The route based emergency message dissemination scheme using multihop wireless network for VANETs

Safety-related applications in Vehicular Ad Hoc Networks (VANETs) have stringent Quality of Service (QoS) requirements, including scalability, reliability, and low dissemination delay. Multi-cast and unicast communication have emerged as promising approaches to mitigate broadcast storms and hidden terminal problems in these applications. This paper introduces a novel mechanism called the Route Based Emergency Message Dissemination Scheme using a Multi-hop Wireless Network, designed to reduce latency and minimize flooding. The proposed scheme features a new message-forwarding route that leverages directions based on the Emergency Vehicle (EV). It employs a single-node structure for initial emergency message forwarding, followed by a dynamic multicast/unicast design tailored to the EV’s state. The scheme considers five EV cases: (i) EV as Cluster Head (CH), (ii) EV as Bridge Node (BN), (iii) EV as Cluster Member (CM), (iv) EV as both CH and BN, and (v) Road Side Unit (RSU) as an emergency node. The EV determines the uni-cast or multi-cast communication for the first node, and the forwarding structure is subsequently followed. This approach ensures the timely delivery of emergency messages, addresses broadcast storm issues and maximizes coverage in single-lane highway scenarios. Omnet++ simulations demonstrate improved performance compared to existing methods, with lower end-to-end delay and enhanced coverage in high-density vehicle environments. The evaluation section highlights the scheme’s ability to achieve maximum information coverage, reduced average waiting time, and rapid emergency message delivery.