An IVC Broadcast Scheme Based on Traffic Phase for Emergency Message Dissemination at Road Intersection

Broadcast transmission is an effective approach for safe-related information transmission to achieve cooperative driving in Inter-Vehicle Communication (IVC), especially in the scenario of an urban intersection. In the past, several approaches have been proposed to solve the broadcast storm problem in multi-hop wireless networks. However, none of them take the traffic phase and traffic signal lights of real-world scenarios into consideration. In this paper, we propose An Intersection Broadcast Scheme Based on Traffic Phase (IBSTP), which extends the CLMP protocol only conceiving for single-direction environments. Moreover, it resolves several fundamental challenges such as message redundancy, hidden terminals, and broadcast storms. When there is an intersection in the path of the message dissemination, IBSTP ensures that a relaying node is selected to initialize directional broadcast along every road segment. The intersection is divided into several areas according to the traffic phase information from traffic lights. We define the valid areas and only the vehicles in valid areas can participate in contending for relaying nodes. Since every road has a relaying node broadcasting message to the next intersection, the reliability of transmitting emergency message is improved, and the time of broadcasting message to the next intersection decreases. Network simulator (NS-2) simulation results are given to confirm our analysis that the IBSTP not only can improve reliability of initializing directional broadcast but can reduce the time of broadcasting to around intersections.