Beam failure recovery using contention based random access

1. An apparatus, comprising:

at least one processor configured to cause a wireless device to:

detect beam failure; and

perform a contention based random access procedure based at least in part on detecting beam failure, wherein an indication of the detected beam failure is provided to the cellular base station by the wireless device as part of the contention based random access procedure, wherein performing the contention based random access procedure comprises:

transmitting a first message with a preamble of the contention based random access procedure to the cellular base station, wherein the first message includes wireless device identification information and beam failure indication; and

receiving a second message resolving the contention based at least in part on the wireless device identification information being included in the first message of the contention based random access procedure.

2. The apparatus of claim 1 , wherein the wireless device is further configured to receive beam reconfiguration information, wherein the beam reconfiguration information indicates a new beam for downlink communications from the cellular base station, wherein the beam reconfiguration information is provided via one of radio resource control (RRC) beam set reconfiguration information or a media access control (MAC) control element adjusting an activated beam subset.

3. The apparatus of claim 1 , wherein the at least one processor is further configured to cause the wireless device to:

receive an indication of a beam failure recovery specific pool of PRACH preambles and resources, wherein the indication of the beam failure recovery specific pool of PRACH preambles and resources is received via one of wireless device specific radio resource control configuration information or broadcast configuration information; and

receive an indication of one or more pools of PRACH preambles and resources that are available for one or more other contention based random access procedure triggers according to the cellular link with the cellular base station, wherein the beam failure recovery specific pool of PRACH preambles and resources and the one or more pools of PRACH preambles and resources that are available for one or more other contention based random access procedure triggers comprise different PRACH preambles and resources.

4. The apparatus of claim 3 ,

wherein the indication of the detected beam failure is provided by initiating the contention based random access procedure using physical random access channel (PRACH) resources and a PRACH preamble configured to indicate a detected beam failure,

wherein the PRACH resources and the PRACH preamble used to initiate the contention based random access procedure are selected from the beam failure recovery specific pool of PRACH preambles and resources.

5. The apparatus of claim 3 ,

wherein the beam failure recovery specific pool of PRACH preambles and resources comprises one or more PRACH preamble and resource combinations associated with specific beams, wherein use of a PRACH preamble and resource combination associated with a specific beam to initiate a contention based random access procedure indicates a request to activate the specific beam.

6. The apparatus of claim 1 ,

wherein the indication of the detected beam failure is provided by including message content configured to indicate a detected beam failure,

wherein the message content configured to indicate a detected beam failure is comprised in the first message of the contention based random access procedure.

7. The apparatus of claim 6 , wherein the message content configured to indicate a detected beam failure comprises an indication of one or more of:

a request to perform beam failure recovery;

an indication of one or more preferred beams;

a beam measurement result for an active beam;

carrier identification information for a carrier associated with the detected beam failure; or

bandwidth part (BWP) identification information for a BWP associated with the detected beam failure.

8. The apparatus of claim 1 , wherein beam failure is detected based at least in part on measurement of a beam failure detection reference symbol provided by the cellular base station.

9. A wireless device, comprising:

an antenna;

a radio operably coupled to the antenna; and

at least one processor operably coupled to the radio; wherein the wireless device is configured to:

establish a cellular link with a cellular base station,

detect beam failure; and

perform a contention based random access procedure based at least in part on detecting beam failure, wherein the wireless device provides a request for beam failure recovery during the contention based random access procedure, wherein performing the contention based random access procedure comprises:

transmitting a first message with a preamble of the contention based random access procedure to the cellular base station, wherein the first message includes wireless device identification information and beam failure indication; and

receiving a second message resolving the based at least in part on the wireless device identification information being included in the first message of the contention based random access procedure.

10. The wireless device of claim 9 , wherein the wireless device is further configured to receive beam reconfiguration information, wherein the beam reconfiguration information indicates a new beam for downlink communications from the cellular base station.

11. The wireless device of claim 9 ,

wherein the wireless device is configured to receive beam configuration information;

wherein the beam configuration information further indicates a set of physical random access channel (PRACH) resources and PRACH preambles configured to indicate a detected beam failure,

wherein the indication of the detected beam failure is provided by initiating the contention based random access procedure using one or more of PRACH resources or a PRACH preamble selected from the set of PRACH resources and PRACH preambles configured to indicate a detected beam failure.

12. The wireless device of claim 9 , wherein the indication of the detected beam failure is provided using media access control or radio resource control signaling in the first message of the contention based random access procedure.

13. The wireless device of claim 9 , wherein the wireless device is configured to receive beam configuration information indicating s a configured set of candidate beams, wherein the wireless device is further configured to:

determine a preferred beam among the configured set of candidate beams,

wherein an indication of the preferred beam is provided to the cellular base station by the wireless device as part of the contention based random access procedure.

14. The wireless device of claim 9 , wherein the at least one processor is further configured to:

receive an indication of a beam failure recovery specific pool of PRACH preambles and resources, wherein the indication of the beam failure recovery specific pool of PRACH preambles and resources is received via one of wireless device specific radio resource control configuration information or broadcast configuration information; and

receive an indication of one or more pools of PRACH preambles and resources that are available for one or more other contention based random access procedure triggers according to the cellular link with the cellular base station;

wherein the beam failure recovery specific pool of PRACH preambles and resources and the one or more pools of PRACH preambles and resources that are available for one or more other contention based random access procedure triggers comprise different PRACH preambles and resources.

15. The wireless device of claim 9 , wherein beam failure is detected based at least in part on measurement of a beam failure detection reference symbol provided by the cellular base station.

16. A cellular base station, comprising:

an antenna;

a radio operably coupled to the antenna; and

at least one processor operably coupled to the radio; wherein the cellular base station is configured to:

establish a cellular link with a wireless device,

receive a request for beam failure recovery from the wireless device during a contention based random access procedure initiated by the wireless device, wherein the contention based random access procedure comprises receiving wireless device identification information from the wireless device in a first message of the contention based random access procedure; and

provide a second message resolving the contention based at least in part on the request for beam failure recovery, and wherein the second message is based at least in part on the wireless device identification information being included in the first message of the contention based random access procedure.

17. The cellular base station of claim 16 , wherein the cellular base station is further configured to:

determine a set of physical random access channel (PRACH) resources and PRACH preambles configured to indicate beam failure when used to initiate a contention based random access procedure,

provide beam configuration information to the wireless device, wherein the beam configuration information indicates the set of PRACH resources and PRACH preambles configured to indicate beam failure when used to initiate a contention based random access procedure;

wherein the request for beam failure recovery comprises initiation of the contention based random access procedure by the wireless device using PRACH resources and a PRACH preamble selected from the set of PRACH resources and PRACH preambles configured to indicate beam failure when used to initiate a contention based random access procedure.

18. The cellular base station of claim 17 , wherein the cellular base station is further configured to:

provide beam configuration information indicating the set of PRACH resources and PRACH preambles configured to indicate beam failure when used to initiate a contention based random access procedure to one or more other wireless devices, wherein the set of PRACH resources and PRACH preambles configured to indicate beam failure when used to initiate a contention based random access procedure are shared among the wireless device and the one or more other wireless devices.

19. The cellular base station of claim 17 , wherein the beam configuration information further indicates a configured set of candidate beams, wherein the cellular base station is further configured to:

receive an indication of a preferred beam by the wireless device as part of the contention based random access procedure.

20. The cellular base station of claim 16 ,

wherein the request for beam failure recovery comprises media access control or radio resource control signaling received by the cellular base station in the first message of the contention based random access procedure.