Method and apparatus for handover of terminal in wireless communication system

1 . A method comprising:

receiving, by a user equipment (UE), system information from a first node,

wherein the system information includes i) a list of standalone non-public network (SNPN) identity (ID) information, and ii) information related to whether access using credentials from a credentials holder is supported;

transmitting, by the UE, a registration request message in a radio resource control (RRC) message to the first node,

wherein the RRC message includes SNPN ID information related to the source network, and

wherein the registration request message includes SNPN capability information related to the UE supporting a handover to a target network having a different SNPN ID from the source network; and

based on i) the UE being capable of accessing the source network and the target network based on the credentials from the credentials holder, and ii) an N14 interface being present between the source network and the target network, performing, by the UE, the handover from the first node to a second node in the target network having the different SNPN ID from the source network,

wherein the second node in the target network is determined based on the SNPN capability information.

2 . The method of claim 1 , wherein the first node selects a first access and mobility management function (AMF) based on the SNPN ID information related to the source network and transmits an initial UE message including the SNPN ID information related to the source network to the first AME, and receives an initial context setup request message from the first AMF based on the first AMF allowing registration of the UE.

3 . The method of claim 2 , wherein the initial context setup request message comprises a list of allowed SNPNs to which the UE is capable of being handed over.

4 . The method of claim 3 ,

wherein candidate nodes to which the UE is capable of being handed over are set to other nodes in the source network and nodes having SNPN IDs of SNPNs included in the list of allowed SNPNs, and

wherein the UE is handed over to any one of the candidate nodes.

5 . The method of claim 4 , wherein the target network is determined based on information pre-configured through the first node and the list of allowed SNPNs.

6 . The method of claim 5 , wherein the UE is handed over to the second node in the target network based on any one of Xn-based handover or NG-based handover.

7 . The method of claim 6 , wherein, based on the UE being handed over to the second node in the target network through the Xn-based handover and the second node in the target network accepting handover the UE, the second node in the target network provides updated serving SNPN ID information to the UE through the first node.

8 . The method of claim 6 ,

wherein, based on the UE being handed over to the second node in the target network through the NG-based handover, the first AMF transmits a handover required message to a second AMF corresponding to the second node in the target network,

wherein the second AMF transmits a handover request message to the second node in the target network, obtains updated serving SNPN ID information, and sends the updated serving SNPN ID information to the first node through the first AMF, and

wherein the UE receives a handover command message including the updated serving SNPN ID information from the first node.

9 . The method of claim 2 , wherein the initial context setup request message comprises the SNPN capability information.

10 . The method of claim 9 ,

wherein the UE is handed over from the first node to an arbitrary target node, based on the UE being handed over from the first node to another node based on a measurement result, and

wherein the first node transmits a handover required message to the first AMF, based on the handover of the UE being necessary based on the measurement result.

11 . The method of claim 10 ,

wherein the handover required message comprises SNPN ID information related to the target network,

wherein the first AMF transmits a handover request message to a second AMF in the target network based on the SNPN ID information related to the target network, and

wherein the second AMF checks whether the UE is capable of accessing the target network based on the credentials from the credentials holder.

12 . The method of claim 11 ,

wherein, based on the UE being capable of accessing the target network based on the credentials from the credentials holder, the second AMF transmits a handover request message including the SNPN capability information to the second node in the target network, and obtains updated serving SNPN ID information, and

wherein the updated serving SNPN ID information is sent to the first node through the first AMF.

13 . The method of claim 12 , wherein the UE receives a handover command message including the updated serving SNPN ID information from the first node.

14 . A user equipment (UE) UE comprising:

at least one processor; and

at least one memory operably connected to the at least one processor and storing instructions, based on being executed by the at least one processor, cause the UE to perform operations comprising,

receiving system information from a first node,

wherein the system information includes i) a list of standalone non-public network (SNPN) identity (ID) information, and ii) information related to whether access using credentials from a credentials holder is supported;

transmitting a registration request message in a radio resource control (RRC) message to the first node,

wherein the RRC message includes SNPN ID information related to the source network, and

wherein the registration request message includes SNPN capability information related to the UE supporting a handover to a target network having a different SNPN ID from the source network; and

based on i) the UE being capable of accessing the source network and the target network based on the credentials from the credentials holder, and ii) an N14 interface being present between the source network and the target network, performing the handover from the first node accessed to a second node in the target network having the different SNPN ID from the source network,

wherein the second node in the target network is determined based on the SNPN capability information.

15 . A first node comprising:

at least one processor; and

at least one memory operably connected to the at least one processor and storing instructions, based on being executed by the at least one processor, cause the first node to perform operations comprising,

transmitting system information to a user equipment (UE),

wherein the system information includes i) a list of standalone non-public network (SNPN) identity (ID) information, and ii) information related to whether access using credentials from a credentials holder is supported;

receiving a registration request message in a radio resource control (RRC) message from the UE,

wherein the RRC message includes SNPN ID information related to a source network, and

wherein the registration request message includes SNPN capability information related to the UE supporting a handover to a target network having a different SNPN ID from the source network; and

based on i) the UE being capable of accessing the source network and the target network based on the credentials from the credentials holder, and ii) an N14 interface being present between the source network and the target network, handing over the UE to a second node in the target network having the different SNPN ID from the source network,

wherein the second node in the target network is determined based on the SNPN capability information.