Techniques for mitigating redundant beam failure recovery medium access signaling
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may determine that a first beam failure recovery (BFR) has been triggered; determine BFR information associated with the BFR; determine whether at least part of the BFR information has not been transmitted since a second BFR was triggered; and transmit, based at least in part on the determination that the BFR has been triggered and the determination that at least part of the BFR information as not been transmitted since a second BFR was triggered, a BFR message including the BFR information. Numerous other aspects are provided.
1 . A method of wireless communication performed by a user equipment (UE), comprising:
determining that a beam failure recovery (BFR) has been triggered;
determining, for a length of time corresponding to an evaluation period for identifying one or more candidate beams associated with the BFR and following detection of a beam failure associated with the BFR, BFR information associated with the BFR, wherein the length of time spans at least one opportunity for BFR message transmission during which uplink shared channel resources are available for transmission, and during the length of time, the UE skips transmission of a BFR message in response to at least one of: the BFR information having not changed relative to the BFR information most recently transmitted for a current beam failure recovery event, or the BFR information not yet being evaluated or determined based on the evaluation period; and
transmitting, after completion of the evaluation period and after determining the BFR information, the BFR message including the BFR information.
2 . The method of claim 1 , wherein the transmission of the BFR message including the BFR information is further based at least in part on the uplink shared channel resources available for a new transmission having a size at least equal to a combined size of the BFR message and a subheader of the BFR message.
3 . The method of claim 2 , wherein the BFR message comprises a truncated BFR message.
4 . The method of claim 1 , wherein the transmission of the BFR message including the BFR information is further based at least in part on determining that the BFR has been triggered and not cancelled.
5 . The method of claim 1 , wherein the BFR is for one or more secondary cells of the UE.
6 . The method of claim 1 , wherein the BFR information includes a candidate beam availability indication for one or more secondary cells indicated in a bitmap of the BFR message.
7 . The method of claim 1 , wherein at least part of the BFR information comprises a secondary cell index associated with the BFR.
8 . The method of claim 7 , wherein the secondary cell index is included in a bitmap of the BFR message.
9 . The method of claim 7 , wherein the BFR information is in a first octet of a medium access control control element of the BFR message.
10 . The method of claim 7 , further comprising:
determining, based at least in part on transmitting the BFR message, that the at least part of the BFR information has been transmitted based at least in part on the secondary cell index being included in the BFR message.
11 . The method of claim 1 , wherein the BFR information is defined as a secondary cell index associated with the BFR.
12 . The method of claim 11 , wherein the secondary cell index is included in a bitmap of the BFR message.
13 . A user equipment (UE) for wireless communication, comprising:
one or more memories; and
one or more processors coupled to the one or more memories, the one or more processors configured to:
determine that a beam failure recovery (BFR) has been triggered;
determine, for a length of time corresponding to an evaluation period for identifying one or more candidate beams associated with the BFR and following detection of a beam failure associated with the BFR, BFR information associated with the BFR, wherein the length of time spans at least one opportunity for BFR message transmission during which uplink shared channel resources are available for transmission, and during the length of time, the UE skips transmission of a BFR message in response to at least one of: the BFR information having not changed relative to the BFR information most recently transmitted for a current beam failure recovery event, or the BFR information not yet being evaluated or determined based on the evaluation period; and
transmit, after completion of the evaluation period and after determining the BFR information, the BFR message including the BFR information.
14 . The UE of claim 13 , wherein the transmission of the BFR message including the BFR information is further based at least in part on the uplink shared channel resources available for a new transmission having a size at least equal to a combined size of the BFR message and a subheader of the BFR message.
15 . The UE of claim 14 , wherein the BFR message comprises a truncated BFR message.
16 . The UE of claim 13 , wherein the transmission of the BFR message including the BFR information is further based at least in part on the BFR being triggered and not cancelled.
17 . The UE of claim 13 , wherein the BFR is for one or more secondary cells of the UE.
18 . The UE of claim 13 , wherein the BFR information includes a candidate beam availability indication for one or more secondary cells indicated in a bitmap of the BFR message.
19 . The UE of claim 13 , wherein at least part of the BFR information comprises a secondary cell index associated with the BFR.
20 . The UE of claim 19 , wherein the secondary cell index is included in a bitmap of the BFR message.
21 . The UE of claim 19 , wherein the BFR information is provided in a first octet of a medium access control control element of the BFR message.
22 . The UE of claim 19 , wherein the one or more processors are further configured to:
determine, based at least in part on the BFR message, that the at least part of the BFR information has been transmitted based at least in part on the secondary cell index being included in the BFR message.
23 . The UE of claim 13 , wherein the BFR information is defined as a secondary cell index associated with the BFR.
24 . The UE of claim 23 , wherein the secondary cell index is included in a bitmap of the BFR message.
25 . A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising:
one or more instructions that, when executed by one or more processors of a user equipment (UE), cause the one or more processors to:
determine that a beam failure recovery (BFR) has been triggered;
determine, for a length of time corresponding to an evaluation period for identifying one or more candidate beams associated with the BFR and following detection of a beam failure associated with the BFR, BFR information associated with the BFR, wherein the length of time spans at least one opportunity for BFR message transmission during which uplink shared channel resources are available for transmission, and during the length of time, the UE skips transmission of a BFR message in response to at least one of: the BFR information having not changed relative to the BFR information most recently transmitted for a current beam failure recovery event, or the BFR information not yet being evaluated or determined based on the evaluation period; and
transmit, after completion of the evaluation period and after determining the BFR information, the BFR message including the BFR information.
26 . The non-transitory computer-readable medium of claim 25 , wherein the transmission of the BFR message including the BFR information is further based at least in part on the uplink shared channel resources available for a new transmission having a size at least equal to a combined size of the BFR message and a subheader of the BFR message.
27 . The non-transitory computer-readable medium of claim 26 , wherein the BFR message comprises a truncated BFR message.
28 . The non-transitory computer-readable medium of claim 25 , wherein the transmission of the BFR message including the BFR information is further based at least in part on the BFR having been triggered and not cancelled.
29 . The non-transitory computer-readable medium of claim 25 ,
wherein the BFR has been triggered for one or more secondary cells of the UE.
30 . The non-transitory computer-readable medium of claim 25 ,
wherein the BFR information includes a candidate beam availability indication for one or more secondary cells indicated in a bitmap of the BFR message.
31 . An apparatus for wireless communication, comprising:
means for determining that a beam failure recovery (BFR) has been triggered;
means for determining, for a length of time corresponding to an evaluation period for identifying one or more candidate beams associated with the BFR and following detection of a beam failure associated with the BFR, BFR information associated with the BFR, wherein the length of time spans at least one opportunity for BFR message transmission during which uplink shared channel resources are available for transmission, and during the length of time, the apparatus skips transmission of a BFR message in response to at least one of: the BFR information having not changed relative to the BFR information most recently transmitted for a current beam failure recovery event, or the BFR information not yet being evaluated or determined based on the evaluation period; and
means for transmitting, after completion of the evaluation period and after determining the BFR information, the BFR message including the BFR information.
32 . The apparatus of claim 31 , wherein the transmission of the BFR message including the BFR information is further based at least in part on the uplink shared channel resources available for a new transmission having a size at least equal to a combined size of the BFR message and a subheader of the BFR message.
33 . The apparatus of claim 32 , wherein the BFR message comprises a truncated BFR message.
34 . The apparatus of claim 31 , wherein the transmission of the BFR message including the BFR information is further based at least in part on the BFR having been triggered and not cancelled.
35 . The apparatus of claim 31 , wherein the BFR is for one or more secondary cells of the apparatus.