Radio vehicle-to-anything negative acknowledgement based multicast

1. A method for wireless communication at a first device, comprising:

receiving a multicast packet from a second device;

decoding control header information in the received multicast packet, the control header information comprising at least a portion of a transmitter identifier associated with the multicast packet;

determining that a decoding procedure associated with a payload of the received multicast packet is unsuccessful; and

transmitting a negative acknowledgement (NACK) based at least in part on decoding the control header information and determining that the decoding procedure associated with the payload is unsuccessful.

2. The method of claim 1 , further comprising:

retrieving a list of transmitter identifiers, wherein transmitting the NACK is based at least in part on the list of transmitter identifiers.

3. The method of claim 2 , further comprising:

determining the transmitter identifier associated with the multicast packet based at least in part on the decoded control header information; and

determining that the transmitter identifier is present in the list of transmitter identifiers, wherein transmitting the NACK is based at least in part on the transmitter identifier being present in the list of transmitter identifiers.

4. The method of claim 2 , wherein:

the list of transmitter identifiers is based at least in part on one or more transmitters located within a determined distance, a type of a sensor information, a combination of one or more types of sensor information, or a combination thereof.

5. The method of claim 1 , further comprising:

generating a sequence associated with the multicast packet, wherein the transmitted NACK comprises the sequence associated with the multicast packet.

6. The method of claim 5 , further comprising:

determining a sequence identifier based at least in part on the transmitter identifier, wherein generating the sequence associated with the multicast packet is based at least in part on the sequence identifier.

7. The method of claim 5 , further comprising:

identifying time and frequency resources associated with transmission of the multicast packet; and

determining a sequence identifier based at least in part on the time and frequency resources, wherein generating the sequence associated with the multicast packet is based at least in part on the sequence identifier.

8. The method of claim 7 , further comprising:

determining at least one resource block associated with the multicast packet; and

identifying an energy level associated with the at least one resource block, wherein identifying the time and frequency resources based at least in part on the energy level.

9. The method of claim 7 , wherein:

timing and frequency resources associated with the sequence is same as the time and frequency resources associated with the transmission of the multicast packet.

10. The method of claim 5 , wherein:

timing and frequency resources associated with the sequence are derived randomly.

11. The method of claim 5 , wherein:

a length of the sequence is based at least in part on a length of a transmission associated with the multicast packet.

12. The method of claim 5 , wherein:

a length of the sequence is preconfigured.

13. The method of claim 1 , further comprising:

identifying a symbol occurring after one or more transmission time intervals (TTIs), wherein transmitting the NACK occurs on the identified symbol.

14. The method of claim 13 , wherein:

the identified symbol is a last symbol of a TTI, wherein transmitting the NACK occurs on the last symbol of the TTI.

15. The method of claim 13 , wherein:

the identified symbol is a gap symbol after a determined number of TTIs, wherein transmitting the NACK occurs on the gap symbol after the determined number of TTIs.

16. The method of claim 13 , wherein:

the identified symbol is a gap symbol of a TTI within a determined period, wherein transmitting the NACK occurs on the gap symbol of the TTI within the determined period.

17. The method of claim 1 , wherein:

the first device, or the second device, or both include a stationary vehicle, a vehicle in motion, a user equipment (UE), a motion sensor, a camera sensor, a light detection and ranging (LIDAR) sensor, a radio detection and ranging (RADAR) sensor, or any combination thereof.

18. A method for wireless communication, comprising:

determining a transmitter identifier associated with a multicast packet;

transmitting the multicast packet comprising control header information and a payload to one or more devices, the control header information comprising at least a portion of the transmitter identifier;

receiving a negative acknowledgement (NACK), the NACK including a sequence identifier indicating that a decoding procedure associated with the payload of the multicast packet is unsuccessful; and

retransmitting the multicast packet to the one or more devices based at least in part on the NACK.

19. The method of claim 18 , further comprising:

adding at least the portion of the transmitter identifier to the control header information in the multicast packet before transmitting.

20. The method of claim 19 , further comprising:

determining the sequence identifier from the NACK; and

comparing the sequence identifier with the transmitter identifier associated with the multicast packet, wherein retransmitting the multicast packet is based at least in part on the comparing.

21. The method of claim 18 , further comprising:

determining time and frequency resources associated with transmission of the multicast packet;

determining the sequence identifier associated with the NACK; and

determining time and frequency resources associated with the sequence identifier, wherein retransmitting the multicast packet is based at least in part on the time and frequency resources associated with the sequence identifier and the time and frequency resources associated with the transmission of the multicast packet.

22. The method of claim 18 , further comprising:

determining a first sequence associated with the NACK, wherein the NACK is received from a first device;

receiving a second NACK from a second device different from the first device; and

determining a second sequence associated with the second NACK, the first sequence and the second sequence being orthogonal to each other, wherein retransmitting the multicast packet is based at least in part on the first sequence and the second sequence.

23. The method of claim 22 , wherein:

the first device, or the second device, or both include a stationary vehicle, a vehicle in motion, a user equipment (UE), a motion sensor, a camera sensor, a light detection and ranging (LIDAR) sensor, a radio detection and ranging (RADAR) sensor, or any combination thereof.

24. The method of claim 18 , further comprising:

flushing a buffer associated with retransmitting the multicast packet at a time satisfying a threshold period after transmitting the multicast packet to the one or more devices, wherein the NACK is received after the threshold period.

25. An apparatus for wireless communication, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to:

receive a multicast packet from a second device;

decode control header information in the received multicast packet, the control header information comprising at least a portion of a transmitter identifier associated with the multicast packet;

determine that a decoding procedure associated with a payload of the received multicast packet is unsuccessful; and

transmit a negative acknowledgement (NACK) based at least in part on decoding the control header information and determining that the decoding procedure associated with the payload is unsuccessful.

26. An apparatus for wireless communication, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to:

determine a transmitter identifier associated with a multicast packet;

transmit the multicast packet comprising control header information and a payload to one or more devices, the control header information comprising at least a portion of the transmitter identifier;

receive a negative acknowledgement (NACK), the NACK including a sequence identifier indicating that a decoding procedure associated with the payload of the multicast packet is unsuccessful; and

retransmit the multicast packet to the one or more devices based at least in part on the NACK.

27. A non-transitory computer-readable medium storing code for wireless communication at a first device, the code comprising instructions executable by a processor to:

receive a multicast packet from a second device;

decode control header information in the received multicast packet, the control header information comprising at least a portion of a transmitter identifier associated with the multicast packet;

determine that a decoding procedure associated with a payload of the received multicast packet is unsuccessful; and

transmit a negative acknowledgement (NACK) based at least in part on decoding the control header information and determining that the decoding procedure associated with the payload is unsuccessful.

28. The non-transitory computer-readable medium of claim 27 , wherein the instructions are further executable by the processor to:

retrieve a list of transmitter identifiers, wherein transmitting the NACK is based at least in part on the list of transmitter identifiers.

29. The non-transitory computer-readable medium of claim 28 , wherein the instructions are further executable by the processor to:

determine the transmitter identifier associated with the multicast packet based at least in part on the decoded control header information; and

determine that the transmitter identifier is present in the list of transmitter identifiers, wherein transmitting the NACK is based at least in part on the transmitter identifier being present in the list of transmitter identifiers.

30. The non-transitory computer-readable medium of claim 28 , wherein:

the list of transmitter identifiers is based at least in part on one or more transmitters located within a determined distance, a type of a sensor information, a combination of one or more types of sensor information, or a combination thereof.

31. The non-transitory computer-readable medium of claim 27 , wherein the instructions are further executable by the processor to:

generate a sequence associated with the multicast packet, wherein the transmitted NACK comprises the sequence associated with the multicast packet.

32. The non-transitory computer-readable medium of claim 31 , wherein the instructions are further executable by the processor to:

determine a sequence identifier based at least in part on the transmitter identifier, wherein generating the sequence associated with the multicast packet is based at least in part on the sequence identifier.

33. The non-transitory computer-readable medium of claim 31 , wherein the instructions are further executable by the processor to:

identify time and frequency resources associated with transmission of the multicast packet; and

determine a sequence identifier based at least in part on the time and frequency resources, wherein generating the sequence associated with the multicast packet is based at least in part on the sequence identifier.

34. The non-transitory computer-readable medium of claim 33 , wherein the instructions are further executable by the processor to:

determine at least one resource block associated with the multicast packet; and

identify an energy level associated with the at least one resource block, wherein identifying the time and frequency resources based at least in part on the energy level.

35. The non-transitory computer-readable medium of claim 33 , wherein:

timing and frequency resources associated with the sequence is same as the time and frequency resources associated with the transmission of the multicast packet.

36. The non-transitory computer-readable medium of claim 31 , wherein:

timing and frequency resources associated with the sequence are derived randomly.

37. The non-transitory computer-readable medium of claim 31 , wherein:

a length of the sequence is based at least in part on a length of a transmission associated with the multicast packet.

38. The non-transitory computer-readable medium of claim 31 , wherein:

a length of the sequence is preconfigured.

39. The non-transitory computer-readable medium of claim 27 , wherein the instructions are further executable by the processor to:

identify a symbol occurring after one or more transmission time intervals (TTIs), wherein transmitting the NACK occurs on the identified symbol.

40. The non-transitory computer-readable medium of claim 39 , wherein:

the identified symbol is a last symbol of a TTI, wherein transmitting the NACK occurs on the last symbol of the TTI.

41. The non-transitory computer-readable medium of claim 39 , wherein:

the identified symbol is a gap symbol after a determined number of TTIs, wherein transmitting the NACK occurs on the gap symbol after the determined number of TTIs.

42. The non-transitory computer-readable medium of claim 39 , wherein:

the identified symbol is a gap symbol of a TTI within a determined period, wherein transmitting the NACK occurs on the gap symbol of the TTI within the determined period.

43. The non-transitory computer-readable medium of claim 27 , wherein:

the first device, or the second device, or both include a stationary vehicle, a vehicle in motion, a user equipment (UE), a motion sensor, a camera sensor, a light detection and ranging (LIDAR) sensor, a radio detection and ranging (RADAR) sensor, or any combination thereof.

44. A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to:

determine a transmitter identifier associated with a multicast packet;

transmit the multicast packet comprising control header information and a payload to one or more devices, the control header information comprising at least a portion of the transmitter identifier;

receive a negative acknowledgement (NACK), the NACK including a sequence identifier indicating that a decoding procedure associated with the payload of the multicast packet is unsuccessful; and

retransmit the multicast packet to the one or more devices based at least in part on the NACK.

45. The non-transitory computer-readable medium of claim 44 , wherein the instructions are further executable by the processor to:

add at least the portion of the transmitter identifier to the control header information in the multicast packet before transmitting.

46. The non-transitory computer-readable medium of claim 45 , wherein the instructions are further executable by the processor to:

determine the sequence identifier from the NACK; and

compare the sequence identifier with the transmitter identifier associated with the multicast packet, wherein retransmitting the multicast packet is based at least in part on the comparing.

47. The non-transitory computer-readable medium of claim 44 , wherein the instructions are further executable by the processor to:

determine time and frequency resources associated with transmission of the multicast packet;

determine the sequence identifier associated with the NACK; and

determine time and frequency resources associated with the sequence identifier, wherein retransmitting the multicast packet is based at least in part on the time and frequency resources associated with the sequence identifier and the time and frequency resources associated with the transmission of the multicast packet.

48. The non-transitory computer-readable medium of claim 44 , wherein the instructions are further executable by the processor to:

determine a first sequence associated with the NACK, wherein the NACK is received from a first device;

receive a second NACK from a second device different from the first device; and

determine a second sequence associated with the second NACK, the first sequence and the second sequence being orthogonal to each other, wherein retransmitting the multicast packet is based at least in part on the first sequence and the second sequence.

49. The non-transitory computer-readable medium of claim 48 , wherein:

the first device, or the second device, or both include a stationary vehicle, a vehicle in motion, a user equipment (UE), a motion sensor, a camera sensor, a light detection and ranging (LIDAR) sensor, a radio detection and ranging (RADAR) sensor, or any combination thereof.

50. The non-transitory computer-readable medium of claim 44 , wherein the instructions are further executable by the processor to:

flush a buffer associated with retransmitting the multicast packet at a time satisfying a threshold period after transmitting the multicast packet to the one or more devices, wherein the NACK is received after the threshold period.

51. An apparatus for wireless communication, comprising:

means for receiving a multicast packet from a second device;

means for decoding control header information in the received multicast packet, the control header information comprising at least a portion of a transmitter identifier associated with the multicast packet;

means for determining that a decoding procedure associated with a payload of the received multicast packet is unsuccessful; and

means for transmitting a negative acknowledgement (NACK) based at least in part on decoding the control header information and determining that the decoding procedure associated with the payload is unsuccessful.

52. An apparatus for wireless communication, comprising:

means for determining a transmitter identifier associated with a multicast packet;

means for transmitting the multicast packet comprising control header information and a payload to one or more devices, the control header information comprising at least a portion of the transmitter identifier;

means for receiving a negative acknowledgement (NACK), the NACK including a sequence identifier indicating that a decoding procedure associated with the payload of the multicast packet is unsuccessful; and

means for retransmitting the multicast packet to the one or more devices based at least in part on the NACK.