Wireless Device Resource Selection for D2D Collision Avoidance
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Solution Overview
Problem
Designing a medium access control (MAC) protocol for wireless devices in device-to-device (D2D) broadcasting communication without base station support to prevent data collisions and ensure quality of service (QoS) is challenging, especially in half-duplex mode where feedback messages are not supported and channel status monitoring is limited.
Innovation Solution
A resource selection method for wireless devices that determines whether to broadcast a scheduling assignment (SA) signal, selects an available SA channel based on recorded lists of available and used channels, and updates these lists to avoid channel collisions, allowing devices to dynamically choose SA broadcasting resources and corresponding data transmission resources to prevent collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If wireless devices operate in half-duplex mode without feedback messages, then device complexity is reduced, but data collision prevention capability deteriorates
Solution Approach 1:
The patent applies preliminary action by having wireless devices perform listening operations in the first sub-phase of the SA phase to identify used SA channels before selecting their own broadcasting resources in the second sub-phase. This advance detection of channel usage allows devices to proactively avoid collisions without requiring feedback messages, thus maintaining low device complexity while improving collision prevention capability.
2Reliability
If wireless devices listen to all SA channels to avoid collisions, then data collision prevention capability is improved, but use of energy deteriorates
Solution Approach 1:
The patent applies segmentation by dividing the SA phase into two distinct sub-phases: a first sub-phase for listening to SA channels and identifying used resources, and a second sub-phase for selecting and broadcasting on SA channels. This temporal segmentation allows devices to concentrate their listening efforts in a specific time window rather than continuously monitoring all channels, thereby reducing overall energy consumption while maintaining effective collision avoidance.
3Adaptability or versatility
If wireless devices select SA broadcasting resources dynamically, then adaptability is improved, but device complexity deteriorates
Solution Approach 1:
The patent applies parameter changes by having wireless devices select SA broadcasting resources based on detected channel usage patterns and predefined probabilities. Devices dynamically adjust their resource selection parameters (such as which SA channel to use and when to broadcast) based on the listening results from the first sub-phase, enabling adaptability to changing channel conditions without requiring complex centralized coordination or feedback mechanisms.
Data Source
AI summary
A resource selection method and a wireless device are disclosed. The method includes: determining whether the wireless device is desired to broadcast a first scheduling assignment (SA) signal in an SA slot of an SA phase; if yes, selecting an SA broadcasting resource for broadcasting the first SA signal based on a first list and a second list recorded by the wireless device; if no, listening to all SA channels included in an SA channel resource pool, and removing a first SA channel from the first list after a second SA signal being carried on the first SA channel is listened to.