Serving aperiodic traffic over sidelink using resource adaptation of periodic resource reservations

1. An apparatus for wireless communication at a wireless device, comprising:

a memory; and

at least one processor coupled to the memory and configured to:

reserve periodic resources for sidelink transmission;

modify the reserved periodic resources within a period based on a traffic load for the period, wherein to modify the reserved periodic resources, the at least one processor is further configured to:

reduce or expand the reserved periodic resources according to a ratio of modified periodic resources to the reserved periodic resources; and

transmit sidelink communication in the period based on the modified periodic resources.

2. The apparatus of claim 1 , wherein the ratio of the modified periodic resources to the reserved periodic resources for the sidelink transmission is within a range.

3. The apparatus of claim 1 , wherein if the modified periodic resources comprise fewer resources than the reserved periodic resources for the period, the at least one processor is further configured to:

modify the reserved periodic resources for the period so that the modified periodic resources are contained within the reserved periodic resources.

4. The apparatus of claim 1 , wherein if the modified periodic resources comprise more resources than the reserved periodic resources for the period, the at least one processor is further configured to:

modify the reserved periodic resources for the period so that the reserved periodic resources are contained within the modified periodic resources.

5. The apparatus of claim 1 , wherein the at least one processor is further configured to:

transmit a first indication in sidelink control information (SCI) to indicate that the reserved periodic resources are resources capable of being modified, or

transmit a second indication in the SCI to indicate that the reserved periodic resources are resources incapable of being modified.

6. The apparatus of claim 1 , wherein to modify the reserved periodic resources within the period, the at least one processor is further configured to:

increase or decrease the reserved periodic resources within the period in one or more of a time domain or a frequency domain.

7. The apparatus of claim 6 , wherein the at least one processor is further configured to:

transmit sidelink control information (SCI) indicating a direction of expansion for the modified periodic resources for the period, wherein the direction includes one or more of a first direction in the time domain or a second direction in the frequency domain.

8. The apparatus of claim 1 , wherein the at least one processor is further configured to:

modify the reserved periodic resources to expand the reserved periodic resources for the period based on a priority level of the sidelink communication meeting a threshold.

9. The apparatus of claim 1 , wherein the at least one processor is further configured to:

monitor for a conflicting resource reservation from a second wireless device, and

modify the reserved periodic resources to expand the reserved periodic resources for the period based on an absence of the conflicting resource reservation.

10. The apparatus of claim 1 , wherein to modify the reserved periodic resources for the period, the at least one processor is further configured to:

expand the reserved periodic resources to include expanded resources; and

map data of the sidelink communication jointly to a set of resources that includes the reserved periodic resources and the expanded resources.

11. The apparatus of claim 1 , wherein to modify the reserved periodic resources for the period, the at least one processor is further configured to:

expand the reserved periodic resources to include expanded resources; and

map code blocks of data for the sidelink communication to the reserved periodic resources and the expanded resources.

12. The apparatus of claim 1 , wherein to modify the reserved periodic resources for the period, the at least one processor is further configured to:

expand the reserved periodic resources to include expanded resources;

transmit a transmission in the reserved periodic resources; and

repeat the transmission in the expanded resources.

13. The apparatus of claim 1 , further comprising a transceiver coupled to the at least one processor.

14. A method of wireless communication at a wireless device, comprising:

reserving periodic resources for sidelink transmission;

modifying the reserved periodic resources within a period based on a traffic load for the period, wherein modifying the reserved periodic resources includes reducing or expanding the reserved periodic resources according to a ratio of modified periodic resources to the reserved periodic resources; and

transmitting sidelink communication in the period based on the modified periodic resources.

15. The method of claim 14 , wherein if the modified periodic resources comprise fewer resources than the reserved periodic resources for the period, the wireless device modifies the reserved periodic resources for the period so that the modified periodic resources are contained within the reserved periodic resources.

16. The method of claim 14 , wherein if the modified periodic resources comprise more resources than the reserved periodic resources for the period, the wireless device modifies the reserved periodic resources for the period so that the reserved periodic resources are contained within the modified periodic resources.

17. The method of claim 14 , further comprising:

transmitting a first indication in sidelink control information (SCI) to indicate that the reserved periodic resources are resources capable of being modified, or

transmitting a second indication in the SCI to indicate that the reserved periodic resources are resources incapable of being modified.

18. The method of claim 14 , wherein modifying the reserved periodic resources within the period comprises:

increasing or decreasing the reserved periodic resources within the period in one or more of a time domain or a frequency domain; and

transmitting sidelink control information (SCI) indicating a direction of expansion for the modified periodic resources for the period, wherein the direction includes one or more of a first direction in the time domain or a second direction in the frequency domain.

19. The method of claim 14 , further comprising:

monitoring for a conflicting resource reservation from a second wireless device,

wherein the wireless device modifies the reserved periodic resources to expand the reserved periodic resources for the period based on an absence of the conflicting resource reservation.

20. The method of claim 14 , wherein modifying the reserved periodic resources for the period includes expanding the reserved periodic resources to include expanded resources, the method further comprising:

mapping data of the sidelink communication jointly to a set of resources that includes the reserved periodic resources and the expanded resources.

21. The method of claim 14 , wherein modifying the reserved periodic resources for the period includes expanding the periodic resources to include expanded resources, wherein the wireless device transmits a transmission in the periodic resources and repeats the transmission in the expanded resources.

22. An apparatus for wireless communication at a wireless device, comprising:

a memory; and

at least one processor coupled to the memory and configured to:

receive a periodic resource reservation for reserved periodic resources for sidelink transmission;

receive a modification of the periodic resource reservation for a period, wherein the modification of the periodic resource reservation includes reduced resources or increased resources for the period according to a ratio of modified periodic resources to the reserved periodic resources; and

transmit or receive sidelink communication in the period based on the modified periodic resources.

23. The apparatus of claim 22 , wherein the at least one processor is further configured to:

receive a first indication in sidelink control information (SCI) to indicate that the reserved periodic resources are resources capable of being modified, or

receive a second indication in SCI to indicate that the reserved periodic resources are resources incapable of being modified.

24. The apparatus of claim 22 , wherein the at least one processor is further configured to:

receive sidelink control information (SCI) indicating a direction of expansion for the modified periodic resource reservation for the period, the direction including one or more of a first direction in a time domain or a second direction in a frequency domain.

25. The apparatus of claim 22 , further comprising a transceiver coupled to the at least one processor.

26. A method of wireless communication at a wireless device, comprising:

receiving a periodic resource reservation for reserved periodic resources for sidelink transmission;

receiving a modification of the periodic resource reservation for a period, wherein the modification of the periodic resource reservation includes reduced resources or increased resources for the period according to a ratio of modified periodic resources to the reserved periodic resources; and

transmitting or receiving sidelink communication in the period based on the modified periodic resources.