SL BWP mismatch
Methods, apparatuses, and computer-readable storage medium for SL communications are provided. An example method may include transmitting, to a second UE, a SL BWP switching request message requesting a switch from a first BWP to a second BWP. The example method may further include receiving, from the second UE, an SL BWP switching decision message confirming the switch from the first BWP to the second BWP. The example method may further include switching from the first BWP to the second BWP upon receiving the SL BWP switching decision message. The example method may further include transmitting, to the second UE, an SL BWP switching confirmation message confirming the switch from the first BWP to the second BWP. The example method may further include reverting back to the first BWP.
1. An apparatus for wireless communication at a first user equipment (UE), comprising:
a memory; and
at least one processor coupled to the memory and configured to:
transmit, to a second UE, a sidelink (SL) bandwidth part (BWP) switching request message requesting a switch from a first BWP to a second BWP;
receive, from the second UE, an SL BWP switching decision message confirming the switch from the first BWP to the second BWP;
switch from the first BWP to the second BWP upon receiving the SL BWP switching decision message;
transmit, to the second UE, an SL BWP switching confirmation message confirming the switch from the first BWP to the second BWP after the switch from the first BWP to the second BWP; and
revert back to the first BWP based on an expiration of a BWP mismatch timer or based on reception of a BWP information associated with the second UE representing a BWP mismatch between the first UE and the second UE.
2. The apparatus of claim 1 , wherein the at least one processor coupled to the memory is further configured to:
initiate the BWP mismatch timer upon transmitting the SL BWP switching confirmation message; and
disregard the BWP mismatch timer based on a matching transmission resource pool and a matching reception resource pool between the first UE and the second UE.
3. The apparatus of claim 1 , wherein a duration of the BWP mismatch timer is set by a base station.
4. The apparatus of claim 1 , wherein a duration of the BWP mismatch timer is set by the first UE.
5. The apparatus of claim 1 , wherein a duration of the BWP mismatch timer is based on a physical sidelink feedback channel (PSFCH) configuration of the first UE.
6. The apparatus of claim 1 , wherein the at least one processor coupled to the memory is further configured to:
transmit, to the second UE, an SL transmission in a transmission pool of the first UE that matches a reception pool of the second UE; and
receive, from the second UE in response to the SL transmission, the BWP information associated with the second UE.
7. The apparatus of claim 1 , wherein the at least one processor coupled to the memory is further configured to:
transmit, to a third UE, an SL transmission in a transmission pool of the first UE that matches with a reception pool of the third UE; and
receive, from the third UE in response to the SL transmission, the BWP information associated with the second UE.
8. The apparatus of claim 1 , wherein to revert back to the first BWP, the at least one processor coupled to the memory is further configured to:
perform a BWP switch with a group of UEs, wherein the group of UEs comprises one or more SL peer UEs of the first UE besides the second UE; and
communicate with the second UE based on the first BWP.
9. The apparatus of claim 1 , wherein the at least one processor coupled to the memory is further configured to:
retransmit, to the second UE, the SL BWP switching confirmation message confirming the switch from the first BWP to the second BWP.
10. The apparatus of claim 9 , wherein the at least one processor coupled to the memory is further configured to:
transmit, to a group of UEs, an indication that the first UE is reverting back to the first BWP, wherein the group of UEs comprises one or more SL peer UEs of the first UE besides the second UE.
11. The apparatus of claim 9 , wherein the second BWP comprises a matching resource pool that corresponds with a resource pool in the first BWP.
12. The apparatus of claim 1 , wherein the at least one processor coupled to the memory is further configured to:
retransmit, to the second UE via a third UE, the SL BWP switching confirmation message confirming the switch from the first BWP to the second BWP.
13. The apparatus of claim 1 , wherein the first BWP and the second BWP are associated with a same component carrier (CC).
14. The apparatus of claim 1 , further comprising a transceiver or an antenna coupled to the at least one processor.
15. An apparatus for wireless communication at a first user equipment (UE), comprising:
a memory; and
at least one processor coupled to the memory and configured to:
receive, from a second UE, a sidelink (SL) bandwidth part (BWP) switching request message requesting a switch from a first BWP to a second BWP;
transmit, to the second UE, an SL BWP switching decision message confirming the switch from the first BWP to the second BWP; and
receive, by the first UE and from a third UE, an SL BWP switching confirmation message confirming the switch from the first BWP to the second BWP.
16. The apparatus of claim 15 , wherein the first BWP and the second BWP are associated with a same component carrier (CC).
17. The apparatus of claim 15 , further comprising a transceiver or an antenna coupled to the at least one processor.
18. A method for wireless communication at a first user equipment (UE), comprising:
transmitting, to a second UE, a sidelink (SL) bandwidth part (BWP) switching request message requesting a switch from a first BWP to a second BWP;
receiving, from the second UE, an SL BWP switching decision message confirming the switch from the first BWP to the second BWP;
switching from the first BWP to the second BWP upon receiving the SL BWP switching decision message;
transmitting, to the second UE, an SL BWP switching confirmation message confirming the switch from the first BWP to the second BWP after switching from the first BWP to the second BWP; and
reverting back to the first BWP based on an expiration of a BWP mismatch timer or based on reception of a BWP information associated with the second UE representing a BWP mismatch between the first UE and the second UE.
19. The method of claim 18 , further comprising:
initiating the BWP mismatch timer upon transmitting the SL BWP switching confirmation message; and
disregarding the BWP mismatch timer based on a matching transmission resource pool and a matching reception resource pool between the first UE and the second UE.
20. The method of claim 18 , wherein a duration of the BWP mismatch timer is set by a base station.
21. The method of claim 18 , wherein a duration of the BWP mismatch timer is set by the first UE.
22. The method of claim 18 , wherein a duration of the BWP mismatch timer is based on a physical sidelink feedback channel (PSFCH) configuration of the first UE.
23. The method of claim 18 , further comprising:
transmitting, to the second UE, an SL transmission in a transmission pool of the first UE that matches a reception pool of the second UE; and
receiving, from the second UE in response to the SL transmission, the BWP information associated with the second UE in response to the SL transmission.
24. The method of claim 18 , further comprising:
transmitting, to a third UE, an SL transmission in a transmission pool of the first UE that matches with a reception pool of the third UE; and
receiving, from the third UE in response to the SL transmission, the BWP information associated with the second UE in response to the SL transmission.
25. The method of claim 18 , further comprising reverting back to the first BWP by:
performing a BWP switch with a group of UEs, wherein the group of UEs comprises one or more SL peer UEs of the first UE besides the second UE; and
communicating with the second UE based on the first BWP.
26. The method of claim 18 , further comprising:
retransmitting, to the second UE, the SL BWP switching confirmation message confirming the switch from the first BWP to the second BWP.
27. The method of claim 18 , further comprising:
transmitting, to a group of UEs, an indication that the first UE is reverting back to the first BWP, wherein the group of UEs comprises one or more SL peer UEs of the first UE besides the second UE.
28. The method of claim 27 , wherein the second BWP comprises a matching resource pool that correspond with a resource pool in the first BWP.
29. The method of claim 18 , further comprising:
retransmitting, to the second UE via a third UE, the SL BWP switching confirmation message confirming the switch from the first BWP to the second BWP.
30. A method for wireless communication at a first user equipment (UE), comprising:
receiving, from a second UE, a sidelink (SL) bandwidth part (BWP) switching request message requesting a switch from a first BWP to a second BWP;
transmitting, to the second UE, an SL BWP switching decision message confirming the switch from the first BWP to the second BWP; and
receiving, by the first UE and from a third UE, an SL BWP switching confirmation message confirming the switch from the first BWP to the second BWP.