Candidate Cell Timing Advance Handling for Uplink Handover Failures

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Solution Overview

Problem

In communication systems, terminals may fail to send uplink signals or experience timing advance (TA) changes to unavailable states during cell handovers, leading to inefficiencies and potential communication disruptions.

Innovation Solution

A method and device for determining and addressing uplink signal failures or TA unavailability by acquiring the TA of candidate cells or stopping the uplink signal, and sending failure information to network devices to manage handovers effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the terminal pre-acquires TA of candidate cells to improve handover efficiency, then handover efficiency is improved, but the terminal may fail to send uplink signals or experience TA changes to unavailable states

Engineering Contradiction:
Improvehandover efficiencyVSAvoiduplink signal transmission reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The terminal pre-acquires TA of candidate cells before handover to enable direct communication after handover, improving handover efficiency. This preliminary action allows the terminal to skip the TA acquisition process in the target cell, achieving faster handover while maintaining communication reliability through proper failure detection and reporting mechanisms

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The terminal monitors the validity of pre-acquired TA values and detects when uplink signal transmission fails or TA becomes unavailable. Failure information is reported to the network device, which provides feedback to adjust handover parameters or reconfigure candidate cells, ensuring reliable communication despite the preliminary TA acquisition approach

Inventive Principle:
Principle #23Feedback

2Reliability

If the terminal sends uplink signal to acquire TA of candidate cell, then TA acquisition reliability is improved, but handover efficiency deteriorates due to additional processing time

Engineering Contradiction:
ImproveTA acquisition reliabilityVSAvoidhandover processing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The terminal acquires TA of candidate cells in advance during the cell selection and evaluation phase, before the actual handover is triggered. This preliminary TA acquisition eliminates the need for uplink signal transmission and TA measurement in the target cell, reducing handover processing time while ensuring reliable TA values through proper validation and monitoring mechanisms

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4712562A1Processing method, apparatus, device, and storage medium
Publication Date: 2026.03.18 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP4712562A1 patent drawingFigure 1~3
  • EP4712562A1 patent drawingFigure 4~8a
  • EP4712562A1 patent drawingFigure 8b~10

AI summary

The present invention provides a processing method, an apparatus, a device, and a storage medium. The method comprises: when determining that transmission of an uplink signal of a terminal on a candidate cell fails, and/or determining that TA of the candidate cell is changed into an unavailable state, executing first processing, wherein the first processing is used for implementing one of the following: acquiring TA of a candidate cell, and stopping transmitting an uplink signal. Embodiments of the present invention provide a processing method for the situation where "transmission of an uplink signal of a terminal on a candidate cell fails, and/or TA of the candidate cell is changed into an unavailable state", and provide a deterministic reference for further action, so as to avoid the occurrence of the situation of "signal transmission interference and power loss caused by the terminal not knowing what processing needs to be executed when transmission of the uplink signal of the terminal on the candidate cell fails, and/or TA of the candidate cell acquired by the terminal is changed from an available state into an unavailable state", thereby ensuring the communication stability of the terminal.