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

Day 1

1. Introduction and Ecosystem Overview

• Diverse perspectives on the 5G standard: business, standardization, implementation, transport, RAN, Core, and DevOps.

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

• Continuity across mobile network generations: seamless transition from 4.5G to 5G via 3GPP Releases 15–17.

2. IMT-2020 Vision

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

• Constraints of 4G/LTE, limited EPC flexibility, and transport network hurdles.

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

• General system requirements defining the 5G network framework.

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

3. Physical Foundations of UE Communication with NG-RAN

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

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

• Connection establishment: RACH (Msg 1-4), Paging, and RRC.

4. NG-RAN Architecture

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

• Options for Functional Split and their respective implications.

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

• Distinct separation of Control Plane and User Plane.

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

5. NG-RAN Mechanisms and Procedures

• PDCP and Radio Bearers.

• Measurement processes: configuration, reporting, and application in other procedures.

• RRC Reconfiguration as a central 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 dispelling the "just cables" misconception: IP/MPLS as a foundational technology.

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

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

• Distribution and synchronization of time and phase for radio transmission utilizing PTP (IEEE 1588).

2. Inside the SBA Architecture as the 5GC Foundation

• Conventional IT stack elements: HTTP/2, JSON, and OAuth2.

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

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

• NRF as the primary coordinator: Service Registration and Service Discovery.

• (Conceptual Overview) Stateless architecture and state retention 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 point for the Control Plane (termination and demultiplexing of NAS and NGAP signaling).

• UPF as the core of the User Plane: 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.

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

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

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

5. Network Slicing

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

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

• Introduction to MEC, Uplink Classifier (UL CL) / 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 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 correctness: Success Ratio, Failure Ratio, and absolute vs. percentage values.

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

• Data normalization 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 determine root causes of failures.

5. Chaos Engineering and Troubleshooting

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

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

• Intentional failure injection and observing failover behavior.

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