D2D Cell Selection Offset for Load Distribution
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Solution Overview
Problem
In device-to-device (D2D) communication, existing methods face challenges with frequency overload in base stations due to concentrated terminal device interest, and difficulty in configuring priority levels for D2D communication, especially in FDD systems.
Innovation Solution
A terminal device determines if D2D communication is possible in the serving cell and evaluates neighboring cells with supported frequency bands, prioritizing communication in neighboring cells with higher priority levels, allowing for efficient D2D communication by selecting the most suitable cell.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If terminal devices raise the priority level of the frequency at which D2D transmission and reception are possible to the maximum extent in the cell reselection procedure, then transmission or reception of the D2D service is made possible, but the base station capacity at that frequency is exceeded (overloaded)
Solution Approach 1:
The patent applies local quality by introducing a specific offset parameter (Q_offset_D2D) that is applied only to frequencies supporting D2D communication, rather than uniformly increasing priority across all frequencies. This localized adjustment allows terminal devices to preferentially select D2D-capable frequencies while the base station can control the magnitude of this preference through parameter configuration, preventing excessive concentration of devices on a single frequency and avoiding capacity overload.
2Reliability
If the priority level of frequency is changed in the cell reselection procedure, then D2D service is enabled, but the method is difficult to apply in FDD systems where priority level is not configured for D2D frequency
Solution Approach 1:
The patent employs parameter changes by introducing a new offset parameter (Q_offset_D2D) that modifies the existing cell reselection evaluation formula. Instead of changing the fundamental priority level configuration mechanism, the patent adds an offset parameter that can be configured independently for D2D frequencies. This approach maintains compatibility with existing FDD system configurations while enabling D2D service prioritization through parameter adjustment rather than structural changes.
Data Source
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AI summary
Provided is a technology relating to a terminal device, a base station apparatus, a communication system, a communication method, and an integrated circuit, in all of which it is possible that a communication procedure relating to device-to-device communication is efficiently performed. A terminal device that is capable of direct communication with a different terminal device makes a determination of whether or not transmission and reception of data relating to the direct communication at a frequency in a serving cell are not possible and transmission and reception of data relating to the direct communication at a frequency in a neighboring cell are possible, based on capability information relating to a combination of frequency bands that are supported by the terminal device, the frequency in the serving cell, and the frequency in the neighboring cell, and starts evaluation for selecting the neighboring cell, at a frequency in the neighboring cell in which the transmission and reception of the data relating to the direct communication are possible, in a case where the terminal device is interested in the direct communication.