NR V2X—methods for data transmission in wireless systems
A method and apparatus for selecting a resource for transmission may be performed by a WTRU. The method may comprise determining a priority of a data packet and determining a CBR of a resource pool. The WTRU may set a backoff counter to an initial backoff value, in accordance with at least one of the priority of the packet or the CBR. A CCA may be performed in a plurality of resource slots to determine whether the resource slots are available. The backoff counter may be decreased by the number of available resources in each slot. When the backoff counter reaches a threshold value, which may be set at 0, the resource for transmission may be randomly selected. The WTRU may then transmit data to another WTRU on the randomly selected resource.
1. A method performed by a wireless transmit/receive unit (WTRU), the method comprising:
transmitting first sidelink control information (SCI) which indicates one or more transmission resources;
determining: (a) based on receiving an SCI from another WTRU, that the one or more transmission resources indicated by the first SCI overlap with one or more transmission resources associated with a higher priority reservation associated with the another WTRU and (b) that a sidelink reference signal received power (SL-RSRP) measurement is larger than an SL-RSRP threshold, wherein the determination that the SL-RSRP measurement is larger than the SL-RSRP threshold is based on receipt of the SCI from the another WTRU, and wherein the determination that the one or more transmission resources indicated by the SCI overlap with one or more transmission resources associated with a higher priority reservation associated with another WTRU is based on receiving the SCI from the another WTRU; and
based on the determination, transmitting second SCI which indicates one or more different transmission resources;
wherein the SL-RSRP measurement is a measurement associated with a resource reserved by the another WTRU.
2. The method of claim 1 , wherein the second SCI indicates a subset of the one or more transmission resources indicated by the first SCI.
3. The method of claim 1 , wherein the SL-RSRP threshold is configured via higher layer signaling.
4. The method of claim 1 , wherein the SL-RSRP threshold is configured via radio resource control (RRC) signaling.
5. A wireless transmit/receive unit (WTRU) comprising:
a transmitter; and
a processor;
wherein the transmitter and processor are configured to:
transmit first sidelink control information (SCI) which indicates one or more transmission resources;
determine, based on receiving an SCI from another WTRU, that the one or more transmission resources indicated by the first SCI overlap with one or more transmission resources associated with a higher priority reservation associated with the another WTRU and that a sidelink reference signal received power (SL-RSRP) measurement is larger than an SL-RSRP threshold, wherein the determination that the SL-RSRP measurement is larger than the SL-RSRP threshold is based on receipt of an SCI from the another WTRU, and wherein the determination that the one or more transmission resources indicated by the SCI overlap with one or more transmission resources associated with a higher priority reservation associated with another WTRU is based on receiving the SCI from the another WTRU; and
based on the determination, transmit second SCI which indicates one or more different transmission resources;
wherein the SL-RSRP measurement is a measurement associated with a resource reserved by the another WTRU.
6. The WTRU of claim 5 , wherein the determination to select one or more different transmission resources is further based on a determination that a sidelink reference signal received power (SL-RSRP) measurement is larger than a SL-RSRP threshold.
7. The WTRU of claim 6 , wherein the SL-RSRP measurement is a measurement associated with a resource reserved by the another WTRU.
8. The WTRU of claim 6 , wherein the determination that the SL-RSRP measurement is larger than the SL-RSRP threshold is based on receipt of an SCI from the another WTRU.
9. The WTRU of claim 5 , wherein the processor is further configured to select one or more different transmission resources.
10. The WTRU of claim 5 , wherein the determination that the one or more transmission resources indicated by the first SCI overlap with one or more transmission resources associated with a higher priority reservation associated with another WTRU is based on receiving an SCI from the another WTRU.