An Efficient Emergency Message Broadcasting Scheme in Vehicular Ad Hoc Networks

Broadcasting of emergency message (EM) in the vehicular Ad hoc networks (VANETs) plays a significant role in safety applications, which require immediate broadcasting of EM to the relevant vehicles located in the risk zone (RZ). This paper proposes an efficient emergency message broadcasting (EEMB) scheme in VANETs. This scheme aims at avoiding multiple accidents and reducing traffic jams by broadcasting EM at high speed and with low overhead. When an accident takes place, the crashed vehicle (CV) will choose the best relayer(s) and broadcast the EM. The relayer will also choose the best next relayer(s) and rebroadcast the EM further. This process continues until the EM covers the whole RZ. The EEMB scheme reduces the overhead caused by beacons by using the prediction method. Our proposed scheme also overcomes the network fragmentation problem either by choosing the vehicles moving in the opposite direction as the relayer(s) if there are no vehicles in the same direction or by using the store-carry-forward (SCF) mechanism when there are no vehicles moving in both directions. The simulation results have shown that the proposed scheme has better performance in terms of the risk zone latency (RZL) and the beacons overhead (BCO).