Mobile Communications Systems Development: A Practical Introduction to System Understanding, Implementation and Deployment

Description

Provides a thorough introduction to the development, operation, maintenance, and troubleshooting of mobile communications systems Mobile Communications Systems Development: A Practical Approach for System Understanding, Implementation and Deployment is a comprehensive “how to” manual for mobile communications system design, deployment, and support. Providing a detailed overview of end-to-end system development, the book encompasses operation, maintenance, and troubleshooting of currently available mobile communication technologies and systems. Readers are introduced to different network architectures, standardization, protocols, and functions including 2G, 3G, 4G, and 5G networks, and the 3GPP standard. In-depth chapters cover the entire protocol stack from the Physical (PHY) to the Application layer, discuss theoretical and practical considerations, and describe software implementation based on the 3GPP standardized technical specifications. The book includes figures, tables, and sample computer code to help readers thoroughly comprehend the functions and underlying concepts of a mobile communications network. Each chapter includes an introduction to the topic and a chapter summary. A full list of references, and a set of exercises are also provided at the end of the book to test comprehension and strengthen understanding of the material. Written by a respected professional with more than 20 years’ experience in the field, this highly practical guide: Provides detailed introductory information on GSM, GPRS, UMTS, and LTE mobile communications systems and networks Describes the various aspects and areas of the LTE system air interface and its protocol layers Covers troubleshooting and resolution of mobile communications systems and networks issues Discusses the software and hardware platforms used for the development of mobile communications systems network elements Includes 5G use cases, enablers, and architectures that cover the 5G NR (New Radio) and 5G Core Network Mobile Communications Systems Development is perfect for graduate and postdoctoral students studying mobile communications and telecom design, electronic engineering undergraduate students in their final year, research and development engineers, and network operation and maintenance personnel. Cover Title Page Copyright Page Contents About the Author Preface Acknowledgments List of Abbreviations Chapter 1 Introduction: Career Opportunities in Mobile Communications Networks Space Part I Network Architectures, Standardization, Protocols, and Functions Chapter 2 Network Architectures, Standardizations Process Introduction 2.1 Network Elements and Basic Networks Architectures 2.1.1 GSM (2G) Network Architecture 2.1.2 General Packet Radio Service (GPRS-2.5G) Network Architecture 2.1.3 Universal Mobile Telecommunications System (3G) Network Architecture 2.1.4 LTE (4G) Network Architecture 2.1.5 GSM, UMTS, LTE, and 5G Network Elements: A Comparison 2.1.6 Circuit Switched (CS) vs Packet Switched (PS) 2.2 Mobile Communication Network Domains 2.2.1 AN Domain 2.2.2 Core Network (CN) Domain 2.2.3 Network Domains and Its Elements 2.2.4 Example: End-to-End Mobile Network Information Flow 2.2.5 Example: GSM MO Call 2.3 Mobile Communications Systems Evolutions 2.3.1 Evolutions of Air Interface 2.3.2 Evolutions of 3GPP Networks Architectures 2.4 Mobile Communications Network System Engineering 2.4.1 Mobility Management 2.4.2 Air Interface Management 2.4.3 Subscribers and Services Management 2.4.4 Security Management 2.4.5 Network Maintenance 2.5 Standardizations of Mobile Communications Networks 2.5.1 3rd Generation Partnership Project (3GPP) 2.5.2 3GPP Working Groups 2.5.3 3GPP Technical Specification and Technical Report 2.5.4 Stages of a 3GPP Technical Specification 2.5.5 Release Number of 3GPP Technical Specification 2.5.6 3GPP Technical Specification Numbering Nomenclature 2.5.7 Vocabulary of 3GPP Specifications 2.5.8 Examples in a 3GPP Technical Specification 2.5.9 Standardization of Technical Specifications by 3GPP 2.5.10 Scope of 3GPP Technical Specification (TS) 2.5.11 3GPP TS for General Description of a Protocol Layer 2.5.12 3GPP TS Drafting Rules: Deriving Requirements 2.5.13 Download 3GPP Technical Specifications 2.5.14 3GPP Change Requests 2.5.15 Learnings from 3GPP Meetings TDocs 2.6 3GPP Releases and Its Features Chapter Summary Chapter 3 Protocols, Interfaces, and Architectures Introduction 3.1 Protocol Interface and Its Stack 3.1.1 Physical Interface 3.1.2 Logical Interface 3.1.3 Logical Interfaces’ Names and Their Protocol Stack 3.1.4 Examples of Logical Interface and Its Protocol Layers 3.2 Classifications of Protocol Layers 3.2.1 Control Plane or Signaling Protocols 3.2.2 User Plane Protocols 3.3 Grouping of UMTS, LTE, and 5G Air Interface Protocol Layers 3.3.1 Access Stratum (AS): UMTS UE – UTRAN; LTE UE – E-UTRAN;5G UE - NG-RAN 3.3.2 Non-Access Stratum: UMTS UE – CN, LTE UE – EPC; 5G UE-Core 3.4 Initialization of a Logical Interface 3.5 Protocol Layer Termination 3.6 Protocol Sublayers 3.7 Protocol Conversion 3.8 Working Model of a 3GPP Protocol Layer: Services and Functions 3.9 General Protocol Model Between RAN and CN (UMTS, LTE, 5G) 3.10 Multiple Transport Networks, Protocols, and Physical Layer Interfaces 3.11 How to Identify and Understand Protocol Architectures 3.11.1 Identifying a Logical Interface, Protocol Stack, and Its Layers 3.11.2 Identification of Technical Requirements Using Interface Name 3.12 Protocol Layer Procedures over CN Interfaces 3.12.1 Similar Functions and Procedures over the CN Interfaces 3.12.2 Specific Functions and Procedures over the CN Interfaces Chapter Summary Chapter 4 Encoding and Decoding of Messages Introduction 4.1 Description and Encoding/Decoding of Air Interface Messages 4.1.1 Encoding/Decoding: Air Interface Layer 3 Messages 4.1.2 Encoding/Decoding: LTE and 5G NR Layer 2: RLC Protocol 4.1.3 Encoding/Decoding: LTE and 5G NR Layer 2: MAC Protocol 4.1.4 CSN.1 Encoding/Decoding: GPRS Layer 2 Protocol (RLC/MAC) 4.1.5 ASN.1 Encoding/Decoding: UMTS, LTE, and 5G NR Layer 3 Protocol 4.1.6 Direct/Indirect Encoding Method 4.1.7 Segmented Messages over the Air Interface 4.1.8 Piggybacking a Signaling Message 4.2 Encoding/Decoding of Signaling Messages: RAN and CN Chapter Summary Chapter 5 Network Elements: Identities and Its Addressing Introduction 5.1 Network Elements and Their Identities 5.2 Permanent Identities 5.3 Temporary Identities Assigned by CN 5.3.1 GSM System Temporary Identities 5.3.2 GPRS System Temporary Identities 5.3.3 LTE/EPS System Temporary Identities 5.4 Temporary Identities Assigned by RAN: RNTI 5.5 Usages of Network Identities 5.6 Native and Mapped Network Identities 5.7 LTE UE Application Protocol Identity Chapter Summary Chapter 6 Interworking and Interoperations of Mobile Communications Networks Introduction 6.1 Requirements and Types of Interworking 6.2 Interworking Through Enhanced Network Elements 6.2.1 Interworking for Voice Call Through IMS: VoLTE 6.2.1.1 IP Multimedia Subsystem (IMS) 6.2.1.2 UE Registration and Authentication 6.2.2 Interworking for VoLTE Call Through LTE/EPS: SRVCC 6.2.3 Interworking for Voice Call Through LTE/EPS: CSFB 6.3 Interworking Through Legacy Network Elements 6.4 Interworking Between LTE/EPS and 5G Systems 6.5 Interoperations of Networks: LTE/EPS Roaming 6.5.1 Roaming Through Interoperations of Enhanced Networks Elements 6.5.2 Roaming Through Interoperations of Legacy Networks Elements 6.6 UE Mode of Operation 6.7 Function of E-UTRAN in a VoLTE Call Chapter Summary Chapter 7 Load Balancing and Network Sharing Introduction 7.1 Core Network Elements Load Balancing 7.1.1 Identification of NAS Node: NRI and Its Source 7.1.2 NAS Node Selection Function 7.2 Network Sharing 7.2.1 GSM/GPRS/LTE RAN Sharing Through MOCN Feature 7.2.2 5G NG-RAN Sharing Through MOCN Feature (Release 16) Chapter Summary Chapter 8 Packets Encapsulations and Their Routing Introduction 8.1 User Data Packets Encapsulations 8.1.1 Packets Encapsulations at the CN and RAN 8.1.2 Packet Encapsulations over Air Interface 8.2 IP Packet Routing in Mobile Communications Networks 8.3 IP Header Compression and Decompression Chapter Summary Chapter 9 Security Features in Mobile Communications Networks Introduction 9.1 A Brief on the Security Architecture: Features and Mechanisms 9.2 Security Features and Its Mechanisms 9.3 GSM Security Procedures 9.4 UMTS, LTE, and 5G: AS and NAS Layer Security Procedures 9.5 Security Contexts 9.6 Security Interworking Chapter Summary Part II Operations and Maintenances Chapter 10 Alarms and Faults Managements Introduction 10.1 Network Elements Alarm and Its Classifications 10.2 Sources of Abnormal Events and Alarms 10.3 Identifying Sources of Alarms from 3GPP TSs 10.3.1 Abnormal Conditions 10.3.2 Protocol Layer Error Handling 10.3.3 Abnormal Conditions Due to Local Errors 10.4 Design and Implementation of an Alarm Management System 10.4.1 Design and Components of an Alarm 10.4.2 Alarm Application Programming Interfaces (APIs) 10.4.3 Alarm Database 10.5 Alarm Due to Protocol Error 10.5.1 Sample Protocol Error Alarm Description 10.6 Alarm Due to Abnormal Conditions 10.6.1 Normal Scenario 10.6.2 Abnormal Scenario 10.6.3 Sample Alarm Description 10.6.4 Sample Alarm Generation 10.6.5 Sample Protocol Error Alarm Generation 10.7 How to Troubleshoot Protocol Error Using the Alarm Data Chapter Summary Chapter 11 Performance Measurements and Optimizations of Mobile Communications Networks Introduction 11.1 Counters for Performance Measurements and Optimizations 11.2 Performance and Optimizations Management System 11.3 Key Performance Indicator (KPI) 11.3.1 What Is a KPI? 11.3.2 KPI Domains 11.3.3 KPI for Signaling or Control Plane 11.3.4 KPI for User or Data Plane 11.3.5 KPI Categories 11.3.6 KPI Evaluation Steps 11.3.7 Troubleshooting and Improving KPI 11.3.8 Components of a KPI Definition Chapter Summary Chapter 12 Troubleshooting of Mobile Communications Networks Issues Introduction 12.1 Air Interface-Related Issues 12.1.1 Drive Test, Data Collection, and Its Analysis 12.2 Debugging Issues with IP-Based Logical Interface 12.2.1 IP Protocol Analyzer 12.2.2 Network/Application Throughput Issue 12.2.3 Switch Port Mirroring 12.3 Conformance Testing Issues 12.3.1 Example: Mobile Device (MS)/User Equipment (UE) Conformance Test 12.3.2 Example: Location Area Update Request 12.4 Interoperability Testing (IOT) Issues 12.5 Interworking Issues 12.6 Importance of Log/Traces and Its Collections 12.7 Steps for Troubleshooting Chapter Summary Part III Mobile Communications Systems Development Chapter 13 Core Software Development Fundamentals Introduction 13.1 A Brief on Software Development Fundamentals 13.1.1 Requirements Phase 13.1.2 Design 13.1.3 Implementation 13.1.4 Integration and Testing 13.1.5 Operation and Maintenance 13.2 Hardware Platforms: Embedded System, Linux Versus PC 13.2.1 System Development Using Embedded System Board 13.2.2 System Development Using Multicore Hardware Platform 13.2.2.1 What Is a Core? 13.2.2.2 Network Element Development Using Multicore Platform 13.2.2.3 Runtime Choices of Multicore Processor 13.2.2.4 Software Programming Model for Multicore Processor 13.3 Selecting Software Platforms and Features 13.3.1 Selecting Available Data/Logical Structures 13.3.1.1 Advanced Data Structures 13.3.1.2 How Data Structure Affects the Application’s Performance 13.3.2 Selecting an Operating System Services/Facilities 13.3.2.1 Advance Features of Operating System: IPC 13.4 Software Simulators for a Mobile Communications Network 13.5 Software Root Causes and Their Debugging 13.5.1 Incorrect Usages of Software Library System Calls/APIs 13.5.2 Incorrect Usages of System Resources 13.5.3 Bad Software Programming Practices 13.6 Static Code Analysis of Software 13.7 Software Architecture and Software Organization Example 13.1 13.8 System and Software Requirements Analysis 13.9 Software Quality: Reliability, Scalability, and Availability 13.9.1 Reliability 13.9.2 Scalability 13.9.3 Availability Chapter Summary Chapter 14 Protocols, Protocol Stack Developments, and Testing Introduction 14.1 Components of a 3GPP Protocol TS 14.2 3GPP Protocol Layer Structured Procedure Description 14.3 Protocol Layer Communications 14.3.1 Layer-to-Layer Communication Using Service Primitives 14.3.2 Layer-to-Layer Communication: SAP 14.3.3 Peer-to-Peer Layer Communication: PDU and Service Data Unit (SDU) 14.3.4 Types of PDU 14.3.5 Formats of PDU 14.4 Air Interface Message Format: Signaling Layer 3 14.4.1 A Brief on the Air Interface Layer 3 Protocol Stack 14.4.2 Classification of Layer 3 Messages 14.4.3 Layer 3 Protocol Header: Signaling Message Format 14.4.4 Layer 3 Protocol Header: Protocol Discriminator 14.4.5 Layer 3 Protocol Header: GSM, GPRS Skip Indicator 14.4.6 Layer 3 Protocol Header: GSM, GPRS Transaction Identifier 14.4.7 Layer 3 Protocol Header: LTE/EPS Bearer Identity 14.4.8 Layer 3 Protocol Header: 5GSM PDU Session Identity 14.4.9 Constructing a Layer 3 Message 14.4.10 Security Protected LTE/EPS and 5G NAS Layer MM Messages 14.4.11 Layer 3 Protocol Layer’s Message Dump 14.5 Air Interface Message Format: Layer 2 14.6 RAN – CN Signaling Messages 14.6.1 Protocol Layer Elementary Procedure 14.6.2 Types and Classes of EPs 14.6.3 EPs Code 14.6.4 Criticality of IE 14.6.5 Types of Protocol Errors and Its Handling 14.6.6 Choices of Triggering Message 14.6.7 Message Type 14.6.8 Message Description 14.6.9 Example: LTE/EPS S1 Interface: S1 Setup Procedure 14.7 Modes of Operation of a Protocol Layer 14.8 Example of a Protocol Primitive and PDU Definition 14.9 Example of a Protocol Layer Frame Header Definition 14.10 Examples of System Parameters 14.11 Examples of Protocol Information Elements and Its Identifier 14.12 3GPP Release Specific Changes Implementation 14.13 Examples of Protocol Messages Types 14.14 Protocol Layer Timer Handling 14.15 Protocol Layer Development Using State Machine 14.16 Protocol Layer Development Using Message Passing 14.17 Protocol Layer Data and its Types 14.18 Protocol Layer Control and Configuration 14.19 Protocol Context Information 14.20 Protocol Layer Message Padding 14.21 Device Driver Development 14.22 Guidelines for Protocol Stack/Layer Development 14.23 Software Profiling, Tools and Performance Improvement 14.24 Protocol Stack Testing and Validation Chapter Summary Chapter 15 Deriving Requirements Specifications from a TS Introduction 15.1 3GPP Protocol Layer Procedures 15.1.1 LTE UE Mode of Operation Requirements 15.1.2 LTE UE ATTACH Procedure Requirements 15.1.3 LTE UE DETACH Procedure Requirements 15.1.4 LTE UE Tracking Area Update Procedure Requirements 15.2 3GPP System Feature Development Requirements 15.2.1 Identification of System/Network Elements Interfaces Changes 15.2.2 Identifications of Impacts on Performance 15.2.3 Identifications of Impacts on Feature Management 15.2.4 Identification of Interworking Requirements with Existing Features 15.2.5 Charging and Accounting Aspects 15.3 Example Feature: Radio Access Network Sharing 15.3.1 Effects on Network Elements 15.3.2 Effects on Logical Interfaces 15.3.3 Selection of Core Network Operator: PLMN Id 15.4 Example: Interworking/Interoperations 15.4.1 Circuit-Switched Fall Back (CSFB) 15.4.2 Single Radio Voice Call Continuity (SRVCC) 15.5 3GPP System Feature and High-Level Design Chapter Summary Part IV 5G System and Network Chapter 16 5G Network: Use Cases and Architecture Introduction 16.1 5G System (5GS) Use Cases 16.1.1 Enablers and Key Principles of 5GS Use Cases 16.1.2 Other Enablers in 5G System 16.2 Support of Legacy Services by 5G System 16.3 5G System Network Architecture 16.3.1 3GPP Access Architecture 16.3.2 Non-3GPP Access Architecture 16.4 5G System NG–RAN/gNB Logical Architecture 16.5 5GC System Architecture Elements 16.6 5G System Deployment Solutions 16.6.1 E–UTRA–NR Dual Connectivity (EN–DC) for NSA Deployment 16.7 5G System and LTE/EPS Interworking 16.7.1 RAN-Level Interworking 16.7.2 Core Network (CN) Level Interworking: N26 Interface 16.7.2.1 Single Registration Mode with N26 Interface 16.7.2.2 Dual Registration Mode: Without N26 Interface 16.8 5G System Native and Mapped Network Identities 16.8.1 Mobility Area Identifiers 16.8.2 UE/Subscriber Permanent Identifiers 16.8.3 Core Network Identifiers 16.8.4 RAN Identifiers 16.8.5 Core Network Temporary Identities 16.9 5G System Network Slicing 16.9.1 Identities for a Network Slice 16.9.2 Impacts of Network Slicing Feature 16.10 Management and Orchestration (MANO) of 5G Network 16.11 5G System Security 16.11.1 UE Authentication Frameworks and Methods 16.11.2 Primary Authentication and Secondary Authentication 16.11.3 Key Hierarchy and Authentication Vector 16.11.4 New Security Requirements in 5G System 16.11.5 Subscriber Identities/Privacy Protection Chapter Summary Chapter 17 Introduction to GSM, UMTS, and LTE Systems Air Interface Introduction 17.1 Air Interfaces Protocol Architectures 17.2 Protocol Sublayers 17.3 Control Plane and User Plane Protocols 17.4 Protocols Domains Classifications 17.5 Access Stratum and Non-access Stratum 17.6 Message Formats 17.7 Security Over the Air Interface 17.8 Piggybacking for Reduction of Signaling Overhead 17.8.1 Examples Piggybacking of Signaling Messages Chapter Summary Chapter 18 5G NR Air Interface: Control Plane Protocols Introduction 18.1 NR Control Plane Protocol Layers 18.2 Session Management (5G SM) Layer 18.2.1 Procedures of 5G SM Layer 18.2.2 PDU Session Types 18.2.3 PDU Session and Service Continuity (SSC) 18.2.4 PDU Sessions for Network Slices 18.2.5 Session Management (SM) Layer States 18.3 Quality of Service (5G QoS) 18.3.1 LTE/EPS QoS Model: EPS Bearer 18.3.2 5GS QoS Model: QoS Flow 18.3.3 GTP-U Plane Tunnel for PDU Session 18.3.4 Service Data Flow and PCC Rule 18.3.5 Binding of Service Data Flow 18.3.6 QoS Profile and QFI 18.3.7 QoS Rule and QRI 18.3.8 Mapping QoS Flow to Data Radio Bearer 18.3.9 Downlink Data Flow Through GTP-U Plane Tunnels 18.4 Mobility Management (5G MM) Layer 18.4.1 Mobility Area Concepts and Identifiers 18.4.2 Requirements of Mobility Management Functions 18.4.3 Functions and Procedures of 5G MM Layer 18.4.4 Mobility Management Layer States 18.4.5 Connection Management (CM) and Service Request 18.4.6 Mobility Pattern of UE 18.5 RRC Layer 18.5.1 Functions and Procedures of RRC Layer 18.5.2 System Information (SI) Broadcast 18.5.3 RRC Layer States 18.5.4 RRC INACTIVE State 18.5.5 Mobility of UE 18.5.5.1 UE Mobility in RRC IDLE State 18.5.5.2 UE Mobility in RRC INACTIVE State 18.5.5.3 UE Mobility in RRC CONNECTED State 18.5.6 Admission Control Chapter Summary Chapter 19 5G NR Air Interface: User Plane Protocols Introduction 19.1 NR User Plane Protocol Layers 19.2 SDAP Layer 19.3 PDCP Layer 19.4 RLC Layer 19.5 MAC Layer 19.5.1 Functions and Procedures 19.5.2 Scheduling Procedure 19.5.3 Random Access Procedure 19.5.4 Error Correction Through HARQ Procedure 19.5.5 Buffer Status Reporting (BSR) Procedure 19.5.6 Scheduling Request (SR) Procedure 19.5.7 Low Latency in the NR Due to Configured Scheduling 19.5.8 MAC Layer PDU and Header Structures 19.5.9 How MAC Layer Ensures Low-Latency Requirements 19.5.10 Channel Structures in NR 19.6 Physical Layer 19.6.1 Principles of Transmissions and Its Directions 19.6.2 Physical Layer Functions, Procedures, and Services 19.6.3 OFDM Symbol 19.6.4 NR Frame and Slot Format 19.6.4.1 Subcarrier Spacing (SCS)/Numerologies (μ) 19.6.4.2 Slots per NR Frame and Subframe 19.6.4.3 Slot Formats in TDD Mode 19.6.4.4 Dynamic TDD 19.6.5 Resource Grid and Resource Block 19.6.5.1 Control Resource Set (CORESET) 19.6.5.2 Common Resource Blocks (CRB) 19.6.5.3 Physical Resource Block (PRB) 19.6.5.4 Virtual Resource Block (VRB) 19.6.5.5 Interleaved and Non-interleaved PRB Allocation 19.6.5.6 PRB Bundling and VRB to PRB Mapping 19.6.5.7 Reference Point “A” 19.6.6 Channel and Transmission Bandwidths 19.6.7 Bandwidth Part (BWP) 19.6.7.1 Types of BWP 19.6.7.2 BWP Configuration 19.6.7.3 BWP Switching and Associated Delay 19.6.8 NR Resource Allocations 19.6.8.1 Frequency Domain Resource Allocation for FDD Transmission 19.6.8.2 Time-Domain Resources Allocation for FDD Transmission 19.6.8.3 Time-Domain Resources Allocation for TDD 19.6.9 Transport Channels and Their Processing Chain 19.6.9.1 CRC Calculation and its Attachment to a Transport Block 19.6.9.2 Code Block Segmentation 19.6.9.3 Channel Encoding with LDPC 19.6.9.4 Rate Matching and Concatenation 19.6.9.5 Multiplexing of UL-SCH Data and Uplink Control Information 19.6.9.6 LDPC Encoding Examples 19.6.10 Physical Channels and Their Processing Chain 19.6.10.1 Physical Channels 19.6.10.2 Channel Mappings 19.6.10.3 Multiple Physical Antenna Transmissions 19.6.10.4 Physical Channel Processing Chain 19.6.10.5 Physical Downlink Control Channel (PDCCH) 19.6.10.6 Physical Uplink Control Channel (PUCCH) and Information (UCI) 19.6.11 Code Block Group-Based Transmissions and Receptions 19.6.12 Physical Signals 19.6.12.1 Reference Signals Transmitted as Part of Physical Channels 19.6.12.2 Sounding Reference Signals 19.6.13 Downlink Synchronization 19.6.14 Millimeter Wave Transmission, Beamforming, and Its Management 19.6.15 Cell-Level Radio Link Monitoring (RLM) 19.6.16 RRM Measurements for UE Mobility 19.6.16.1 RRM Measurement Signals and Their Quantities 19.6.16.2 RRM Measurements Framework 19.6.16.3 Overall RRM Process 19.6.17 Channel State Information (CSI) 19.6.18 Modulation and Coding Schemes (MCSs) 19.6.19 Link Adaptation Procedure 19.6.20 Random Access (RACH) Procedure 19.6.21 NR Radio Resources Management (RRM) Procedure 19.6.22 UE Transmit Power Control 19.6.22.1 Types of Power Control Procedure in NR 19.6.22.2 UE Transmit Power Determination Procedure in NR 19.6.23 Effect of Physical Layer on Data Throughputs Chapter Summary Chapter 20 5G Core Network Architecture Introduction 20.1 Control Plane and User Plane Separation – CUPS 20.1.1 Impacts of CUPS Feature 20.1.2 CUPS in the LTE/EPC Network 20.1.3 CUPS Feature in 5G Core Network 20.2 Service-Based Architecture (SBA) 20.2.1 Network Functions and Its Instances 20.2.2 Network Functions (NFs) and Their Services Interfaces 20.2.3 5G System Architecture with NF 20.2.4 Network Functions and Their Services and Operations 20.2.5 Network Functions Services Framework 20.2.6 Services API for Network Functions 20.2.7 Network Function Selection 20.3 Network Function Virtualization (NFV) Chapter Summary Chapter 21 5G System: Low-level Design Introduction 21.1 Design of 5GC Service Interface and Its Operations 21.2 Design of 5GC NF Service Interface Using UML and C++ Class Diagram 21.3 Usages of C++ Standard Template Library (STL) 21.4 Software Architecture for 5G System 21.4.1 NG-RAN Logical Nodes Software Architecture 21.4.2 5GC Software Architecture 21.5 Data Types Used in 5GC SBI Communications Chapter Summary Chapter 22 3GPP Release 16 and Beyond Introduction 22.1 5GS Enhancements as Part of Release 16 22.2 5GS New Features as Part of Release 16 22.3 3GPP Release 17 Chapter Summary Test Yourself! Introductions A.1 5G Mobile Communications and Systems Concepts A.2 Software Program Development Exercises A.2.1 Generic Utility and Re-Useable Software A.2.2 5G System Protocol Layer Development References Index EULA