Adaptive REACT protocol for Emergency Applications in Vehicular Networks

Vehicular communication is gaining more and more interest from big consortia and companies in the car industry. Wireless communication in a vehicular environment creates unique opportunities but poses also its own challenges. Therefore we proposed in previous work a new routing protocol, REACT, which uses geographical information and is able to react to a fast changing environment. In this paper, we will look at a few optimizations for this protocol in order to make it more adaptive to the current network conditions. As vehicles move very fast, link breaks occur more often. We attempt to predict this behavior, trying to use a link as long as possible but not longer than it really exists. Another important part of the REACT protocol consists of beaconing as means of exchanging position information with neighbors. The interval between two consecutive beacons is an important parameter in determining the end-to-end delay and we propose an algorithm that adapts this parameter in order to speed up neighbor discovery without generating too much beaconing overhead. The two optimizations were implemented and tested in a simulator and the results show a performance amelioration in the end-to-end delay in scenarios with sparse and dense road traffic.