Random access procedure with preamble repetitions

1 . A method comprising:

transmitting, by a wireless device, a user equipment (UE) capability message indicating support for transmitting a first number of preamble repetitions for multiple physical random-access channel (PRACH) transmissions;

receiving, via a first cell, random-access configuration parameters indicating a plurality of reference signals (RSs);

initiating a random-access (RA) procedure for a reconfiguration with sync procedure to a second cell;

selecting an RS, among the plurality of RSs, for the RA procedure, associated with the first number of preamble repetitions via a second number of valid PRACH occasions of the second cell, wherein:

each of the second number of valid PRACH occasions is associated with the RS; and

the first number is the same as the second number;

transmitting, via the second number of valid PRACH occasions, the first number of preamble repetitions, wherein each repetition, of the first number of preamble repetitions, is associated with:

the same preamble index; and

the same spatial filter.

2 . The method of claim 1 , wherein a valid PRACH occasion of the second number of valid PRACH occasions comprises a PRACH occasion that is applicable to the wireless device.

3 . The method of claim 1 , wherein the configuration parameters are received by the wireless device in a configuration message from a base station.

4 . The method of claim 3 , wherein the configuration message is:

a radio resource control (RRC) message; or

a system information message.

5 . The method of claim 1 , wherein the configuration parameters indicate one or more thresholds associated with a number of RA preamble repetitions.

6 . The method of claim 1 , wherein the configuration parameters indicate one or more offset values for the plurality of RSs.

7 . The method of claim 1 , wherein the RA procedure is initiated by:

the wireless device; or

a base station.

8 . The method of claim 1 , wherein the RA procedure is a:

contention-based RA procedure; or

contention-free RA procedure.

9 . 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:

transmit a user equipment (UE) capability message indicating support for transmitting a first number of preamble repetitions for multiple physical random-access channel (PRACH) transmissions;

receive, via a first cell, random-access configuration parameters indicating a plurality of reference signals (RSs);

initiate a random-access (RA) procedure for a reconfiguration with sync procedure to a second cell;

select an RS, among the plurality of RSs, for the RA procedure, associated with the first number of preamble repetitions via a second number of valid PRACH occasions of the second cell, wherein:

each of the second number of valid PRACH occasions is associated with the RS; and

the first number is the same as the second number;

transmit, via the second number of valid PRACH occasions, the first number of preamble repetitions, wherein each repetition, of the first number of preamble repetitions, is associated with:

the same preamble index; and

the same spatial filter.

10 . The wireless device of claim 9 , wherein a valid PRACH occasion of the second number of valid PRACH occasions comprises a PRACH occasion that is applicable to the wireless device.

11 . The wireless device of claim 9 , wherein the configuration parameters are received by the wireless device in a configuration message from a base station.

12 . The wireless device of claim 11 , wherein the configuration message is:

a radio resource control (RRC) message; or

a system information message.

13 . The wireless device of claim 9 , wherein the configuration parameters indicate one or more thresholds associated with a number of RA preamble repetitions.

14 . The wireless device of claim 9 , wherein the configuration parameters indicate one or more offset values for the plurality of RSs.

15 . The wireless device of claim 9 , wherein the RA procedure is a:

contention-based RA procedure; or

contention-free RA procedure.

16 . 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:

transmit a user equipment (UE) capability message indicating support for transmitting a first number of preamble repetitions for multiple physical random-access channel (PRACH) transmissions;

receive, via a first cell, random-access configuration parameters indicating a plurality of reference signals (RSs);

initiate a random-access (RA) procedure for a reconfiguration with sync procedure to a second cell;

select an RS, among the plurality of RSs, for the RA procedure, associated with the first number of preamble repetitions via a second number of valid PRACH occasions of the second cell, wherein:

each of the second number of valid PRACH occasions is associated with the RS; and

the first number is the same as the second number;

transmit, via the second number of valid PRACH occasions, the first number of preamble repetitions, wherein each repetition, of the first number of preamble repetitions, is associated with:

the same preamble index; and

the same spatial filter.

17 . The non-transitory computer-readable medium of claim 16 , wherein a valid PRACH occasion of the second number of valid PRACH occasions comprises a PRACH occasion that is applicable to the wireless device.

18 . The non-transitory computer-readable medium of claim 16 , wherein the configuration parameters are received by the wireless device in a configuration message from a base station, wherein the configuration message is:

a radio resource control (RRC) message; or

a system information message.

19 . The non-transitory computer-readable medium of claim 16 , wherein the configuration parameters indicate one or more thresholds associated with a number of RA preamble repetitions.

20 . The non-transitory computer-readable medium of claim 16 , wherein the configuration parameters indicate one or more offset values for the plurality of RSs.