Beacon Channel Selection for D2D Discovery in OFDM Networks
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Solution Overview
Problem
In dynamic and mobile optimized local access (OLA) networks, efficient discovery of neighbor devices for device-to-device (D2D) connections is challenging due to the need for fast and efficient beaconing and handshaking, especially in environments where devices are highly synchronized and use Orthogonal Frequency Division Multiplexing (OFDM) transmission schemes.
Innovation Solution
The method involves identifying beacon opportunities and selecting available beacon channels randomly from a plurality of channels in a flexibly allocated frequency resource, transmitting beacon signals within an OFDM beacon frame, and receiving multiplexed beacon frames to determine the presence of neighbor devices, allowing for simultaneous D2D beaconing and efficient connection establishment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sequential beacon transmission is used, then interference between beacons is reduced, but discovery time increases and efficiency decreases
Solution Approach 1:
The patent transitions from sequential time-based beacon transmission to parallel frequency-based transmission by allocating different beacon channels to different devices within the same beacon period, enabling simultaneous beacon transmission across multiple frequency resources
Solution Approach 2:
The beacon period is segmented into multiple beacon channels in the frequency domain, allowing different devices to transmit beacons on different channels simultaneously, thereby dividing the single time slot into multiple parallel transmission paths
2Productivity
If multiple devices transmit beacons simultaneously on the same channel, then discovery speed improves, but signal interference increases
Solution Approach 1:
The patent resolves signal interference by moving multiple beacon transmissions from the same frequency channel to different frequency channels within the OFDM spectrum, allowing simultaneous transmission without interference through frequency separation
Solution Approach 2:
The OFDM beacon frame structure is designed to universally accommodate multiple beacon channels, where each channel can carry beacon signals from different devices simultaneously, making the single beacon period serve multiple transmission functions
3Stability of the object's composition
If fixed beacon slot allocation is used, then network synchronization is maintained, but adaptability to dynamic device加入 decreases
Solution Approach 1:
The patent introduces dynamic device self-selection of beacon channels within the structured beacon period, where devices autonomously choose available channels based on current network conditions, making the system adaptive to dynamic device加入 while preserving overall synchronization through the fixed beacon period framework
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
This approach enables multiple devices to transmit beacons simultaneously, allowing for quick and efficient detection of neighboring devices and establishment of D2D connections, improving energy efficiency and reducing the need for sequential beacon transmissions.
Implementation Method 1
The OFDM transmission scheme breaks up one data stream into multiple signals. Many carriers, also known as 'subcarriers,' are used for a single data channel.
Data Source
Figure 1a~1b
Figure 2
Figure 3~4
AI summary
In accordance with an example embodiment of the present invention, a method comprises identifying at least one beacon opportunity at a wireless network device; selecting a beacon channel from a beacon slot that is a flexibly allocated frequency resource; and transmitting at least one beacon signal in the selected beacon channel multiplexed in a beacon frame during the identified beacon opportunity.