Method and apparatus for declaring radio link failure in multiple active bandwidth parts in a wireless communication system
A method and an apparatus for declaring radio link failure in multiple active bandwidth parts in a wireless communication system are provided. A wireless device activates a first bandwidth part (BWP) and a second BWP for a serving cell. A wireless device performs a radio link monitoring (RLM) on the first BWP and the second BWP. A wireless device detects a radio link problem on the first BWP. A wireless device decides whether to declare a radio link failure (RLF) for the serving cell based on radio link state of both the first BWP and the second BWP.
1. A method performed by a wireless device in a wireless communication system, the method comprising,
activating a first bandwidth part and a second bandwidth part for a serving cell;
performing a radio link monitoring for the first bandwidth part and the second bandwidth part;
detecting a radio link problem of the first bandwidth part;
deciding not to declare a radio link failure for the serving cell based on that the second bandwidth part is activated;
deactivating the first bandwidth part upon detecting the radio link problem on the first bandwidth part;
performing a transmission to inform the serving cell of the radio link problem of the first bandwidth part, wherein the transmission is performed via the second bandwidth part;
detecting a radio link problem of the second bandwidth part;
deactivating the second bandwidth part upon detecting the radio link problem of the second bandwidth part;
deciding to declare the radio link failure for the serving cell based on both the first bandwidth part and the second bandwidth part are deactivated;
declaring the radio link failure for the serving cell; and
initiating a recovery procedure upon declaring the radio link failure for the serving cell.
2. The method of claim 1 , wherein the radio link failure for the serving cell is decided based on radio state of all of activated bandwidth parts for the serving cell.
3. The method of claim 1 , wherein the radio link problem on the first bandwidth part is detected upon detecting that measurement result of the first bandwidth part is lower than a threshold.
4. The method of claim 1 , wherein the radio link problem on the first bandwidth part is detected upon receiving, by an upper layer of the wireless device, consecutive “out-of-sync” indications from a physical layer of the wireless device.
5. The method of claim 1 , wherein the method further comprises,
starting a radio link problem timer upon detecting a physical layer problem on the first bandwidth part.
6. The method of claim 5 , wherein the radio link problem on the first bandwidth part is detected upon detecting expiry of the radio link problem timer.
7. The method of claim 5 , wherein the radio link problem timer is configured for each of the first bandwidth part and the second bandwidth part, respectively.
8. 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.
9. 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 bandwidth part and a second bandwidth part for a serving cell;
perform a radio link monitoring for the first bandwidth part and the second bandwidth part;
detect a radio link problem of the first bandwidth part;
decide not to declare a radio link failure for the serving cell based on that the second bandwidth part is activated;
deactivate the first bandwidth part upon detecting the radio link problem on the first bandwidth part;
perform a transmission to inform the serving cell of the radio link problem of the first bandwidth part, wherein the transmission is performed via the second bandwidth part;
detect a radio link problem of the second bandwidth part;
deactivate the second bandwidth part upon detecting the radio link problem of the second bandwidth part;
decide to declare the radio link failure for the serving cell based on both the first bandwidth part and the second bandwidth part are deactivated;
declare the radio link failure for the serving cell; and
initiate a recovery procedure upon declaring the radio link failure for the serving cell.
10. A non-transitory computer-readable medium having stored thereon a plurality of instructions, which, when executed by a processor of a wireless device, cause the wireless device to:
activate a first bandwidth part and a second bandwidth part for a serving cell;
perform a radio link monitoring for the first bandwidth part and the second bandwidth part;
detect a radio link problem of the first bandwidth part;
decide not to declare a radio link failure for the serving cell based on that the second bandwidth part is activated;
deactivate the first bandwidth part upon detecting the radio link problem on the first bandwidth part;
perform a transmission to inform the serving cell of the radio link problem of the first bandwidth part, wherein the transmission is performed via the second bandwidth part;
detect a radio link problem of the second bandwidth part;
deactivate the second bandwidth part upon detecting the radio link problem of the second bandwidth part;
decide to declare the radio link failure for the serving cell based on both the first bandwidth part and the second bandwidth part are deactivated;
declare the radio link failure for the serving cell; and
initiate a recovery procedure upon declaring the radio link failure for the serving cell.