Research On Trusted Routing Protocol In Vehicular Ad Hoc Networks

Vehicular Ad Hoc Networks (VANET) is a kind of Mobile Ad hoc Networks (MANET) that focuses on inter-vehicle communications. VENET merges the wireless communication technologies and the information gathering technologies, and applies them to transportation field, it plays an important role in intelligent transportation systems. Since VANET has a high social and business value in improving road safety and traffic efficiency, it has become a hot topic and made a number of important research results.As a special application of MANET, VANET inherits its defects such as the topology changes frequently, the link is unstable and vulnerable and so on. It faces many serious security threats. Trust mechanism is an abstraction of complex relationships in human society and an important basis for the establishment of a reliable route. This thesis conducted in-depth research on VANET trusted routing protocol.Firstly, a trust management model that based on subjective logic is proposed. In this model, according to the characteristics of VANET, we consider a variety of possible elements that may impact the trust of nodes and extract four trust factors. This model designed a trust management framework and defines the direct trust, recommendation trust, history trust, the formula for calculating the trust value and trust decisions.Based on this trust management framework, a trusted opportunistic routing protocol is proposed. This routing protocol has achieved trust management, such as detecting trust factors, calculating or updating the trust value and giving some punitive measures. Then, the definition of TOR(Trust-based Opportunistic Routing) is given.Traffic simulator VanetMobiSim and network simulator NS-2 were applied in this thesis to do simulations of TOR routing protocol. We configured simulation parameters for VANET and compared the TOR routing protocol with other routing protocols in average delay and packet delivery ratio. The results showed:compared with other traditional routing protocols, TOR protocol has a good ability to resist malicious attacks. In the case of malicious nodes, the packet delivery ratio increased significantly, showing its excellent performance in safety.