Content for  TS 23.502  Word version:  18.5.0

The AMF establishes UE Policy Association with the (V-)PCF when a UE Policy Container is received from the UE. If a UE Policy Container is not received from the UE, the AMF may establish UE Policy Association with the (V-)PCF based on AMF local configuration.

The AMF sends a Npcf_UEPolicyControl Create Request with the following information: SUPI, may include Access Type and RAT, PEI, ULI, UE time zone, Serving Network (PLMN ID, or PLMN ID and NID, see clause 5.34 of TS 23.501), the Internal-Group-ID-list and UE Policy Container (the list of stored PSIs, operating system identifier, Indication of UE support for ANDSP, indication of UE capability of reporting URSP rule enforcement to network, indication of support of URSP delivery in EPS). In roaming scenario, based on operator policies, the AMF may provide to the V-PCF the PCF ID of the selected H-PCF. The V-PCF contacts the H-PCF. In roaming case, steps 3 and 4 are executed, otherwise step 5 follows. If the AMF, based on configuration, is aware that the UE is accessing over a gNB using satellite backhaul, the AMF includes the Satellite backhaul category as described in clause 5.43 of TS 23.501.

The V-PCF forwards the information received from AMF in step 2 to the H-PCF. When a UE Policy Container is received at initial registration, the H-PCF may store the PEI, the OSId, indication of UE capability of reporting URSP rule enforcement to network, indication of support of URSP delivery in EPS or the indication of UE support for ANDSP in the UDR using Nudr_DM_Create including DataSet "Policy Data" and Data Subset "UE context policy control data". The V-PCF may retrieve the Application guidance on URSP Rule for inbound roamers of the PLMN of the SUPI, if not available, using Nudr_DM_Query or Nudr_DM_Subscribe including the Data Set "Application Data" and Data Subset "Service Specific Information" and DataKey set to "PLMN ID(s) of inbound roamers". The V-PCF may retrieve the Application guidance on URSP Rule for inbound roamers of the PLMN of the SUPI, if not available, using Nudr_DM_Query or Nudr_DM_Subscribe including the Data Set "Application Data".

The H-PCF sends a Npcf_UEPolicyControl Create Response to the V-PCF. The H-PCF may provide the Policy Control Request Trigger parameters in the Npcf_UEPolicyControl Create Response. Before sending the response, the H-PCF may determine that the decision about UE policy control depends on the status of the policy counters available at the CHF and if such reporting is not established for the subscriber, the H-PCF initiates an Initial Spending Limit Report Retrieval as defined in clause 4.16.8.2. If policy counter status reporting is already established for the subscriber and the H-PCF determines that the status of additional policy counters are required, the H-PCF initiates an Intermediate Spending Limit Report Retrieval as defined in clause 4.16.8.3. The (H-)PCF in roaming and the PCF in non-roaming may register to the BSF as the PCF serving this UE, if not already registered at the AM Policy Association establishment. This is performed by using the Nbsf_Management_Register operation, providing as inputs the UE SUPI/GPSI and the PCF identity.

The (V-) PCF sends a Npcf_UEPolicyControl Create Response to the AMF. The (V-)PCF relays the Policy Control Request Trigger parameters in the Npcf_UEPolicyControl Create Response. The (V-)PCF also subscribes to notification of N1 message delivery of policy information to the UE using Namf_Communication_N1N2MessageSubscribe service which is not shown in this figure.

The (H-)PCF gets policy subscription related information and the latest list of PSIs from the UDR using Nudr_DM_Query service operation (SUPI, Policy Data, UE context policy control data, Policy Set Entry) if either or both are not available and makes a policy decision. The (H-)PCF may get the PEI, the OSId, indication of UE capability of reporting URSP rule enforcement to network or the indication of UE support for ANDSP in the UDR using Nudr_DM_Query including DataSet "Policy Data" and Data Subset "UE context policy control data" if the AMF relocates and the PCF changes. In the roaming scenario, the H-PCF may provide the indication of UE support for ANDSP to the V-PCF, if the indication was not present in the Npcf_UEPolicyControl Create request from V-PCF and the H-PCF gets this information from the H-UDR. The (H-)PCF may get the 5G VN group data and 5G VN group membership for each Internal-Group-ID received from the AMF using Nudr_DM_Query (Internal-Group-Id, Subscription Data, 5G VN Group Configuration). The (H-)PCF may store the 5G VN group data and 5G VN group membership for later use for other SUPIs that belong to the same Internal-Group-ID. The (H-)PCF may request notifications from the UDR on changes in the subscription information by invoking Nudr_DM_Subscribe (Policy Data, SUPI, DNN, S-NSSAI, Notification Target Address (+ Notification Correlation Id), Event Reporting Information (continuous reporting), UE context policy control data) service. The (H-)PCF may request notifications from the UDR on changes in the 5G VN group data or 5G VN group membership associated to each of the Internal-Group-Id provided to the PCF by invoking Nudr_DM_Subscribe (Subscription Data, 5G VN Group Configuration, Internal Group ID, Notification Target Address (+ Notification Correlation Id), Event Reporting Information (continuous reporting)) service. The (H-)PCF creates the UE policy container including UE policy information as defined in clause 6.6 of TS 23.503 and in the case of roaming H-PCF provides the UE policy container in the Npcf_UEPolicyControl UpdateNotify Request. In the non-roaming case, the PCF may subscribe to Analytics from NWDAF as defined in clause 6.1.1.3 of TS 23.503.

The V-PCF sends a response to H-PCF using Npcf_UEPolicyControl UpdateNotify Response.

The (V-)PCF triggers UE Configuration Update Procedure in clause 4.2.4.3 to sends the UE policy container including UE policy information to the UE. The (V-)PCF checks the size limit as described in clause 6.1.2.2.2 of TS 23.503.

If the V-PCF received notification of the reception of the UE Policy container then the V-PCF forwards the notification response of the UE to the H-PCF using Npcf_UEPolicyControl_Update Request. If the V-PCF is notified by the V-UDR about the Service Specific Information applicable to inbound roamers from the HPLMN of the UE as specified in clause 4.15.6.10, the V-PCF provides the Service Parameters to the H-PCF.

The H-PCF sends a response to the V-PCF. If the V-PCF received a UE Policy Container step 8 will follow.

If (H-)PCF subscribed to notification of subscriber's policy data change or 5G VN Group Configuration (5G VN group data, 5G VN group membership) change and a change is detected, the UDR notifies that the subscriber's policy data of a UE or 5G VN Group Configuration (5G VN group data, 5G VN group membership) has been changed. The UDR notifies the (H-)PCF of the updated policy control subscription information profile via Nudr_DM_Notify (Notification correlation Id, Policy Data, either UE context policy control data or Policy Set Entry data or both, SUPI), or The UDR notifies the (H-)PCF of the updated 5G VN Group Configuration (5G VN group data, 5G VN group membership) via Nudr_DM_Notify (Notification correlation Id, 5G VN Group Configuration, Internal-Group-Identifier), or The (V-)UDR notifies the (V-)PCF of the updated policy control subscription information profile via Nudr_DM_Notify (Notification correlation Id, Policy Data, PolicySetEntry Data. PLMN ID). The (V-)UDR notifies the (V-)PCF of the updated Service Parameters via Nudr_DM_Notify.

PCF determines locally that UE policy information needs to be sent to the UE.

The CHF notifies the (H-)PCF about the change of the status of the subscribed policy counters available at the CHF for that subscriber.

The PCF makes the policy decision. If the group data is updated, the (H-) PCF checks the UE Policy Associations for those SUPIs within the Internal-Group-Id and may need to perform step 3 to step 9 for each UE Policy Association that needs to be updated with new UE Policies sent to each UE. In the non-roaming case, the PCF may subscribe to Analytics from NWDAF as defined in clause 6.1.1.3 of TS 23.503.

In the roaming case, the V-PCF may provide the updated Service Parameters received from the V-UDR as specified in clause 4.15.6.10 to the H-PCF using the Npcf_UEPolicyControl_Update Request. The H-PCF sends a response to the V-PCF.

The (H-)PCF may create the UE policy container including UE policy information as defined in clause 6.1.2.2.2 of TS 23.503. In the case of roaming, the H-PCF may send the UE policy container in the Npcf_UEPolicyControl UpdateNotify Request. The H-PCF may provide updated policy control triggers for the UE policy association. If there is the received Service Parameters from the V-PCF in step 2, the H-PCF may take the Service Parameters obtained from V-PCF to generate URSP rules applicable in the VPLMN as specified in clause 4.15.6.10.

The V-PCF sends a response to H-PCF using Npcf_UEPolicyControl UpdateNotify Response.

The (V-)PCF provides the Policy Control Request Trigger parameters in the Npcf_UEPolicyControl UpdateNotify Request to the AMF. In the case of roaming, the V-PCF may also provide UE policy information to the UE. The V-PCF may also provide updated policy control triggers for the UE policy association to the AMF.

The AMF sends a response to (V-)PCF. Steps 7, 8 and 9 are the same as steps 8, 9 and 10 of procedure UE Policy Association Establishment in clause 4.16.11.

The AMF decides to terminate the UE Policy Association.

The AMF sends the Npcf_UEPolicyControl_Delete service operation including UE Policy Association ID to the (V-)PCF.

The (V-)PCF removes the policy context for the UE and replies to the AMF with an Acknowledgement including success or failure. The V-PCF may interact with the H-PCF. The (V-)PCF may unsubscribe to subscriber policy data changes with UDR by Nudr_DM_Unsubscribe (Subscription Correlation Id). The AMF removes the UE Policy Context. If the PCF has previously registered to the BSF as the PCF that is serving this UE, the PCF shall deregister from the BSF if no AM Policy Association for this UE exists anymore. This is performed by using the Nbsf_Management_Deregister service operation, providing the Binding Identifier that was obtained earlier from the BSF when performing the Nbsf_Management_Register service operation. Step 4 and Step 5 apply only to the roaming case.

The V-PCF sends the Npcf_UEPolicyControl_Delete service operation including UE Policy Association ID to the H-PCF.

The H-PCF removes the policy context for the UE and replies to the V-PCF with an Acknowledgement including success or failure. The H-PCF may unsubscribe to subscriber policy data changes with UDR by Nudr_DM_Unsubscribe (Subscription Correlation Id) for subscriber policy changes. In the non-roaming case, the PCF may unsubscribe to analytics from NWDAF. The H-PCF may invoke the procedure defined in clause 4.16.8 to unsubscribe to policy counter status reporting or to modify the subscription to policy counter status reporting (if remaining Policy association for this subscriber requires policy counter status reporting).

The Policy data is removed, either the Data Set "Policy Data" or the Data Subset "UE context policy control".

The UDR sends the Nudr_DM_Notify_Request (Notification correlation Id, Policy Data, SUPI, UE Context Policy Control data, updated data) including the SUPI, the Data Set Identifier, the Data Subset Identifier and the Updated Data including empty "Policy Data" or empty "UE context policy control".

The PCF sends the Nudr_DM_Notify_Response to confirm reception and the result to UDR.

The PCF may notify the AMF of the removal of the UE Policy Association via Npcf_UEPolicyControl_UpdateNotify service operation. Alternatively, the PCF may decide to maintain the Policy Association if a default profile is applied, in this case steps 4, 5 and 6 are not executed. In the non-roaming case, the PCF unsubscribes to analytics from NWDAF if any.

The AMF acknowledges the operation.

Steps 2-5 in clause 4.16.13.1 AMF-initiated UE Policy Association Termination are performed to remove the UE Policy Association for this UE and the subscription to Policy Control Request Triggers for that UE Policy Association.