Method and apparatus for handling BWP switching in random access procedure
A method for random access performed by a MAC entity of a UE is provided. The method includes: receiving a first beam failure recovery configuration of a first UL BWP; receiving a second beam failure recovery configuration of a second UL BWP; initiating a first RA procedure on the first UL BWP by applying at least one first RA parameter configured in the first beam failure recovery configuration, when a number of beam failure instances that have been received from lower layers is larger than or equal to a threshold; switching an active UL BWP of the UE from the first UL BWP to a second UL BWP before completion of the first RA procedure; and initiating a second RA procedure on the second UL BWP by applying at least one second RA parameter configured in the second beam failure recovery configuration, after switching to the second UL BWP.
1. A user equipment (UE) comprising:
one or more non-transitory computer-readable media having computer-executable instructions embodied thereon; and
at least one processor coupled to the one or more non-transitory computer-readable media, the at least one processor is configured to execute the computer-executable instructions to:
receive, by a Medium Access Control (MAC) entity of the UE, a first beam failure recovery configuration of a first uplink (UL) bandwidth part (BWP);
receive, by the MAC entity of the UE, a second beam failure recovery configuration of a second UL BWP;
initiate, by the MAC entity of the UE, a first Random Access (RA) procedure on the first UL BWP for notifying a base station of a beam failure occurrence in a serving cell by applying at least one first RA parameter configured in the first beam failure recovery configuration of the first UL BWP when a number of beam failure instances that have been received from lower layers of the UE is larger than or equal to a threshold;
receive a Radio Resource Control (RRC) message that triggers BWP switching before completion of the first RA procedure;
switch, by the MAC entity of the UE, an active UL BWP of the UE from the first UL BWP to the second UL BWP upon receiving the RRC message and before completion of the first RA procedure; and
initiate, by the MAC entity of the UE, a second RA procedure on the second UL BWP for notifying the base station of the beam failure occurrence regardless of a number of beam failure instances received after switching the active UL BWP of the UE to the second UL BWP by applying at least one second RA parameter configured in the second beam failure recovery configuration of the second UL BWP, after switching the active UL BWP of the UE to the second UL BWP.
2. The UE of claim 1 , wherein the at least one second RA parameter comprises a power ramping step applied for a prioritized RA procedure.
3. The UE of claim 1 , wherein the at least one second RA parameter comprises a scaling factor for a backoff indicator (BI).
4. The UE of claim 1 , wherein the at least one processor is further configured to execute the computer-executable instructions to:
stop the first RA procedure.
5. The UE of claim 1 , wherein the first UL BWP is not configured with Physical Random Access Channel (PRACH) occasions, and the second UL BWP is an initial UL BWP of the UE.
6. A method for random access (RA) performed by a Medium Access Control (MAC) entity of a user equipment (UE), the method comprising:
receiving a first beam failure recovery configuration of a first uplink (UL) bandwidth part (BWP);
receiving a second beam failure recovery configuration of a second UL BWP;
initiating a first Random Access (RA) procedure on the first UL BWP for notifying a base station of a beam failure occurrence in a serving cell by applying at least one first RA parameter configured in the first beam failure recovery configuration of the first UL BWP when a number of beam failure instances that have been received from lower layers of the UE is larger than or equal to a threshold;
receiving a Radio Resource Control (RRC) message that triggers BWP switching before completion of the first RA procedure;
switching an active UL BWP of the UE from the first UL BWP to the second UL BWP upon receiving the RRC message and before completion of the first RA procedure; and
initiating a second RA procedure on the second UL BWP for notifying the base station of the beam failure occurrence regardless of a number of beam failure instances received after switching the active UL BWP of the UE to the second UL BWP by applying at least one second RA parameter configured in the second beam failure recovery configuration of the second UL BWP, after switching the active UL BWP of the UE to the second UL BWP.
7. The method of claim 6 , wherein the at least one second RA parameter comprises a power ramping step applied for a prioritized RA procedure.
8. The method of claim 6 , wherein the at least one second RA parameter comprises a scaling factor for a backoff indicator (BI).
9. The method of claim 6 , further comprising:
stopping the first RA procedure.
10. The method of claim 6 , wherein the first UL BWP is not configured with Physical Random Access Channel (PRACH) occasions, and the second UL BWP is an initial UL BWP of the UE.