 Business Drivers Role of Standards Role of Open Source Competition Challenges Summary 34 References 35 5G System Overview Introduction 5G Core Network Sebastian Speicher Contents 3.2.1 Introduction 37 3.2.2 Service-Based Architecture 3.2.2.1 Fostering Functional Reuse 3.2.2.2 Overview of 5GC Control-Plane Functions 3.2.3 Control-User Plane Separation (CUPS) 3.2.4 Common Access-Agnostic Core Network 3.2.5 Enablers for Concurrent and Efficient Access to Local and Centralized Services 46 3.2.5.1 Overview 46 3.2.5.2 Single PDU Session-Based Access to Local Services 3.2.5.3 Multiple PDU Session-Based Access to Local Services 3.2.6 Network Slicing 3.2.7 Private Networks 3.2.7.1 Overview 53 3.2.7.2 Stand-Alone Non-public Networks 3.2.7.3 Public-Network-Integrated Non-public Network References 57 NG Radio Access Network Sasha Sirotkin 3.3.1 Introduction 59 3.3.2 Network Protocol Stacks 62 3.3.2.1 Control-Plane Protocol Stack 3.3.2.2 User-Plane Protocol Stack 3.3.2.3 Standards 63 3.3.3 NG Interface 3.3.3.1 NG-C Interface 3.3.3.2 NG-U Interface 3.3.4 Xn Interface 3.3.4.1 Xn Control Plane (Xn-C) Interface 3.3.4.2 Xn User Plane (Xn-U) Interface 3.3.5 Additional NG-RAN Features 3.3.5.1 RAN Sharing 3.3.5.2 Slicing 77 3.3.5.3 Virtualization 3.3.5.4 Non-3GPP Access References 79 NR Protocol Stack Sudeep Palat 3.4.1 Introduction 3.4.2 NG-RAN Architecture 3.4.3 NR User Plane 3.4.4 Supporting QoS with 5GC 3.4.5 NR Control Plane 3.4.5.1 RRC States 3.4.5.2 RRC Procedures and Functions Contents 3.4.6 Summary References 98 NR Physical Layer Alexei Davydov 3.5.1 Introduction 99 3.5.2 Waveform and Numerology 3.5.3 Frame Structure 3.5.4 Synchronization and Initial Access 3.5.4.1 Downlink Synchronization Signals 3.5.4.2 Random Access Channel 3.5.5 Downlink Control Channel 3.5.6 Uplink Control Channel 3.5.7 Reference Signals 3.5.7.1 CSI-RS 3.5.7.2 DM-RS 3.5.7.3 PT-RS 3.5.7.4 3.5.8 Beam Management 3.5.9 Channel Coding and Modulation 3.5.10 Co-Existence with LTE, Forward Compatibility and Uplink Coverage Enhancement References NG-RAN Archite