Radio network node, wireless device, and methods for performing random access in a wireless communication network

1. A method of operating a wireless device in a wireless communication network, the method comprising:

transmitting to a radio network node in the wireless communication network, a first preamble associated with a selected downlink beam;

monitoring the wireless communication network for a random access response, RAR, during a first RAR reception window;

responsive to the RAR not being received during the first RAR reception window, monitoring the wireless communication network for the RAR during a second RAR reception window of a different beam; and

transmitting, to the radio network node, a second preamble associated with a second beam, wherein the first preamble is associated with a channel state information reference signal and the second preamble is associated with a synchronization signal block.

2. The method of claim 1 , wherein transmitting the second preamble comprises, responsive to the RAR not being received during the second RAR reception window, transmitting the second preamble associated with the second beam,

the method further comprising, responsive to a RAR associated with the second preamble not being received during a third RAR reception window, transmitting a third preamble of a newly selected beam.

3. The method of claim 2 , further comprising:

responsive to a RAR associated with the third preamble not being received during a fourth RAR reception window, performing power ramping procedures based on system information.

4. The method of claim 1 , wherein the second RAR reception window is an extension of the first RAR reception window.

5. The method of claim 1 , wherein the different beam and the second beam are wider than the selected downlink beam.

6. The method of claim 5 , further comprising

acquiring synchronization with a cell of the selected downlink beam; and

detecting and selecting the second beam using the acquired synchronization.

7. The method of claim 1 , further comprising:

receiving a radio resource control, RRC, connection reconfiguration message including random access channel, RACH, mapping configuration;

responsive to receiving the RRC connection reconfiguration message, selecting the selected downlink beam based on the RACH mapping configurations; and

responsive to the RAR not being received during the first RAR reception window, selecting the second beam based on the RACH mapping configurations.

8. A wireless device operating in a wireless communication network, the wireless device comprising:

processing circuitry; and

memory coupled to the processing circuitry and having instructions stored therein that are executable by the processing circuitry to cause the wireless device to perform operations, the operations comprising:

transmitting, to a radio network node in the wireless communication network, a first preamble associated with a selected downlink beam;

monitoring the wireless communication network for a random access response, RAR, during a first RAR reception window;

responsive to the RAR not being received during the first RAR reception window, monitoring the wireless communication network for the RAR during a second RAR reception window of a different beam; and

transmitting, to the radio network node, a second preamble associated with a second beam wherein the first preamble is associated with a channel state information reference signal and the second preamble is associated with a synchronization signal block.

9. The wireless device of claim 8 , wherein transmitting the second preamble comprises, responsive to the RAR not being received during the second RAR reception window, transmitting the second preamble associated with the second beam,

the operations further comprising, responsive to a RAR associated with the second preamble not being received during a third RAR reception window, transmitting a third preamble of a newly selected beam.

10. The wireless device of claim 9 , the operations further comprising:

responsive to a RAR associated with the third preamble not being received during a fourth RAR reception window, performing power ramping procedures based on system information.

11. The wireless device of claim 8 , wherein the second RAR reception window is an extension of the first RAR reception window.

12. The wireless device of claim 8 , wherein the different beam are wider than the selected downlink beam.

13. The wireless device of claim 12 , the operations further comprising:

acquiring synchronization with a cell of the selected downlink beam; and

detecting and selecting the second beam using the acquired synchronization.

14. The wireless device of claim 8 , the operations further comprising:

receiving a radio resource control, RRC, connection reconfiguration message including random access channel, RACH, mapping configuration;

responsive to receiving the RRC connection reconfiguration message, selecting the selected downlink beam based on the RACH mapping configurations; and

responsive to the RAR not being received during the first RAR reception window, selecting the second beam based on the RACH mapping configurations.

15. A non-transitory computer-readable medium having instructions stored therein that are executable by processing circuitry of a wireless device in a wireless communication network to cause the wireless device to perform operations, the operations comprising:

transmitting, to a radio network node in the wireless communication network, a first preamble associated with a selected downlink beam;

monitoring the wireless communication network for a random access response, RAR, during a first RAR reception window;

responsive to the RAR not being received during the first RAR reception window, monitoring the wireless communication network for the RAR during a second RAR reception window of a different beam; and

transmitting, to the radio network node, a second preamble associated with a second beam wherein the first preamble is associated with a channel state information reference signal and the second preamble is associated with a synchronization signal block.

16. The non-transitory computer-readable medium of claim 15 , wherein transmitting the second preamble comprises, responsive to the RAR not being received during the second RAR reception window, transmitting the second preamble associated with the second beam,

the operations further comprising, responsive to a RAR associated with the second preamble not being received during a third RAR reception window, transmitting a third preamble of a newly selected beam.

17. The non-transitory computer-readable medium of claim 15 , wherein the second RAR reception window is an extension of the first RAR reception window.

18. The non-transitory computer-readable medium of claim 15 , wherein the different beam and the second beam are wider than the selected downlink beam.

19. The non-transitory computer-readable medium of claim 18 , further comprising

acquiring synchronization with a cell of the selected downlink beam; and

detecting and selecting the second beam using the acquired synchronization.

20. The non-transitory computer-readable medium of claim 15 , the operations further comprising:

receiving a radio resource control, RRC, connection reconfiguration message including random access channel, RACH, mapping configuration;

responsive to receiving the RRC connection reconfiguration message, selecting the selected downlink beam based on the RACH mapping configurations; and

responsive to the RAR not being received during the first RAR reception window, selecting the second beam based on the RACH mapping configurations.