Efficient alert messages dissemination in vanets using single-hop distributed protocols

Large efforts are being performed globally by governments, industries and academic institutions for the reduction of high speed road traffic accidents. Alert messages dissemination protocols based on vehicular ad hoc networks (VANETs) have strong potential in the reduction of high speed road traffic accidents. Alert messages can convey early warning messages to the vehicles about an emergency situation ahead. While designing alert messaging protocols in VANETs, it is crucial to satisfy reliable messages reception, high messages reach-ability and low end-to-end communication delays. A number of research work proposed alert messages dissemination protocols using multi-hop propagation with help of intermediate relay nodes. In most works, symmetric range of communication between vehicles is assumed which is not true due to vehicles high mobility, adverse channel effects and radio obstacles. In addition, protocols´ performance is evaluated while considering nonrealistic wireless channel conditions and mobility models. This research proposes a novel alert messages dissemination protocol for warning possible endangered vehicles while taking into account asymmetric and adverse radio channel communication scenario. For that, real-time single-hop neighboring nodes information is utilized for computing the next most suitable relay node(s). High messages reception reliability and reach-ability are expected to be achieved while keeping end-to-end communication delays, data traffic redundancy and bandwidth utilization at acceptable levels. With this proposed protocol, the reduction of chain traffic accidents will also be investigated by providing a simulated evaluation of chain crash scenarios. A second protocol is proposed for selection of the node that will perform initial alert messages disseminating in case of multiple cars collision. Performance of the second protocol will be compared with a random initial node selection, where both techniques will be evaluated w.r.t. thei- effects in improving overall reliability, reach-ability and timeliness of an alert messaging system.