Section: 4.11.0a.2a.7 UE Policy Association Modification initiated by the PCF for a PDU Session
Content: This procedure addresses the scenario where a Policy Control Request Trigger condition is met by the PCF for a PDU Session. The procedure is based on the one defined in clause 4.16.12.1.1 with the following differences: In the non-roaming case, the V-PCF is not involved, the AMF is replaced by the PCF for the PDU Session, and the role of the H-PCF is performed by the PCF for the UE. For the Home Routed roaming scenarios, the V-PCF is not involved, the AMF is replaced by the H-PCF for the PDU Session, and the role of the H-PCF is performed by the H-PCF for the UE. For the LBO roaming scenarios, the AMF is replaced by the V-PCF for the PDU Session, the role of the V-PCF is performed by the V-PCF for the UE and the role of the H-PCF is performed by the H-PCF for the UE. - Step 1: Same as in clause 4.16.12.1.1 step 1, with the following exceptions: In LBO roaming the V-PCF for the PDU Session contacts the V-PCF for the UE and steps 2 and 3 are executed. The V-PCF for the UE contacts with the H-PCF for the UE discovered during the establishment of the UE Policy association as described in clause 4.11.0a.2a.5. For non-roaming or Home Routed roaming the (H-)PCF for the PDU Session contacts the (H-)PCF for the UE and step 4 follows. - Steps 2, 3,4: Same as in clause 4.16.12.1.1. - Step 5: The (H-)PCF may create the UE policy container including UE policy information as defined in clause 6.6 of TS 23.503[ Policy and charging control framework for the 5G System (5GS); Stage 2 ]  [20]. The (H-) PCF checks whether the UE Policy Association for the UE is established for a UE in EPS by checking the RAT-Type of the UE Policy Association and in this case the (H-)PCF may send the UE Policy Container in the Npcf_UEPolicyControl UpdateNotify Request. - Step 6: Same as in clause 4.16.12.1.1. - Steps 7, 8 and 9 are replaced by steps 10-13 of procedure UE Policy Association Establishment in EPS from clause 4.11.0a.2a.5.