Channel occupancy time contention grant for sidelink communications
Wireless communications systems and methods related to communicating control information are provided. A method of wireless communication performed by a sidelink user equipment (UE) may include receiving, from a base station (BS), a configuration indicating a listen-before-talk (LBT) window, wherein the configuration indicates a start and an end associated with the LBT window, performing, during the LBT window, an LBT for a channel occupancy time (COT) in a shared radio frequency band, and transmitting, to another sidelink UE, based on the LBT being successful, one or more transport blocks (TBs) during the COT.
1. A method of wireless communication performed by a first sidelink user equipment (UE), the method comprising:
transmitting to a base station (BS), a buffer status report (BSR) indicating an amount of data to be transmitted from the first sidelink UE to a second sidelink UE;
receiving, from the BS, a configuration indicating a listen-before-talk (LBT) window for sidelink communications between the first sidelink UE and the second sidelink UE, wherein the configuration indicates a start and an end associated with the LBT window and a maximum channel occupancy time (COT) duration, wherein the maximum COT duration is based on the BSR;
performing, during the LBT window, an LBT for a COT in a shared radio frequency band; and
transmitting, to the second sidelink UE, based on the LBT being successful, one or more transport blocks (TBs) during the COT using the maximum COT duration.
2. The method of claim 1 , wherein the configuration is based on a topology of a wireless network comprising at least the first sidelink UE and the BS.
3. The method of claim 1 , wherein:
the start associated with the LBT window is based on at least one of a first slot index or a first sub-slot index; and
the end associated with the LBT window is based on at least one of a second slot index or a second sub-slot index.
4. The method of claim 1 , wherein:
the maximum COT duration extends past the end associated with the LBT window.
5. The method of claim 1 , further comprising:
transmitting, to the BS based on the LBT being unsuccessful, a request for a second configuration indicating another LBT window.
6. The method of claim 1 ,
wherein the configuration further indicates frequency resources associated with the maximum COT duration.
7. The method of claim 1 , wherein:
the configuration further indicates a start and an end associated with the COT; and
the transmitting the one or more TBs during the COT comprises transmitting the one or more TBs after the start associated with the COT and before the end associated with the COT.
8. A method of wireless communication performed by a base station (BS), the method comprising:
receiving, from a first sidelink user equipment (UE), a buffer status report (BSR) indicating an amount of data to be transmitted from the first sidelink UE to a second sidelink UE;
transmitting, to the first sidelink UE, a configuration indicating:
a listen-before-talk (LBT) window for sidelink communications between the first sidelink UE and the second sidelink UE, wherein the configuration indicates a start and an end associated with the LBT window and a maximum channel occupancy time (COT) duration for a COT, wherein the maximum COT duration is based on the BSR; and
the COT in a shared radio frequency band for the sidelink communications.
9. The method of claim 8 , wherein the configuration is based on a topology of a wireless network comprising at least the BS and the first sidelink UE.
10. The method of claim 8 , wherein:
the start associated with the LBT window is based on at least one of a first slot index or a first sub-slot index; and
the end associated with the LBT window is based on at least one of a second slot index or a second sub-slot index.
11. The method of claim 8 , wherein:
the maximum COT duration extends past the end associated with the LBT window.
12. The method of claim 8 ,
wherein the configuration further indicates frequency resources associated with the maximum COT duration.
13. A first user equipment (UE) comprising:
a transceiver, a memory, and a processor coupled to the transceiver and the memory, the first UE configured to:
transmit to a base station (BS), a buffer status report (BSR) indicating an amount of data to be transmitted from the first UE to a second UE;
receive, from the BS, a configuration indicating a listen-before-talk (LBT) window for sidelink communications between the first UE and the second UE, wherein the configuration indicates a start and an end associated with the LBT window and a maximum channel occupancy time (COT) duration, wherein the maximum COT duration is based on the BSR;
perform, during the LBT window, an LBT for a COT in a shared radio frequency band; and
transmit, to the second UE, based on the LBT being successful, one or more transport blocks (TBs) during the COT using the maximum COT duration.
14. The first UE of claim 13 , wherein:
the LBT comprises a category four LBT.
15. The first UE of claim 13 , wherein:
the configuration is based on a topology of a wireless network comprising at least the first UE and the BS.
16. The first UE of claim 13 , wherein:
the maximum COT duration extends past the end associated with the LBT window.
17. The first UE of claim 13 , wherein:
the first UE is further configured to receive the configuration in a licensed radio frequency band.
18. The first UE of claim 13 , wherein:
the first UE is further configured to receive the configuration in a downlink control information (DCI) message.
19. The first UE of claim 13 , wherein:
the configuration comprises a frequency domain resource allocation (FDRA) that indicates at least one frequency range in the shared radio frequency band; and
the first UE is further configured to perform the LBT in the at least one frequency range in the shared radio frequency band.
20. The first UE of claim 19 , wherein:
the at least one frequency range in the shared radio frequency band comprises a first plurality of frequencies, wherein the first plurality of frequencies is interlaced with a second plurality of frequencies in the shared radio frequency band.
21. The first UE of claim 13 , wherein:
the configuration comprises at least one beam direction associated with the LBT;
the first UE is further configured to perform the LBT in the at least one beam direction; and
the first UE is further configured to transmit the one or more TBs in the at least one beam direction.
22. The first UE of claim 13 , wherein:
the start associated with the LBT window is based on at least one of a first slot index or a first sub-slot index; and
the end associated with the LBT window is based on at least one of a second slot index or a second sub-slot index.
23. The first UE of claim 13 , wherein:
the first UE is further configured to transmit, to the BS based on the LBT being unsuccessful, a request for a second configuration indicating another LBT window.
24. The first UE of claim 13 ,
wherein the configuration further indicates frequency resources associated with the maximum COT duration.
25. A base station (BS) comprising:
a transceiver, a memory, and a processor coupled to the transceiver and the memory, the BS configured to:
receive, from a first sidelink user equipment (UE), a buffer status report (BSR) indicating an amount of data to be transmitted from the first sidelink UE to a second sidelink UE;
transmit, to a first sidelink UE, a configuration indicating:
a listen-before-talk (LBT) window for sidelink communications between the first sidelink UE and the second sidelink UE, wherein the configuration indicates a start and an end associated with the LBT window and a maximum channel occupancy time (COT) duration for a COT, wherein the maximum COT duration is based on the BSR; and
the COT in a shared radio frequency band for the sidelink communications.
26. The BS of claim 25 , wherein the configuration is based on a topology of a wireless network comprising at least the BS and the first sidelink UE.
27. The BS of claim 25 , wherein:
the start associated with the LBT window is based on at least one of a first slot index or a first sub-slot index; and
the end associated with the LBT window is based on at least one of a second slot index or a second sub-slot index.
28. The BS of claim 25 , wherein:
the maximum COT duration extends past the end associated with the LBT window.
29. The BS of claim 25 , wherein the configuration comprises a first frequency domain resource allocation (FDRA) indicating at least one frequency range in the shared radio frequency band.
30. The BS of claim 25 ,
wherein the configuration further indicates frequency resources associated with the maximum COT duration.