MAC CE Cell Switch Control for RLM, BFD, and PUCCH

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Solution Overview

Problem

In future radio communication systems, the configuration of cells for cell switch operations is not clearly defined, leading to unclear UE operation and potential deterioration of communication quality, particularly in scenarios involving multi-TRP and inter-cell mobility.

Innovation Solution

A terminal equipped with a receiving section for Medium Access Control Control Elements (MAC CE) to manage configurations of radio link monitoring (RLM), beam failure detection (BFD), and uplink control channel (PUCCH) for specific cells, based on information received in the MAC CE.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If cell switch operations are performed without clear configuration definitions, then system flexibility is improved, but communication quality deteriorates

Engineering Contradiction:
Improvecell switch operation flexibilityVSAvoidcommunication quality
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies different configuration rules to different cell types (SpCell versus SCell) during cell switch operations. SpCell configurations include RLM, BFD, and PUCCH settings, while SCell configurations may be selectively applied or maintained based on specific conditions. This local differentiation resolves the contradiction by providing appropriate configuration quality where needed while maintaining overall system flexibility.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements dynamic configuration application where the UE determines whether to apply SpCell or SCell configurations based on the received cell switch command and current operational state. The configuration application is not static but adapts dynamically to the specific cell switch scenario, resolving the contradiction between flexibility and reliability.

Inventive Principle:
Principle #15Dynamics

2Reliability

If different configurations are applied for SpCell and SCell, then communication reliability is improved, but device complexity increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidconfiguration management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the configuration management into distinct handling for SpCell and SCell. SpCell configurations (RLM, BFD, PUCCH) are managed separately from SCell configurations. The UE processes cell switch commands by identifying the target cell type and applying the appropriate configuration set, reducing overall complexity through structured segmentation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes configuration parameters dynamically based on cell type and switch scenario. Instead of maintaining fixed complex configurations for all cells, the system adjusts which configuration parameters are applied (SpCell vs. SCell configurations) based on the specific cell switch operation, reducing complexity while maintaining reliability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4704468A1Terminal, wireless communication method, and base station
Publication Date: 2026.03.04 NTT DOCOMO INC
  • EP4704468A1 patent drawingFigure 1A~1D
  • EP4704468A1 patent drawingFigure 2A~2B
  • EP4704468A1 patent drawingFigure 3A~3B

AI summary

A terminal according to one aspect of the present disclosure includes a receiving section that receives a Medium Access Control Control Element (MAC CE) related to a cell switch, and a control section that controls application of a configuration of at least one of radio link monitoring (RLM), beam failure detection (BFD), and an uplink control channel (PUCCH) for a specific cell, based on information included in the MAC CE.