Timing offset selection in non-terrestrial network

1. A user equipment (UE) for wireless communication, comprising:

a memory; and

one or more processors, coupled to the memory, configured to:

receive, from a non-terrestrial network (NTN) entity, a message that is associated with an uplink grant;

select, based at least in part on the message, either a cell-specific offset or an updated offset that is indicated after initial access, as a timing offset that accounts for a propagation delay between a base station of the NTN and the UE, wherein the cell-specific timing offset is included in a previously received message, wherein the message includes downlink control information (DCI) that is scrambled with a radio network temporary identifier (RNTI), and wherein the one or more processors are configured to select the timing offset based at least in part on a type of the RNTI; and

transmit, to the NTN entity, an uplink communication using the timing offset.

2. The UE of claim 1 , wherein the updated offset is a UE-specific offset.

3. The UE of claim 1 , wherein the updated offset is a UE group-specific offset.

4. The UE of claim 1 , wherein the updated offset is a beam-specific offset.

5. The UE of claim 1 , wherein the updated offset is an update over the cell-specific offset.

6. The UE of claim 1 , wherein a duration of the updated offset is shorter than a duration of the cell-specific offset.

7. The UE of claim 1 , wherein the one or more processors, to select the timing offset, are configured to select the updated offset as the timing offset if a resource allocation is indicated in a message other than downlink control information.

8. The UE of claim 1 , wherein the one or more processors, to select the timing offset, are configured to select the cell-specific offset as the timing offset if the DCI is scrambled with an RNTI that is not UE-specific.

9. The UE of claim 1 wherein the one or more processors, to select the timing offset, are configured to select the updated offset as the timing offset if the DCI is scrambled with an RNTI that is UE-specific.

10. The UE of claim 1 , wherein the cell-specific offset is selected if the DCI is scrambled with an RNTI that is UE-specific and the DCI indicates a physical downlink control channel order.

11. The UE of claim 1 , wherein the one or more processors, to select the timing offset, are configured to select the cell-specific offset as the timing offset if the UE is performing one or more of initial access or random access.

12. The UE of claim 1 , wherein the one or more processors, to select the timing offset, are configured to select the updated offset as the timing offset if the UE is to transmit, in association with the message, hybrid automatic repeat request feedback or a physical uplink shared channel communication.

13. The UE of claim 1 , wherein the message includes DCI, and wherein the one or more processors, to select the timing offset, are configured to select either the cell-specific offset or the updated offset based at least in part on an indication in the DCI of whether to select the cell-specific offset or the updated offset.

14. The UE of claim 1 , wherein the one or more processors are configured to receive a medium access control control element (MAC-CE) or radio resource control (RRC) message that includes an indication of whether to select the cell-specific offset or the updated offset, and wherein the one or more processors, to select the timing offset, are configured to select either the cell-specific offset or the updated offset based at least in part on the indication in the MAC-CE or RRC message.

15. The UE of claim 1 , wherein the one or more processors, to select the timing offset, are configured to select the cell-specific offset if the uplink communication is an initial Msg3 transmission.

16. The UE of claim 1 , wherein the one or more processors, to select the timing offset, are configured to select the cell-specific offset if the uplink communication is a Msg3 retransmission scheduled by downlink control information with a cyclic redundancy check that is scrambled by a temporary cell radio network temporary identifier.

17. The UE of claim 1 , wherein the one or more processors, to select the timing offset, are configured to select the cell-specific offset if the uplink communication is a hybrid automatic repeat request acknowledgement in response to a Msg4 transmission scheduled by downlink control information with a cyclic redundancy check that is scrambled by a temporary cell radio network temporary identifier.

18. The UE of claim 1 , wherein the one or more processors, to select the timing offset, are configured to select the cell-specific offset if the uplink communication is a HARQ ACK in response to a MsgB transmission scheduled by downlink control information with a cyclic redundancy check that is scrambled by a MsgB radio network temporary identifier.

19. A base station of a non-terrestrial network (NTN) for wireless communication, comprising:

a memory; and

one or more processors, coupled to the memory, configured to:

transmit, to a user equipment (UE) via an NTN entity, a message that is associated with an uplink grant;

select, based at least in part on the message, either a cell-specific offset or an updated offset that is indicated after initial access, as a timing offset that accounts for a propagation delay between the base station and the UE, wherein the cell-specific timing offset is included in a previously transmitted message, wherein the message includes downlink control information (DCI) that is scrambled with a radio network temporary identifier (RNTI), and wherein the one or more processors are configured to select the timing offset based at least in part on a type of the RNTI; and

receive, from the UE via the NTN entity, an uplink communication using the timing offset.

20. The base station of claim 19 , wherein the updated offset is a UE-specific offset, a UE group-specific offset, or a beam-specific offset.

21. The base station of claim 19 , wherein the one or more processors, to select the timing offset, are configured to select the updated offset as the timing offset if a resource allocation is indicated in a message other than downlink control information.

22. The base station of claim 19 , wherein the one or more processors, to select the timing offset, are configured to select the cell-specific offset as the timing offset if the DCI is scrambled with an RNTI that is not UE-specific or if the UE is performing one or more of initial access or random access.

23. The base station of claim 19 , wherein the one or more processors, to select the timing offset, are configured to select the updated offset as the timing offset if the DCI is scrambled with an RNTI that is UE-specific or if the UE is to transmit, in association with the message, hybrid automatic repeat request feedback or a physical uplink shared channel communication.

24. The base station of claim 19 , wherein the one or more processors, to select the timing offset, are configured to select the cell-specific offset as the timing offset if the DCI is scrambled with an RNTI that is UE-specific and the DCI indicates a physical downlink control channel order.

25. The base station of claim 19 , wherein the one or more processors are configured to transmit a medium access control control element (MAC-CE) or radio resource control (RRC) message that includes an indication of whether to select the cell-specific offset or the updated offset, and wherein the one or more processors, to select the timing offset, are configured to select either the cell-specific offset or the updated offset based at least in part on the indication in the MAC-CE or RRC message.

26. The base station of claim 19 , wherein the one or more processors, to select the timing offset, are configured to select the cell-specific offset if the uplink communication is a Msg3 transmission or a Msg3 retransmission with scrambling initialized by a radio network temporary identifier that is not UE specific.

27. A method of wireless communication performed by a user equipment (UE), comprising:

receiving, from a non-terrestrial network (NTN) entity, a message that is associated with an uplink grant;

selecting, based at least in part on the message, either a cell-specific offset or an updated offset that is indicated after initial access, as a timing offset that accounts for a propagation delay between a base station of the NTN and the UE, wherein the cell-specific timing offset is included in a previously received message, wherein the message includes downlink control information (DCI) that is scrambled with a radio network temporary identifier (RNTI), and wherein the one or more processors are configured to select the timing offset based at least in part on a type of the RNTI; and

transmitting, to the NTN entity, an uplink communication using the timing offset.

28. A method of wireless communication performed by a base station of a non-terrestrial network (NTN), comprising:

transmitting, to a user equipment (UE) via an NTN entity, a message that is associated with an uplink grant;

selecting, based at least in part on the message, either a cell-specific offset or an updated offset that is indicated after initial access, as a timing offset that accounts for a propagation delay between the base station and the UE wherein the cell-specific timing offset is included in a previously transmitted message, wherein the message includes downlink control information (DCI) that is scrambled with a radio network temporary identifier (RNTI), and wherein the one or more processors are configured to select the timing offset based at least in part on a type of the RNTI; and

receiving, from the UE via the NTN entity, an uplink communication using the timing offset.