Step 1.
The UE Policy Association is established, as described in
clause 4.16.11.
Step 2.
If the (H-)PCF indicates the UE to send reporting of URSP rule enforcement as described in
clause 6.6.2.4 of TS 23.503, then depending on operator policies in the (H-)PCF, the (H-)PCF may subscribe to the BSF, then step 3 follows, or provides its PCF binding information to the AMF in step 1 with the indication to be notified about the PCF for the PDU Session for a UE, then step 4 follows.
Step 3.
The (H-)PCF for the UE determines that URSP rules depend on the UE reporting of URSP rule enforcement, it then subscribes to the BSF to be notified when a PCF for the PDU Session for this SUPI is registered in the BSF, by invoking Nbsf_Management_Subscribe (SUPI; DNN). Steps 4 and 5 are repeated for each PCF registered for a PDU Session to a SUPI included in the Nbsf_Management.
Step 4.
The (H-)SMF establishes a SM Policy Association as described in
clause 4.16.4. The allocated UE address/prefix, SUPI, DNN, S-NSSAI and the PCF address is registered in the BSF, as described in
clause 6.1.1.2.2 of TS 23.503. The SMF may provide the PCF binding information (address(es) of PCF for UE, instance id of PCF for UE) which receives from AMF to the PCF for session during SM Policy Association establishment procedure. If the (H-)SMF has received UE report of URSP rule enforcement via PDU session establishment as described in
clause 4.3.2 (step 4), it includes the received traffic information in the SM Policy Association establishment request.
Step 5a.
If the (H-)PCF for the UE subscribed to the BSF in step 3, then the BSF notifies that a PCF for the PDU Session is registered in the BSF, by invoking Nbsf_Management_Notify (UE address(es), PCF address, PCF instance id, PCF Set ID, level of binding). When there are multiple PDU Sessions to the same UE the BSF provides multiple notification to the PCF.
Step 5b.
If the (H-)PCF for the UE sent the request to notify that a PCF for the PDU Session is available to the AMF in step 1, then the PCF for the PDU Sessions sends Npcf_PolicyAuthorization_Notify (EventID set to SM Policy Association established, UE address, PCF address, PCF instance is, PCF Set ID) to the PCF indicated in the PCF binding information provided by the SMF.
Step 6.
The (H-)PCF for the UE subscribes to notifications of event
"UE reporting Connection Capabilities from associated URSP rule" as defined in
clause 6.1.3.18 of TS 23.503, using
Npcf_PolicyAuthorization_Subscribe (EventId set to
"UE reporting Connection Capabilities from associated URSP rule", EventFilter set to at least
"list of Connection Capabilities") and immediate reporting flag set to the PCF for the PDU Session. The response includes the NotificationCorrelationId and any Connection Capabilities if already available at the PCF for the PDU Session.
Step 7.
If not already installed, the PCF installs the Policy Control Request Trigger to detect "UE reporting Connection Capabilities from associated URSP rule" in the SMF.
Step 8.
When the (H-)SMF receives a UE report of URSP rule enforcement via PDU session modification as described in
clause 4.3.3 (step 8a) and the Policy Control Request Trigger is met, it then reports the received traffic information to the PCF serving the PDU Session, by invoking
Npcf_SMPolicyControl_Update as defined in
clause 6.1.3.5 of TS 23.503 (step 8b).
Step 9.
The (H-)PCF for the UE is notified on the
"UE reporting Connection Capabilities from associated URSP rule" by
Npcf_PolicyAuthorization_Notify (NotificationCorrelationId, EventId set to
"UE reporting Connection Capabilities from associated URSP rule", EventInformation including the Connection Capabilities) as defined in
clause 6.1.3.18 of TS 23.503.
Step 10.
The (H-)PCF for the UE checks operator policies and then may make policy control decisions based on awareness of URSP rule enforcement as described in
clause 6.1.1.5 of TS 23.503.
Step 11.
The SM Policy Association is terminated as described in
clause 4.16.6. The allocated UE address/prefix, SUPI, DNN, S-NSSAI and the PCF address are deregistered in the BSF.
Step 12a.
If the (H-)PCF for the UE subscribed to the BSF, then the BSF notifies that the PCF serving a PDU Session is deregistered in the BSF, by invoking Nbsf_Management_Notify (Binding Identifier for the PDU Session).
Step 12b.
If the (H-)PCF for the UE sent the request to notify that a PCF for the PDU Session is available to the AMF in step 1, then the PCF for the PDU Session sends Npcf_PolicyAuthoritation_Notify (EventID set to SM Policy Association termination, Notification Correlation Id).