 67 3.6.1 Signalling Protocol Architecture 67 3.6.2 Signalling Radio Bearers 68 References 69 4 Spectrum, Antennas and Propagation 73 4.1 Radio Spectrum 73 4.1.1 Radio Waves 73 4.1.2 Use of Radio Spectrum 74 4.1.3 Spectrum Allocations for 5G 75 4.2 Antennas and Propagation 75 4.2.1 Antenna Gain 75 4.2.2 Radio Propagation in Free Space 77 4.2.3 Antenna Arrays for 5G 78 4.3 Radio Propagation Issues for Millimetre Waves 79 4.3.1 Diffraction and Reflection 79 4.3.2 Penetration Losses 80 4.3.3 Foliage Losses 80 4.3.4 Atmospheric Losses 82 4.4 Multipath, Fading and Coherence 83 4.4.1 Introduction 83 4.4.2 Angular Spread and Coherence Distance 83 4.4.3 Doppler Spread and Coherence Time 85 4.4.4 Delay Spread and Coherence Bandwidth 86 4.4.5 Channel Reciprocity 87 References 87 5 Digital Signal Processing 91 5.1 Modulation and Demodulation 91 5.1.1 Carrier Signal 91 5.1.2 Modulation 92 5.1.3 The Modulation Process 94 5.1.4 The Demodulation Process 95 5.1.5 Channel Estimation 96 5.1.6 Adaptive Modulation 96 5.2 Radio Transmission in a Mobile Cellular Network 97 5.2.1 Multiplexing and Multiple Access 97 5.2.2 FDD and TDD Modes 97 5.3 Orthogonal Frequency Division Multiple Access 98 5.3.1 Subcarriers 98 5.3.2 The OFDM Transmitter 99 5.3.3 The OFDM Receiver 101 5.3.4 The Fast Fourier Transform 102 5.3.5 Block Diagram of the OFDMA Downlink 103 5.3.6 Block Diagram of the OFDMA Uplink 104 5.4 Other Features of OFDMA 105 5.4.1 Frequency-specific Scheduling 105 5.4.2 Subcarrier Orthogonality 107 5.4.3 Inter-symbol Interference and the Cyclic Prefix 107 5.5 Signal-processing Issues for 5G 110 5.5.1 Power Consumption 110 5.5.2 Timing Jitter and Phase Noise 111 5.5.3 Choice of Symbol Duration and Subcarrier Spacing 111 5.6 Error Management 112 5.6.1 Forward Error Correction 112 5.6.2 Automatic Repeat Request 113 5.6.3 Hybrid ARQ 113 5.6.4 Hybrid ARQ Processes 114 5.6.5 Higher-layer Retransmissions 115 References 116 6 Multiple-antenna Techniques 117 6.1 Analogue Beam Selection 117 6.1.1 Spatial Filtering 117 6.1.2 Beam Steering 119 6.1.3 Beamwidth of the Antenna Array 120 6.1.4 Grating Lobes 121 6.1.5 Analogue Signal-processing Issues 121 6.1.6 Beam Management 122 6.2 Digital Beamforming 122 6.2.1 Precoding and Postcoding 122 6.2.2 Digital Signal-processing Issues 124 6.2.3 Diversity Processing 124 6.3 Spatial Multiplexing 125 6.3.1 Principles of Spatial Multiplexing 125 6.3.2 Matrix Representation 126 6.3.3 MIMO and Coherence 127 6.3.4 Uplink Multiple-user MIMO 127 6.3.5 Downlink Multiple-user MIMO 129 6.3.6 Management of Multiple-user MIMO 131 6.3.7 Single-user MIMO 131 6.3.8 Signal Processing for Single-user MIMO 132 6.3.9 Management of Single-user MIMO 134 6.4 Massive MIMO 135 6.4.1 Architecture 135 6.4.2 Received Signal Power 136 6.4.3 Energy Efficiency 136 6.4.4 Spectral Efficiency 137 6.5 Hybrid Beamforming 138 6.5.1 Partly Connected Architecture 138 6.5.2 Fully Connected Architecture 139 6.5.3 Millimetre Wave MIMO 140 6.6 Multiple Antennas at the Mobile 141 6.6.1 Architecture 141 6.6.2 Beam Management 142 References 143 7 Architecture of the 5G New Radio 145 7.1 Air Interface Protocol Stack 145 7.1.1 5G Protocol Stack 145 7.1.2 Dual Connectivity 147 7.1.3 Channels and Signals 147 7.1.4 Information Flows 148 7.2 Frequency Bands and Combinations 152 7.2.1 Frequency Bands 152 7.2.2 Band Combinations 154 7.2.3 Bandwidth Classes 155 7.3 Frequency Domain Structure 155 7.3.1 Numerologies 155 7.3.2 Transmission Bandwidth Configuration 156 7.3.3 Global and Channel Frequency Rasters 157 7.3.4 Common Resource Blocks 158 7.3.5 Bandwidth Parts 159 7.3.6 Virtual and Physical Resource Blocks 159 7.4 Time Domain Structure 160 7.4.1 Frame Structure 160 7.4.2 Timing Advance 161 7.4.3 TDD Configurations 162 7.4.4 Slot Format Combinations 163 7.4.5 Resource Grid 164 7.5 Multiple Antennas 164 7.5.1 Antenna Ports 164 7.5.2 Relationships Between Antenna Ports 165 7.6 Data Transmission 166 7.6.1 Transport Channel Processing 166 7.6.2 Physical Channel Processing 167 7.6.3 Analogue Processing 168 References 169 8 Cell Acquisition 173 8.1 Acquisition Procedure 173 8.1.1 Introduction 173 8.1.2 Non-standalone Operation 174 8.1.3 Standalone Operation 175 8.2 Resource Mapping 175 8.2.1 SS/PBCH Blocks 175 8.2.2 Transmission Frequency 175 8.2.3 Transmission Timing 177 8.3 Acquisition of the SS/PBCH Block 178 8.3.1 Primary Synchronization Signal 178 8.3.2 Secondary Synchronization Signal 179 8.3.3 Demodulation Reference Signal for the PBCH 179 8.3.4 Physical Broadcast Channel 179 8.4 System Information 179 8.4.1 Master Information Block 179 8.4.2 System Information Block 1 180 8.4.3 Other System Information Blocks 180 8.4.4 Transmission and Reception of the System Information 181 References 182 9 Random Access 183 9.1 Physical Random Access Channel 183 9.1.1 PRACH Formats 183 9.1.2 Generation of the PRACH Preamble 185 9.1.3 Resource Mapping 186 9.2 Random Access Procedure 187 9.2.1 Random Access Preamble 187 9.2.2 Random Access Response 188 9.2.3 Message 3 189 9.2.4 Contention Resolution 189 9.2.5 Contention-free Procedure 189 References 190 10 Link Adaptation 191 10.1 CSI Reference Signals 191 10.1.1 Transmission and Reception 191 10.1.2 Resource Mapping 192 10.1.3 CSI-RS Resources 193 10.1.4 CSI-RS Resource Sets 194 10.2 Channel State Information 195 10.2.1 Introduction 195 10.2.2 CSI-RS and SS/PBCH Block Resource Indicators 195 10.2.3 Layer 1 RSRP 195 10.2.4 Rank Indication 195 10.2.5 Precoding Matrix Indicator 195 10.2.6 Channel Quality Indicator 197 10.2.7 Layer Indicator 197 10.2.8 CSI Reporting 197 10.3 Physical Uplink Control Channel 199 10.3.1 Introduction 199 10.3.2 PUCCH Formats 199 10.3.3 PUCCH Resources 201 10.4 Sounding 201 10.4.1 Transmission and Reception 201 10.4.2 Resource Mapping 202 10.4.3 SRS Resources 202 References 204 11 Data Transmission and Reception 205 11.1 Introduction 205 11.1.1 Data Transmission Procedure 205 11.1.2 Downlink Control Information 206 11.1.3 Radio Network Temporary Identifiers 206 11.2 Transmission and Reception of the PDCCH 207 11.2.1 Transmission of the PDCCH 207 11.2.2 Control Resource Sets 209 11.2.3 Search Spaces 209 11.2.4 Reception of the PDCCH 210 11.3 Scheduling Messages 211 11.3.1 DCI Formats 0_0 and 1_0 211 11.3.2 Time Domain Resource Assignment 211 11.3.3 Frequency Domain Resource Assignment 213 11.3.4 Modulation and Coding Scheme 214 11.3.5 Other Fields 214 11.3.6 DCI Formats 0_1 and 1_1 215 11.4 Transmission and Reception of the PUSCH and PDSCH 215 11.4.1 Transport Channel Processing 215 11.4.2 Physical Channel Processing 216 11.4.3 Downlink MIMO 217 11.4.4 Uplink Codebook-based MIMO 218 11.4.5 Uplink Non-codebook-based MIMO 218 11.5 Reference Signals 219 11.5.1 Demodulation Reference Signals 219 11.5.2 Phase-tracking Reference Signals 219 11.6 Hybrid ARQ Acknowledgements 220 11.6.1 Downlink Acknowledgements of Uplink Data 220 11.6.2 Uplink Acknowledgements of Downlink Data 221 11.6.3 Timing of Uplink Acknowledgements 221 11.7 Other DCI Formats 222 11.7.1 Introduction 222 11.7.2 Slot Format Indications 223 11.7.3 Pre-emption Indications 223 11.7.4 Transmit Power Control Commands 223 11.8 Related Procedures 224 11.8.1 Scheduling Requests 224 11.8.2 Semi-persistent and Configured Scheduling 224 11.8.3 Discontinuous Reception 225 11.9 Performance of 5G 226 11.9.1 Peak Data Rate 226 11.9.2 Typical Cell Capacity 229 References 230 12 Air Interface Layer 2 233 12.1 Medium Access Control 233 12.1.1 Protocol Architecture 233 12.1.2 Scheduling 233 12.1.3 Logical Channel Prioritization 234 12.1.4 Multiplexing and De-multiplexing 235 12.1.5 MAC Control Elements 236 12.2 Radio Link Control 237 12.2.1 Protocol Architecture 237 12.2.2 Transparent Mode 238 12.2.3 Unacknowledged Mode 238 12.2.4 Acknowledged Mode 240 12.3 Packet Data Convergence Protocol 241 12.3.1 Protocol Architecture 241 12.3.2 Transmission and Reception 241 12.3.3 PDCP Duplication 242 12.3.4 Prevention of Packet Loss during a Change of Node 243 12.3.5 Header Compression 244 12.4 Service Data Adaptation Protocol 244 References 245 13 Registration Procedures 247 13.1 Power-on Sequence 247 13.2 Network and Cell Selection 248 13.2.1 Network Selection 248 13.2.2 Cell Selection 249 13.3 RRC Connection Establishment 250 13.3.1 RRC Connection Establishment with a gNB 250 13.3.2 Initial UE Message 251 13.3.3 RRC Connection Establishment with an eNB 252 13.4 Registration Procedure 252 13.4.1 Registration Without AMF Change 252 13.4.2 Registration with a New AMF 255 13.4.3 Registration with AMF Re-allocation 257 13.5 Deregistration Procedure 259 References 259 14 Security 261 14.1 Security Principles 261 14.2 Network Access Security 262 14.2.1 Network Access Security Architecture 262 14.2.2 Key Hierarchy 263 14.3 Network Access Security Procedures 264 14.3.1 Subscription Concealed Identifier 264 14.3.2 Authentication and Key Agreement 265 14.3.3 Activation of Non-access Stratum Security 267 14.3.4 Activation of Access Stratum Security 268 14.3.5 Key Handling During Mobility 269 14.3.6 Key Handling During State Transitions 269 14.3.7 Ciphering 269 14.3.8 Integrity Protection 270 14.4 Network Domain Security 271 14.4.1 Network Domain Security Architecture 271 14.4.2 Network Domain Security Protocols 271 14.5 Service-based Architecture Domain Security 272 14.5.1 Security Architecture 272 14.5.2 Initial Handshake Procedures over N32-c 273 14.5.3 Forwarding of JOSE Protected Messages over N32-f 274 References 275 15 Session Management, Policy and Charging 279 15.1 Types of PDU Session 279 15.1.1 IP PDU Sessions 279 15.1.2 Ethernet PDU Sessions 280 15.1.3 Unstructured PDU Sessions 281 15.2 Quality of Service 281 15.2.1 Packet Flows, Service Data Flows, and QoS Flows 281 15.2.2 QoS Parameters 282 15.2.3 Charging Parameters 285 15.3 Implementation of PDU Sessions 286 15.3.1 Bearers and Tunnels 286 15.3.2 User Plane Protocols 287 15.3.3 End-to-end Protocol Stack 288 15.3.4 Multiple PDU Session Anchors 289 15.3.5 PDU Session Anchor Relocation 290 15.4 Policy and Charging Control Architecture 290 15.4.1 High-level Architecture 290 15.4.2 Support for 3GPP Services 292 15.4.3 Northbound API 293 15.4.4 Charging and Billing System 294 15.5 PDU Session Establishment Procedures 295 15.5.1 PDU Session Establishment 295 15.5.2 Interactions with the Policy and Charging Control System 298 15.5.3 PDU Session Release 298 15.6 Traffic Steering 299 15.6.1 Traffic Steering Request 299 15.6.2 Addition of a PDU Session Anchor 301 15.6.3 Change of PDU Session Anchor 302 References 302 16 Mobility Management in RRC_CONNECTED 307 16.1 Introduction to RRC_CONNECTED 307 16.1.1 Principles 307 16.1.2 Dual Connectivity 308 16.1.3 PDU Sessions 308 16.2 Measurement Configuration and Reporting 308 16.2.1 Measurement Configuration and Reporting Procedure 308 16.2.2 Measurement Objects 309 16.2.3 Reporting Configurations 311 16.2.4 Measurement Gaps 312 16.2.5 Measurement Reporting 313 16.3 Handover Procedures 313 16.3.1 Xn-based Handover Procedure 313 16.3.2 Path Switch Procedure 316 16.3.3 NG-based Handover Procedure 317 16.3.4 Handovers Between a gNB and an ng-eNB 317 16.4 Dual Connectivity Procedures 317 16.4.1 Secondary Node Addition 317 16.4.2 QoS Flow Mobility Procedure 319 16.4.3 Other Dual Connectivity Procedures 320 16.5 State Transitions out of RRC_CONNECTED 321 16.5.1 Core Network Assistance Information 321 16.5.2 Transition to RRC_IDLE 321 16.5.3 Transition to RRC_INACTIVE 322 References 323 17 Mobility Management in RRC_IDLE 325 17.1 Introduction to RRC_IDLE 325 17.1.1 Principles 325 17.1.2 Inactive PDU Sessions 326 17.2 Cell Reselection Procedures 326 17.2.1 Introduction 326 17.2.2 Intra-frequency Measurement Triggering 327 17.2.3 Intra-frequency Cell Reselection 327 17.2.4 Inter-frequency Measurement Triggering 328 17.2.5 Inter-frequency Cell Reselection 329 17.2.6 Fast-moving Mobiles 329 17.3 Registration Updating 330 17.3.1 Registration Update Procedure 330 17.3.2 Network Reselection 331 17.4 State Transitions out of RRC_IDLE 331 17.4.1 Mobile-triggered Service Request 331 17.4.2 Network-triggered Service Request 333 References 334 18 Mobility Management in RRC_INACTIVE 337 18.1 Introduction to RRC_INACTIVE 337 18.1.1 Principles 337 18.1.2 Suspended PDU Sessions 338 18.2 Mobility Management 339 18.2.1 RAN-based Notification Area Update 339 18.2.2 Registration Update 341 18.2.3 Mobility between a gNB and an ng-eNB 341 18.3 State Transitions 341 18.3.1 Transition to RRC_IDLE 341 18.3.2 Mobile-triggered Resumption of the RRC Connection 342 18.3.3 Network-triggered Resumption of the RRC Connection 344 References 345 19 Inter-operation with the Evolved Packet Core 347 19.1 Inter-operation Architectures 347 19.1.1 Migration Architecture 347 19.1.2 Interworking Architecture 348 19.1.3 Signalling Protocols 349 19.1.4 State Diagrams 350 19.2 Registration Modes 350 19.2.1 Single Registration Mode 350 19.2.2 Dual Registration Mode 350 19.2.3 Temporary Identities 351 19.3 Use of the Migration Architecture 351 19.3.1 Configuration Procedures 351 19.3.2 Mobility in RRC_IDLE 352 19.3.3 RRC Release with Redirection from RRC_CONNECTED 353 19.4 Interworking Without N26 353 19.4.1 Configuration Procedures 353 19.4.2 Mobility in Single Registration Mode 353 19.4.3 Mobility in Dual Registration Mode 354 19.5 Interworking with N26 354 19.5.1 Configuration Procedures 354 19.5.2 Mobility in RRC_IDLE 355 19.5.3 Handovers in RRC_CONNECTED 357 References 359 20 Release 16 and Beyond 361 20.1 Vehicle-to-everything (V2X) Communications 361 20.1.1 Introduction 361 20.1.2 Architectural Enhancements 362 20.1.3 Device-to-device Communications 363 20.2 Location Services 364 20.2.1 Introduction 364 20.2.2 System Architecture 365 20.2.3 Enhancements to the Air Interface 366 20.3 Integrated Access and Backhaul 367 20.3.1 Introduction 367 20.3.2 High-level Architecture 367 20.3.3 Architectural Details 368 20.4 Non-terrestrial Networks 369 20.4.1 Introduction 369 20.4.2 Design Challenges 370 20.5 Massive Machine-type Communications 371 20.5.1 Introduction 371 20.5.2 Enhancements to the 5G Core Network 371 20.5.3 NR Light 372 20.6 Other New Features and Studies 372 20.6.1 Enhancements to the Service-based Architecture 372 20.6.2 Support for Vertical and LAN Services 373 20.6.3 Self-optimizing Networks 373 20.6.4 Use of Unlicensed Spectrum 373 20.6.5 Reduction of Cross-link Interference 374 20.6.6 Further Enhancements to the 5G New Radio 374 References 375 Further Reading 379 Long-term Evolution (LTE) 379 Voice over LTE (VoLTE) and the IP Multimedia Subsystem 379 Spectrum, Antennas and Propagation 380 Wireless Communications 380 Multiple Antennas 380 Digital Signal Processing 380 Mathematics 381 5G System 381 5G Air Interface 381 Index 383