Method and apparatus for handling measurement in wireless communication system

1. A method performed by a User Equipment (UE) for handling measurement operations in a wireless communication system, the method comprising:

receiving a first measurement configuration in system information from a first serving cell, the first measurement configuration indicating at least one first cell applicable for being measured by the UE in a first Radio Resource Control (RRC) state which is an RRC idle state or an RRC inactive state;

performing, in the first RRC state, a first measurement operation based on the first measurement configuration to generate a first measurement result of the at least one first cell;

generating the first measurement result after performing the first measurement operation;

receiving a measurement report request in an RRC resume message from a second serving cell;

retaining the first measurement result after the UE transitions from the first RRC state to a second RRC state which is an RRC connected state; and

transmitting, in response to receiving the measurement report request, the first measurement result to the second serving cell in an RRC resume complete message.

2. The method of claim 1 , wherein the first measurement configuration further indicates a first carrier frequency to which the at least one first cell belongs.

3. The method of claim 2 , wherein the first measurement configuration further indicates a subcarrier spacing associated with the first carrier frequency.

4. The method of claim 2 , further comprising:

receiving a second measurement configuration in the system information from the first serving cell, the second measurement configuration indicating at least one second cell applicable for being measured by the UE in the first RRC state and a second carrier frequency to which the at least one second cell belongs.

5. The method of claim 4 , wherein the at least one first cell is associated with a first Radio Access Technology (RAT) and the at least one second cell is associated with a second RAT.

6. The method of claim 4 , further comprising:

performing, in the first RRC state, a second measurement operation based on the second measurement configuration to generate a second measurement result of the at least one second cell, the first measurement result being associated with a first RAT and the second measurement result being associated with a second RAT.

7. The method of claim 1 , wherein the first serving cell is associated with a first RAT and the second serving cell is associated with a second RAT.

8. The method of claim 1 , further comprising:

receiving the RRC resume message in a Random Access Response (RAR) message during a 2-step Random Access (RA) procedure.

9. The method of claim 1 , further comprising:

receiving the RRC resume message during a 4-step Random Access (RA) procedure.

10. The method of claim 1 , further comprising:

receiving another measurement report request in an RRC setup message from the second serving cell; and

transmitting, in response to receiving the other measurement report request, the first measurement result to the second serving cell in an RRC setup complete message.

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

12. The method of claim 10 , further comprising:

receiving the RRC setup message in an RAR message during a 2-step Random Access (RA) procedure.

13. The method of claim 10 , further comprising:

receiving the RRC setup message during a 4-step RA procedure.

14. The method of claim 1 , wherein the first RRC state is associated with a first RAT and the second RRC state is associated with a second RAT.

15. A User Equipment (UE) for handling measurement operations in a wireless communication system, the UE comprising:

a memory; and

at least one processor coupled to the memory, the at least one processor being configured to:

receive a first measurement configuration in system information from a first serving cell, the first measurement configuration indicating at least one first cell applicable for being measured by the UE in a first Radio Resource Control (RRC) state which is an RRC idle state or an RRC inactive state;

perform, in the first RRC state, a first measurement operation based on the first measurement configuration to generate a first measurement result of the at least one first cell;

generate the first measurement result after performing the first measurement operation;

receive a measurement report request in an RRC resume message from a second serving cell;

retain the first measurement result after the UE transitions from the first RRC state to a second RRC state which is an RRC connected state; and

transmit, in response to receiving the measurement report request, the first measurement result to the second serving cell in an RRC resume complete message.

16. The UE of claim 15 , wherein the first measurement configuration further indicates a first carrier frequency to which the at least one first cell belongs.

17. The UE of claim 16 , wherein the first measurement configuration further indicates a subcarrier spacing associated with the first carrier frequency.

18. The UE of claim 16 , wherein the at least one processor is further configured to:

receive a second measurement configuration in the system information from the first serving cell, the second measurement configuration indicating at least one second cell applicable for being measured by the UE in the first RRC state and a second carrier frequency to which the at least one second cell belongs.

19. The UE of claim 18 , wherein the at least one first cell is associated with a first Radio Access Technology (RAT) and the at least one second cell is associated with a second RAT.

20. The UE of claim 18 , wherein the at least one processor is further configured to:

perform, in the first RRC state, a second measurement operation based on the second measurement configuration to generate a second measurement result of the at least one second cell, the first measurement result being associated with a first RAT and the second measurement result being associated with a second RAT.

21. The UE of claim 15 , wherein the first serving cell is associated with a first RAT and the second serving cell is associated with a second RAT.

22. The UE of claim 15 , wherein the at least one processor is further configured to:

receive the RRC resume message in a Random Access Response (RAR) message during a 2-step Random Access (RA) procedure.

23. The UE of claim 15 , wherein the at least one processor is further configured to:

receive the RRC resume message during a 4-step Random Access (RA) procedure.

24. The UE of claim 15 , wherein the at least one processor is further configured to:

receive another measurement report request in an RRC setup message from the second serving cell; and

transmit, in response to receiving the other measurement report request, the first measurement result to the second serving cell in an RRC setup complete message.

25. The UE of claim 24 , wherein the first serving cell is associated with a first RAT and the second serving cell is associated with a second RAT.

26. The UE of claim 24 , wherein the at least one processor is further configured to:

receive the RRC setup message in an RAR message during a 2-step RA procedure.

27. The UE of claim 24 , wherein the at least one processor is further configured to:

receive the RRC setup message during a 4-step RA procedure.

28. The UE of claim 15 , wherein the first RRC state is associated with a first RAT and the second RRC state is associated with a second RAT.