Random access preambles using transmit beams of base station

1. A method comprising:

receiving, by a base station from a wireless device via a cell, one or more random access preambles from transmit beams of the wireless device;

transmitting at least one random access response identified by a cell radio identifier of the wireless device, wherein:

the at least one random access response comprises a first preamble identifier corresponding to a first random access preamble of the one or more random access preambles; and

the first random access preamble is transmitted by a first transmit beam of the transmit beams; and

receiving, from the wireless device, data using the first transmit beam.

2. The method of claim 1 , further comprising transmitting, by the base station to a second base station, configuration parameters indicating the cell radio identifier of the wireless device, wherein the receiving of the one or more random access preambles is in response to the transmitting of the configuration parameters.

3. The method of claim 2 , wherein the configuration parameters further indicate random access preambles of the cell of the base station, wherein the random access preambles comprise the one or more random access preambles.

4. The method of claim 2 , wherein the configuration parameters are transmitted via one or more radio resource configuration (RRC) messages.

5. The method of claim 2 , wherein the configuration parameters indicate a number of allowed transmissions of the one or more random access preambles.

6. The method of claim 5 , wherein a number of the one or more random access preambles is equal to or less than the number of allowed transmissions of the one or more random access preambles.

7. The method of claim 2 , wherein the configuration parameters further indicate a handover from the second base station to the base station.

8. The method of claim 1 , wherein the cell radio identifier is a cell radio network temporary identifier.

9. The method of claim 1 , wherein the at least one random access response comprises:

a medium access control subheader comprising the first preamble identifier; and

a medium access control random access response corresponding to the medium access control subheader.

10. The method of claim 9 , wherein the medium access control random access response comprises a timing advance command and an uplink grant.

11. A base station comprising:

one or more processors; and

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

receive, from a wireless device via a cell, one or more random access preambles via transmit beams of the wireless device;

transmit at least one random access response identified by a cell radio identifier of the wireless device, wherein:

the at least one random access response comprises a first preamble identifier corresponding to a first random access preamble of the one or more random access preambles; and

the first random access preamble is transmitted by a first transmit beam of the transmit beams; and

receive, from the wireless device, data using the first transmit beam.

12. The base station of claim 11 , wherein the instructions further cause the base station to transmit, to a second base station, configuration parameters indicating the cell radio identifier of the wireless device, wherein the receiving of the one or more random access preambles is in response to the transmitting of the configuration parameters.

13. The base station of claim 12 , wherein the configuration parameters further indicate random access preambles of the cell of the base station, wherein the random access preambles comprise the one or more random access preambles.

14. The base station of claim 12 , wherein the configuration parameters are transmitted via one or more radio resource configuration (RRC) messages.

15. The base station of claim 12 , wherein the configuration parameters indicate a number of allowed transmissions of the one or more random access preambles.

16. The base station of claim 15 , wherein a number of the one or more random access preambles is equal to or less than the number of allowed transmissions of the one or more random access preambles.

17. The base station of claim 12 , wherein the configuration parameters further indicate a handover from the second base station to the base station.

18. The base station of claim 11 , wherein the cell radio identifier is a cell radio network temporary identifier.

19. The base station of claim 11 , wherein the at least one random access response comprises:

a medium access control subheader comprising the first preamble identifier; and

a medium access control random access response corresponding to the medium access control subheader.

20. A system comprising:

a wireless device comprising one or more first processors and first memory storing first instructions that, when executed by the one or more first processors, cause the wireless device to transmitting, via a cell, one or more random access preambles using transmit beams; and

a base station comprising one or more second processors and second memory storing second instructions that, when executed by the one or more second processors, cause the base station to:

receive the one or more random access preambles;

transmit at least one random access response identified by a cell radio identifier of the wireless device, wherein:

the at least one random access response comprises a first preamble identifier corresponding to a first random access preamble of the one or more random access preambles; and

the first random access preamble is transmitted by a first transmit beam of the transmit beams; and

receive, from the wireless device, data using the first transmit beam.