Satellite Cell Reselection Using Positional Thresholds
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Solution Overview
Problem
In non-terrestrial network scenarios, terminals experience rapid satellite coverage changes, necessitating frequent cell reselection due to the dynamic nature of satellite positions, which can lead to inefficiencies and instability in wireless communication.
Innovation Solution
A method for cell reselection in terminals that determines whether to perform cell reselection based on the positional relationship between the terminal and a reference position of the source cell, using ephemeris information to maintain a consistent reference point and threshold ranges for distance and angle considerations, thereby reducing unnecessary reselections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If cell reselection is performed frequently to maintain connection with moving satellite, then communication coverage is maintained, but communication reliability deteriorates due to unstable handovers
Solution Approach 1:
The patent changes the decision parameter for cell reselection from signal strength to positional relationship. By calculating the distance between terminal and reference position using ephemeris data, and comparing it with threshold values, the system determines handover timing based on predictable satellite motion geometry rather than fluctuating signal measurements, thereby improving handover reliability while maintaining coverage.
2Ease of operation
If cell reselection is performed based on signal strength, then handover decisions are simple to make, but handover reliability deteriorates due to rapid signal fluctuations from satellite motion
Solution Approach 1:
The patent introduces reference position as an intermediary concept derived from ephemeris information. Instead of directly comparing signal strengths, the system calculates a reference position based on satellite ephemeris data and terminal position, then compares the terminal's distance to this reference position against thresholds. This intermediary approach transforms the complex signal strength comparison into a simpler geometric calculation that is more reliable for moving satellite scenarios.
3Duration of action of stationary object
If cell reselection is performed continuously to track satellite motion, then communication continuity is maintained, but system resources are wasted due to unnecessary handovers
Solution Approach 1:
The patent applies partial action by performing cell reselection only when necessary - specifically when the terminal's distance to the reference position exceeds the threshold. Instead of continuous reselection, the system calculates the threshold based on satellite signal coverage characteristics and performs handovers only when the terminal moves beyond the acceptable range, thereby avoiding unnecessary handovers and reducing system resource consumption while maintaining communication continuity.
Data Source
AI summary
Embodiments of the present application provide a cell reselection method. The method is performed by a terminal, and the method includes: determining, on the basis of the positional relationship between the terminal and a source cell, whether to perform a cell reselection operation, where the cell is a cell covered by satellite signals.