Method and device for supporting voice handover in wireless communication system
The present disclosure relates to a 5G or pre-5G communication system for supporting higher data transmission rates than 4G communication systems such as LTE. The present invention relates to a method and device for supporting voice handover in a wireless communication system and increasing service quality in a mobile communication system, and more specifically, to a method for a UE connected to a first network to communicate with a network in a wireless communication system, the method comprising the steps of: connecting a voice call to a second network; receiving, from a base station of the second network, a message including control information for controlling wireless access of the UE; and using the control information to determine the radio access technology (RAT) to be used and the PLMN to be accessed after the voice call is completed, wherein the first network and the second network communicate using different RATs, and the voice call is connected to the second network by circuit switching (CS).
1 . A method performed by a user equipment (UE) in a wireless communication system, the method comprising:
exchanging information indicating support of a single radio voice call continuity (SRVCC) handover with a fifth generation (5G) network in a registration procedure;
connecting a voice call to the 5G network when the UE has been registered in the 5G network, wherein SRVCC is triggered for the UE based on a state and a location of the UE and a network configuration;
receiving, from an access and mobility management function (AMF) in the 5G network, an SRVCC handover command comprising a non-access stratum (NAS) message including control information for a radio access operation of the UE in a 5G network;
when the UE receives the SRVCC handover command, connecting the voice call to a 3G network using the SRVCC handover from the 5G network to the 3G network; and
determining, based on the control information, a radio access technology (RAT) for the radio access operation and a public land mobile network (PLMN) to be accessed using the RAT after completing the voice call, wherein the voice call is connected to the 3G network in a circuit switched (CS) manner, the voice call being transitioned from a packet switched (PS) manner.
2 . The method of claim 1 , wherein the control information includes at least one of a subscriber profile identifier (SPID) or a PLMN ID, and wherein the message comprises a radio resource control (RRC) release message.
3 . The method of claim 1 , wherein the control information includes priority information for RATs and PLMNs.
4 . The method of claim 3 , wherein the UE communicates with the 5G network using a first RAT before connecting the voice call, and wherein the priority information indicates that a priority of a PLMN of the 5G network is higher than a priority of a PLMN of the 3G network and a priority of the first RAT is higher than a priority of a second RAT.
5 . A user equipment (UE) in a wireless communication system, the UE comprising: a transceiver; and a controller communicatively coupled to the transceiver; and memory, communicatively coupled to the controller, storing instructions executable by the controller to cause the UE to:
exchange information indicating support of a single radio voice call continuity (SRVCC) handover with a fifth-generation (5G) network in a registration procedure,
connect a voice call to the 5G network when the UE has been registered in the 5G network, wherein SRVCC is triggered for the UE based on a state and a location of the UE and a network configuration, receive, from an access and mobility management function (AMF) in the 5G network, an SRVCC handover command comprising a non-access stratum (NAS) message including control information for a radio access operation of the UE in the 5G network,
when the UE receives the SRVCC handover command, connect the voice call to a 3G network using the SRVCC handover from the 5G network to the 3G network, and determine, based on the control information, a radio access technology (RAT) for the radio access operation and a public land mobile network (PLMN) to be accessed using the RAT after completing the voice call, wherein the voice call is connected to the 3G network in a circuit switched (CS) manner, the voice call being transitioned from a packet switched (PS) manner.
6 . The UE of claim 5 , wherein the control information includes at least one of a subscriber profile identifier (SPID) or a PLMN ID, and wherein the message comprises a radio resource control (RRC) release message.
7 . The UE of claim 5 , wherein the control information includes priority information for RATs and PLMNs.
8 . The UE of claim 7 , wherein the UE communicates with the 5G network using a first RAT before connecting the voice call, and wherein the priority information indicates that a priority of a PLMN of the 5G network is higher than a priority of a PLMN of the 3G network and a priority of the first RAT is higher than a priority of a second RAT.