Transmission countdown and improvements for a beam based channel access procedure
This disclosure provides systems, methods, and apparatuses for a beam-based channel access countdown procedure. In one aspect, a channel sensing beam may be permitted to include one or more transmit beams and, thus, may differ from a transmit beam that is to be used for a transmission. As such, defining a manner in which a channel access countdown procedure is performed is desirable. Some aspects described herein provide techniques and apparatus for a beam-based channel access countdown procedure. In some aspects, the systems, methods, and apparatuses described herein provide a beam-based channel access countdown procedure that allows a single channel sensing beam, including multiple transmit beams, to be utilized in association with determining channel availability for the multiple transmit beams, thereby improving performance of beam-based directional transmissions.
1. A method of wireless communication performed at a base station, comprising:
performing a channel access countdown procedure for each of one or more channel sensing beams, wherein a channel sensing beam, of the one or more channel sensing beams, includes multiple transmit beams;
determining whether a channel, associated with the multiple transmit beams, is available by using the channel sensing beam; and
outputting information, for transmission via the multiple transmit beams to one or more user equipment (UEs), if the channel is available.
2. The method of claim 1 , wherein outputting the information outputting the information after performing the channel access countdown procedure.
3. The method of claim 1 , wherein the channel access countdown procedure is performed based at least in part on a respective set of one or more channel access parameters that include at least one of:
a contention window size;
a randomly selected value; or
a defer period.
4. The method of claim 1 , further comprising:
performing the channel access countdown procedure for a particular channel sensing beam that includes a particular subset of transmit beams unavailable for wireless communication, wherein the particular subset of transmit beams includes the multiple transmit beams; and
switching, after performing the channel access countdown procedure for the particular channel sensing beam, from the particular channel sensing beam to the one or more channel sensing beams.
5. The method of claim 4 , further comprising:
resetting a counter value associated with the channel access countdown procedure for the particular channel sensing beam.
6. The method of claim 4 , further comprising:
maintaining a counter value associated with the channel access countdown procedure for the particular channel sensing beam.
7. The method of claim 6 , wherein the counter value is maintained based at least in part on at least one channel sensing beam, of the one or more channel sensing beams, being within a footprint of the particular channel sensing beam.
8. The method of claim 1 , further comprising:
applying a wait time penalty in association with performing the channel access countdown procedure for at least one of the one or more channel sensing beams.
9. The method of claim 1 , wherein at least a minimum duration passes between when the channel access procedure is performed and the information is outputted.
10. The method of claim 9 , wherein the minimum duration matches a channel reservation signaling periodicity.
11. An apparatus for wireless communication, comprising:
a processing system configured to:
perform a channel access countdown procedure for each of one or more channel sensing beams, wherein a channel sensing beam, of the one or more channel sensing beams, includes multiple transmit beams;
determine whether a channel, associated with the multiple transmit beams, is available by using the channel sensing beam; and
output information, for transmission via the multiple transmit beams to one or more user equipment (UEs), if the channel is available.
12. The apparatus of claim 11 , wherein, when outputting the information, the processing system is configured to output the information after performing the channel access countdown procedure.
13. The apparatus of claim 11 , wherein the channel access countdown procedure is performed based at least in part on a respective set of one or more channel access parameters that include at least one of:
a contention window size;
a randomly selected value; or
a defer period.
14. The apparatus of claim 11 , wherein the processing system is further configured to:
perform the channel access countdown procedure for a particular channel sensing beam that includes a particular subset of transmit beams unavailable for wireless communication, wherein the particular subset of transmit beams includes the multiple transmit beams; and
switch, after performing the channel access countdown procedure for the particular channel sensing beam, to the one or more channel sensing beams.
15. The apparatus of claim 14 , wherein the processing system is further configured to:
reset a counter value associated with the channel access countdown procedure for the particular channel sensing beam.
16. The apparatus of claim 14 , wherein the processing system is further configured to:
maintain a counter value associated with the channel access countdown procedure for the particular channel sensing beam.
17. The apparatus of claim 16 , wherein the counter value is maintained based at least in part on at least one channel sensing beam, of the one or more channel sensing beams, being within a footprint of the particular channel sensing beam.
18. The apparatus of claim 11 , wherein the processing system is further configured to:
apply a wait time penalty in association with performing the channel access countdown procedure for at least one of the one or more channel sensing beams.
19. The apparatus of claim 11 , wherein at least a minimum duration passes between when the channel access procedure is performed and the information is outputted.
20. The apparatus of claim 19 , wherein the minimum duration matches a channel reservation signaling periodicity.
21. An apparatus for wireless communication, comprising:
means for performing a channel access countdown procedure for each of one or more channel sensing beams, wherein a channel sensing beam, of the one or more channel sensing beams, includes multiple transmit beams;
means for determining whether a channel, associated with the multiple transmit beams, is available by using the channel sensing beam; and
means for outputting information, for transmission via the multiple transmit beams to one or more user equipment (UEs), if the channel is available.
22. A base station, comprising:
a processing system configured to:
perform a channel access countdown procedure for each of one or more channel sensing beams,
wherein a channel sensing beam, of the one or more channel sensing beams, includes multiple transmit beams;
determine whether a channel, associated with the multiple transmit beams, is available by using the channel sensing beam; and
a transmitter configured to:
transmit information via the multiple transmit beams to one or more user equipment (UEs) if the channel is available.
23. The base station of claim 22 , wherein, when transmitting the information, the transmitter is configured to transmit the information after performing the channel access countdown procedure.
24. The base station of claim 22 , wherein the channel access countdown procedure is performed based at least in part on a respective set of one or more channel access parameters that include at least one of:
a contention window size;
a randomly selected value; or
a defer period.
25. The base station of claim 22 , wherein the processing system is further configured to:
perform the channel access countdown procedure for a particular channel sensing beam that includes a particular subset of transmit beams unavailable for wireless communication, wherein the particular subset of beams includes the multiple transmit beams; and
switch, after performing the channel access countdown procedure for the particular channel sensing beam, to the one or more channel sensing beams.
26. The base station of claim 25 , wherein the processing system is further configured to:
reset a counter value associated with the channel access countdown procedure for the particular channel sensing beam.
27. The base station of claim 25 , wherein the processing system is further configured to:
maintain a counter value associated with the channel access countdown procedure for the particular channel sensing beam.
28. The base station of claim 27 , wherein the counter value is maintained based at least in part on at least one channel sensing beam, of the one or more channel sensing beams, being within a footprint of the particular channel sensing beam.
29. The base station of claim 22 , wherein the processing system is further configured to:
apply a wait time penalty in association with performing the channel access countdown procedure for at least one of the one or more channel sensing beams.
30. The base station of claim 22 , wherein at least a minimum duration passes between when the channel access procedure is performed and the information is outputted.