CHANNEL ACCESS PRIORITY CLASS SELECTION FOR SIDELINK OPERATION WITH SHARED SPECTRUM CHANNEL ACCESS

1 . A user equipment (UE) for wireless communication, comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the UE to:

generate an Sidelink (SL) transport block (TB) to be transmitted to a set of receiving UEs (Rx UEs), wherein the SL TB comprises data units associated with a plurality of SL logical channels (LCHs), each SL LCH associated with a respective channel access priority class (CAPC);

determine a highest priority CAPC associated with the SL TB;

select a CAPC value for the SL TB based at least in part on the highest priority CAPC satisfying a threshold;

perform a listen-before-talk (LBT) procedure using a set of LBT parameters corresponding to the selected CAPC value; and

transmit the SL TB based at least in part on a success of the LBT procedure.

2 . The UE of claim 1 , wherein to select the CAPC value, the at least one processor is configured to cause the UE to select the highest priority CAPC in response to the highest priority CAPC satisfying the threshold.

3 . The UE of claim 2 , wherein to select the CAPC value, the at least one processor is configured to cause the UE to select a lowest priority CAPC in response to the highest priority CAPC not satisfying the threshold, wherein the lowest priority CAPC is associated with a longer contention window (CW) than the highest priority CAPC.

4 . The UE of claim 1 , wherein to select the CAPC value, the at least one processor is configured to cause the UE to further select the CAPC value based at least in part on an amount or a ratio of data associated with the highest priority CAPC satisfying a predetermined amount or a predetermined ratio.

5 . The UE of claim 1 , wherein the at least one processor is further configured to cause the UE to initiate a SL communication with the set of Rx UEs over an unlicensed band, and wherein the SL communication corresponds to the one or more SL LCHs.

6 . The UE of claim 5 , wherein to initiate the SL communication, the at least one processor is configured to cause the UE to select a SL grant, wherein the SL grant fails to indicate a CAPC value for a corresponding SL transmission.

7 . The UE of claim 5 , wherein to initiate the SL communication, the at least one processor is configured to cause the UE to:

perform a sensing procedure associated with the unlicensed band; and

determine an available SL resource for the SL communication based at least in part on a result of the sensing procedure.

8 . The UE of claim 1 , wherein the plurality of SL LCHs comprises at least one SL traffic channel (STCH).

9 . The UE of claim 1 , wherein the respective CAPC is based at least in part on a delay requirement of a corresponding SL LCH.

10 . The UE of claim 1 , wherein the at least one processor is further configured to cause the UE to remove one or more data units from the SL TB in response to the selected CAPC not satisfying a packet delay budget associated with one of the plurality of SL LCHs, wherein the data units comprise medium access control (MAC) service data units (SDUs).

11 . A method performed by a user equipment (UE), the method comprising:

generating an Sidelink (SL) transport block (TB) to be transmitted to a set of receiving UEs (Rx UEs), wherein the SL TB comprises data units associated with a plurality of SL logical channels (LCHs), each SL LCH associated with a respective channel access priority class (CAPC);

determining a highest priority CAPC associated with the SL TB;

selecting a CAPC value for the SL TB based at least in part on the highest priority CAPC satisfying a threshold;

performing a listen-before-talk (LBT) procedure using a set of LBT parameters corresponding to the selected CAPC value; and

transmitting the SL TB based at least in part on a success of the LBT procedure.

12 . The method processer of claim 11 , wherein selecting the CAPC value comprises selecting the highest priority CAPC in response to the highest priority CAPC satisfying the threshold.

13 . The method of claim 12 , wherein selecting to select the CAPC value comprises selecting a lowest priority CAPC in response to the highest priority CAPC not satisfying the threshold, wherein the lowest priority CAPC is associated with a longer contention window (CW) than the highest priority CAPC.

14 . The method processor of claim 11 , wherein selecting the CAPC value further comprises selecting the CAPC value based at least in part on an amount or a ratio of data associated with the highest priority CAPC satisfying a predetermined amount or a predetermined ratio.

15 . The method processer of claim 11 , further comprising initiating a SL communication with the set of Rx UEs over an unlicensed band, and wherein the SL communication corresponds to the one or more SL LCHs.

16 . The method of claim 15 , wherein initiating the SL communication comprises selecting a SL grant, wherein the SL grant fails to indicate a CAPC value for a corresponding SL transmission.

17 . The method of claim 15 , wherein initiating the SL communication comprises:

performing a sensing procedure associated with the unlicensed band; and

determining an available SL resource for the SL communication based at least in part on a result of the sensing procedure.

18 . The method of claim 11 , wherein the plurality of SL LCHs comprises at least one SL traffic channel (STCH).

19 . The method of claim 11 , wherein the respective CAPC is based at least in part on a delay requirement of a corresponding SL LCH.

20 . The method of claim 11 , further comprising removing one or more data units from the SL TB in response to the selected CAPC not satisfying a packet delay budget associated with one of the plurality of SL LCHs, wherein the data units comprise medium access control (MAC) service data units (SDUs).