Method and device for reselecting sidelink transmission resource in NR V2X

1. A method for performing sidelink communication by a first device, the method comprising:

reserving periodic transmission resources, based on a first priority value;

generating a medium access control (MAC) protocol data unit (PDU) related to a second priority value;

determining whether to reselect a first sidelink (SL) resource from among the periodic transmission resources, based on the second priority value; and

transmitting the MAC PDU and sidelink control information (SCI) including the second priority value to a second device, based on the determination on whether to reselect the first SL resource,

wherein the first SL resource is at least one SL resource after a time at which the MAC PDU is generated.

2. The method of claim 1 , wherein a time at which the second priority value is transferred from a MAC layer of the first device to a physical (PHY) layer is before a start time of the first SL resource.

3. The method of claim 1 , wherein the transmitting of the MAC PDU and the SCI including the second priority value further comprises transmitting the MAC PDU and the SCI including the second priority value to the MAC PDU through a second SL resource among the periodic transmission resources, based on the determination on that the first SL resource is to be reselected.

4. The method of claim 1 , wherein the transmitting of the MAC PDU and the SCI including the second priority value further comprises transmitting the MAC PDU and the SCI including the second priority value through the first SL resource, based on the determination on that the first SL resource is not to be reselected.

5. The method of claim 1 , further comprising:

transmitting SCI including the first priority value to the second device, based on a third SL resource among the periodic transmission resources.

6. The method of claim 5 , wherein whether to reselect the first SL resource is determined based on determination on whether pre-emption is applied to the first SL resource.

7. The method of claim 6 , wherein it is determined that the pre-emption is applied to the first SL resource, based on that the second priority value is greater than a third priority value included in SCI received by the first device.

8. The method of claim 1 , wherein whether to reselect the first SL resource is determined, based on determination on whether re-evaluation is applied to the first SL resource.

9. The method of claim 1 , wherein the second priority value is a layer 1 (L1) priority value related to the MAC PDU.

10. A first device adapted to perform sidelink communication, the first device comprising:

at least one memory storing instructions;

at least one transceiver; and

at least one processor connecting the at least one memory and the at least one transceiver, wherein the at least one processor executes the instructions to:

reserve periodic transmission resources, based on a first priority value;

generate a medium access control (MAC) protocol data unit (PDU) related to a second priority value;

determine whether to reselect a first sidelink (SL) resource from among the periodic transmission resources, based on the second priority value; and

control the at least one processor to transmit the MAC PDU and sidelink control information (SCI) including the second priority value to a second device, based on the determination on whether to reselect the first SL resource,

wherein the first SL resource is at least one SL resource after a time at which the MAC PDU is generated.

11. The first device of claim 10 , wherein a time at which the second priority value is transferred from a MAC layer of the first device to a physical (PHY) layer is before a start time of the first SL resource.

12. The first device of claim 10 , wherein the at least one processor further executes the instructions to control the at least one transceiver to transmit the MAC PDU and the SCI including the second priority value to the MAC PDU through a second SL resource among the periodic transmission resources, based on the determination on that the first SL resource is to be reselected.

13. A processing device adapted to control a first device, the processing device comprising:

at least one processor; and

at least one computer memory operably connected by the at least one processor and storing instructions, wherein the at least one processor executes the instructions to:

reserve periodic transmission resources, based on a first priority value;

generate a medium access control (MAC) protocol data unit (PDU) related to a second priority value;

determine whether to reselect a first sidelink (SL) resource from among the periodic transmission resources, based on the second priority value; and

transmit the MAC PDU and sidelink control information (SCI) including the second priority value to a second device, based on the determination on whether to reselect the first SL resource,

wherein the first SL resource is at least one SL resource after a time at which the MAC PDU is generated.

14. The processing device of claim 13 , wherein a time at which the second priority value is transferred from a MAC layer of the first device to a physical (PHY) layer is before a start time of the first SL resource.

15. The processing device of claim 13 , wherein the transmitting of the MAC PDU and the SCI including the second priority value further comprises transmitting the MAC PDU and the SCI including the second priority value to the MAC PDU through a second SL resource among the periodic transmission resources, based on the determination on that the first SL resource is to be reselected.

16. The processing device of claim 13 , wherein the transmitting of the MAC PDU and the SCI including the second priority value further comprises transmitting the MAC PDU and the SCI including the second priority value through the first SL resource, based on the determination on that the first SL resource is not to be reselected.

17. The processing device of claim 13 , wherein the at least one processor further executes the instructions to: transmit SCI including the first priority value to the second device, based on a third SL resource among the periodic transmission resources.

18. The processing device of claim 17 , wherein whether to reselect the first SL resource is determined based on determination on whether pre-emption is applied to the first SL resource.

19. The processing device of claim 18 , wherein it is determined that the pre-emption is applied to the first SL resource, based on that the second priority value is greater than a third priority value included in SCI received by the first device.

20. The processing device of claim 13 , wherein whether to resoled the first SL resource is determined, based on determination on whether re-evaluation is applied to the first SL resource.