Enhancement of voice domain selection in 5GS and fast return from EPS to 5GS

摘要

Various examples and schemes pertaining to enhancement of voice domain selection in 5^th-Generation Systems (5GS) and fast return from Evolved Packet System (EPS) to 5GS are described. A processor of a user equipment (UE) receive an indication of whether a packet-switched (PS) voice service is supported in a first mobile communication system. The processor performs, based on the indication, voice domain selection (VDS) by selecting and engaging with one of a plurality of mobile communication systems comprising the first mobile communication system and at least a second mobile communication system. The processor performs the VDS before receiving signaling from one of the plurality of communication systems about availability of support for the PS voice service in that mobile communication system.