4.2.7 Npcf_PolicyAuthorization_Unsubscribe service operation

29.5143GPP5G SystemPolicy Authorization ServiceRelease 18Stage 3TS

4.2.7.1 General

The Npcf_PolicyAuthorization_Unsubscribe service operation enables NF service consumers to remove subscription to all subscribed events for the existing application session context. Subscription to events shall be removed:

– by invoking the Npcf_PolicyAuthorization_Unsubscribe service operation for the existing application session context, as described in clause 4.2.7.2; or

– within the application session context modification procedure by invoking the Npcf_PolicyAuthorization_Update service operation, as described in clause 4.2.3; or

– within the application session context termination procedure by invoking the Npcf_PolicyAuthorization_Delete service operation, as described in clause 4.2.4.

The following procedure using the Npcf_PolicyAuthorization_Unsubscribe service operation is supported:

– Unsubscription to events.

4.2.7.2 Unsubscription to events

This procedure is used to unsubscribe to all subscribed events for the existing AF application session context, as defined in 3GPP TS 23.501 [2], 3GPP TS 23.502 [3] and 3GPP TS 23.503 [4].

Figure 4.2.7.2-1 illustrates the unsubscription to events using the HTTP DELETE method.

Figure 4.2.7.2-1: Removal of events subscription information using HTTP DELETE

When the NF service consumer decides to unsubscribe to all subscribed events for the existing application session context, the NF service consumer shall invoke the Npcf_PolicyAuthorization_Unsubscribe service operation by sending the HTTP DELETE request message to the resource URI representing the "Events Subscription" sub-resource in the PCF, as shown in figure 4.2.7.2-1, step 1.

Upon the reception of the HTTP DELETE request message from the NF service consumer, the PCF shall decide whether the received HTTP request message is accepted.

If the HTTP DELETE request message from the NF service consumer is accepted, the PCF shall delete "Events Subscription" sub-resource and shall send to the NF service consumer a HTTP "204 No Content" response message. The PCF may delete the existing subscription to event notifications for the related PDU session from the SMF as described in 3GPP TS 29.512 [8].

If the HTTP DELETE request message from the NF service consumer is rejected, the PCF shall indicate in the HTTP response message the cause for the rejection as specified in clause 5.7.