Terminal Timing Advance Control Across Candidate Cells

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Solution Overview

Problem

In future radio communication systems, controlling uplink transmission timing advance during inter-cell mobility between a serving cell and candidate cells is challenging, leading to potential degradation of communication quality if not managed appropriately.

Innovation Solution

A terminal and base station system that includes a receiving section for configuration information and a control section to manage timers for candidate cells, enabling appropriate control of timing advance commands for seamless communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If inter-cell mobility with candidate cells is implemented, then communication capacity and flexibility are improved, but timing advance control complexity increases

Engineering Contradiction:
Improveinter-cell mobility capabilityVSAvoidtiming advance control complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the cell group into multiple timing advance groups (TAGs), where each TAG independently manages timing advance for specific cells. This segmentation allows separate timing advance control for serving cells and candidate cells, reducing the overall control complexity while maintaining mobility flexibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies timing advance commands from candidate cells in advance before actual cell switching occurs. The terminal maintains timing advance information for candidate cells beforehand, so when switching happens, the timing advance is already prepared, simplifying the switching process.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If timing advance command from candidate cell is applied, then uplink synchronization is improved, but risk of timing conflict between cells increases

Engineering Contradiction:
Improveuplink synchronizationVSAvoidtiming conflict
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent divides cells into different timing advance groups (TAGs) with independent timing advance control. By assigning candidate cells and serving cells to different TAGs, the patent prevents timing conflicts between them while maintaining uplink synchronization within each group.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies timing advance commands locally to specific timing advance groups rather than globally to all cells. This localized application ensures that timing adjustments affect only the intended cell group, preventing unintended timing conflicts with other cells.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If separate candidate cell configuration is used, then cell switching flexibility is improved, but communication quality degradation risk increases

Engineering Contradiction:
Improvecell switching flexibilityVSAvoidcommunication quality
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent configures candidate cells with their own timing advance parameters in advance. When cell switching occurs, the terminal already has the necessary timing advance information ready, ensuring seamless transition without communication quality degradation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements monitoring of timing advance timer status and communication quality metrics. When quality degradation is detected during or after cell switching, the system can trigger timing advance re-adjustment or initiate recovery procedures to restore communication quality.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4701289A1Terminal, wireless communication method, and base station
Publication Date: 2026.02.25 NTT DOCOMO INC
  • EP4701289A1 patent drawingFigure 1A~1B
  • EP4701289A1 patent drawingFigure 2
  • EP4701289A1 patent drawingFigure 3A~3B

AI summary

A terminal according to one aspect of the present disclosure includes a receiving section that receives configuration information related to configuration of one or more candidate cells and information related to a certain timer associated with the one or more candidate cells, and a control section that, when a timing advance command corresponding to a certain candidate cell is indicated, controls, based on the information related to the timer associated with the one or more candidate cells, start or restart of a certain timer for at least one of the certain candidate cell, another candidate cell, and a serving cell.