Abstract: An overall architecture to integrate multicast and broadcast service into a general 5G core network. The architecture may provide methods and systems to switch the delivery mode of transmitting messages to User Equipment (UE)s from a unicast mode to a multicast mode. The method includes triggering events at UE, network functions, content provider or RAN node to initiate the switch process; a procedure for UE initiated switch from unicast to multicast; a procedure for network-initiated switch from unicast mode to multicast mode; and a procedure for RAN initiated switch from unicast mode to multicast mode. The architecture may also provide methods to switch the delivery mode from multicast mode to unicast mode.

Abstract: Network Slice Selection Assistance information (NSSA1) may be signaled between U ser Equipment (UE) and a network. NSSA1 sent from the network to the UE may include, for example. Operating Frequency Band (OFB) for each Single NSSAI(S-NSSA1) in the NSSAI, as well as a Radio Access Technology (RAT) Frequency Selection Priority (RFSP) index, which the network configures as a part of UE access and mobility; subscription, during a UE registration procedure. RAT restrictions may be enhanced to indicate to the UE that certain slices are not accessible via certain RATs. A UE may be provided by the network with an alternative NSSAI and corresponding OFBs for each S-NSSAI thereby indicating to the UE that these S-NSSAI would have been allowed had they been requested. A UE may be able to choose an alternative Allowed NSSAI and send a registration update request to the network.