Channel occupancy time (COT) sharing for sidelink

1 . A method of wireless communication performed by a first user equipment (UE), the method comprising:

receiving, from a second UE, a first sidelink transmission during a first channel occupancy time (COT), wherein the first COT is associated with the second UE, wherein receiving the first sidelink transmission includes receiving sidelink control information (SCI) including a COT structure indicator (COT-SI) indicating whether the COT sharing in the first COT is allowed;

determining whether the second UE is one of two or more UEs intended to receive a second sidelink transmission; and

transmitting, to the two or more UEs, the second sidelink transmission during a portion of the first COT based on COT sharing, the COT sharing being in response to determining the second UE is one of the two or more UEs intended to receive the second sidelink transmission, and further based on the COT-SI indicating the COT sharing in the first COT is allowed.

2 . The method of claim 1 , wherein:

the receiving the first sidelink transmission further comprises:

receiving, from the second UE, the SCI indicating whether the second UE is an initiating UE of the first COT; and

the transmitting the second sidelink transmission during the portion of the first COT based on the COT sharing is further based on the SCI indicating that the second UE is the initiating UE of the first COT.

3 . The method of claim 1 , wherein the transmitting the second sidelink transmission comprises:

transmitting the second sidelink transmission in a broadcast mode.

4 . The method of claim 1 , wherein the transmitting the second sidelink transmission comprises:

transmitting the second sidelink transmission in a groupcast mode.

5 . The method of claim 1 , further comprising:

receiving, from a third UE during a second COT, a third sidelink transmission comprising data;

determining whether the third UE is an initiating UE of the second COT; and

transmitting, during a portion of the second COT in response to determining the third UE is the initiated UE of the second COT, an acknowledgement/negative-acknowledgement (ACK/NACK) feedback for the data.

6 . The method of claim 1 , further comprising:

receiving, from a third UE during a second COT, a third sidelink transmission comprising data;

monitoring for COT sharing information associated with the second COT; and

determining, based on the monitoring, whether to transmit an acknowledgement/negative-acknowledgement (ACK/NACK) feedback for the data during a portion of the second COT.

7 . The method of claim 1 , further comprising:

determining whether the second UE is one of two or more UEs intended to receive a third sidelink transmission; and

refraining from transmitting the third sidelink transmission during the portion of the first COT in response to determining the second UE is not one of the two or more UEs intended to receive the third sidelink transmission.

8 . A first user equipment (UE) comprising:

a memory;

a transceiver; and

at least one processor coupled to the memory and the transceiver, wherein the first UE is configured to:

receive, from a second UE, a first sidelink transmission during a first channel occupancy time (COT), wherein the first COT is associated with the second UE, wherein reception of the first sidelink transmission includes reception of sidelink control information (SCI) including a COT structure indicator (COT-SI) indicating whether the COT sharing in the first COT is allowed;

determine whether the second UE is one of two or more UEs intended to receive a second sidelink transmission; and

transmit, to the two or more UEs, the second sidelink transmission during a portion of the first COT based on COT sharing, the COT sharing being in response to determining the second UE is one of the two or more UEs intended to receive the second sidelink transmission, and further based on the COT-SI indicating the COT sharing in the first COT is allowed.

9 . The first UE of claim 8 , wherein:

the first UE is further configured to:

receive, from the second UE, the SCI indicating whether the second UE is an initiating UE of the first COT; and

transmit the second sidelink transmission during the portion of the first COT further based on the SCI indicating that the second UE is the initiating UE of the first COT.

10 . The first UE of claim 8 , wherein the first UE is further configured to:

transmit the second sidelink transmission in a broadcast mode.

11 . The first UE of claim 8 , wherein the first UE is further configured to:

transmit the second sidelink transmission in a groupcast mode.

12 . The first UE of claim 8 , wherein:

the first UE is further configured to:

receive, from a third UE during a second COT, a third sidelink transmission comprising data;

determine whether the third UE is an initiating UE of the second COT; and

transmit, during a portion of the second COT in response to determining the third UE is the initiated UE of the second COT, an acknowledgement/negative-acknowledgement (ACK/NACK) feedback for the data.

13 . The first UE of claim 8 , wherein:

the first UE is further configured to:

receive, from a third UE during a second COT, a third sidelink transmission comprising data;

monitor for COT sharing information associated with the second COT; and

determine, based on the monitoring, whether to transmit an acknowledgement/negative-acknowledgement (ACK/NACK) feedback for the data during a portion of the second COT.

14 . The first UE of claim 13 , wherein:

the first UE is further configured to:

determine to refrain from transmitting the ACK/NACK feedback during the portion of the second COT in response to determining that there is no COT sharing information associated with the second COT detected from the monitoring;

perform a category 4 (CAT4) LBT; and

transmit, during a third COT based on the CAT4 LBT, the ACK/NACK feedback.

15 . A non-transitory computer-readable medium having program code recorded thereon, the program code comprising:

code for causing a first user equipment (UE) to receive, from a second UE, a first sidelink transmission during a first channel occupancy time (COT), wherein the first COT is associated with the second UE, wherein reception of the first sidelink transmission includes reception of sidelink control information (SCI) including a COT structure indicator (COT-SI) indicating whether the COT sharing in the first COT is allowed;

code for causing the first UE to determine whether the second UE is one of two or more UEs intended to receive a second sidelink transmission; and

code for causing the first UE to transmit, to the two or more UEs, the second sidelink transmission during a portion of the first COT based on COT sharing, the COT sharing being in response to determining the second UE is one of the two or more UEs intended to receive the second sidelink transmission, and further based on the COT-SI indicating the COT sharing in the first COT is allowed.

16 . The non-transitory computer-readable medium of claim 15 , wherein:

the code for causing the first UE to receive the first sidelink transmission is configured to:

receive, from the second UE, the SCI indicating whether the second UE is an initiating UE of the first COT; and

the code for causing the first UE to transmit the second sidelink transmission during the portion of the first COT is configured to:

transmit the second sidelink transmission during the portion of the first COT further based on the SCI indicating that the second UE is the initiating UE of the first COT.

17 . The non-transitory computer-readable medium of claim 15 , wherein code for causing the first UE to transmit the second sidelink transmission is configured to:

transmit the second sidelink transmission in a broadcast mode.

18 . The non-transitory computer-readable medium of claim 15 , wherein the code for causing the first UE to transmit the second sidelink transmission is configured to:

transmit the second sidelink transmission in a groupcast mode.

19 . The non-transitory computer-readable medium of claim 15 , further comprising:

code for causing the first UE to receive, from a third UE during a second COT, a third sidelink transmission comprising data;

code for causing the first UE to determine whether the third UE is an initiating UE of the second COT; and

code for causing the first UE to transmit, during a portion of the second COT in response to determining the third UE is the initiated UE of the second COT, an acknowledgement/negative-acknowledgement (ACK/NACK) feedback for the data.

20 . The non-transitory computer-readable medium of claim 15 , further comprising:

code for causing the first UE to receive, from a third UE during a second COT, a third sidelink transmission comprising data;

code for causing the first UE to monitor for COT sharing information associated with the second COT; and

code for causing the first UE to determine, based on the monitoring, whether to transmit an acknowledgement/negative-acknowledgement (ACK/NACK) feedback for the data during a portion of the second COT.

21 . The non-transitory computer-readable medium of claim 15 , wherein the program code further comprises:

code for causing the first UE to determine whether the second UE is one of two or more UEs intended to receive a third sidelink transmission; and

code for causing the first UE to refrain from transmitting the third sidelink transmission during the portion of the first COT in response to determining the second UE is not one of the two or more UEs intended to receive the third sidelink transmission.

22 . A first user equipment (UE) comprising:

means for receiving, from a second UE, a first sidelink transmission during a first channel occupancy time (COT), wherein the first COT is associated with the second UE, wherein reception of the first sidelink transmission includes reception of sidelink control information (SCI) including a COT structure indicator (COT-SI) indicating whether the COT sharing in the first COT is allowed;

means for determining whether the second UE is one of two or more UEs intended to receive a second sidelink transmission; and

means for transmitting, to the two or more UEs, the second sidelink transmission during a portion of the first COT based on COT sharing, the COT sharing being in response to determining the second UE is one of the two or more UEs intended to receive the second sidelink transmission, and further based on the COT-SI indicating the COT sharing in the first COT is allowed.

23 . The first UE of claim 22 , wherein:

the means for receiving the first sidelink transmission is configured to:

receive, from the second UE, the SCI indicating whether the second UE is an initiating UE of the first COT; and

the means for transmitting the second sidelink transmission during the portion of the first COT is configured to:

transmit the second sidelink transmission during the portion of the first COT further based on the SCI indicating that the second UE is the initiating UE of the first COT.

24 . The first UE of claim 22 , wherein the means for transmitting the second sidelink transmission is configured to:

transmit the second sidelink transmission in at least one of:

a broadcast mode; or

a groupcast mode.

25 . The first UE of claim 22 , further comprising:

means for receiving, from a third UE during a second COT, a third sidelink transmission comprising data;

means for determining whether the third UE is an initiating UE of the second COT; and

means for transmitting, during a portion of the second COT in response to determining the third UE is the initiated UE of the second COT, an acknowledgement/negative-acknowledgement (ACK/NACK) feedback for the data.

26 . The first UE of claim 22 , further comprising:

means for receiving, from a third UE during a second COT, a third sidelink transmission comprising data;

means for monitoring for COT sharing information associated with the second COT; and

means for determining, based on the monitoring, whether to transmit an acknowledgement/negative-acknowledgement (ACK/NACK) feedback for the data during a portion of the second COT.

27 . The first UE of claim 22 , further comprising:

means for determining whether the second UE is one of two or more UEs intended to receive a third sidelink transmission; and

means for refraining from transmitting the third sidelink transmission during the portion of the first COT in response to determining the second UE is not one of the two or more UEs intended to receive the third sidelink transmission.