Channelization and BWP
Methods, systems, and apparatus designed to support flexible carrier bandwidths in new radio. Multiple carrier bands may be combined into a single composite carrier depending on channel availability in the carrier bands. A composite carrier indicator (CCI) indicates to network devices, the available carrier bands within the channel occupancy time. In addition, bandwidth part inactivity time is suspended when channel access is not available.
1. An apparatus that performs wireless communication comprising:
a processor; and
a memory coupled with the processor, the memory comprising executable instructions stored thereon that when executed by the processor cause the processor to effectuate operations comprising:
determining that a channel is available in multiple frequency bands;
generating a composite carrier indicator (CCI) that indicates one or more of the frequency bands of the multiple frequency bands that are within a composite carrier;
sending the CCI to a wireless transmit/receive unit (WTRU), wherein the CCI is communicated via downlink control information of a physical downlink control channel (PDCCH) transmissions;
determining that a category four (CAT4) listen-before talk (LBT) is successful on a first frequency band of the one or more frequency bands; and
based on the CAT4 LBT being successful on the first frequency band of the one or more frequency bands, performing a category two (CAT2) LBT on a second frequency band, wherein the first frequency band and the second frequency band are in the composite carrier.
2. The apparatus of claim 1 , wherein each frequency band is 20 MHz.
3. The apparatus of claim 1 , wherein the apparatus is a base station.
4. The apparatus of claim 1 , wherein the PDCCH transmission is a group-common PDCCH transmission.
5. The apparatus of claim 1 , wherein the downlink control information comprises WTRU-specific downlink control information or multicast downlink control information.
6. The apparatus of claim 1 , wherein the one or more frequency bands are composited when adjacent in frequency.
7. The apparatus of claim 1 , wherein the first frequency band is adjacent to the second frequency band of the one or more frequency bands.
8. The apparatus of claim 1 , wherein the CCI indicates channel occupancy time duration for a transmitter.
9. A method comprising:
determining that a channel is available in multiple frequency bands;
generating a composite carrier indicator (CCI) that indicates one or more of the frequency bands of the multiple frequency bands that are within the composite carrier;
sending the CCI to a wireless transmit/receive unit (WTRU), wherein the CCI is communicated via downlink control information of a physical downlink control channel (PDCCH) transmission;
determining that a category four (CAT4) listen-before talk (LBT) is successful on a first frequency band of the one or more frequency bands; and
based on the CAT4 LBT being successful on the first frequency band of the one or more frequency bands, performing a category two (CAT2) LBT on a second frequency band, wherein the first frequency band and the second frequency band are in the composite carrier.
10. The method of claim 9 , wherein the PDCCH transmission is a group-common PDCCH transmission.
11. The method of claim 9 , the operations further comprising:
wherein the first frequency band is adjacent to the second frequency band of the one or more frequency bands.
12. The method of claim 9 , wherein the CCI indicates the channel occupancy time duration for a transmitter.
13. The method of claim 9 , wherein the multiple frequency bands are composited when adjacent in frequency.
14. A wireless transmit/receive unit (WTRU) that performs wireless communication, the WTRU comprising:
a processor; and
a memory coupled with the processor, the memory comprising executable instructions stored thereon that when executed by the processor cause the processor to effectuate operations comprising:
receiving, from a network node, a composite carrier indicator (CCI) wherein the CCI is communicated via downlink control information of a physical downlink control channel (PDCCH) transmission, wherein the CCI is for identification of one or more frequency bands in a composite carrier;
performing measurements, transmission, reception, or synchronization in the one or more frequency bands in the composite carrier;
determining that a category four (CAT4) listen-before talk (LBT) is successful on a first frequency band of the one or more frequency bands; and
based on the CAT4 LBT being successful on the first frequency band of the one or more frequency bands, performing a category two (CAT2) LBT on a second frequency band, wherein the first frequency band and the second frequency band are in the composite carrier.
15. The WTRU of claim 14 , wherein the downlink control information comprises WTRU-specific downlink control information or multicast downlink control information.
16. The WTRU of claim 14 , wherein the CCI indicates channel occupancy time duration for a transmitter.
17. The WTRU of claim 14 , wherein the PDCCH transmission is a group-common PDCCH transmission.
18. The WTRU of claim 14 , the operations further comprising:
sharing a channel occupancy time with the network node; and
transmitting data to the network node after successful CAT2 channel sensing in the one or more frequency bands spanning its data resources.