24.5013GPPNon-Access-Stratum (NAS) protocol for 5G System (5GS)Release 17Stage 3TS
The PCF may provide the UE with one or more UE policies using the network-requested UE policy management procedure. The UE provides the PCF with a list of one or more stored UE policy section identifiers (UPSIs), and the PCF provides each UE policy using one or more UE policy sections, each identified by a UPSI. The UPSI is composed of two parts:
a) a PLMN ID part containing:
1) the PLMN ID for the PLMN; or
2) the PLMN ID part of the SNPN identity for the SNPN;
of the PCF which provides the UE policies; and
b) a UE policy section code (UPSC) containing a value assigned by the PCF.
The UE processes the UE policy sections, each identified by the UPSI, received from the PCF and informs the PCF of the result.
The UE provides the PCF with the UE policy related capabilities such as the UE’s support for ANDSP and the UE’s OS Id.
The UE can also request the PCF to provide V2XP as specified in 3GPP TS 24.587 [19B].
The UE can also request the PCF to provide ProSeP as specified in 3GPP TS 24.554 [19E].
D.1.2 Principles of PTI handling for UE policy delivery service procedures
When the PCF or the UE initiates a procedure, it shall include a valid PTI value in the message header of the command message or the request message. When the UE initiates a procedure, the UE shall use a PTI value in range between 01H and 77H. When the PCF initiates a procedure, the PCF shall use a PTI value in range between 80H and FEH.
When the PCF initiates a transaction related procedure (i.e. a procedure consisting of more than one message and the messages are related), it shall include a valid PTI value in the message header of the command message.
If a response message is sent as result of a received command or request message, the UE or the PCF shall include in the response message the PTI value received within the received command or request message (see examples in figure D.1.2.1, figure D.1.2.2 and figure D.1.2.3).
If a command message is sent as result of a received request message, the PCF shall include in the command message the PTI value received with the request message (see examples in figure D.1.2.3).
Figure D.1.2.1: Network-requested transaction related procedure
Figure D.1.2.2: UE-requested transaction related procedure rejected by the network
Figure D.1.2.3: UE-requested transaction related procedure triggering a network-requested transaction related procedure
NOTE: In earlier versions of this protocol, the UE can include in the response message a PTI value which is not the same as the one received within the command message, and therefore the PCF could not associate the response message from the UE to the command message sent.