E.4 IP-CAN type change Notification for a MA PDU session

29.2143GPPPolicy and charging control over Rx reference pointRelease 17TS

If the AF has successfully subscribed to change notifications in UE’s IP-CAN type and RAT type, the ATSSS feature is supported and the PDU session is a MA PDU session:

– if the PCF previously requested to the SMF to be updated with access type changes, the PCF shall include in the AAA command:

i. the IP-CAN-Type AVP, RAT-Type AVP (if applicable) for the UE’s IP-CAN/RAT type values; and

ii. if both, 3GPP and non-3GPP access information is available, the additional IP-CAN type information and RAT type information (if available) in the MA-Information AVP;

– otherwise, the PCF shall subscribe to access type changes as described in clause 4.2.6.4 of 3GPP TS 29.512 [57] and shall send an RAR command when the corresponding IP-CAN event occurs, i.e.:

a) when a UE’s IP-CAN type or RAT type (if applicable) changes; or

b) a new IP-CAN type and RAT type (if applicable) become available for the UE and the MA PDU session; or

c) an IP-CAN type and RAT type (if applicable) become unavailable (are released) for the UE and the MA PDU session.

The RAR from the PCF shall include the Specific-Action AVP for the subscribed event and:

a. if it is the first IP-CAN change report:

i. the IP-CAN-Type AVP, RAT-Type AVP (if applicable) for the UE’s IP-CAN/RAT type values; and

ii. if both, 3GPP and non-3GPP access information is available, the additional IP-CAN type information and RAT type information (if available) in the MA-Information AVP;

b. if it is a subsequent IP-CAN change report:

i. if a new IP-CAN type is added to the MA PDU session, the MA-Information AVP with the added IP-CAN type information encoded in the IP-CAN-Type AVP and the RAT type information encoded within the RAT-Type AVP if applicable;

ii. if an IP-CAN type is released in the MA PDU session, the MA-Information AVP with the released IP-CAN type information encoded in the IP-CAN-Type AVP, the RAT type information encoded within the RAT-Type AVP, if applicable, and the MA-Information-Action AVP set to 1 (RELEASE).

NOTE: For a MA PDU session, if the ATSSS feature is not supported by the AF the PCF includes the IP-CAN-Type AVP and the RAT-Type AVP with a currently active combination of IP-CAN type and RAT type (if applicable for the notifed access type). When both 3GPP and non-3GPP accesses are available, the PCF includes the information corresponding to the 3GPP access.