IMT and 5G Network Lifecycle: Architecture, Design, Deployment, and Operations Training Course

Day 1

1. Introduction and Ecosystem Overview

• Multi-faceted perspectives on the 5G standard: business, standardisation, implementation, transport, RAN, Core, and DevOps.

• Clarifying related concepts: 5G, IMT-2020, NG-RAN, NR, 5GC, and 5GS.

• The continuity of mobile generations: seamless evolution from 4.5G to 5G within 3GPP Releases 15–17.

2. IMT-2020 Vision

• The UE as a catalyst for change and a source of new requirements: broadening the definition of UE to encompass IoT/mMTC (sensors), RedCap devices (cameras), and UAVs (drones).

• Limitations of 4G/LTE, the inflexibility of the EPC, and challenges in transport networks.

• Advanced requirements for eMBB, URLLC, and mMTC: use cases and their impact on RAN and Core.

• General system requirements defining the 5G network.

• Transverse capabilities: Network Slicing, 5QI, CUPS, Multi-access Edge Computing (MEC), and Privacy by Design.

3. Physical Foundations of UE Communication with NG-RAN

• Fundamental radio concepts: Cell, Band, and Channel Width.

• Basics of UE network access: radio protocol stack, MIB/SIB, Cell Selection mechanisms, and the Physical Layer.

• Establishing connections: RACH (Msg 1-4), Paging, and RRC.

4. NG-RAN Architecture

• Logical division of the gNB into CU and DU components.

• Functional split options and their respective implications.

• O-RAN as an alternative and reference framework for RAN interoperability standards.

• Separation of the Control Plane and User Plane.

• The RRC protocol and its role in coordinating UE operations within NG-RAN and NAS tunneling.

5. NG-RAN Mechanisms and Procedures

• PDCP and Radio Bearers.

• Measurements: configuration, reporting, and their utilisation in other procedures.

• RRC Reconfiguration as a critical procedure for all NG-RAN operations.

• Carrier Aggregation and Band Combination.

• The role of the AMF in NG-RAN coordination and the NGAP protocol.

• Handover procedures.

Day 2

1. Transport Network Foundations

• The complexity of transport engineering and debunking the 'just cables' myth: IP/MPLS as a core technology.

• Segmentation into Fronthaul, Midhaul, and Backhaul: requirements, expectations, and applications (including eCPRI).

• Mapping 5QI from the 5GS domain to IP router QoS.

• Distribution and synchronisation of time and phase for radio transmission using PTP (IEEE 1588).

2. Inside the SBA Architecture as the 5GC Foundation

• The classic IT stack: HTTP/2, JSON, and OAuth2.

• Communication mechanisms for Core Network Functions: Request-Response versus Subscribe-Notify.

• Key NFs from the perspective of access handling and traffic termination from NG-RAN: NRF, AMF, SMF, and UPF.

• The NRF as the central coordinator: Service Registration and Service Discovery.

• (Conceptual Overview) Stateless architecture and storing state for any NF using UDSF.

• (Conceptual Overview) Load balancing and proxy mechanisms via SCP.

3. Data Path and User Plane Separation

• Data flow from UE to 5GC: correlating NG-RAN interfaces (N2, N3) with NFs (AMF, SMF, UPF).

• AMF as the entry gateway for the Control Plane (termination and demultiplexing of NAS and NGAP signaling).

• UPF as the User Plane core: implementation of user data routing and GTP-U tunnel encapsulation.

• PDU Session Establishment call flow: End-to-End Call Flow including QoS Flow allocation.

• N4 interface (PFCP protocol), TEID allocation, and rules (PDR, FAR) linking radio traffic to external Data Networks (DN).

4. Subscription Management, Identity, and Service Policies

• Databases: UDR for structured data and UDM for subscriber processing logic.

• The 5G-AKA authentication process involving AUSF, NAS key exchange, and the SUCI mechanism.

• PCF as the policy manager and distributor: session, mobility, and SLA policies.

• Binding PDU sessions to PCF instances via BSF—a key feature for IMS/VoNR.

5. Network Slicing

• Introduction to Network Slicing and the setup of the S-NSSAI parameter identifier.

• Selection mechanisms for AMF and SMF instances based on service profiles via NSSF.

• Introduction to MEC, Uplink Classifier (UL CL), and Branching Point in UPF.

6. External 5GC Exposure and APIs

• SEPP for securing roaming traffic.

• Non-3GPP access: subscriber traffic originating outside NG-RAN via N3IWF.

• Exposure and integration with external Application Functions (AF) via NEF.

7. Analysis of Selected End-to-End Scenarios

• Initial Registration and PDU Session Establishment: querying NRF, AUSF credentials, and retrieving subscriptions from UDM and policies from PCF.

• Path Switch Request and UPF relocation procedure for active sessions during Inter-gNB handover.

• Uplink Classifier (UL CL) mechanism at UPF and SMF levels for MEC scenarios and Local Breakout (LBO) routing.

• Paging and Network Triggered Service Request waking up the UE on UPF initiative in response to downlink traffic.

Day 3

1. Transitional Architecture

• Overview of EPC and E-UTRAN architectures.

• 5G deployment options (Standalone SA and Non-Standalone EN-DC).

2. Coexistence of 5GS and EPS

• EPS Fallback and Redirect mechanisms.

• Hybrid implementations (PGW-C+SMF and PGW-U+UPF).

• N26 interface for Inter-System Handover procedures between MME and AMF.

• Analysis of EN-DC as the predominant variant of MR-DC (Multi-RAT Dual Connectivity).

• DSS (Dynamic Spectrum Sharing) as a spectrum-sharing mechanism.

3. Telemetry, Counters, and Data Correlation

• Monitoring phenomena via Counters and aggregating them into KPIs.

• Approaches to evaluating procedure accuracy: Success Ratio, Failure Ratio, and absolute versus percentage values.

• Event correlation: tracking complex procedures that lack dedicated counters.

• Data normalisation and a broader perspective on orders of magnitude.

4. Anomaly Diagnostics and Log Analysis

• Identifying issues indicative of software or configuration errors (e.g., 'Sleeping Cell').

• Statistical deviations and mapping Cause Values from 3GPP protocols to identify the root causes of failures.

5. Chaos Engineering and Troubleshooting

• Fundamentals of managing an open-source 5GC implementation in a dev/cloud environment.

• Testing the Cloud-Native paradigm: replacing core microservice elements without interrupting operations.

• Intentional failure injection and observing failover behaviour.

• Simulating NG-RAN degradation and correlating logs on the AMF side.