A Study On Routing Protocols And Algorithms Based On Social Network Theory For Vehicular Ad Hoc Networks

Vehicular Ad Hoc Network(VANET) is specifically designed for the communication of Vehicle-to-X(X: Vehicle, Human, Infrastructure etc). In recent years, with the rapid development of wireless network technology and vehicle application technology, VANET has attracted widespread concern of government, enterprises and research institutions which has huge market potential. VANET is also a special Mobile Ad Hoc Network(MANET), with the characteristics of highly dynamic topology, wireless link easy to break, the motion path fixity and others, the routing protocols research faced more challenges in VANET compared to traditional MANET.In the second part of this thesis, summarized social network theory, classified routing algorithm of VANET and described social-network-theory-based routing algorithm. First, overviewed of social network theory and classification of existing social relations, and then, assessed the impact of social relations on the routing algorithm performance. Secondly, classified and analyzed the existing routing algorithms in VANET and assecced the performance of the algorithms. Finally, summarized and analyzed existing social routing algorithms advantages and disadvantages.To solve current routing algorithms in VANET forward different types of packets in the same way caused network overload problems, a routing algorithm based on Task-Assignment-Model(TAR) is proposed in the third part of this thesis.First, according to the node access different areas different frequencies mechanism divided communities. Then, using consultation mechanism allocated the different message tasks to the communities and then communities signed tasks to the node. Last, established incentive mechanisms to incentive or punish node. Through theoretical analysis and simulation in Network Simulator2(NS2), result shows TAR reduced the network load well by using different ways forwarded different types of packets to reduce the packets forwarding number.Traditional society routing algorithm in VANET does not consider the node movement regional features, resulted packet delivery efficiency is low due to forwarded packets to single node. A Self-adaptived Area Explored Routing algorithm(SAE) is proposed in the fourth part of this thesis. First, the nodes frequently activities regional discovered by adaptive mechanism. Secondly, the information of the destination node movement regional tells other node and hot by contagion mechanism. Last, establishing transfer mechanism to send packets between hots and setting up rules to send packets to the destination movement regional. Then, the algorithms forward packets to the destination movement regional instead of sending packets to destination, so as to improve the efficiency of packet delivery. Through theoretical analysis and simulation, result shows SAE improved packet success delivery rate.