Methods for unlicensed resource selection
Methods and apparatuses are described herein for accessing an unlicensed spectrum using portions of a carrier's bandwidth (BW). For example, a wireless transmit receive unit (WTRU) may access a serving cell through an initial bandwidth part (BWP). The WTRU may be configured with a plurality of BWPs within an unlicensed frequency spectrum. The WTRU may then determine any of at least one monitoring period and at least one offset per each BWP. The WTRU may then monitor the BWPs based on any of the at least one monitoring period and the at least one offset. The WTRU may receive at least one signal from the serving cell. The signal may be at least one of a downlink control information (DCI), a synchronization signal block (SSB), a reference signal, or a preamble.
1. A method for use in a wireless transmit receive unit (WTRU), the method comprising:
receiving configuration information indicating periodic monitoring occasions to be used for monitoring a plurality of bandwidth sub bands (BWSBs) in an unlicensed frequency spectrum to determine availability of an uplink channel, wherein the periodic monitoring occasions comprise a set of periodic monitoring occasions associated with a time offset per BWSB, wherein each BWSB is associated with a different time offset;
determining that the uplink channel is available in a BWSB of the plurality of BWSBs based on monitoring the plurality of BWSBs according to the periodic monitoring occasions, wherein each of the plurality of BWSBs is monitored repeatedly until the uplink channel is determined to be available in the BWSB; and
transmitting on the BWSB.
2. The method of claim 1 , further comprising receiving, by the WTRU, grant information for an uplink transmission and transmitting the uplink transmission on the BWSB based on the grant information, wherein the grant information indicates uplink resources not specific to any BWSB of the plurality of BWSBs.
3. The method of claim 1 , further comprising receiving, by the WTRU prior to said monitoring, grant information for an uplink transmission, wherein said transmitting on the BWSB comprises transmitting the uplink transmission based on the grant information.
4. The method of claim 3 , wherein the grant information indicates uplink resources not specific to any BWSB of the plurality of BWSBs.
5. The method of claim 1 , wherein the plurality of BWSBs is sequentially monitored.
6. The method of claim 1 , wherein listen before talk (LBT) is performed to determine whether the uplink channel is available.
7. The method of claim 1 , further comprising suspending said monitoring the plurality of BWSBs after determining that the uplink channel is available, and resuming said monitoring the plurality of BWSBs upon a determination that a channel occupancy time (COT) has elapsed after the uplink channel has been determined to be available in the BWSB.
8. The method of claim 7 , wherein the COT is set to a dynamically indicated value.
9. A wireless transmit receive unit (WTRU), comprising:
a processor;
a transceiver operatively coupled to the processor;
the processor being further configured to:
receive configuration information indicating periodic monitoring occasions to be used for monitoring a plurality of bandwidth sub bands (BWSBs) in an unlicensed frequency spectrum to determine availability of an uplink channel, wherein the periodic monitoring occasions comprise a set of periodic monitoring occasions associated with a time offset per BWSB, wherein each BWSB is associated with a different time offset;
determine that the uplink channel is available in a BWSB of the plurality of BWSBs based on monitoring the plurality of BWSBs according to the periodic monitoring occasions, wherein each of the plurality of BWSBs is monitored repeatedly until the uplink channel is determined to be available in the BWSB; and
transmit on the BWSB.
10. The WTRU of claim 9 , wherein the processor is further configured to receive grant information for an uplink transmission and to transmit the uplink transmission on the BWSB based on the grant information, wherein the grant information indicates uplink resources not specific to any BWSB of the plurality of BWSBs.
11. The WTRU of claim 9 , wherein listen before talk (LBT) is performed to determine whether the uplink channel is available.
12. The WTRU of claim 9 , wherein the processor is further configured to receive, prior to said monitoring, grant information for an uplink transmission, wherein said transmit on the BWSB comprises transmit the uplink transmission based on the grant information.
13. The WTRU of claim 12 , wherein the grant information indicates uplink resources not specific to any BWSB of the plurality of BWSBs.
14. The WTRU of claim 9 , wherein said monitoring the plurality of BWSBs is suspended after the uplink channel has been determined to be available in the BWSB, and wherein said monitoring the plurality of BWSBs is resumed upon a determination that a channel occupancy time (COT) has elapsed after the uplink channel has been determined to be available in the BWSB.
15. A method for use in a wireless transmit receive unit (WTRU), the method comprising:
receiving configuration information indicating periodic monitoring occasions to be used for monitoring a plurality of bandwidth sub bands (BWSBs) in an unlicensed frequency spectrum wherein the periodic monitoring occasions comprise a set of periodic monitoring occasions associated with a time offset per BWSB, wherein each BWSB is associated with a different time offset;
receiving at least one signal in a BWSB of the plurality of BWSBs based on monitoring the plurality of BWSBs according to the periodic monitoring occasions, wherein each of the plurality of BWSBs is monitored repeatedly until the at least one signal is received in the BWSB; and
using the BWSB to receive one or more transmissions from a serving base station.
16. The method of claim 15 , wherein the at least one signal comprises downlink control information (DCI), and wherein a DCI format is detected from at least one search space in at least one of the monitored plurality of BWSBs.
17. The method of claim 15 , wherein the at least one signal comprises a synchronization signal block (SSB) or a component thereof.
18. The method of claim 15 , wherein the at least one signal is a reference signal.
19. The method of claim 15 , wherein the at least one signal is received by detecting a sequence on a set of resources mapped to a preamble indicating that the serving base station has acquired at least one BWSB of the monitored plurality of BWSBs.
20. A wireless transmit receive unit (WTRU), comprising:
a processor;
a transceiver operatively coupled to the processor;
the processor being further configured to:
receive configuration information indicating periodic monitoring occasions to be used for monitoring a plurality of bandwidth sub bands (BWSBs) in an unlicensed frequency spectrum, wherein the periodic monitoring occasion comprise a set of periodic monitoring occasions associated with a time offset per BWSB, wherein each BWSB is associated with a different time offset;
receive at least one signal in a BWSB of the plurality of BWSBs based on monitoring the plurality of BWSBs according to the periodic monitoring occasions, wherein each of the plurality of BWSBs is monitored repeatedly until the at least one signal is received in the BWSB; and
the transceiver and processor being further configured to use the BWSB to receive one or more transmissions from a serving base station.