Wireless device initiated channel occupancy in unlicensed spectrum
This disclosure relates to techniques for a wireless device to initiate channel occupancy in unlicensed spectrum in a wireless communication system. The wireless device may establish a wireless link with a cellular base station. The wireless device may determine to perform an uplink transmission to the cellular base station on an unlicensed frequency channel. The wireless device may determine whether the cellular base station has channel occupancy of the unlicensed frequency channel. The wireless device may determine whether to initiate channel occupancy of the unlicensed frequency channel. The decision whether to initiate channel occupancy may be based at least in part on whether the cellular base station has channel occupancy of the unlicensed frequency channel.
1. A baseband processor configured to perform operations comprising:
determining to perform an uplink transmission to a cellular base station on an unlicensed frequency channel;
determining that the cellular base station has initiated a first channel occupancy of the unlicensed frequency channel;
determining a length of the uplink transmission; and
determining whether to initiate channel occupancy of the unlicensed frequency channel or use the first channel occupancy, comprising:
determining to initiate a new channel occupancy of the unlicensed frequency channel if the length of the uplink transmission would overlap a first idle period at an end of a current first fixed frame period of the cellular base station;
determining to use the first channel occupancy of the unlicensed frequency channel if the length of the uplink transmission would not overlap the first idle period at the end of the current first fixed frame period of the cellular base station; and
performing the uplink transmission to the cellular base station on the unlicensed frequency channel,
wherein the uplink transmission extends at least into a clear channel assessment period for a next fixed frame period of the cellular base station based at least in part on the new channel occupancy being initiated while the cellular base station has already initiated channel occupancy of the unlicensed frequency channel.
2. The baseband processor of claim 1 , the operations further comprising
determining to share the first channel occupancy to perform the uplink transmission to the cellular base station based at least in part on determining that the uplink transmission to the cellular base station can be performed using the first channel occupancy without performing clear channel assessment.
3. The baseband processor of claim 1 , the operations further comprising determining a latency sensitivity of the uplink transmission,
wherein whether to initiate the new channel occupancy of the unlicensed frequency channel or to use the first channel occupancy initiated by the cellular base station is determined further based at least in part on the latency sensitivity of the uplink transmission.
4. The baseband processor of claim 1 , wherein the baseband processor is further configured to perform operations comprising:
determining an energy detection threshold to use to perform clear channel assessment of the unlicensed frequency channel.
5. The baseband processor of claim 1 , wherein a first fixed frame period duration is different from a second fixed frame period duration.
6. A method, comprising:
determining to perform an uplink transmission to a cellular base station on an unlicensed frequency channel;
determining that the cellular base station has initiated a first channel occupancy of the unlicensed frequency channel;
determining a length of the uplink transmission; and
determining whether to initiate channel occupancy of the unlicensed frequency channel or use the first channel occupancy, comprising:
determining to initiate a new channel occupancy of the unlicensed frequency channel if the length of the uplink transmission would overlap a first idle period at an end of a current first fixed frame period of the cellular base station;
determining to use the first channel occupancy of the unlicensed frequency channel if the length of the uplink transmission would not overlap the first idle period at the end of the current first fixed frame period of the cellular base station; and
performing the uplink transmission to the cellular base station on the unlicensed frequency channel,
wherein the uplink transmission extends at least into a clear channel assessment period for a next fixed frame period of the cellular base station based at least in part on the new channel occupancy being initiated while the cellular base station has already initiated channel occupancy of the unlicensed frequency channel.
7. The method of claim 6 , further comprising:
determining to share the first channel occupancy to perform the uplink transmission to the cellular base station based at least in part on determining that the uplink transmission to the cellular base station can be performed using the first channel occupancy without performing clear channel assessment.
8. The method of claim 6 , further comprising:
determining a latency sensitivity of the uplink transmission,
wherein whether to initiate the new channel occupancy of the unlicensed frequency channel or to use the first channel occupancy is determined further based at least in part on the latency sensitivity of the uplink transmission.
9. The method of claim 6 , further comprising:
determining an energy detection threshold to use to perform clear channel assessment of the unlicensed frequency channel.
10. The method of claim 6 , wherein a first fixed frame period duration is different from a second fixed frame period duration.
11. A method, comprising:
initiating, by a cellular base station, a first channel occupancy of an unlicensed frequency channel; and
receiving, from a user equipment (UE), an uplink transmission on the unlicensed frequency channel, wherein:
the uplink transmission is received during a new channel occupancy of the unlicensed frequency channel if a length of the uplink transmission overlaps a first idle period at an end of a current first fixed frame period of the cellular base station; or
the uplink transmission is received during the first channel occupancy of the unlicensed frequency channel if the length of the uplink transmission does not overlap the first idle period at the end of the current first fixed frame period of the cellular base station, wherein the uplink transmission extends at least into a clear channel assessment period for a next fixed frame period of the cellular base station based at least in part on the new channel occupancy being initiated while the cellular base station has already initiated channel occupancy of the unlicensed frequency channel.
12. The method of claim 11 , wherein uplink transmission is received during the first channel occupancy when the uplink transmission to the cellular base station can be performed using the first channel occupancy without performing clear channel assessment.
13. The method of claim 11 , wherein a first fixed frame period duration is different from a second fixed frame period duration.