Beam Failure Recovery Control in Secondary Cells

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Solution Overview

Problem

In next-generation mobile communication systems, the procedure for detecting and recovering from beam failures is not adequately addressed, leading to potential delays and performance degradation due to inappropriate execution of the beam failure recovery (BFR) procedure.

Innovation Solution

A user terminal is designed with a control section that manages beam failure recovery by limiting the number of secondary cells for BFR to 1 and utilizing a specific secondary cell for uplink control channels, ensuring appropriate execution of the BFR procedure by transmitting a beam failure recovery request to one of multiple cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If beam failure recovery is applied to multiple secondary cells, then the system can handle beam failures in more cells, but the complexity of managing BFRQ transmission and BFR response reception increases significantly

Engineering Contradiction:

Improvenumber of secondary cells for BFRVSAvoidBFR procedure management complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the BFR procedure into distinct roles: one secondary cell is designated as the PUCCH-SCell responsible for transmitting BFRQ and receiving BFR response, while other secondary cells are separated out. This segmentation resolves the contradiction by limiting the complexity of BFR management to a single cell while maintaining the ability to handle beam failures across multiple secondary cells through the segmented architecture.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If beam failure recovery is applied to multiple secondary cells, then more beam failures can be recovered, but the delay in BFR procedure increases due to inappropriate procedure execution

Engineering Contradiction:

Improvenumber of secondary cells for BFRVSAvoidBFR delay

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent extracts the critical BFR signaling functions (BFRQ transmission and BFR response reception) from the general secondary cell set and assigns them specifically to the PUCCH-SCell. This extraction ensures that time-sensitive BFR operations are concentrated in a single cell with dedicated resources, reducing procedural delays while still allowing beam failure monitoring across multiple secondary cells.

Inventive Principle:

Principle #2Taking out (Extraction)

3Ease of operation

If a specific secondary cell for uplink control channel is configured, then BFRQ transmission is simplified to one cell, but the adaptability to handle beam failures in other secondary cells is reduced

Engineering Contradiction:

ImproveBFRQ transmission simplicityVSAvoidbeam failure coverage

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent merges the functions of beam failure monitoring across multiple secondary cells with the centralized BFRQ transmission and BFR response reception in the PUCCH-SCell. This merging allows the system to maintain comprehensive beam failure coverage while simplifying the actual BFR procedure execution to a single cell, resolving the contradiction between operational simplicity and adaptability.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS11871290B2Methods and devices for monitoring a radio link quality

Publication Date: 2024.01.09 NTT DOCOMO INC

AI summary

A user terminal includes a control section that, in a case where a maximum number of secondary cells to which a beam failure recovery is applied is 1 and where a specific secondary cell for an uplink control channel is configured, applies the beam failure recovery to the specific secondary cell, and a transmitting section that transmits, in the beam failure recovery, a beam failure recovery request to one of a plurality of cells. According to one aspect of the present disclosure, a BFR procedure can be appropriately executed.