Cooperation enhancement for message transmission in VANETs

As one special case of the Mobile Ad Hoc Networks (MANET), vehicular ad-hoc networking (VANET) is featured by its high mobility and constantly changing topology. In VANET, nodes can work properly only if the participating vehicles cooperate with each other during communications. However, as a distributed network, individual vehicles might be non-cooperative for their own benefits. In order to prevent non-cooperative vehicles from tampering packet relaying in the network, we propose a cooperation enhancement mechanism using '' Neighborhood WatchDog '' to generate Trust Token based on the first-hand observation. Therefore, trust relationships and packet-acceptance decisions of the receiving nodes are based on the instant observation and the token-proved relaying behavior of the benign neighboring vehicles. With the inherit mapping between the Electronic ID of one vehicle and its public key, keys can be distributed on-the-fly. As a network layer solution, the cooperation enhancement mechanism proposed in this paper is built on the top of our previous proposed Media Access Control (MAC) protocol: Relative Position Based-MAC (RPB-MAC).