Target Cell TA Signaling to Avoid Handover Uplink Synchronization

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Solution Overview

Problem

Existing communication technologies face challenges in efficiently indicating a timing advance (TA) value to a terminal during cell handover, leading to unnecessary uplink synchronization delays.

Innovation Solution

A method and apparatus for indicating a TA value by sending first information from a network device to a terminal, which includes identification information and a TA value of a target cell, either in a cell handover command or downlink control information, ensuring the terminal obtains the TA value before handover, thereby avoiding the need for uplink synchronization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a random access process is performed to obtain uplink synchronization during cell handover, then uplink synchronization is achieved, but time overhead increases

Engineering Contradiction:

Improveuplink synchronizationVSAvoidtime overhead

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The network device measures and indicates the TA value of the target cell to the terminal before the handover is executed. This preliminary provision of timing advance information allows the terminal to perform cell handover without performing uplink synchronization random access, thereby reducing time overhead while ensuring uplink synchronization is maintained

Inventive Principle:

Principle #10Preliminary action

2Ease of operation

If the TA value is not indicated to the terminal in advance, then the terminal can perform random access for uplink synchronization, but the handover time increases

Engineering Contradiction:

Improverandom access processVSAvoidhandover time

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The network device measures and indicates the TA value of the target cell to the terminal before the handover is executed. This preliminary action provides the terminal with the necessary timing advance information in advance, eliminating the need for time-consuming random access procedures during handover

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If the network device measures and indicates TA value for multiple candidate cells, then the terminal can quickly switch to any candidate cell, but signaling overhead increases

Engineering Contradiction:

Improvecandidate cell selectionVSAvoidsignaling overhead

Core Design Contradiction:

Adaptability or versatilityVSLoss of information

Solution Approach 1:

The TA information is segmented and organized by associating each candidate cell with a unique identification. The network device indicates TA values for multiple candidate cells, each linked to its identification, allowing the terminal to efficiently select and switch to any candidate cell while managing signaling overhead through structured information organization

Inventive Principle:

Principle #1Segmentation

Data Source

PatentEP4694323A1Ta indication method and apparatus, device, storage medium, and program product

Publication Date: 2026.02.11 BEIJING XIAOMI MOBILE SOFTWARE CO LTD

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AI summary

A TA indication method and apparatus, a device, a storage medium, and a program product, relating to the technical field of communications. The method comprises: a terminal device receives first information from a network device, the first information being used for determining a TA value of a target cell (310). The network device sends to the terminal device the first information used for determining the TA value of the target cell, thereby ensuring that the terminal device has obtained the TA value of the target cell when performing cell handover, there is no need to further perform uplink synchronization, and thus the time cost required by a cell handover process is reduced.