3GPP 23.501 v20.2.0 — the document's own text

4.2.2 Network Functions and entities

Taught in 3. The shape of the 5G core (The 5G system architecture, in depth), 1. What this document actually describes (The 5G system architecture, overview), 2. Who does what in the core (The 5G system architecture, overview), 2. The pieces a 5G core is made of (The 5G system architecture, quick start).

The 5G System architecture consists of the following network functions (NF):

Authentication Server Function (AUSF).
Access and Mobility Management Function (AMF).
Data Network (DN), e.g. operator services, Internet access or 3rd party services.
Unstructured Data Storage Function (UDSF).
Network Exposure Function (NEF).
Network Repository Function (NRF).
Network Slice Admission Control Function (NSACF).
Network Slice-specific and SNPN Authentication and Authorization Function (NSSAAF).
Network Slice Selection Function (NSSF).
Policy Control Function (PCF).
Session Management Function (SMF).
Unified Data Management (UDM).
Unified Data Repository (UDR).
User Plane Function (UPF).
UE radio Capability Management Function (UCMF).
Application Function (AF).
User Equipment (UE).
(Radio) Access Network ((R)AN).
5G-Equipment Identity Register (5G-EIR).
Network Data Analytics Function (NWDAF).
CHarging Function (CHF).
Time Sensitive Networking AF (TSN AF).
Time Sensitive Communication and Time Synchronization Function (TSCTSF).
Data Collection Coordination Function (DCCF).
Analytics Data Repository Function (ADRF).
Messaging Framework Adaptor Function (MFAF).
Non-Seamless WLAN Offload Function (NSWOF).

NOTE: The functionalities provided by DCCF and/or ADRF can also be hosted by an NWDAF.

The 5G System architecture also comprises the following network entities:

The functional descriptions of these Network Functions and entities are specified in clause 6.