A Relay Vehicle Selection Scheme for Delivery of Emergency Message Considering Density and Trajectory of Moving Vehicles for VANET

Dissemination of safety alert messages through the broadcast is one of the most important applications for VANET. Excessive channel contention due to the simultaneous transmission of packets leads to the broadcast storm. To reduce the contention and redundant messages, it requires an effective multihop relay vehicle selection scheme. Therefore, we propose a relay vehicle selection scheme for delivery of emergency message considering the density of moving vehicles for VANET. In this paper, the most far vehicle from the previous relay vehicle while it belongs to the tolerant angle considering density is selected as a relay vehicle for next hop in distributed manner. To analyze its performance, we evaluate the number of hops for delivery of emergency messages and the number of candidate relay vehicles participating in competition for accessing the wireless channel. Simulation results show that the numbers of competition vehicles and hops can be reduced by application of an adequate tolerant angle considering with density of vehicle and location window size.