Techniques for channel occupancy time sharing between a user equipment and a network entity
Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for channel access for wireless communications, for example, in unlicensed frequency bands. In some cases, a UE may act as an initiating device, initiating access to a wireless channel if it detects a network entity has failed to access a channel during a channel occupancy time (COT) of a frame period (FP).
1. A method for wireless communications by a user equipment (UE), comprising:
detecting a network entity has failed to access a channel during a channel occupancy time (COT) of a frame period (FP) of the network entity; and
initiating access of the channel to start a UE COT in response to the detection, wherein the network entity is allowed to share the channel during the UE COT.
2. The method of claim 1 , wherein initiating access to the channel comprises:
performing a listen before talk (LBT) procedure; and
sending an uplink transmission to notify the network entity of the UE COT.
3. The method of claim 2 , further comprising determining a period to send the uplink transmission.
4. The method of claim 3 , wherein:
the period is determined based on a radio resource control (RRC) configuration of one or more uplink transmission periods.
5. The method of claim 4 , wherein the determined period occurs at least a determined period after a start of the FP of the network entity.
6. The method of claim 4 , wherein:
the uplink transmission is sent in one of a subset of the uplink transmission periods available to start a UE COT.
7. The method of claim 4 , wherein:
the uplink transmission is sent in a period reserved for uplink transmission only if the network entity has failed to access a channel during the COT of the FP of the network entity.
8. The method of claim 4 , wherein:
the uplink transmission is sent in an uplink transmission period dedicated for the UE to contend for the channel if the UE detects the network entity has failed to access the channel during the COT of the FP of the network entity.
9. The method of claim 1 , wherein:
the network entity is allowed to share the channel until a boundary of a subsequent FP of the network entity.
10. The method of claim 1 , wherein:
the network entity is allowed to share the channel until an end of the UE COT.
11. The method of claim 1 , wherein:
one or more other UEs are also allowed to share the channel during the UE COT.
12. The method of claim 11 , wherein:
one or more other UEs are not allowed to share the channel during the UE COT at least for data transmission.
13. The method of claim 12 , wherein:
the network entity transmits one or more signals indicating the network entity is not an owner of the UE COT.
14. The method of claim 13 , wherein the one or more signals are conveyed via a downlink control information (DCI).
15. The method of claim 12 , wherein detection that the network entity has failed to access a channel during a beginning of the COT of the FP of the network entity indicates the UE COT is a shared COT.
16. A method for wireless communications by a network entity, comprising:
receiving an uplink transmission from a user equipment (UE) indicating a start of a UE channel occupancy time (COT) associated with a channel in response to the network entity failing to access the channel during a COT of a frame period (FP) of the network entity; and
sharing access to the channel during the UE COT.
17. The method of claim 16 , wherein failing to access the channel comprises failing a listen before talk (LBT) procedure.
18. The method of claim 17 , further comprising determining a period to monitor for the uplink transmission from the UE.
19. The method of claim 18 , wherein:
the period is determined based on a radio resource control (RRC) configuration of one or more uplink transmission periods.
20. The method of claim 19 , wherein the determined period occurs at least a determined period after a start of the FP of the network entity.
21. The method of claim 19 , wherein:
the uplink transmission is sent in one of a subset of the uplink transmission periods available to start a UE COT.
22. The method of claim 19 , wherein:
the uplink transmission is sent in a period reserved for uplink transmission only if the network entity has failed to access a channel during the COT of the FP of the network entity.
23. The method of claim 19 , wherein:
the uplink transmission is sent in an uplink transmission period dedicated for the UE to contend for the channel if the UE detects the network entity has failed to access the channel during the COT of the FP of the network entity.
24. The method of claim 16 , wherein:
the network entity is allowed to share the channel until a boundary of a subsequent FP of the network entity.
25. The method of claim 16 , wherein:
the network entity is allowed to share the channel until an end of the UE COT.
26. The method of claim 16 , wherein:
one or more other UEs are also allowed to share the channel during the UE COT; and
the network entity serves the one or more other UEs during the UE COT.
27. The method of claim 26 , wherein:
one or more other UEs are not allowed to share the channel during the UE COT at least for data transmission.
28. The method of claim 27 , further comprising:
transmitting one or more signals indicating the network entity is not an owner of the UE COT.
29. The method of claim 28 , wherein the one or more signals are conveyed via a downlink control information (DCI).
30. An apparatus for wireless communications by a user equipment (UE), comprising:
means for detecting a network entity has failed to access a channel during a channel occupancy time (COT) of a frame period (FP) of the network entity; and
means for initiating access of the channel to start a UE COT in response to the detection, wherein the network entity is allowed to share the channel during the UE COT.
31. An apparatus for wireless communications by a network entity, comprising:
means for an uplink transmission from a user equipment (UE) indicating a start of a UE channel occupancy time (COT) associated with a channel in response to the network entity failing to access the channel during a COT of a frame period (FP) of the network entity; and
means for sharing access to the channel during the UE COT.
32. An apparatus for wireless communications by a user equipment (UE), comprising:
at least one processor and a memory configured to detect a network entity has failed to access a channel during a channel occupancy time (COT) of a frame period (FP) of the network entity; and
initiate access of the channel to start a UE COT in response to the detection, wherein the network entity is allowed to share the channel during the UE COT.
33. An apparatus for wireless communications by a network entity, comprising:
at least one processor and a memory configured to
receive an uplink transmission from a user equipment (UE) indicating a start of a UE channel occupancy time (COT) after the network entity has failed to access a channel during a COT of a frame period (FP) of the network entity; and
share access to the channel during the UE COT.
34. A non-transitory computer-readable medium for wireless communications, comprising
instructions that, when executed by one or more processors of a user equipment (UE), cause the UE to:
detect a network entity has failed to access a channel during a channel occupancy time (COT) of a frame period (FP) of the network entity; and
initiate access of the channel to start a UE COT in response to the detection, wherein the network entity is allowed to share the channel during the UE COT.
35. A non-transitory computer-readable medium for wireless communications, comprising
instructions that, when executed by one or more processors of a network entity, cause the network entity to:
receive an uplink transmission from a user equipment (UE) indicating a start of a UE channel occupancy time (COT) after the network entity has failed to access a channel during a COT of a frame period (FP) of the network entity; and
share access to the channel during the UE COT.