Relevance estimation of cooperative awareness messages in VANETs

In Vehicular Ad-Hoc Networks (VANETs) a vehicle receives multiple Cooperative Awareness Messages (CAMs) from neighboring nodes which inform it about their status. As the rate of received CAMs may be high, their processing may be a challenge especially in series vehicles because their resources are constrained for economic reasons. In this work, we assume that only a fraction of the received CAMs can be handled. We suggest that most relevant messages should be preferably processed. This requires a simple function that calculates with little effort an estimate of the relevance of CAMs based on information such as location and speed of the sender that is contained in any CAM. We propose a function that - roughly speaking - calculates the relevance of a CAM for its receiver. That value increases with the potential of collision with the sender of the CAM. The function has only a few parameters. Another contribution of the paper is the receiver-centric analysis of the chosen relevance function. It illustrates the effect of the function´s parameters on the relevance of CAMs originating from vehicles in different positions and movements relative to the receiver.