Method and apparatus for radio link monitoring for multiple active bandwidth parts in a wireless communication system

1. A method performed by a wireless device in a wireless communication system, the method comprising:

receiving a Bandwidth Part (BWP) configuration including information on (i) multiple BWPs, and (ii) a priority for the multiple BWPs;

activating a first BWP and a second BWP among the multiple BWPs;

performing Radio Link Monitoring (RLM) procedure only for the first BWP which has been determined as a primary active BWP;

initiating a first random access procedure for the first BWP;

determining to change the primary active BWP from the first BWP to the second BWP upon detecting a BWP failure for the first BWP, wherein the second BWP is selected based on the information on the priority for the multiple BWPs;

stopping the first random access procedure for the first BWP, upon detecting the BWP failure for the first BWP;

performing RLM procedure for the second BWP which is selected as the primary active BWP;

initiating a second random access procedure for the second BWP, after changing the primary active BWP from the first BWP to the second BWP; and

transmitting a BWP failure information informing the BWP failure for the first BWP via the second BWP, after completing the second random access procedure.

2. The method of claim 1 , wherein the BWP failure information includes a BWP identity of the first BWP.

3. The method of claim 1 , wherein the BWP failure information includes a cause of the BWP failure for the first BWP.

4. The method of claim 3 , wherein the cause of the BWP failure includes at least one of (i) a Medium Access Control (MAC) layer problem, (ii) Radio Link Control (RLC) layer problem, and/or (iii) a Physical (PHY) layer problem.

5. The method of claim 1 , wherein the method further comprises, deactivating the first BWP, upon detecting the BWP failure for the first BWP.

6. The method of claim 1 , wherein the method further comprises, declaring a radio link failure, based on detecting a BWP failure for all activate BWPs among the multiple BWPs.

7. The method of claim 1 , wherein the wireless device is in communication with at least one of a user equipment, a network, or an autonomous vehicle other than the wireless device.

8. A wireless device in a wireless communication system comprising:

a transceiver;

a memory; and

at least one processor operatively coupled to the transceiver and the memory, and configured to:

activate a first BWP and a second BWP among the multiple BWPs;

perform Radio Link Monitoring (RLM) procedure only for the first BWP which has been determined as a primary active BWP;

initiate a first random access procedure for the first BWP;

determine to change the primary active BWP from the first BWP to the second BWP upon detecting a BWP failure for the first BWP, wherein the second BWP is selected based on the information on the priority for the multiple BWPs;

stop the first random access procedure for the first BWP, upon detecting the BWP failure for the first BWP;

perform RLM procedure for the second BWP which is selected as the primary active BWP;

initiate a second random access procedure for the second BWP, after changing the primary active BWP from the first BWP to the second BWP; and

transmit a BWP failure information informing the BWP failure for the first BWP via the second BWP, after completing the second random access procedure.

9. A processor for a wireless device in a wireless communication system, wherein the processor is configured to control the wireless device to perform operations comprising:

activating a first BWP and a second BWP among the multiple BWPs;

performing Radio Link Monitoring (RLM) procedure only for the first BWP which has been determined as a primary active BWP;

initiating a first random access procedure for the first BWP;

determining to change the primary active BWP from the first BWP to the second BWP upon detecting a BWP failure for the first BWP, wherein the second BWP is selected based on the information on the priority for the multiple BWPs; and

stopping the first random access procedure for the first BWP, upon detecting the BWP failure for the first BWP;

performing RLM procedure for the second BWP which is selected as the primary active BWP;

initiating a second random access procedure for the second BWP, after changing the primary active BWP from the first BWP to the second BWP; and

transmitting a BWP failure information informing the BWP failure for the first BWP via the second BWP, after completing the second random access procedure.