Mechanism for beam failure detection
Embodiments of the present disclosure relates to beam failure detection. According to embodiments of the present disclosure, after a serving cell is activated from a deactivated state, a terminal device monitors a beam failure on a serving beam of the serving cell. If a beam failure instance indication is received within a short period after the activation, the terminal device determines that the beam failure is detected on the serving beam. In this way, a beam failure recovery can be quicker triggered to perform candidate beam search.
1 . An apparatus, comprising:
at least one processor; and
at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to:
perform an activation procedure on a serving cell which was deactivated;
monitor a beam failure on a serving beam of the serving cell after activating the serving cell;
in accordance with a determination that at least one beam failure instance indication is detected by the apparatus, determine that the beam failure is detected on the serving beam, regardless of configuration for a timer for beam failure detection or a counter for the beam failure detection; and
transmit a beam failure report to a network device.
2 . The apparatus of claim 1 , wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to determine that the beam failure is detected on the serving beam by:
in accordance with a determination that a quality of the serving beam before deactivation was below a threshold quality and the at least one beam failure instance indication is detected by the apparatus, determining that the beam failure is detected on the serving beam.
3 . The apparatus of claim 1 , wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to determine that the beam failure is detected on the serving beam by:
in accordance with a determination that a first timer for the beam failure detection was running before deactivation and the at least one beam failure instance indication is detected by the apparatus, determining that the beam failure is detected on the serving beam.
4 . The apparatus of claim 1 , wherein the counter for the beam failure detection is a second counter, and wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to determine that the beam failure is detected on the serving beam by:
in accordance with a determination that a determination that a first counter for the beam failure detection was larger than a predetermined number and the at least one beam failure instance indication is detected by the apparatus, determining that the beam failure is detected on the serving beam.
5 . The apparatus of claim 1 , wherein
the determination that the at least one beam failure instance indication is detected by the apparatus is performed within a predetermined period that comprises one of:
a first predetermined number of symbols,
a second predetermined number of milliseconds, or
a third predetermined number of slots; and
the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to determine the predetermined period based on an interval for beam failure instance indication determination.
6 . The apparatus of claim 1 , wherein the timer for the beam failure detection is a second timer and the counter for the beam failure detection is a second counter, wherein the determination that the at least one beam failure instance indication is detected by the apparatus is performed within a predetermined period and wherein, and wherein the at least one memory stores instructions that, when executed by the at least one processor, further cause the apparatus to:
receive a configuration from the network device, the configuration indicating at least one of:
a first timer for the beam failure detection and the second timer for the beam failure detection, the first timer being shorter than the second timer; or
a first counter for the beam failure detection and the second counter for the beam failure detection, a maximum value of the first counter being smaller than a maximum value of the second counter.
7 . The apparatus of claim 6 , wherein
the at least one memory stores instructions that, when executed by the at least one processor, further cause the apparatus to: in accordance with a determination that the at least one beam failure instance indication is detected by the apparatus within the predetermined period, starting the first timer; and
wherein determining that the beam failure is detected on the serving beam comprises: in accordance with a determination that another beam failure instance indication is detected by the apparatus before an expiration of the first timer, determining that the beam failure is detected on the serving beam.
8 . The apparatus of claim 6 , wherein
the at least one memory stores instructions that, when executed by the at least one processor, further cause the apparatus to: in accordance with a determination that the at least one beam failure instance indication is detected by the apparatus within the predetermined period, apply the first counter; and
the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to determine that the beam failure is detected on the serving beam by: in accordance with a determination that the first counter hit the maximum value of the first counter, determining that the beam failure is detected on the serving beam.
9 . The apparatus of claim 6 , wherein the at least one memory stores instructions that, when executed by the at least one processor, further cause the apparatus to: in accordance with a determination that no beam failure instance indication is detected within the predetermined period, apply at least one of: the second timer or the second counter.
10 . The apparatus of claim 1 , wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to transmit the beam failure report by:
in accordance with a determination that a candidate beam is different from the serving beam, transmitting the beam failure report indicating the candidate beam; or
in accordance with a determination that a quality of the candidate beam is better than a quality of the serving beam, transmitting the beam failure report indicating the candidate beam.
11 . The apparatus of claim 1 , wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to transmit the beam failure report by: in accordance with a determination that a candidate beam is same as the serving beam or a determination that a quality of the candidate beam is worse than a quality of the serving beam, transmitting the beam failure report without indicating the candidate beam.
12 . The apparatus of claim 1 , wherein the serving cell is a secondary cell or a secondary cell group.
13 . The apparatus of claim 1 , wherein the apparatus comprises or is comprised in a terminal device.
14 . A method, comprising:
performing, at a terminal device, an activation procedure on a serving cell which was deactivated;
monitoring a beam failure on a serving beam of the serving cell after activating the serving cell;
in accordance with a determination that at least one beam failure instance indication is detected by the terminal device, determining that the beam failure is detected on the serving beam, regardless of configuration for a timer for beam failure detection or a counter for the beam failure detection; and
transmitting a beam failure report to a network device.
15 . The method of claim 14 , wherein the timer for the beam failure detection is a second timer and the counter for the beam failure detection is a second counter, and wherein determining that the beam failure is detected on the serving beam comprises at least one of:
in accordance with a determination that a quality of the serving beam before deactivation was below a threshold quality and the at least one beam failure instance indication is detected by the terminal device, determining that the beam failure is detected on the serving beam;
in accordance with a determination that a first timer for the beam failure detection was running before the deactivation and the at least one beam failure instance indication is detected by the terminal device, determining that the beam failure is detected on the serving beam; or
in accordance with a determination that a determination that a first counter for the beam failure detection was larger than a predetermined number and the at least one beam failure instance indication is detected by the terminal device, determining that the beam failure is detected on the serving beam.
16 . The method of claim 14 , wherein the timer for the beam failure detection is a second timer and the counter for the beam failure detection is a second counter, and further comprising:
receiving a configuration from the network device, the configuration indicating at least one of: a first timer for the beam failure detection and the second timer for the beam failure detection, the first timer being shorter than the second timer; or
a first counter for the beam failure detection and the second counter for the beam failure detection, a maximum value of the first counter being smaller than a maximum value of the second counter.
17 . The method of claim 16 :
wherein the determining that the at least one beam failure instance indication is detected by the terminal device is performed within a predetermined period;
further comprising in accordance with a determination that the at least one beam failure instance indication is detected by the terminal device within the predetermined period, starting the first timer; and
wherein determining that the beam failure is detected on the serving beam comprises: in accordance with a determination that another beam failure instance indication is detected by the terminal device before an expiration of the first timer, determining that the beam failure is detected on the serving beam.
18 . The method of claim 14 , wherein transmitting the beam failure report comprises:
in accordance with a determination that a candidate beam is different from the serving beam, transmitting the beam failure report indicating the candidate beam; or
in accordance with a determination that a quality of the candidate beam is better than a quality of the serving beam, transmitting the beam failure report indicating the candidate beam.
19 . An apparatus, comprising:
at least one processor; and
at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to:
send, to a terminal device, configuration comprising at least one of a timer for beam failure detection or a counter for the beam failure detection; and
receive a beam failure report from the terminal device, regardless of the configuration that was sent for the timer for the beam failure detection or the counter for the beam failure detection.
20 . The apparatus of claim 19 , wherein the timer for the beam failure detection is a second timer and the counter for the beam failure detection is a second counter, and wherein the at least one memory stores instructions that, when executed by the at least one processor, further cause the apparatus to:
transmit the configuration to the terminal device, the configuration indicating at least one of:
a first timer for the beam failure detection and the second timer for the beam failure detection, the first timer being shorter than the second timer; or
a first counter for the beam failure detection and the second counter for the beam failure detection, a maximum value of the first counter being smaller than a maximum value of the second counter.