Terminal Timing Advance Selection for Inter-Cell Mobility

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

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

Innovation Solution

A terminal equipped with a receiving section to acquire timing advance information for a candidate cell using a method selected based on higher layer parameters and rules, enabling appropriate control of communication during inter-cell mobility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If inter-cell mobility is implemented with multiple cells including non-serving cells, then communication capacity and flexibility are improved, but control of uplink transmission timing becomes more difficult

Engineering Contradiction:
Improveinter-cell mobility capabilityVSAvoiduplink transmission timing control
Core Design Contradiction:
Adaptability or versatilityVSReliability

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 control for serving and non-serving cells, resolving the contradiction by enabling flexible inter-cell mobility while maintaining reliable timing synchronization through dedicated TAG management.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by configuring timing advance values and TAG assignments in advance before inter-cell mobility operations. The base station pre-configures multiple TAGs with appropriate timing advance parameters, enabling the terminal to quickly switch between cells without timing synchronization issues, thus improving both adaptability and reliability.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If timing advance is acquired for each candidate cell during inter-cell mobility, then uplink transmission accuracy is improved, but signaling overhead and processing complexity increase

Engineering Contradiction:
Improvetiming advance accuracyVSAvoidtiming advance management complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes timing advance groups universal by allowing a single TAG to serve multiple cells that share the same timing advance characteristics. This multi-functionality reduces the number of separate timing advance configurations needed, thereby maintaining measurement precision while reducing device complexity and signaling overhead.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent changes the parameter organization from individual cell-level timing advance values to group-level TAG configurations. By parameterizing timing advance at the TAG level rather than individual cell level, the system achieves efficient timing management with reduced complexity, as multiple cells can share the same timing advance parameters when appropriate.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4661523A1Terminal, wireless communication method, and base station
Publication Date: 2025.12.10 NTT DOCOMO INC
  • EP4661523A1 patent drawingFigure 1A~1B
  • EP4661523A1 patent drawingFigure 2
  • EP4661523A1 patent drawingFigure 3

AI summary

A terminal according to one aspect of the present disclosure includes: a receiving section that receives information regarding a serving cell and a candidate cell; and a control section that uses, when a plurality of methods of acquiring timing advance corresponding to the candidate cell are supported, a method of acquiring timing advance selected based on at least one of a higher layer parameter and a certain rule, to acquire the timing advance corresponding to the candidate cell.