If the AMF decides to initiate PCF communication, e.g. the AMF has not yet obtained Access and Mobility policy for the UE or if the Access and Mobility policy in the AMF are no longer valid, the AMF acts as follows.
If the new AMF receives PCF ID(s) included in UE context from the old AMF in step 5, the AMF contacts the (V-)PCF identified by the (V-)PCF ID.
If the (V-)PCF identified by the (V-)PCF ID cannot be used (e.g. no response from the (V-)PCF) or there is no PCF ID received from the old AMF in step 5, the AMF selects a (V)-PCF and may select an H-PCF (for roaming scenario) as described in TS 23.501 , clause 126.96.36.199 and according to the V-NRF to H-NRF interaction described in clause 188.8.131.52.3.3.