Beam selection in beam failure recovery request retransmission
Systems, apparatuses, and methods are described for beam (or any other communication resource) failure recovery in wireless communications. If a beam failure recovery request is repeated, the wireless device may send the second request using a new beam a threshold distance, in time and/or frequency, from a beam used for the prior request.
1. A method comprising:
receiving, by a wireless device from a base station, at least one message comprising at least one configuration parameter, wherein the at least one configuration parameter indicates:
a first random-access channel (RACH) resource for a first reference signal (RS) associated with a first candidate beam of a cell; and
a second RACH resource for a second RS associated with a second candidate beam of the cell;
determining, based on a detected beam failure associated with the cell, a first measurement of the first RS and a second measurement of the second RS;
selecting, based on determining that the first measurement is greater than a threshold and is greater than the second measurement, the first RS for sending a first preamble;
sending, via the first RACH resource for the first RS, the first preamble;
monitoring, via the first candidate beam, a downlink control channel for downlink control information (DCI);
selecting, after the monitoring and based on the second measurement being greater than the threshold, the second RS for sending a second preamble; and
sending, via the second RACH resource for the second RS, the second preamble.
2. The method of claim 1 , wherein the threshold comprises at least one of:
a minimum block error rate (BLER); or
a minimum reference signal received power (RSRP).
3. The method of claim 1 , further comprising determining a third measurement of a third RS associated with a third candidate beam of the cell, and wherein the selecting the first RS is further based on the first measurement being greater than the third measurement.
4. The method of claim 1 , further comprising determining a difference between a first transmission time interval (TTI) associated with the first RS and a second TTI associated with the second RS, and wherein the selecting the second RS comprises selecting, based on the difference exceeding a second threshold, the second RS.
5. The method of claim 1 , further comprising determining a difference between a first frequency associated with the first RS and a second frequency associated with the second RS, and wherein the selecting the second RS comprises selecting, based on the difference exceeding a second threshold, the second RS.
6. The method of claim 1 , further comprising:
determining a first difference between a first transmission time interval (TTI) associated with the first RS and a second TTI associated with the second RS; and
determining a second difference between a first frequency associated with the first RS and a second frequency associated with the second RS,
wherein the selecting the second RS comprises selecting, based on the first difference exceeding a second threshold and based on the second difference exceeding a third threshold, the second RS.
7. A method comprising:
receiving, by a wireless device from a base station, at least one message comprising at least one configuration parameter associated with a plurality of reference signals comprising a first reference signal (RS), a second RS, and a third RS;
determining, based on a detected beam failure associated with a cell, a first measurement of the first RS, a second measurement of the second RS, and a third measurement of the third RS;
sending, via a first random-access channel (RACH) resource for the first RS, and based on determining that the first measurement is greater than the second measurement and is greater than the third measurement, a first preamble;
monitoring, via a first candidate beam associated with the first RS, a downlink control channel for downlink control information (DCI);
determining, after the monitoring and based on determining that the second measurement and the third measurement exceed a threshold, a plurality of alternative RSs comprising the second RS and the third RS;
selecting, from the plurality of alternative RSs, the second RS for sending a second preamble; and
sending, via a second RACH resource for the second RS, the second preamble.
8. The method of claim 7 , wherein the threshold comprises at least one of:
a minimum block error rate (BLER); or
a minimum reference signal received power (RSRP).
9. The method of claim 7 , wherein the selecting the second RS comprises selecting, randomly from the plurality of alternative RSs, the second RS.
10. The method of claim 7 , further comprising determining a difference between a first transmission time interval (TTI) associated with the first RS and a second TTI associated with the second RS, and wherein the selecting the second RS comprises selecting, based on the difference exceeding a second threshold, the second RS.
11. The method of claim 7 , further comprising determining a difference between a first frequency associated with the first RS and a second frequency associated with the second RS, and wherein the selecting the second RS comprises selecting, based on the difference exceeding a second threshold, the second RS.
12. The method of claim 7 , further comprising:
determining a first difference between a first transmission time interval (TTI) associated with the first RS and a second TTI associated with the second RS; and
determining a second difference between a first frequency associated with the first RS and a second frequency associated with the second RS,
wherein the selecting the second RS comprises selecting, based on the first difference exceeding a second threshold, and based on the second difference exceeding a third threshold, the second RS.
13. The method of claim 7 , wherein the selecting the second RS is further based on determining that the second measurement is greater than the third measurement.
14. A method comprising:
receiving, by a wireless device from a base station, at least one message comprising at least one configuration parameter, wherein the at least one configuration parameter indicates:
a first random-access channel (RACH) resource for a first reference signal (RS) associated with a first candidate beam of a cell;
a second RACH resource for a second RS associated with a second candidate beam of the cell; and
a third RACH resource for a third RS associated with a third candidate beam of the cell;
determining, based on a detected beam failure associated with the cell, a first measurement of the first RS, a second measurement of the second RS, and a third measurement of the third RS;
selecting, based on the detected beam failure and based on determining that the first measurement is greater than the second measurement and is greater than the third measurement, the first RS for sending a first preamble;
sending, via the first RACH resource for the first RS, the first preamble;
monitoring, via the first candidate beam associated with the first RS, a downlink control channel for downlink control information (DCI);
selecting, after the monitoring and based on determining that the second measurement is greater than the third measurement, the second RS for sending a second preamble; and
sending, via the second RACH resource for the second RS, the second preamble.
15. The method of claim 14 , wherein the selecting the first RS is further based on the first measurement being greater than a threshold.
16. The method of claim 15 , wherein the threshold comprises at least one of:
a minimum block error rate (BLER); or
a minimum reference signal received power (RSRP).
17. The method of claim 14 , further comprising determining a difference between a first transmission time interval (TTI) associated with the first RS and a second TTI associated with the second RS, and wherein the selecting the second RS comprises selecting, based on the difference exceeding a second threshold, the second RS.
18. The method of claim 14 , further comprising determining a difference between a first frequency associated with the first RS and a second frequency associated with the second RS, and wherein the selecting the second RS comprises selecting, based on the difference exceeding a second threshold, the second RS.
19. 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, from a base station, at least one message comprising at least one configuration parameter, wherein the at least one configuration parameter indicates:
a first random-access channel (RACH) resource for a first reference signal (RS) associated with a first candidate beam of a cell; and
a second RACH resource for a second RS associated with a second candidate beam of the cell;
determine, based on a detected beam failure associated with the cell, a first measurement of the first RS and a second measurement of the second RS;
select, based on determining that the first measurement is greater than a threshold and is greater than the second measurement, the first RS for sending a first preamble;
send, via the first RACH resource for the first RS, the first preamble;
monitor, via the first candidate beam, a downlink control channel for downlink control information (DCI);
select, after monitoring the downlink control channel and based on the second measurement being greater than the threshold, the second RS for sending a second preamble; and
send, via the second RACH resource for the second RS, the second preamble.
20. The wireless device of claim 19 , wherein the threshold comprises at least one of:
a minimum block error rate (BLER); or
a minimum reference signal received power (RSRP).
21. The wireless device of claim 19 , wherein the instructions, when executed by the one or more processors, cause the wireless device to determine a third measurement of a third RS associated with a third candidate beam of the cell, and wherein the instructions, when executed by the one or more processors, cause the wireless device to select the first RS further based on the first measurement being greater than the third measurement.
22. The wireless device of claim 19 , wherein the instructions, when executed by the one or more processors, cause the wireless device to determine a difference between a first transmission time interval (TTI) associated with the first RS and a second TTI associated with the second RS, and wherein the instructions, when executed by the one or more processors, cause the wireless device to select the second RS further based on the difference exceeding a second threshold.
23. The wireless device of claim 19 , wherein the instructions, when executed by the one or more processors, cause the wireless device to determine a difference between a first frequency associated with the first RS and a second frequency associated with the second RS, and wherein the instructions, when executed by the one or more processors, cause the wireless device to select the second RS further based on the difference exceeding a second threshold.
24. The wireless device of claim 19 , wherein the instructions, when executed by the one or more processors, cause the wireless device to:
determine a first difference between a first transmission time interval (TTI) associated with the first RS and a second TTI associated with the second RS; and
determine a second difference between a first frequency associated with the first RS and a second frequency associated with the second RS,
wherein the instructions, when executed by the one or more processors, cause the wireless device to select the second RS further based on the first difference exceeding a second threshold and based on the second difference exceeding a third threshold.
25. 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, from a base station, at least one message comprising at least one configuration parameter associated with a plurality of reference signals comprising a first reference signal (RS), a second RS, and a third RS;
determine, based on a detected beam failure associated with a cell, a first measurement of the first RS, a second measurement of the second RS, and a third measurement of the third RS;
send, via a first random-access channel (RACH) resource for the first RS, and based on determining that the first measurement is greater than the second measurement and is greater than the third measurement, a first preamble;
monitor, via a first candidate beam associated with the first RS, a downlink control channel for downlink control information (DCI);
determine, after monitoring the downlink control channel and based on determining that the second measurement and the third measurement exceed a threshold, a plurality of alternative RSs comprising the second RS and the third RS;
select, from the plurality of alternative RSs, the second RS for sending a second preamble; and
send, via a second RACH resource for the second RS, the second preamble.
26. The wireless device of claim 25 , wherein the threshold comprises at least one of:
a minimum block error rate (BLER); or
a minimum reference signal received power (RSRP).
27. The wireless device of claim 25 , wherein the instructions, when executed by the one or more processors, cause the wireless device to select the second RS by selecting, randomly from the plurality of alternative RSs, the second RS.
28. The wireless device of claim 25 , wherein the instructions, when executed by the one or more processors, cause the wireless device to determine a difference between a first transmission time interval (TTI) associated with the first RS and a second TTI associated with the second RS, and the instructions, when executed by the one or more processors, cause the wireless device to select the second RS further based on the difference exceeding a second threshold.
29. The wireless device of claim 25 , wherein the instructions, when executed by the one or more processors, cause the wireless device to determine a difference between a first frequency associated with the first RS and a second frequency associated with the second RS, and wherein the instructions, when executed by the one or more processors, cause the wireless device to select the second RS further based on the difference exceeding a second threshold.
30. The wireless device of claim 25 , wherein the instructions, when executed by the one or more processors, cause the wireless device to:
determine a first difference between a first transmission time interval (TTI) associated with the first RS and a second TTI associated with the second RS; and
determine a second difference between a first frequency associated with the first RS and a second frequency associated with the second RS,
wherein the instructions, when executed by the one or more processors, cause the wireless device to select the second RS further based on the first difference exceeding a second threshold and based on the second difference exceeding a third threshold.
31. The wireless device of claim 25 , wherein the instructions, when executed by the one or more processors, cause the wireless device to select the second RS further based on determining that the second measurement is greater than the third measurement.
32. 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, from a base station, at least one message comprising at least one configuration parameter, wherein the at least one configuration parameter indicates:
a first random-access channel (RACH) resource for a first reference signal (RS) associated with a first candidate beam of a cell;
a second RACH resource for a second RS associated with a second candidate beam of the cell; and
a third RACH resource for a third RS associated with a third candidate beam of the cell;
determine, based on a detected beam failure associated with the cell, a first measurement of the first RS, a second measurement of the second RS, and a third measurement of the third RS;
select, based on the detected beam failure and based on determining that the first measurement is greater than the second measurement and is greater than the third measurement, the first RS for sending a first preamble;
send, via the first RACH resource for the first RS, the first preamble;
monitor, via the first candidate beam associated with the first RS, a downlink control channel for downlink control information (DCI);
select, after monitoring the downlink control channel and based on determining that the second measurement is greater than the third measurement, the second RS for sending a second preamble; and
send, via the second RACH resource for the second RS, the second preamble.
33. The wireless device of claim 32 , wherein the instructions, when executed by the one or more processors, cause the wireless device to select the first RS further based on the first measurement being greater than a threshold.
34. The wireless device of claim 33 , wherein the threshold comprises at least one of:
a minimum block error rate (BLER); or
a minimum reference signal received power (RSRP).
35. The wireless device of claim 32 , wherein the instructions, when executed by the one or more processors, cause the wireless device to determine a difference between a first transmission time interval (TTI) associated with the first RS and a second TTI associated with the second RS, and wherein the instructions, when executed by the one or more processors, cause the wireless device to select the second RS further based on the difference exceeding a second threshold.
36. The wireless device of claim 32 , wherein the instructions, when executed by the one or more processors, cause the wireless device to determine a difference between a first frequency associated with the first RS and a second frequency associated with the second RS, and wherein the instructions, when executed by the one or more processors, cause the wireless device to select the second RS further based on the difference exceeding a second threshold.