Methods, apparatus, and antenna techniques for new radio (NR) operations in unlicensed bands
An LBT method and apparatus are disclosed for a WTRU and gNB. A method may comprise receiving a gNB beam direction schedule and an LBT measurement configuration. The WTRU may switch a receiver so as to receive a beam based on the beam direction schedule and monitor for a DCI. The WTRU may be configured to determine whether there is a transmission for the WTRU and if there is, the transmission may be received. The transmission may be a DCI for an uplink transmission of the WTRU. A WTRU may be configured to receive the gNB beam direction schedule and the LBT measurement configuration at a start of an MCOT.
1 . A listen before talk (LBT) method performed by a wireless transmit/receive unit (WTRU), the method comprising:
performing a first LBT sensing on a first beam for a channel;
performing a second LBT sensing on a second beam for the channel;
determining that the channel is idle based on the first LBT sensing and the second LBT sensing;
transmitting a first transmission on the channel using the first beam to a network;
based on the channel being idle for the second beam determined based on the second LBT sensing, and prior to transmitting on the second beam, performing a third LBT sensing on the second beam for the channel; and
on condition that the channel is idle for the second beam based on the third LBT sensing, transmitting a second transmission on the channel using the second beam to the network.
2 . The method of claim 1 , further comprising receiving beam scheduling information prior to performing the first LBT sensing.
3 . The method of claim 2 , further comprising switching from the first beam to the second beam for transmission based on the beam scheduling information.
4 . The method of claim 1 , wherein the first LBT sensing and the second LBT sensing are directional sensing procedures performed simultaneously.
5 . The method of claim 1 , wherein performing the first LBT sensing and the second LBT sensing include using a contention window with a random backoff, and wherein the random backoff determines a duration of time during which the channel is sensed to be idle before the WTRU transmits on the channel using the first beam.
6 . The method of claim 1 , wherein performing the third LBT sensing includes using a fixed time duration during which the channel is sensed to be idle before the WTRU transmits on the channel using the second beam.
7 . The method of claim 1 , wherein transmitting the first transmission on the channel using the first beam comprises transmitting on the channel within a channel occupancy time (COT) using the first beam.
8 . The method of claim 7 , wherein transmitting the second transmission on the channel using the second beam comprises transmitting on the channel within the COT using the second beam.
9 . The method of claim 1 , wherein the second LBT sensing is a first type of LBT sensing, and the third LBT sensing is a second type of LBT sensing, and wherein the first type of LBT sensing is different than the second type of LBT sensing.
10 . The method of claim 1 , wherein the method further comprises:
performing the third LBT sensing on the second beam for the channel after the first transmission; and
transmitting the second transmission on the channel using the second beam on condition that the channel is idle based on both the second LBT sensing and the third LBT sensing.
11 . A wireless transmit/receive unit (WTRU) having circuitry to perform a listen before talk (LBT) multibeam method, the circuitry configured to:
perform a first LBT sensing on a first beam for a channel;
perform a second LBT sensing on a second beam for the channel;
determine that the channel is idle based on the first LBT sensing and the second LBT sensing;
transmit a first transmission on the channel using the first beam to a network;
based on the channel being idle for the second beam determined based on the second LBT sensing, and prior to transmitting on the second beam, perform a third LBT sensing on the second beam for the channel; and
on condition that the channel is idle for the second beam based on the third LBT sensing, transmit a second transmission on the channel using the second beam to the network.
12 . The WTRU of claim 11 , wherein the WTRU transmits a beam schedule to a receiver prior to performing the first LBT sensing.
13 . The WTRU of claim 11 , wherein the first LBT sensing and the second LBT sensing are directional sensing procedures performed simultaneously.
14 . The WTRU of claim 11 , wherein the first LBT sensing and the second LBT sensing includes use of a contention window with a random backoff, and wherein the random backoff determines a duration of time during which the channel is sensed to be idle before the WTRU transmits on the channel using the first beam.
15 . The WTRU of claim 11 , wherein the third LBT sensing includes use of a fixed time duration during which the channel is sensed to be idle before the WTRU transmits on the channel using the second beam.
16 . The WTRU of claim 11 , wherein the WTRU transmits the first transmission on the channel using the first beam within a channel occupancy time (COT).
17 . The WTRU of claim 16 , wherein the WTRU transmits the second transmission on the channel using the second beam within the COT.
18 . The WTRU of claim 11 , wherein the second LBT sensing is a first type of LBT sensing, and the third LBT sensing is a second type of LBT sensing, and wherein the first type of LBT sensing is different than the second type of LBT sensing.
19 . The WTRU of claim 11 , wherein the processor is configured to:
perform a third LBT sensing on the second beam for the channel after the first transmission; and
transmit the second transmission on the channel using the second beam on condition that the channel is idle based on both the second LBT sensing and the third LBT sensing.
20 . A wireless transmit/receive unit (WTRU) having circuitry to perform a listen before talk (LBT) multibeam method, the circuitry configured to:
perform a first LBT sensing on a first beam for a channel;
perform a second LBT sensing on a second beam for the channel;
determine that the channel is idle based on the first LBT sensing and the second LBT sensing;
transmit a first transmission on the channel using the first beam to a network;
perform a third LBT sensing on the second beam for the channel after the first transmission;
based on the condition that the channel is idle for the second beam based on both the second LBT sensing and the third LBT sensing, transmit a second transmission on the channel using the second beam to the network.