Contention resolution in non-terrestrial networks

1 . A method comprising:

receiving, by a wireless device, one or more configuration parameters indicating a first value for a contention resolution timer of a first random access configuration;

starting the contention resolution timer based on an initial transmission of a transport block of a random access (RA) procedure via a non-terrestrial network, wherein a length of the contention resolution timer is initialized to the first value;

receiving, while the contention resolution timer is running, a first downlink control information (DCI) indicating a retransmission of the transport block;

determining the contention resolution timer has expired based on an elapsed time exceeding the first value;

not discarding a temporary cell (TC) radio network temporary identifier (RNTI) of the wireless device in response to:

the first DCI being received while the contention resolution timer is running; and

the contention resolution timer having expired before transmission of the retransmission; and

transmitting the retransmission of the transport block based on the TC-RNTI.

2 . The method of claim 1 , further comprising receiving a random access response (RAR), of the RA procedure, indicating:

the TC-RNTI; and

an uplink grant for an initial transmission of the transport block.

3 . The method of claim 2 , further comprising transmitting the initial transmission of the transport block based on the TC-RNTI and the uplink grant.

4 . The method of claim 1 , further comprising:

receiving a second DCI indicating a second uplink grant for an initial transmission of the transport block, wherein the second DCI is with a cyclic redundancy check (CRC) scrambled by the TC-RNTI; and

transmitting the initial transmission of the transport block based on the TC-RNTI and the second uplink grant.

5 . The method of claim 1 , further comprising, in response to transmitting the retransmission of the transport block, monitoring a physical downlink control channel (PDCCH) using the TC-RNTI.

6 . The method of claim 5 , further comprising receiving a third DCI scheduling a physical downlink shared channel (PDSCH) of the RA procedure, wherein:

the third DCI is received based on a cyclic redundancy check (CRC) scrambled by the TC-RNTI; and

the PDSCH is for contention resolution.

7 . The method of claim 1 , further comprising at least one of:

not determining contention resolution, of the RA procedure, is unsuccessful;

not indicating the contention resolution is unsuccessful;

not flushing a hybrid repeat request (HARQ) buffer of the initial transmission of the RA procedure;

not stopping a time alignment timer; or

not retransmitting a preamble of the RA procedure.

8 . A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors of a wireless device, cause the wireless device to:

receive one or more configuration parameters indicating a first value for a contention resolution timer of a first random access configuration;

start the contention resolution timer based on an initial transmission of a transport block of a random access (RA) procedure via a non-terrestrial network, wherein a length of the contention resolution timer is initialized to the first value;

receive, while the contention resolution timer is running, a first downlink control information (DCI) indicating a retransmission of the transport block;

determine the contention resolution timer has expired based on an elapsed time exceeding the first value;

not discard a temporary cell (TC) radio network temporary identifier (RNTI) of the wireless device in response to:

the first DCI being received while the contention resolution timer is running; and

the contention resolution timer having expired before transmission of the retransmission; and

transmit the retransmission of the transport block based on the TC-RNTI.

9 . The non-transitory computer-readable medium of claim 8 , wherein the instructions further cause the wireless device to receive a random access response (RAR), of the RA procedure, indicating:

the TC-RNTI; and

an uplink grant for an initial transmission of the transport block.

10 . The non-transitory computer-readable medium of claim 9 , wherein the instructions further cause the wireless device to transmit the initial transmission of the transport block based on the TC-RNTI and the uplink grant.

11 . The non-transitory computer-readable medium of claim 8 , wherein the instructions further cause the wireless device to:

receive a second DCI indicating a second uplink grant for an initial transmission of the transport block, wherein the second DCI is with a cyclic redundancy check (CRC) scrambled by the TC-RNTI; and

transmit the initial transmission of the transport block based on the TC-RNTI and the second uplink grant.

12 . The non-transitory computer-readable medium of claim 8 , wherein the instructions further cause the wireless device to, in response to transmitting the retransmission of the transport block, monitor a physical downlink control channel (PDCCH) using the TC-RNTI.

13 . The non-transitory computer-readable medium of claim 12 , wherein the instructions further cause the wireless device to receive a third DCI scheduling a physical downlink shared channel (PDSCH) of the RA procedure, wherein:

the third DCI is received based on a cyclic redundancy check (CRC) scrambled by the TC-RNTI; and

the PDSCH is for contention resolution.

14 . 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 configuration parameters indicating a first value for a contention resolution timer of a first random access configuration;

start the contention resolution timer based on an initial transmission of a transport block of a random access (RA) procedure via a non-terrestrial network, wherein a length of the contention resolution timer is initialized to the first value;

receive, while the contention resolution timer is running, a first downlink control information (DCI) indicating a retransmission of the transport block;

determine the contention resolution timer has expired based on an elapsed time exceeding the first value;

not discard a temporary cell (TC) radio network temporary identifier (RNTI) of the wireless device in response to:

the first DCI being received while the contention resolution timer is running; and

the contention resolution timer having expired before transmission of the retransmission; and

transmit the retransmission of the transport block based on the TC-RNTI.

15 . The wireless device of claim 14 , wherein the instructions further cause the wireless device to:

receive a random access response (RAR), of the RA procedure, indicating:

the TC-RNTI; and

an uplink grant for an initial transmission of the transport block.

16 . The wireless device of claim 15 , wherein the instructions further cause the wireless device to:

transmit the initial transmission of the transport block based on the TC-RNTI and the uplink grant.

17 . The wireless device of claim 14 , wherein the instructions further cause the wireless device to:

receive a second DCI indicating a second uplink grant for an initial transmission of the transport block, wherein the second DCI is with a cyclic redundancy check (CRC) scrambled by the TC-RNTI; and

transmit the initial transmission of the transport block based on the TC-RNTI and the second uplink grant.

18 . The wireless device of claim 14 , wherein the instructions further cause the wireless device to:

in response to transmitting the retransmission of the transport block, monitor a physical downlink control channel (PDCCH) using the TC-RNTI.

19 . The wireless device of claim 18 , wherein the instructions further cause the wireless device to:

receive a third DCI scheduling a physical downlink shared channel (PDSCH) of the RA procedure, wherein:

the third DCI is received based on a cyclic redundancy check (CRC) scrambled by the TC-RNTI; and

the PDSCH is for contention resolution.

20 . The wireless device of claim 14 , wherein the instructions further cause the wireless device to not perform at least one of:

determine contention resolution, of the RA procedure, is unsuccessful;

indicate the contention resolution is unsuccessful;

flush a hybrid repeat request (HARQ) buffer of the initial transmission of the RA procedure;

stop a time alignment timer; or

retransmit a preamble of the RA procedure.