Section: 4.11.0a.2a.2 SMF initiated SM Policy Association Modification
Content: 4.11.0a.2a.2.1 SMF initiated SM Policy Association Modification due to UE requested bearer resource modification procedure When SMF+PGW-C receives the UE Policy Container in the UE requested bearer resource modification procedure, the SMF+PGW-C provides the UE Policy Container to the PCF. The SM Policy Association Modification procedure in clause 4.16.5.1 applies with the following enhancements is executed with the following differences, applicable between step 4 and step 5: If the PCF receives both the indication that the PCRT "UE Policy Container received" was met and the UE Policy Container, steps 4a to 4d below are executed. - Step 4a: The PCF determines that the SM Policy Association is used to provision URSP rules to the UE by checking the UE Policy Container received from SMF+PGW-C. - Step 4b: The PCF for the PDU Session discovers the PCF for the UE by querying the BSF, using Nbsf_Management_Discovery for the SUPI. If no result is obtained from the BSF the PCF for the PDU Session selects the PCF for the UE by querying NRF, using the URSP delivery in EPS capability of the PCF, as defined in clause 6.3.7.1 of TS 23.501[ System architecture for the 5G System (5GS) ]  [2]. - Step 4c: The PCF for the PDU Session establishes a UE Policy Association towards the PCF for the UE as described in clause 4.11.0a.2a.5. - Step 4d: If the PCF for the UE provides any Policy Control Request Trigger parameters in the Npcf_UEPolicyControl Create Response the PCF for the PDU Session takes them into account for the generation of Policy Control Request Triggers to the SMF+PGW-C. 4.11.0a.2a.2.2 SMF initiated SM Policy Association Modification at mobility between 5GS and EPS During 5GS to EPS mobility procedure, the PCF for the PDU Session establishes a UE Policy Association towards the PCF for the UE if it exists otherwise, it performs PCF discovery and selection then establishes a UE Policy Association. During EPS to 5GS mobility procedure the PCF for the PDU Session terminates the UE Policy Association, if established during 5GS to EPS mobility. The following enhancements are applicable to clause 4.16.5.1 (SMF initiated SM Policy Association Modification procedure): In addition to step 4 in clause 4.16.5.1, the PCF determines that 5GS to EPS or EPS to 5GS mobility applies by checking a change in RAT and Access-Type. - If 5GS to EPS mobility applies, , in non-roaming and Home Routed roaming the (H-)PCF for the PDU Session determines whether the UE supports provisioning of URSP Rules in EPS by checking indication of support of URSP delivery in EPS in UDR and in LBO roaming the V-PCF for the PDU Session determine whether the UE supports provisioning of URSP rules in EPS based on local configuration, e.g. using the PEI, given that the V-PCF has no access to UDR at the HPLMN. The (H-)PCF or the V-PCF determines if the SMF+PGW-C supports delivery of URSP Rules in EPS as reported by the SMF+PGW-C. If the PCF determines that the UE and the SMF+PGW-C support provisioning of URSP Rules in EPS, the PCF for the PDU Session finds the PCF for the UE using Nbsf_Management_Discovery for the SUPI and then performs UE Policy Association Establishment procedure as specified in clause 4.11.0a.2a.5. If no result is obtained from the BSF, the PCF for the PDU Session selects the PCF for the UE by querying NRF, using the URSP delivery in EPS capability of the PCF, as defined in clause 6.3.7.1 of TS 23.501[ System architecture for the 5G System (5GS) ]  [2]. - If EPS to 5GS mobility applies, the PCF for the PDU Session requests the termination of the UE Policy association as described in clause 4.11.0a.2a.8. 4.11.0a.2a.2.3 SMF initiated SM Policy Association Modification for UE reporting URSP update result When the UE reports the result of URSP rule update, the following enhancements are applicable to clause 4.16.5.1 (SM Policy Association Modification procedure): In addition to step 4 in clause 4.16.5.1 if the PCF for the PDU Session receives the "UE Policy" Policy Control Request Trigger and associated UE Policy Container, steps 4a to 4b below are executed: - Step 4a: The PCF for the PDU Session determines that a UE Policy association has been already established towards the PCF for the UE for the SM Policy Association as described in clause 4.11.0a.2a.7. - Step 4b: The PCF for the PDU Session forwards the UE Policy Container to the PCF for the UE in Npcf_UEPolicyControl_Update Request.