B.11 Handling of MCVideo priority call

29.5143GPP5G SystemPolicy Authorization ServiceRelease 18Stage 3TS

B.11.1 General

Within the framework of MCVideo, when the SIP Core (3GPP TS 23.281 [34]) is implemented by an IMS core network, if the P-CSCF receives a SIP request message including a Resource-Priority header field with a namespace field and priority value defined for MCVideo for adjusting the priority of an MCVideo session, the P-CSCF shall provide the "resPrio" attribute and the "mcVideoId" in the Npcf_PolicyAuthorization_Create request as defined in clause B.15.2 to allow the PCF to set the corresponding PCC rule(s) according to the prioritized MCVideo service.

NOTE 1: The process of adjusting priority may occur several times during the course of one session, e.g. a normal MCVideo group call elevated to an MCVideo emergency group call and returned to a normal priority MCVideo group call, elevated to an MCVideo imminent peril group call and returned to a normal priority MCVideo group call.

NOTE 2: Upon reception of a request that requires the adjustment of the MCVideo priority, the PCF is expected to derive the PCC Rules corresponding to the this MCVideo session, as appropriate according to operator policies.

NOTE 3: The PCF can identify an MCVideo call using the IMS Communication Service Identifier specific to MCVideo, which is provided by the P-CSCF in the "afAppId" attribute in the Npcf_PolicyAuthorization_Create request sent to PCF.

B.11.2 Determination of MCVideo priority parameter values

When the P-CSCF receives an authorized Resource-Priority header field containing an appropriate namespace and priority value used for MCVideo in SIP signalling, the P-CSCF shall include the "mcVideoId" attribute and the "resPrio" attribute in the corresponding Npcf_PolicyAuthorization service operation towards the PCF.

The "mcVideoId" attribute shall include the namespace defined for MCVideo as received within the Resource-Priority header field.

The "resPrio" attribute shall contain the priority value of the Resource-Priority header; the lowest priority shall be mapped to PRIO_1 (Resource-Priority header value 0), the next after the lowest to PRIO_2 (Resource-Priority header value 1), and so on up to the highest priority which shall be mapped to PRIO_16 (Resource-Priority header value 15).