Downlink channel quality assessment at user equipment

1 . A user equipment comprising:

at least one processor; and

at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the user equipment to:

determine an evaluation period for a downlink channel quality assessment, the evaluation period being one of a first evaluation period, a second evaluation period, or a third evaluation period;

perform the downlink channel quality assessment by performing a plurality of downlink measurements during the determined evaluation period and generating a channel quality assessment based on the plurality of downlink measurements performed over a duration of the evaluation period;

configure the first evaluation period to have a first duration and a first number of downlink measurements;

configure the second evaluation period to have a second duration longer than the first duration;

configure the third evaluation period to have a third duration shorter than the second duration and longer than the first duration;

configure the third evaluation period to include fewer downlink measurements than at least one of the first evaluation period and the second evaluation period;

determine the evaluation period based on the channel quality assessment generated for a previously performed evaluation period;

determine the channel quality assessment by comparing the channel quality assessment to a first quality threshold and a lower second quality threshold;

select the second evaluation period in response to the channel quality assessment exceeding the first quality threshold;

change from the first evaluation period to the second evaluation period when the channel quality assessment exceeds the first quality threshold;

maintain operation in the second evaluation period while the channel quality assessment continues to exceed the first quality threshold;

change from the second evaluation period to the third evaluation period when the channel quality assessment fails to exceed the first quality threshold while remaining above the second quality threshold;

change from the third evaluation period to the first evaluation period when the channel quality assessment falls below the second quality threshold;

change from the third evaluation period to the second evaluation period when the channel quality assessment exceeds the first quality threshold;

prevent a transition directly from the second evaluation period to the first evaluation period solely in response to the channel quality assessment no longer exceeding the first quality threshold;

determine, for each evaluation period, both a number of downlink measurements and a duration over which the number of downlink measurements is performed;

apply the second duration based on the channel quality assessment exceeding the first quality threshold;

apply the first duration based on the channel quality assessment falling below the second quality threshold; and

apply the third duration based on the channel quality assessment exceeding the second quality threshold and failing to exceed the first quality threshold.

2 . The user equipment of claim 1 , wherein the downlink measurements comprise: reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-noise ratio (SNR), signal-to-interference-plus-noise ratio (SINR), bit error rate (BER), or block error rate (BLER).

3 . The user equipment of claim 2 , wherein the downlink measurements are performed based on reception of at least one of a synchronization signal block (SSB) or a channel state information reference signal (CSI-RS).

4 . The user equipment of claim 3 , wherein the user equipment limits the downlink channel quality assessment to an active downlink bandwidth part.

5 . The user equipment of claim 4 , wherein the first quality threshold corresponds to an in-sync detection level and the second quality threshold corresponds to an out-of-sync detection level defined for radio link monitoring.

6 . The user equipment of claim 5 , wherein each duration of the evaluation period is determined by multiplying a base duration by a scaling factor, the scaling factor being greater for the second evaluation period than for the first evaluation period.

7 . The user equipment of claim 6 , wherein the scaling factor for the third evaluation period is less than the scaling factor for the second evaluation period and greater than the scaling factor for the first evaluation period.

8 . The user equipment of claim 7 , wherein the evaluation period is defined by a sliding or overlapping time window of measurements.

9 . The user equipment of claim 8 , wherein the user equipment performs the downlink channel quality assessment during a connected-mode radio link monitoring procedure.

10 . The user equipment of claim 8 , wherein the user equipment performs the downlink channel quality assessment during a beam failure detection procedure.

11 . The user equipment of claim 10 , wherein the second evaluation period and the third evaluation period correspond to reduced-power measurement modes that reduce power consumption relative to the first evaluation period while maintaining responsiveness to channel quality degradation.

12 . A method performed by a user equipment, the method comprising:

determining an evaluation period for a downlink channel quality assessment, the evaluation period being one of a first evaluation period, a second evaluation period, or a third evaluation period;

performing the downlink channel quality assessment by performing a plurality of downlink measurements during the determined evaluation period and generating a channel quality assessment based on the plurality of downlink measurements performed over a duration of the evaluation period;

configuring the first evaluation period to have a first duration and a first number of downlink measurements;

configuring the second evaluation period to have a second duration longer than the first duration;

configuring the third evaluation period to have a third duration shorter than the second duration and longer than the first duration;

configuring the third evaluation period to include fewer downlink measurements than at least one of the first evaluation period and the second evaluation period;

determining the evaluation period based on the channel quality assessment generated for a previously performed evaluation period;

determining the channel quality assessment by comparing the channel quality assessment to a first quality threshold and a lower second quality threshold;

selecting the second evaluation period in response to the channel quality assessment exceeding the first quality threshold;

changing from the first evaluation period to the second evaluation period when the channel quality assessment exceeds the first quality threshold;

maintaining operation in the second evaluation period while the channel quality assessment continues to exceed the first quality threshold;

changing from the second evaluation period to the third evaluation period when the channel quality assessment fails to exceed the first quality threshold while remaining above the second quality threshold;

changing from the third evaluation period to the first evaluation period when the channel quality assessment falls below the second quality threshold;

changing from the third evaluation period to the second evaluation period when the channel quality assessment exceeds the first quality threshold;

preventing a transition directly from the second evaluation period to the first evaluation period solely in response to the channel quality assessment no longer exceeding the first quality threshold;

determining, for each evaluation period, both a number of downlink measurements and a duration over which the number of downlink measurements is performed;

applying the second duration based on the channel quality assessment exceeding the first quality threshold;

applying the first duration based on the channel quality assessment falling below the second quality threshold; and

applying the third duration based on the channel quality assessment exceeding the second quality threshold and failing to exceed the first quality threshold.

13 . The method of claim 12 , wherein the downlink measurements comprise: reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-noise ratio (SNR), signal-to-interference-plus-noise ratio (SINR), bit error rate (BER), or block error rate (BLER).

14 . The method of claim 13 , wherein the downlink measurements are performed based on reception of at least one of a synchronization signal block (SSB) or a channel state information reference signal (CSI-RS).

15 . The method of claim 14 , wherein the user equipment limits the downlink channel quality assessment to an active downlink bandwidth part.

16 . The method of claim 15 , wherein the first quality threshold corresponds to an in-sync detection level and the second quality threshold corresponds to an out-of-sync detection level defined for radio link monitoring.

17 . The method of claim 16 , wherein each duration of the evaluation period is determined by multiplying a base duration by a scaling factor, the scaling factor being greater for the second evaluation period than for the first evaluation period.

18 . The method of claim 17 , wherein the scaling factor for the third evaluation period is less than the scaling factor for the second evaluation period and greater than the scaling factor for the first evaluation period.

19 . The method of claim 18 , wherein the evaluation period is defined by a sliding or overlapping time window of measurements.

20 . The method of claim 19 , wherein the user equipment performs the downlink channel quality assessment during a connected-mode radio link monitoring procedure.