Sidelink collision detection and indication
Systems, methods, and instrumentalities are described herein for sidelink (SL) collision detection and indication (e.g., in new radio (NR) vehicular communications (V2X)). A wireless transmit/receive unit (WTRU) may send resource reservations (e.g., in sidelink control information (SCI)). A receiving (RX) WTRU may receive SCI from (e.g., multiple) transmitting (TX) WTRUs, where the TX WTRUs are reserving resources for transmission. The TX WTRUs may be unaware of the other TX WTRUs (e.g., unaware of the resources being reserved by other TX WTRUs). Resources may be in conflict, for example, if the reserved resources overlap (e.g., partially or completely). Collision may occur, for example, if multiple TX WTRUs reserve the resources in conflict for transmission and/or if the TX WTRUs reserving the resources in conflict for transmission do not reselect a non-conflicting resource.
1. A first wireless transmit/receive unit (WTRU) comprising:
a processor configured to:
receive configuration information indicating a conflict detection processing time, wherein the conflict detection processing time is a minimum time to report a conflict indication;
receive first sidelink control information (SCI) from a second WTRU, wherein the first SCI indicates a first conflict indication setting and at least a first resource;
receive second SCI from a third WTRU, wherein the second SCI indicates a second conflict indication setting and at least a second resource;
determine that the first SCI and the second SCI are received at a time before a physical sidelink feedback channel (PSFCH) transmission, wherein the time before the PSFCH transmission is at least the conflict detection processing time before the PSFCH transmission;
determine that at least the first resource and at least the second resource overlap; and
send the PSFCH transmission to the second WTRU based on at least a determination that the first conflict indication setting is enabled, wherein the PSFCH transmission comprises a conflict indication.
2. The first WTRU of claim 1 , wherein the processor is further configured to:
determine a measurement associated with the second SCI; and
determine that there is a conflict associated with the first resource and the second resource based on the determination that at least the first resource and at least the second resource overlap and based on a determination that the measurement associated with the second SCI is greater than a first threshold.
3. The first WTRU of claim 2 , wherein the measurement associated with the second SCI is a reference signal received power (RSRP).
4. The first WTRU of claim 1 , wherein the conflict detection processing time is a duration associated with conflict detection performed by the first WTRU and conflict indication sent by the first WTRU.
5. The first WTRU of claim 1 , wherein the determination that at least the first resource and at least the second resource overlap is based on a determination that the first resource at least partially overlaps with the second resource.
6. The first WTRU of claim 1 , wherein the processor is further configured to:
determine a conflict detection triggering occasion based at least on the conflict detection processing time and the first resource, wherein the second SCI is received during the conflict detection triggering occasion.
7. The first WTRU of claim 6 , wherein the conflict detection processing time is a first conflict detection processing time associated with the third WTRU, and wherein the processor is further configured to:
receive an indication that indicates a second conflict detection processing time associated with the second WTRU, wherein the conflict detection triggering occasion is further determined based on the second conflict detection processing time associated with the second WTRU.
8. The first WTRU of claim 1 , wherein the sent PSFCH transmission is further based on the determination that the first SCI and the second SCI are received at the time before the PSFCH transmission.
9. The first WTRU of claim 1 , wherein the sent PSFCH transmission is further based on a determination that the second conflict indication setting is disabled.
10. A method, the method comprising:
receiving configuration information indicating a conflict detection processing time, wherein the conflict detection processing time is a minimum time to report a conflict indication;
receiving first sidelink control information (SCI) from a first wireless transmit/receive unit (WTRU), wherein the first SCI indicates a first conflict indication setting and at least a first resource;
receiving second SCI from a second WTRU, wherein the second SCI indicates a second conflict indication setting and at least a second resource;
determining that the first SCI and the second SCI are received at a time before a physical sidelink feedback channel (PSFCH) transmission, wherein the time before the PSFCH transmission is at least the conflict detection processing time before the PSFCH transmission;
determining that at least the first resource and at least the second resource overlap; and
sending the PSFCH transmission to the first WTRU based on at least a determination that the first conflict indication setting is enabled, wherein the PSFCH transmission comprises a conflict indication.
11. The method of claim 10 , wherein the method further comprises:
determining a measurement associated with the second SCI; and
determining that there is a conflict associated with the first resource and the second resource based on the determination that at least the first resource and at least the second resource overlap and based on a determination that the measurement associated with the second SCI is greater than a first threshold.
12. The method of claim 11 , wherein the measurement associated with the second SCI is a reference signal received power (RSRP).
13. The method of claim 10 , wherein the conflict detection processing time is a duration associated with conflict detection performed by the first WTRU and conflict indication sent by the first WTRU.
14. The method of claim 10 , wherein the determination that at least the first resource and at least the second resource overlap is based on a determination that the first resource at least partially overlaps with the second resource.
15. The method of claim 10 , wherein the method further comprises:
determining a conflict detection triggering occasion based at least on the conflict detection processing time and the first resource, wherein the second SCI is received during the conflict detection triggering occasion.
16. The method of claim 15 , wherein the conflict detection processing time is a first conflict detection processing time associated with the second WTRU, and wherein the method further comprises:
receiving an indication that indicates a second conflict detection processing time associated with the first WTRU, wherein the conflict detection triggering occasion is further determined based on the second conflict detection processing time associated with the first WTRU.
17. The method of claim 10 , wherein the sent PSFCH transmission is further based on the determination that the first SCI and the second SCI are received at the time before the PSFCH transmission.
18. The method of claim 10 , wherein the sent PSFCH transmission is further based on a determination that the second conflict indication setting is disabled.
19. A first wireless transmit/receive unit (WTRU) comprising:
a processor configured to:
receive configuration information indicating a conflict detection processing time, wherein the conflict detection processing time is a minimum time to report a conflict indication;
receive a first sidelink control information (SCI) from a second WTRU, wherein the first SCI indicates a first resource, a first conflict indication setting, and a first priority value, wherein the first conflict indication setting indicates whether the second WTRU supports receiving conflict information;
receive a second SCI from a third WTRU, wherein the second SCI indicates a second resource, a second conflict indication setting, and a second priority value, wherein the second conflict indication setting indicates whether the third WTRU supports receiving conflict information;
determine that the first SCI and the second SCI are received at a time before a physical sidelink feedback channel (PSFCH) transmission, wherein the time before the PSFCH transmission is at least the conflict detection processing time before the PSFCH transmission;
determine that at least the first resource and at least the second resource overlap;
determine an RSRP threshold based on the first priority value and the second priority value;
determine that a reference signal received power (RSRP) measurement associated with the second SCI is greater than an RSRP threshold;
determine that there is a conflict associated with the first resource and the second resource based on the determination that at least the first resource and at least the second resource overlap and based on the determination that the RSRP measurement associated with the second SCI is greater than the RSRP threshold; and
send, based on the determination that at least the first resource and at least the second resource overlap, the PSFCH transmission to the second WTRU based on a determination that the first conflict indication setting is enabled and the second conflict indication setting is disabled or based on a determination that the first conflict indication setting is enabled, the second conflict indication setting is enabled, and the first priority value is greater than the second priority value, wherein the PSFCH transmission comprises a conflict indication.