Section: 4.15.13 Assistance for Member UE selection 4.15.13.0 General
Content: With the initial subscription request, the AF provides a list of target UEs in the form of a list of GPSIs or a list of UE IP addresses and at least one Member UE filtering criterion as part of the service operation parameters to assist the candidate UEs selection. Upon receiving the AF request, NEF triggers corresponding 5GC procedures to retrieve from 5GC NFs the information for each UE in the list of target member UEs. Before sending the list(s) of candidate UEs to the AF, NEF consolidates all the information collected from other 5GC NFs and derives one or more list(s) of candidate UEs and possibly additional information according to the Member UE filtering criteria requested by the AF. AF may subsequently update the Member UE filtering criteria and notify the NEF with Subscription Correlation ID. AF does not include the list of target member UEs. AF may request to update the parameters (e.g. expiry time, time window for selecting the candidate UEs) for the subscribed Member UE filtering criteria with Subscription Correlation ID. AF may also request to update by adding new Member UE filtering criteria or removing part of the subscribed Member UE filtering criteria. The Member UE selection assistance capability can be used to assist the AF to select the list of member UEs to support application service (e.g. FL operation) and it is further defined in clause 5.46.2 of TS 23.501[ System architecture for the 5G System (5GS) ]  [2]. Additionally, AF may leverage the 5GC network exposure for Member UE selection without the NEF assistance as described in clause 5.46.2 of TS 23.501[ System architecture for the 5G System (5GS) ]  [2]. An example of how the AF leverages the 5GC network exposure for Member UE selection is described in (informative) Annex I. AF may also unsubscribe the previous subscription for Member UE selection assistance information as described in clause 4.15.13.7.