Method and device for performing conditional handover in wireless communication system

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

receiving, from a source master node, configuration information including a first configuration of a candidate target primary cell (PCell), a second configuration of a candidate target primary secondary cell group cell (PSCell), a first execution condition for a conditional handover (CHO), and a second execution condition for a conditional PSCell change (CPC); and

in case that the first execution condition and the second execution condition are met, applying the first configuration of the candidate target PCell and the second configuration of the candidate target PSCell.

2 . The method of claim 1 ,

wherein the first execution condition is associated with a first measurement configuration identity (measId), and

wherein the second execution condition is associated with a second measurement configuration identity (measId).

3 . The method of claim 1 , wherein the second execution condition identified by a candidate target master node associated with the candidate target PCell.

4 . The method of claim 1 , wherein the configuration information is based on a handover request acknowledge message transmitted from a candidate target master node to the source master node, the handover request acknowledge message including a cell global identity (CGI) of the candidate target PSCell and a report configuration.

5 . A method performed by a source master node in a wireless communication system, the method comprising:

transmitting, to a candidate target master node, a handover request message;

receiving, from the candidate target master node, a handover request acknowledge message including a first configuration of a candidate target primary cell (PCell), a second configuration of a candidate target primary secondary cell group cell (PSCell), and a second execution condition for a conditional PSCell change (CPC); and

transmitting, to user equipment (UE), configuration information including the first configuration of the candidate target PCell, the second configuration of the candidate target PSCell, a first execution condition for a conditional handover (CHO) and the second execution condition for the CPC, wherein the first configuration of the candidate target PCell and the second configuration of the candidate target PSCell are applied, in case that the first execution condition and the second execution condition are met.

6 . The method of claim 5 ,

wherein the first execution condition is associated with a first measurement configuration identity (measId), and

wherein the second execution condition is associated with a second measurement configuration identity (measId).

7 . The method of claim 5 , wherein the second execution condition is identified by a candidate target master node associated with the candidate target PCell.

8 . The method of claim 5 , wherein the handover request acknowledge message includes a cell global identity (CGI) of the candidate target PSCell and a report configuration.

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

at least one transceiver;

at least one processor communicatively coupled to the at least one transceiver; and

at least one memory, communicatively coupled to the at least one processor, storing instructions executable by the at least one processor individually or in any combination to cause the UE to:

receive, from a source master node, configuration information including a first configuration of a candidate target primary cell (PCell), a second configuration of a candidate target primary secondary cell group cell (PSCell), a first execution condition for a conditional handover (CHO), and a second execution condition for a conditional PSCell change (CPC), and

in case that the first execution condition and the second execution condition are met, applying the first configuration of the candidate target PCell and the second configuration of the candidate target PSCell.

10 . The UE of claim 9 ,

wherein the first execution condition is associated with a first measurement configuration identity (measId), and

wherein the second execution condition is associated with a second measurement configuration identity (measId).

11 . The UE of claim 9 , wherein the second execution condition identified by a candidate target master node associated with the candidate target PCell.

12 . The UE of claim 9 , wherein the configuration information is based on a handover request acknowledge message transmitted from a candidate target master node to the source master node, the handover request acknowledge message including a cell global identity (CGI) of the candidate target PSCell and a report configuration.

13 . A source master node comprising:

at least one transceiver;

at least one processor communicatively coupled to the at least one transceiver; and

at least one memory, communicatively coupled to the at least one processor, storing instructions executable by the at least one processor individually or in any combination to cause the source master node to:

transmit, to a candidate target master node, a handover request message,

receive, from the candidate target master node, a handover request acknowledge message including a first configuration of a candidate target primary cell (PCell), a second configuration of a candidate target primary secondary cell group cell (PSCell), and a second execution condition for a conditional PSCell change (CPC), and

transmit, to user equipment (UE), configuration information including the first configuration of the candidate target PCell, the second configuration of the candidate target PSCell, a first execution condition for a conditional handover (CHO) and the second execution condition for the CPC,

wherein the first configuration of the candidate target PCell and the second configuration of the candidate target PSCell are applied, in case that the first execution condition and the second execution condition are met.

14 . The source master node of claim 13 ,

wherein the first execution condition is associated with a first measurement configuration identity (measId), and

wherein the second execution condition is associated with a second measurement configuration identity (measId).

15 . The source master node of claim 13 , wherein the second execution condition is identified by a candidate target master node associated with the candidate target PCell.

16 . The source master node of claim 13 , wherein the handover request acknowledge message includes a cell global identity (CGI) of the candidate target PSCell and a report configuration.

17 . The method of claim 2 , wherein the first measurement configuration identity (measId) and the second measurement configuration identity (measId) are associated with a master node measurement configuration (measConfig).

18 . The method of claim 6 , wherein the first measurement configuration identity (measId) and the second measurement configuration identity (measId) are associated with a master node measurement configuration (measConfig).

19 . The UE of claim 10 , wherein the first measurement configuration identity (measId) and the second measurement configuration identity (measId) are associated with a master node measurement configuration (measConfig).

20 . The source master node of claim 14 , wherein the first measurement configuration identity (measId) and the second measurement configuration identity (measId) are associated with a master node measurement configuration (measConfig).