5G NG-RAN Signalling

CONTENTS

The course provides a technical description of layer 3 protocols and signaling procedures defined for the 5G radio access ('New Radio, NR') and radio access network ('NG-RAN') as defined by 3GPP standards. A chapter on NR layer 2 protocols is also included to complete the picture.

The course uses a top-down approach starting with a high level description of the functionality of different network entities and the interaction needed between on different interfaces. The layer 3 protocols are then discussed one by one in detail in a logical scenario-based sequence. A number of detailed message-by-message signaling sequences will be presented during the course to tie everything together.

Protocols and signaling procedures related to the 5GC-internal Service Based Architecture are mentioned but not covered in any detail.

PREREQUISITES

Basic knowledge of 5G network architecture and functions is highly recommended but not compulsory. Reasonably good technical knowledge of protocols and signaling within LTE/EPC is beneficial.

NOTE: This course is not delivered with the FoldOut methodology.

5G System Overview

• 5G System (5GS) network nodes and interfaces
• CP and UP protocol stacks
• 5G Releases (3gpp)

Non-Access Stratum Protocols (NAS)

• 5GS NAS protocols
• NAS states and state transitions
• 5G Mobility Management (5GMM) procedures
• 5GS security architecture
• 5G Session Management (5GSM) procedures
• 5GS QoS framework

Radio Resource Control Protocol (RRC)

• RRC procedure summary
• System Information
• RRC states and state transitions
• RRC Connection Establishment
• UE capability handling
• Configuration of SRBs and DRBs

NR Layer 2 Protocols

• NR protocol stack and channel architecture
• Service Data Adaptation Protocol (SDAP)
• Packet Data Convergence Protocol (PDCP)
• Radio Link Control Protocol (RLC)
• Medium Access Control Protocol (MAC)

NG-RAN Protocols

• Protocol stacks for NG/Xn/F1/E1 interfaces
• NG Application Protocol (NGAP) procedures
• Xn Application Protocol (XnAP) procedures
• F1 Application Protocol (F1AP) procedures
• E1 Application Protocol (E1AP) procedures

LTE/NR Interworking

• Interworking architecture
• LTE-NR Idle mode mobility
• Multi-Radio Dual Connectivity (MR-DC)
• Non Stand Alone NR (EN-DC)

Signaling Flows

A number of important message-by-message signaling flows will be presented during the course. Some examples are 5GS Registration, PDU Session Establishment, Service Request, RNA Update, Handover and EN-DC Setup.