TF-DMB: A traffic flow theory-based dynamic multi-hop broadcast protocol

In order to ensure traffic safety, the emergency warning message should be transmitted quickly and reliably in vehicular ad hoc networks by multi-hop broadcast. In this article, we propose a traffic flow theory-based dynamic multi-hop broadcast protocol to address the issue of emergency warning message dissemination in vehicular ad hoc networks. The main goal of our protocol is to reduce delay and enhance reliability no matter the traffic density is high or low. First, according to the simulations of the distribution of vehicles under different traffic densities, a method of dynamically dividing the communication range is proposed, which, to a large extent, could find the candidate forwarders by one non-uniform partition. Next, a mechanism of dynamically adjusting the contention window size and boundary is designed, and the minimum waiting time difference is considered. The complete execution process of theory-based dynamic multi-hop broadcast protocol and corresponding retransmission strategies are included for high reliability. Through extensive simulations, we demonstrate the superior performance of our protocol in terms of one-hop delay, one-hop message processing, and delivery ratio compared with other existing schemes.