Fast and reliable broadcasting in VANETs using SNR with ACK decoupling

Vehicular Ad Hoc Networks (VANETs) is an extension of Mobile Ad Hoc Networks (MANETs) to share traffic information and emergency alerts amongst vehicles on the road. To support many applications in VANETs, most studies use GPS to find the furthest node with ACK to ensure successful message reception. However, this ACK procedure can be removed if a channel between the sender and receiver is clear such that the sender can overhear the broadcasted messages from the receiver. If the sender fails, nodes closer to the sender inform the sender of successful rebroadcasting, which serves as an ACK to the sender. This process will either entirely remove costly ACKing processes or at least decouple the messages propagation from ACKing to the sender, which will significantly improve the speed of message propagation. In this paper, we use Signal-to-Noise Ratio (SNR) with ACK decoupling to ensure fast message propagation with reliable message recovery. Detailed simulation results show that the proposed SNR based approach with ACK decoupling outperforms the Smart Broadcast (SB) by 200% in average throughput and per hop delay, while ensuring the reliable dissemination of emergency messages in typical VANETs environments.