Method and apparatus for conditional PSCell change

1. A master node for performing a Conditional Primary Secondary Cell Group (SCG) Cell (PSCell) Change (CPC) procedure, the master node comprising:

one or more non-transitory computer-readable media storing computer-executable instructions; and

at least one processor coupled to the one or more non-transitory computer-readable media, the at least one processor configured to execute the computer-executable instructions to cause the master node to:

receive, from a user equipment (UE), a UE capability report indicating that the UE supports conditional reconfiguration for a PSCell change;

transmit, to the UE, in an SCG portion of a radio resource control (RRC) reconfiguration message, a first conditional reconfiguration for transitioning from a source PSCell to a target PSCell, the first conditional reconfiguration including a configuration of the target PSCell and an execution condition; and

receive, from the UE, a response message after the first conditional reconfiguration is applied by the UE, wherein

the first conditional reconfiguration enables the UE to:

evaluate the execution condition, and

apply the configuration of the target PSCell and synchronize to the target PSCell after the execution condition is evaluated as satisfied.

2. The master node of claim 1 , wherein both the source PSCell and the target PSCell belong to a secondary node.

3. The master node of claim 2 , wherein the configuration of the target PSCell and the execution condition are generated by the secondary node.

4. The master node of claim 1 , wherein the source PSCell belongs to a source secondary node, the target PSCell belongs to a target secondary node, the configuration of the target PSCell is generated by the target secondary node, and the execution condition is generated by the source secondary node.

5. The master node of claim 1 , wherein the first conditional reconfiguration further enables the UE to:

release all conditional reconfigurations for PSCell change stored in the UE after the first conditional reconfiguration is applied successfully.

6. The master node of claim 1 , wherein the first conditional reconfiguration further enables the UE to:

cease evaluating all execution conditions in other conditional reconfigurations for PSCell change stored in the UE after the first conditional reconfiguration is applied.

7. The master node of claim 1 , wherein the first conditional reconfiguration further enables the UE to:

forgo detaching from the master node when applying the first conditional reconfiguration.

8. The master node of claim 1 , wherein the RRC reconfiguration message includes an indicator that indicates whether the first conditional reconfiguration is for the CPC procedure.

9. The master node of claim 1 , wherein the RRC reconfiguration message is transmitted, and the response message is received, via a signaling radio bearer 1 (SRB1).

10. A method for a Conditional Primary Secondary Cell Group (SCG) Cell (PSCell) Change (CPC) procedure performed by a master node, the method comprising:

receiving, from a user equipment (UE), a UE capability report indicating that the UE supports conditional reconfiguration for a PSCell change;

transmitting, to the UE, in an SCG portion of a radio resource control (RRC) reconfiguration message, a first conditional reconfiguration for transitioning from a source PSCell to a target PSCell, the first conditional reconfiguration including a configuration of the target PSCell and an execution condition; and

receiving, from the UE, a response message after the first conditional reconfiguration is applied by the UE, wherein

the first conditional reconfiguration enables the UE to:

evaluate the execution condition, and

apply the configuration of the target PSCell and synchronize to the target PSCell after the execution condition is evaluated as satisfied.

11. The method of claim 10 , wherein both the source PSCell and the target PSCell belong to a secondary node.

12. The method of claim 11 , wherein the configuration of the target PSCell and the execution condition are generated by the secondary node.

13. The method of claim 10 , wherein the source PSCell belongs to a source secondary node, the target PSCell belongs to a target secondary node, the configuration of the target PSCell is generated by the target secondary node, and the execution condition is generated by the source secondary node.

14. The method of claim 10 , wherein the first conditional reconfiguration further enables the UE to:

release all conditional reconfigurations for PSCell change stored in the UE after the first conditional reconfiguration is applied successfully.

15. The method of claim 10 , wherein the first conditional reconfiguration further enables the UE to:

cease evaluating all execution conditions in other conditional reconfigurations for PSCell change stored in the UE after the first conditional reconfiguration is applied.

16. The method of claim 10 , wherein the first conditional reconfiguration further enables the UE to:

forgo detaching from the master node when applying the first conditional reconfiguration.

17. The method of claim 10 , wherein the RRC reconfiguration message includes an indicator that indicates whether the first conditional reconfiguration is for the CPC procedure.

18. The method of claim 10 , wherein the RRC reconfiguration message is transmitted, and the response message is received, via a signaling radio bearer 1 (SRB1).