24.5013GPPNon-Access-Stratum (NAS) protocol for 5G System (5GS)Release 18Stage 3TS
Three types of 5GSM procedures can be distinguished:
a) Procedures related to PDU sessions:
These procedures are initiated by the network and are used for authentication and authorization or manipulation of PDU sessions:
1) PDU authentication and authorization;
2) network-requested PDU session modification;
3) network-requested PDU session release; and
4) service-level authentication and authorization.
This procedure is initiated by the UE and to request for establishment of PDU sessions or to perform handover of an existing PDU session between 3GPP access and non-3GPP access, or to transfer an existing PDN connection in the EPS to the 5GS:
UE-requested PDU session establishment.
b) Transaction related procedures:
These procedures are initiated by the UE to request for handling of PDU sessions, i.e. to modify a PDU session, or to release a PDU session:
1) UE-requested PDU session modification; and
2) UE-requested PDU session release.
This procedure is initiated by the 5G ProSe UE-to-network relay UE and is used for the manipulation of PDU sessions:
– remote UE report.
A successful transaction related procedure initiated by the UE triggers the network to execute one of the following procedures related to PDU session; network-requested PDU session modification procedure or network-requested PDU session release procedure. The UE treats the start of the procedure related to the PDU session as completion of the transaction related procedure.
c) Common procedure:
The following 5GSM procedure can be related to a PDU session or to a procedure transaction:
5GSM status procedure.