NTN Cell Reselection via Conditional Search and Distance Thresholds

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Solution Overview

Problem

Existing wireless communication systems face challenges in performing seamless cell reselection in non-terrestrial networks (NTN) environments, particularly due to mobility between NTN and terrestrial networks (TN) and the need for efficient power management.

Innovation Solution

A method and apparatus for user equipment (UE) to perform cell reselection based on NTN in a wireless communication system, involving acquiring cell reselection condition information, moving between cells based on UE mobility, and performing an NTN cell search when specific conditions are met, while also configuring reference location and distance threshold information for TN cell searches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the UE performs continuous cell search and measurement in NTN environment, then the cell reselection reliability is improved, but the power consumption increases

Engineering Contradiction:
Improvecell reselection reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The network configures the UE with pre-defined cell reselection conditions including distance thresholds and reference location information before the UE needs to perform cell reselection. This allows the UE to determine in advance when cell search should be performed based on its location relative to configured thresholds, avoiding continuous searching and reducing power consumption while maintaining reliable cell reselection

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces dynamic parameters such as distance thresholds and reference location information that change based on UE mobility and network conditions. By adjusting these parameters, the system optimizes the balance between cell reselection reliability and power consumption, enabling the UE to perform measurements only when necessary rather than continuously

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the UE performs frequent cell measurements to handle mobility between NTN and TN, then the cell reselection accuracy is improved, but the processing complexity increases

Engineering Contradiction:
Improvecell reselection accuracyVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The network provides pre-configured cell reselection condition information including distance thresholds and reference location data before the UE needs to make reselection decisions. This preliminary configuration simplifies the UE's processing by providing ready-to-use parameters, reducing the computational complexity of real-time cell measurement and reselection while maintaining high accuracy

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the cell reselection process into distinct phases: receiving pre-configured parameters, evaluating current location against thresholds, and performing measurements only when conditions are met. This segmentation reduces processing complexity by breaking down the complex mobility management task into manageable steps with clear decision points

Inventive Principle:
Principle #1Segmentation

3Loss of energy

If the UE performs conditional cell searches based on distance thresholds, then the power efficiency is improved, but the cell reselection response time increases

Engineering Contradiction:
Improvepower efficiencyVSAvoidcell reselection response time
Core Design Contradiction:
Loss of energyVSLoss of time

Solution Approach 1:

The network configures distance thresholds and reference location information in advance, allowing the UE to quickly determine whether cell search is needed by simple distance calculation rather than continuous monitoring. This preliminary setup enables rapid response when conditions change while maintaining power efficiency by avoiding unnecessary searches during stable conditions

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4564920A1Method and apparatus for neighboring cell measurement for cell reselection in wireless communication system
Publication Date: 2025.06.04 INNOVATIVE TECH LAB CO LTD
  • EP4564920A1 patent drawingFigure 1
  • EP4564920A1 patent drawingFigure 2
  • EP4564920A1 patent drawingFigure 3

AI summary

Provided is a method of performing, by a user equipment (UE), cell reselection based on non-terrestrial networks (NTN) in a wireless communication system. Here, the method of performing cell reselection may include acquiring cell reselection condition information from a base station; moving from a first cell to a second cell based on mobility of the UE and acquiring measurement related information for cell reselection from the second cell; and performing an NTN cell search when a specific condition for cell reselection is satisfied based on the cell reselection condition information.