Satellite Cell Access Using Frequency Offset Detection
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Solution Overview
Problem
In satellite communication, the use of the S criterion from cellular communication to manage access leads to high signaling overheads due to frequent handovers or reselections when terminal devices move to the edge of a cell, as signal quality differences between central and edge locations are minimal, causing immediate access failures.
Innovation Solution
A method where terminal devices determine frequency offset parameters based on configuration information from satellite base stations, using reference signals to assess whether they are at the edge of a cell, thereby avoiding unnecessary access attempts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the S criterion from cellular communication is used to manage access in satellite communication, then terminal devices at the edge of a cell can meet the access condition, but handover or reselection needs to be performed immediately after access, causing high signaling overheads
Solution Approach 1:
The patent applies preliminary action by having the terminal device detect the frequency offset parameter before accessing the cell. The terminal device determines whether the frequency offset parameter falls within a configured range, and only accesses the cell if the condition is met. This preliminary detection prevents immediate handover or reselection after access, thereby reducing signaling overheads while ensuring access feasibility for edge-location terminal devices
2Adaptability or versatility
If the terminal device accesses the cell based on S criterion, then access is possible, but the terminal device is out of coverage area due to satellite base station movement, requiring immediate handover or reselection
Solution Approach 1:
The patent performs preliminary detection of the frequency offset parameter before cell access. The terminal device determines whether the detected frequency offset parameter is within the configured range, and only proceeds with access if the condition is satisfied. This preliminary action ensures that the terminal device is within the stable coverage area before accessing, preventing immediate handover or reselection caused by satellite movement, thus improving access reliability
Solution Approach 2:
The patent implements feedback by having the network device configure a frequency offset parameter range for the cell and the terminal device detecting and comparing its measured frequency offset parameter against this range. This feedback mechanism ensures that the terminal device only accesses when it is within the stable coverage area, maintaining reliable communication without immediate handover or reselection
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Reduces signaling overheads by preventing access attempts when terminal devices are at the edge of a cell, ensuring stable communication without immediate handovers or reselections.
Implementation Method 1
the terminal device determines a first frequency offset parameter based on a detected first reference signal
Data Source
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AI summary
This application provides an access method and apparatus. A terminal device may determine, based on whether a first frequency offset parameter is in a frequency offset parameter range, whether to access a first cell. If the first frequency offset parameter is in the frequency offset parameter range, a current location of the terminal device is not at an edge of the cell. If the first frequency offset parameter is not in the frequency offset parameter range, the current location of the terminal device may be at the edge of the cell. In this way, the terminal device may determine, based on whether the first frequency offset parameter is in the frequency offset parameter range, whether to access the first cell. This can avoid signaling overheads caused when handover or reselection needs to be performed immediately after the terminal device needs to access the first cell even if the terminal device is located at an edge location of the first cell but an S criterion is met.