Network-Assisted D2D Resource Selection and Collision Avoidance
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Solution Overview
Problem
Conventional medium access control mechanisms in communication networks, such as CSMA/CA and CSMA/CD, are inadequate for providing low latency and high reliability in device-to-device (D2D) communications, especially in emerging applications like vehicle-to-X communications, due to lack of flexibility and scalability.
Innovation Solution
A communication device configured to operate in ad-hoc or network-assisted modes, selecting and broadcasting communication resources to minimize collisions by using ad-hoc mode control channel resources and data channel resources, with the option to switch between modes and receive resource allocation messages from base stations or other devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional medium access control mechanisms (CSMA/CA or CSMA/CD) are used for D2D communication, then device autonomy and simplicity are maintained, but collision avoidance capability and communication reliability deteriorate
Solution Approach 1:
The patent introduces a base station as an intermediary to assist D2D communication. The base station receives communication resource selection information from D2D devices, determines appropriate communication resources, and provides assistance information back to the devices. This mediator approach enables reliable collision avoidance through network coordination while keeping the D2D devices themselves relatively simple.
2Adaptability or versatility
If distributed resource allocation is used for D2D communication, then device autonomy and scalability are improved, but resource coordination capability and collision reduction deteriorate
Solution Approach 1:
The patent implements a dynamic resource allocation mechanism where D2D devices can operate in different modes (autonomous distributed allocation or network-assisted allocation) depending on conditions. The system dynamically selects between distributed autonomy and network coordination based on traffic conditions, device density, and service requirements, providing both flexibility and reliability as needed.
3Speed
If autonomous resource selection by D2D devices is implemented, then response speed and low latency are improved, but resource collision probability increases
Solution Approach 1:
The patent employs preliminary actions in two forms: (1) D2D devices perform autonomous resource selection quickly when conditions permit, and (2) when collision risk is detected or network assistance is available, devices preliminarily report their resource selections to the base station before finalizing transmission. This preliminary reporting allows the base station to detect and resolve potential collisions before they occur, maintaining fast response while reducing collision probability.
Data Source
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AI summary
The invention relates to devices and methods for network-assisted D2D communication. According to a first aspect the invention relates to a communication device (101a-d) configured to operate in an ad-hoc communication mode for communicating with a plurality of communication devices (100a-c, 101a-d). The communication device (101a-d) is configured to select a data channel communication resource from a plurality of data channel communication resources which are reserved for D2D data channel communications. The communication device (100a-d) is configured to select an ad-hoc mode control channel resource from a plurality of ad-hoc mode control channel resources which are reserved for D2D ad-hoc mode control channel communications. The communication device (101a-d) is further configured to broadcast, using the selected ad-hoc mode control channel resource, a communication resource selection message including information about the selected data channel communication resource to the plurality of communication devices (100a-c, 101a-d). The communication device (101a-d) is further configured to communicate with at least one of the plurality of communication devices using the selected data channel communication resource.