UE Cell Switching Using Timing Advance to Skip Random Access

Solution Overview

Problem

The challenge in wireless communication systems is the inefficiency in utilizing limited radio resources for data and control information transmission, particularly in scenarios requiring low latency and high reliability, such as 5G applications, where cell change procedures are time-consuming due to random access procedures.

Innovation Solution

A method and apparatus for performing a cell change procedure in a wireless communication system that allows a user equipment (UE) to switch cells without performing a random access procedure by using a valid timing advance (TA) value, thereby reducing latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a random access procedure is performed during cell change, then connection reliability is ensured, but cell change latency increases

Engineering Contradiction:

Improveconnection reliabilityVSAvoidcell change latency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The network side performs preliminary actions by pre-configuring timing advance values for candidate cells before the cell change occurs. When cell change is needed, the UE can directly use the pre-provided timing advance value to immediately synchronize with the target cell without performing random access procedure, thus reducing cell change latency while maintaining connection reliability through pre-established timing synchronization

Inventive Principle:

Principle #10Preliminary action

2Loss of time

If random access procedure is skipped during cell change, then cell change latency is reduced, but connection reliability may be compromised

Engineering Contradiction:

Improvecell change latencyVSAvoidconnection reliability

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The network side performs preliminary actions by pre-configuring timing advance values for candidate cells before the cell change occurs. When cell change is needed, the UE can directly use the pre-provided timing advance value to immediately synchronize with the target cell without performing random access procedure, thus reducing cell change latency while maintaining connection reliability through pre-established timing synchronization

Inventive Principle:

Principle #10Preliminary action

3Reliability

If traditional cell change procedure is used, then robust connection establishment is achieved, but resource utilization efficiency decreases due to time-consuming procedures

Engineering Contradiction:

Improveconnection establishment robustnessVSAvoidresource utilization efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The network side performs preliminary actions by pre-configuring timing advance values for candidate cells before the cell change occurs. When cell change is needed, the UE can directly use the pre-provided timing advance value to immediately synchronize with the target cell without performing random access procedure, thus reducing cell change latency while maintaining connection reliability through pre-established timing synchronization

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS20250365626A1Method and apparatus for performing cell change procedure in wireless communication system

Publication Date: 2025.11.27 LG ELECTRONICS INC

AI summary

The present disclosure relates to a method of performing operations for a User Equipment (UE) in a wireless communication system. In particular, the method includes receiving, from a first cell, information on candidate cells; receiving, from the first cell, a cell change command to switch a connection from the first cell to a second cell among the candidate cells; and based on the cell change command including a valid timing advance (TA) value related to the second cell, performing a cell switch with skipping a random access procedure related to the second cell.