5G Node Funtional Split - gNB , AMF, SMF, UPF

 Keeping it simple for clarity of understanding.
Let's consider as two part :

Part 1: NG-RAN  -->  gNB/ng-eNB
Part2 : 5GC          --> AMF, SMF, UPF

gNB/ng-eNB Functionality:

1. RRM - Radio Resource Magament 
2. Radio Bearer Control
3. Radio Admission Control 
4. Connetion Mobility Control
5. Dynamic Resource Allocation (Sceduling on UL and DL)
6. IP Header Compression , Encryption and Integrity Protection of Data
7. AMF Selection during Registration when no routing to AMF can be dterimied from the onformation provided by UE.
8. Rounting of user plane data towards UPF
9. Routing of Control plane Information towards AMF

AMF Functionalty:

1. Mobility Management 
2. Support Intra and Inter System Mobility
3. Registraion Area Managament 
4. Idle Mode UE Reachability
5. SMF Selection
6. NAS Signalling 
7. NAS and AS Security

SMF Functionality:

1. Session Mangement 
2. UE IP addrress allocation and management 
3. Downlink Data Notification
4. Selection and Control of User Plane Function 

UPF Funtionality:

1. Anchonr Point for Intra/Inter-RAT Mobility 
2. SDF to QoS flow mapping
3. Packet Routing and Forwarding
4. Packet inspection and User plane part of policy rule enforcement
5. Downlink packet buffering and downlink data notification triggering

Procedures for the 5G System : 23.502 Release 17

 

1. 4 --> System Procedure

a. 4.2 Connection , Registration and Mobility Management Procedures

i. 4.2.2 Registration Management procedures

1) 4.2.2.2 Registration procedures

a) 4.2.2.2.2 General Registration

b) 4.2.2.2.3 Registration with AMF re-allocation

c) 4.2.2.2.4 Registration with Onboarding SNPN 

(Standalone Non Public Network - Means Standalone Private NW)

2) 4.2.2.3 Deregistration procedures

a) 4.2.2.3.2 UE-initiated Deregistration

b) 4.2.2.3.3 Network-initiated Deregistration

ii. 4.2.3 Service Request procedures

1) 4.2.3.2 UE Triggered Service Request

2) 4.2.3.3 Network Triggered Service Request

iii. 4.2.4 UE Configuration Update

1) 4.2.4.2 UE Configuration Update procedure for access and mobility management related parameters

2) 4.2.4.3 UE Configuration Update procedure for transparent UE Policy delivery

iv. 4.2.5 Reachability procedures

v. 4.2.6 AN Release

vi. 4.2.7 N2 procedures

vii. 4.2.8 Void

viii. 4.2.8a UE Capability Match Request procedure

ix. 4.2.9 Network Slice-Specific Authentication and Authorization procedure

x. 4.2.10 N3 data transfer establishment procedure when Control Plane CIoT 5GS Optimisation is enabled

xi. 4.2.11 Network Slice Admission Control Function (NSACF) procedures

b. 4.3 Session Mangement Procedures

c. 4.4 SMF and UPF Interactions

d. 4.5 User Profile Management Procedures

e. 4.6 Security Procedures

f. 4.7 ME Identity Check Procedures

g. 4.8 RAN-CN Interactions

h. Handover Procedures

i. 4.10 NG-RAN Location reporting procedures

j. 4.11 System interworking procedures with EPC

k. 4.12 Procedures for Untrusted non-3GPP access

l. 4.12a Procedures for Trusted non-3GPP access

m. 4.12b Procedures for devices that do not support 5GC NAS over WLAN access

n. 4.13 Specific services

o. 4.14 Support for Dual Connectivity

p. 4.15 Network Exposure

q. 4.16 Procedures and flows for Policy Framework

r. 4.17 Network Function Service Framework Procedure

s. 4.18 Procedures for Management of PFDs

t. 4.19 Network Data Analytics

u. 4.20 UE Parameters Update via UDM Control Plane Procedure

v. 4.21 Secondary RAT Usage Data Reporting Procedure

w. 4.22 ATSSS Procedures

x. 4.23 Support of deployments topologies with specific SMF Service Areas

y. 4.24 Procedures for UPF Anchored Data Transport in Control Plane CIoT 5GS Optimisation

z. 4.25 Procedures for NEF based Non-IP Data Delivery

aa. 4.26 Network Function/NF Service Context Transfer Procedures

bb. 4.27 Procedures for Enhanced Coverage Restriction Control via NEF

2. 5 --> Network Function Procedure

a. 5.1 Network Function Service framework procedures

b. 5.2 Network Function services