Method and apparatus for ran slice cell for service continuity

1 . A method performed by a user equipment (UE) in a wireless communication system, the method comprising:

receiving, from a first base station, a radio resource control (RRC) reconfiguration message including information on measurement objects, while the UE camps on a first cell of the first base station via a first network slice for a first application running in the UE;

identifying that a second application is triggered to start in the UE, and a second network slice for the second application is not supported by the first cell;

transmitting, to the first base station, a service request message for a session establishment of the second network slice, based on identifying that the second application is triggered to start and the second network slice is not supported by the first cell;

in response to a service accept message being received as a response to the service request message, receiving, from a plurality of base stations, system information blocks (SIBs);

identifying, among the SIBs, a SIB including a network slice identity (ID) corresponding to the second network slice for the second application;

identifying that the SIB is received on a second cell of a second base station among the plurality of base stations;

performing a measurement on a measurement object corresponding to the second cell, among the measurement objects;

transmitting, on the second cell, a measurement result of the measurement;

receiving, on the second cell, an RRC reconfiguration message for indicating an addition of the second cell is completed; and

receiving, on the second cell, data of the second application via the second network slice while the UE receives, on the first cell, data of the first application via the first network slice.

2 . The method of claim 1 , wherein the network slice ID included in the SIB received on the second cell indicates that the second cell supports the second network slice, and

wherein the network slice ID is a network slice access stratum (AS) group (NSAG) ID.

3 . The method of claim 1 , wherein, in a case that the second cell corresponds to a secondary cell group (SCG), the second cell is added to a SCG list.

4 . The method of claim 1 , further comprising: receiving, from the first base station, information on a plurality of frequencies within a first radio access technology (RAT).

5 . The method of claim 4 , wherein the first cell is associated with the first RAT, and wherein the second cell is associated with a second RAT.

6 . The method of claim 1 , wherein, in a case that the second cell corresponds to a secondary cell group (SCG), the second cell is added to a SCG list, and

wherein the UE enters dual connectivity (DC) mode based on the second cell being added to the SCG list.

7 . A user equipment (UE) in a wireless communication system, the UE comprising:

at least one processor comprising processing circuitry; and

memory storing instructions that, when executed individually and/or collectively by the at least one processor, cause the UE to:

receive, from a first base station, a radio resource control (RRC) reconfiguration message including information on measurement objects, while the UE camps on a first cell of the first base station via a first network slice for a first application running in the UE,

identify that a second application is triggered to start in the UE, and a second network slice for the second application is not supported by the first cell,

transmit, to the first base station, a service request message for a session establishment of the second network slice, based on identifying that the second application is triggered to start and the second network slice is not supported by the first cell,

in response to a service accept message being received as a response to the service request message, receive, from a plurality of base stations, system information blocks (SIBs),

identify, among the SIBs, a SIB including a network slice identity (ID) corresponding to the second network slice for the second application;

identify that the SIB is received on a second cell of a second base station among the plurality of base stations,

perform a measurement on a measurement object corresponding to the second cell, among the measurement objects;

transmit, on the second cell, a measurement result of the measurement;

receive, on the second cell, an RRC reconfiguration message for indicating an addition of the second cell is completed, and

receive, on the second cell, data of the second application via the second network slice while the UE receives, on the first cell, data of the first application via the first network slice.

8 . The UE of claim 7 , wherein the network slice ID included in the SIB received on the second cell indicates that the second cell supports the second network slice, and wherein the network slice ID is a network slice access stratum (AS) group (NSAG) ID.

9 . The UE of claim 7 , wherein, in a case that the second cell corresponds to a secondary cell group (SCG), the second cell is added to a SCG list.

10 . The UE of claim 7 , wherein the instructions, when executed by the at least one processor, further cause to the UE to:

receive, from the first base station, information on a plurality of frequencies within a first radio access technology (RAT).

11 . The UE of claim 10 , wherein the first cell is associated with the first RAT, and wherein the second cell is associated with a second RAT.

12 . The UE of claim 7 , wherein, in a case that the second cell corresponds to a secondary cell group (SCG), the second cell is added to a SCG list, and

wherein the UE enters dual connectivity (DC) mode based on the second cell being added to the SCG list.