A multi-hop reputation announcement scheme for VANETs

Vehicular ad hoc networks (VANETs) allow vehicles to generate and broadcast messages to inform nearby vehicles about road conditions. We propose a multi-hop announcement scheme for VANETs which supports message broadcasting and forwarding. In this scheme, we propose two algorithms to evaluate the reliability of messages and aggregate the reputation scores respectively. The major principle of the reliability evaluation algorithm is Dempster-Shafter Theory and the reputation aggregation algorithm is a variant of weighted averaging function. To balance the message coverage area and the cost of forwarding messages, we also provide a message forwarding criterion. The proposed multi-hop scheme offers satisfactory robustness and preserves privacy property. Most importantly, the multi-hop scheme not only guarantees better message flexibility, but also can generate more satisfactory message drop rate. In addition, in the message forward criterion of our multi-hop scheme, it is up to vehicles (i.e., user friendly) to regulate the trade-off between the message utility rate and the maximal message broadcasting bandwidth, based on their real needs.