5G Mobile Core Network: Design, Deployment, Automation, and Testing Strategies

Table of Contents
About the Authors
About the Technical Reviewer
Acknowledgments
Introduction
Chapter 1: 5G Overview
	A History of Mobile Communication
	Standards and Evolution of 5G
	Evolution to 5G and Overview of 5G Standalone Network
	Key Concepts in 5G
		Data Network Name
		Packet Data Unit Session
		Subscription Permanent Identifier
		5G Globally Unique Temporary Identifier
		QoS Model in 5G Core
		New Radio
		Access and Mobility Function
		Session Management Function
		User Plane Function
		Policy Control Function
		Charging Function
		Authentication Server Function
		Unified Data Management
		Unified Data Repository
		Network Slice Selection Function
		Network Repository Function
		Service-Based Architecture
	NRF: The Network Repository Function
		Service Communication Proxy
		Network Exposure Function
		Security Edge Protection Proxy
		Application Function
	REST and HTTP2 Methods
		What is REST?
			Client-Server
			Stateless
			Cacheable
			Layered System
			Uniform Interface
		Service-Based Interface in 5GC
			Types of 3GPP API-Based Communication
				Request/Response
				Request/Response with Notification
				Subscribe/Notify
	PDU Session Establishment
Chapter 2: Multi-Access Edge Computing in 5G
	MEC Architecture
	MEC Deployment
	Multi-Access Edge Computing in 5G
		Connectivity Models for Edge Computing
			Distributed Anchor Point
			Session Breakout
			Multiple PDU Sessions
		Key Challenges with MEC
			Selection of an Optimal Edge Application Server
			Edge Relocation
			Network Information Provisioning to Local Applications with Low Latency
			Consecutive Traffic Steering in Different N6-LAN
			Activating the Traffic Routing Toward Local Data Network per AF Request
		Solutions
			Provisioning URSP config to the UE to Establish PDU for Edge Applications
			Local DNS-Based Edge Server Address Discovery
			DNS Application Function
			Discovery of Edge Application Server Based on DNS
			SMF Selection Based on DNAI
	MEC Toolkit for 5GC
		Uplink Classifier Branching Point
		Mobility with ULCL
		IPv6 Multi-Homing
		Session and Service Continuity
			SSC Mode 1
			SSC Mode 2
			SSC Mode 3
			Selection of Session and Service Continuity Mode
		Application Function Influence on Traffic Routing
Chapter 3: 5G NSA Design and Deployment Strategy
	Evolution of the Network from 4G to 5G Non-Standalone
	Dual Connectivity
		New Radio Dual Connectivity
		Multiple Radio Access Technology Dual Connectivity
	Architecture
	Migration Options
		Option 3/3a/3x
		Option 3a
		Option 3x
		Option 3
	Control and User Plane Separation
		CUPS Architecture
		Legacy-Based NSA and CUPS-Based NSA
			NSA on Legacy vs CUPS
			Co-Located CUPS
			Remote CUPS
	NSA Call Flows
	Deployment Considerations
		Device Strategy and Access Point Name Planning
		Gateway Node Selection
		User Plane Selections
		Challenge 1: No Dedicated Gateway Reserved in the Network for 5G NSA Users
		Multi-Access Edge Computing Strategy for NSA
		Role of Automation
		Role of Analytics
		Radion Access Network and Transport Implications
		QoS and Charging in NSA
		Challenge 2: Non-Adaptive IP Pool Allocation
			Adaptive IP Pool Chunk Allocation
			Enable CUPS Control Plane with Adaptive IP Chunk Size Ramp-Down Procedure
			Enable CUPS Control Plane with Adaptive IP Chunk Size Ramp-Up Procedure
		Challenge 3: Frequent Secondary Node Addition and Deletion Can Cause Bad Quality of Experience and Signaling Storm
			Secondary Node Addition Criteria:
			Secondary Node Deletion Criteria
		Redundancy
		Lawful Intercept Implications
Chapter 4: 5G SA Packet Core Design and Deployment Strategies
	5G Core Network Introduction
	Design Considerations for a 5G Core Network Deployment
		Devices
		5G SA Slicing Considerations
			Single-Network Slice Selection Assistance Information
			NSI-ID
			NSSF’s Role in Network Slice Selection
				Dimensioning
				Network Functions Planning per Slice
				Slice Orchestration and Lifespan
		Node Selection
			AMF Selection by 5G Access Node (gNB)
			AMF Selection by Another AMF to Forward Requests from gNB
			NRF Selection
			AUSF/UDM Selection by AMF
			SMF Selection by AMF
			SMF Selection by MME
			PCF Selection by AMF
			PCF and CHF Selection by the SMF
			UPF Selection by SMF
			UPF Selection Logic for UE Mobility
		Interworking with 4G/5G NSA
			N26-Based Interworking
			Interworking Without N26
			Impact Analysis on EPC due to N26 Interface
				MME
				DNS
				SGW
			4G/5G Interworking Design Considerations
				Solution: UE Capability Subscription and APN Mapping
			Voice and Emergency Services Support/Design in 5G
				Voiceover NG-RAN (VoNR)
				EPS Fallback for Voice
				Emergency Voice Service
				Emergency Services Using EPS Fallback
		Redundancy Considerations
			Control Plane NF Resiliency
				Service Redundancy
				SBI-Based Interfaces Redundancy
				No Failure Scenario
				Failure Scenario
				Non-SBI Interface Redundancy (e.g., GTP/PFCP/SCTP)
				No Failure Scenario
				Failure Scenario
				Node Failure Detection and Handling
				NRF Failure Detection and Handling
				Geographical Redundancy
			User Plane Redundancy Considerations
				1:1 Redundancy
				Trigger and Switchover
				N:M Redundancy
				Fallback to Local Configuration
				Overload Protection
Chapter 5: 5G Packet Core Testing Strategies
	Automation Level in Testing
		Manual Testing
		Semi-Automated Testing or Automated Assisted Testing
		Fully Automated Testing
	Release Strategies for 5G SA Core Network
		Component Type Approach
		Release-Centric Approach
		CI/CD Centric Approach for 5G Delivery
			Pipeline
			Code Repository (git)
			Artifactory
			Static Code Analysis
			Quality Gate
	5G SA Testing Framework
		5G SA Testing Type
		Functional Testing
			Unit Testing
			API Testing
			Integration Testing
		Non-Functional Testing
			Performance/Scale Testing
				Signaling Performance Testing
				Data Throughput Performance
				Long Duration Tests
				Latency Tests
				Component-Based Performance Testing
				System Use-Case-Based Performance Testing
			Call Models
			Alpha and Beta Testing
			Production Validation
		Security Testing
		5G NSA Core Network Testing
		Testing Integration Points between 5G SA
		Impact Changes to be Tested in 5G
		Redundancy Testing in 5G
			Node/NF Failure Testing
			Platform Failure Testing
	Monitoring and Troubleshooting
		Host-Level Monitoring
		Container and Cluster Monitoring
		Application/NF Monitoring
	Distributed Tracing
Chapter 6: Automation in 5G
	Network Slicing in 5G
	Fundamental Requirements for Slicing Automation
	Automation for a 5G Packet Core
		Infrastructure
		Deployment
		Function
		Configuration
		5G Abstraction
	End-to-End Slice Automation and Management
		Communication Service
		Network Slice Instance
		Network Slice Subnet Instance
		Network Slice Instance Lifecycle
			Preparation Phase
			Instantiation, Configuration, and Activation Phase
			Run-Time Phase
			Decommissioning Phase
	Service Orchestration Solution
	Service Assurance in 5G
Chapter 7: Architectural Considerations by Service Providers
	Enhanced Service-Based Architecture
		NF Set and NF Service Set
			NF Set
			NF Service Set
			Service Binding
				NF Set Binding
				NF Service Set Binding
		Indirect Communication
			Indirect Communication Without Delegated Discovery
			Indirect Communication with Delegated Discovery
			Failure Handling with NF Service Set and Indirect Communication Without Delegated Discovery
			Failure Handling with NF Service Set and Indirect Communication with Delegated Discovery
			Benefits of Indirect Communication
	5G Policies
		Choosing the SM-PCF, AM-PCF, and UE-PCFs
		Access and Mobility-Related Policy Control
			Service Area Restriction Management
			RAT Frequency Selection PriorityFunctionality Management
			UE Aggregated Maximum Bit Rate Management
			AM and UE Policy Triggers
		UE Policy Control
			Access Network Discovery and Selection Policy
			UE Route Selection Policy
		Session Management Policy Control
		QoS Negotiation
		Local Area Data Network
	Non-Public 5G (Private Network)
		Deployment of Non-Public 5G Network
		Standalone Non-Public Network
		Public Network Integrated NPN
		Key Notes
Index