Hybrid automatic repeat request feedback in radio systems

1. A method comprising:

receiving, by a wireless device, one or more radio resource control (RRC) messages indicating:

a plurality of repetition values of a physical sidelink shared channel (PSSCH); and

a repetition threshold for the PSSCH;

receiving a sidelink control information (SCI):

scheduling a transport block; and

indicating a first repetition value of the plurality of repetition values;

receiving, via the PSSCH, the transport block;

determining, based on a comparison of the first repetition value received via the SCI and the repetition threshold received via the one or more RRC messages, to transmit an acknowledgment for the received transport block; and

transmitting the acknowledgment for the received transport block.

2. The method of claim 1 , wherein the determining, based on the comparison of the first repetition value received via the SCI and the repetition threshold received via the one or more RRC messages, is based on the first repetition value being equal to or less than the repetition threshold.

3. The method of claim 1 , wherein each of the plurality of repetition values of the PSSCH indicates a plurality of repetition transmissions of the PSSCH.

4. The method of claim 3 , wherein the plurality of repetition values of the PSSCH comprise transmission and retransmissions of the PSSCH with different redundancy versions.

5. The method of claim 4 , wherein the different redundancy versions are indicated to the wireless device via the sidelink control information.

6. The method of claim 1 , wherein the repetition threshold for the PSSCH comprises a repetition value for a transmission sent to the wireless device.

7. The method of claim 1 , wherein the receiving the sidelink control information comprises receiving the sidelink control information from a reception resource pool.

8. The method of claim 1 , wherein the transport block is received via a sidelink.

9. The method of claim 1 , wherein the receiving the one or more RRC messages comprises receiving, by the wireless device, the one or more RRC messages from a second wireless device.

10. The method of claim 1 , wherein the receiving the one or more RRC messages comprises receiving, by the wireless device, the one or more RRC messages from a base station.

11. A wireless device comprising:

one or more processors; and

memory storing instructions that, when executed by the one or more processors, cause the wireless device to:

receive one or more radio resource control (RRC) messages indicating:

a plurality of repetition values of a physical sidelink shared channel (PSSCH); and

a repetition threshold for the PSSCH;

receive a sidelink control information (SCI):

scheduling a transport block; and

indicating a first repetition value of the plurality of repetition values;

receive, via the PSSCH, the transport block;

determine, based on a comparison of the first repetition value received via the SCI and the repetition threshold received via the one or more RRC messages, to transmit an acknowledgment for the received transport block; and

transmit the acknowledgment for the received transport block.

12. The wireless device of claim 11 , wherein the determination, based on the comparison of the first repetition value received via the SCI and the repetition threshold received via the one or more RRC messages, is based on the first repetition value being equal to or less than the repetition threshold.

13. The wireless device of claim 11 , wherein each of the plurality of repetition values of the PSSCH indicates a plurality of repetition transmissions of the PSSCH.

14. The wireless device of claim 13 , wherein the plurality of repetition values of the PSSCH comprise transmission and retransmissions of the PSSCH with different redundancy versions.

15. The wireless device of claim 14 , wherein the different redundancy versions are indicated to the wireless device via the sidelink control information.

16. The wireless device of claim 11 , wherein the repetition threshold for the PSSCH comprises a repetition value for a transmission sent to the wireless device.

17. The wireless device of claim 11 , wherein the reception of the sidelink control information comprises receiving the sidelink control information from a reception resource pool.

18. The wireless device of claim 11 , wherein the transport block is received via a sidelink.

19. The wireless device of claim 11 , wherein the reception of the one or more RRC messages from at least one of:

a second wireless device; or

a base station.

20. A system comprising:

a base station comprising:

one or more first processors; and

first memory storing first instructions that, when executed by the one or more first processors, cause the base station to transmit one or more radio resource control (RRC) messages indicating:

a plurality of repetition values of a physical sidelink shared channel (PSSCH); and

a repetition threshold for the PSSCH;

a first wireless device comprising:

one or more second processors; and

second memory storing second instructions that, when executed by the one or more second processors, cause the first wireless device to:

transmit a sidelink control information (SCI):

scheduling a transport block; and

indicating a first repetition value of the plurality of repetition values;

transmit, via the PSSCH, the transport block; and

receive an acknowledgment for the transport block; and

a second wireless device comprising:

one or more third processors; and

third memory storing third instructions that, when executed by the one or more third processors, cause the second wireless device to:

receive the one or more RRC messages;

receive the sidelink control information:

receive, via the PSSCH, the transport block;

determine, based on a comparison of the first repetition value received via the SCI and the repetition threshold received via the one or more RRC messages, to transmit an acknowledgment for the received transport block; and

transmit the acknowledgment for the received transport block.