Intervehicle communication protocol for emergency situations

Intervehicle communications could be very valuable in emergency situations such as after natural or man made disasters or accidents. The main goal in designing protocols for similar situations is to guarantee lower delay, needed throughput and probably most importantly to enable prioritization of emergency information. Reaching such goals is not easy in presence of emergency situations when the intervehicle traffic increases exponentially. We present a reliable hierarchical routing protocol that uses load balancing to keep low message delay even in presence of high level of traffic. Our protocol is based on geographical routing. The protocol is designed for highway travelers but can be used in any mobile ad-hoc network. The highway is divided in virtual cells, which moves as the vehicles moves. The cell members might choose one or more Cell_Leaders that will behave for a certain time interval as Base Stations. Every node has its geographical position given by global positioning system (GPS). Cell_Leaders form a virtual backbone used to forward messages among nodes on different cells. The traffic is distributed among Cell_Leaders in order to optimize the communication delay. We study the effect of load balancing in minimizing delay. Our simulation results show that our proposed protocol improves the network utilization compared to existing inter-vehicles protocols.