Section: 5.46.2 Member UE selection assistance functionality for application operation
Content: 5G System may support Member UE selection assistance functionality to assist the AF to select member UE(s) that can be used in application operations such as AI/ML based applications (e.g. Federated Learning) as specified in clause 5.46.1 according to the AF's inputs. The Member UE selection assistance functionality shall be hosted by NEF, and the features of the Member UE selection assistance functionality hosted by the NEF include (see clause 4.15.13 of TS 23.502[ Procedures for the 5G System (5GS) ]  [3] for details of Member UE selection procedures): - Receiving a request from the AF that shall include a list of target member UE(s) (which may not necessarily be a part of the subsequent updated request), optionally (a) time window(s), and one or more filtering criteria as specified in Table 4.15.13.2-1 of TS 23.502[ Procedures for the 5G System (5GS) ]  [3] (e.g. UE current location, UE historical location, UE direction, UE separation distance, QoS requirements, DNN, preferred access/RAT type, Desired end-to-end data volume transfer time performance, or Service Experience). - Referring to the filtering criteria provided by the AF and then interacting with 5GC NFs using existing services in order to have the corresponding data for all the UEs in the list of target member UE from relevant 5GC NFs (e.g. PCF, NWDAF, AMF, SMF) to derive the list(s) of candidate UE(s) (i.e. UE(s) among the list of target member UE(s) provided by the AF) which fulfil the filtering criteria. - Providing the AF with the Member UE selection assistance information, including one or more lists of candidate UE(s), and optionally other additional information (e.g. one or more recommended time window(s) for performing the application operation, QoS of each target UE, UE(s) location, Access/RAT type, or Service Experience). NEF may also provide the number of UEs per each filtering criterion that do not fulfil the corresponding filtering criterion. The Member UE selection assistance information provided by the NEF may be used by the AF to select member UE(s) used in application AI/ML operation. (See clause 5.2.6.32 of TS 23.502[ Procedures for the 5G System (5GS) ]  [3] for details of parameters). NOTE: The AF can decide whether to use the Member UE selection assistance functionality provided by NEF. Without using the Member UE selection assistance functionality, AF in either trusted or untrusted domain can select the Member UE(s) for e.g. participating in federating learning operation, by collecting the corresponding data using network exposure information as described in clause 4.15 of TS 23.502[ Procedures for the 5G System (5GS) ]  [3], e.g. UE location reporting from the AMF, user plane information from the UPF and network data analytics from NWDAF.