Research On Opportunistic Routing Protocol For Vehicular Ad-Hoc Network

The Vehicular Ad-hoc Network(VANET)is an important component of the Intelligent Traffic System(ITS),and the VANET routing protocol is the key technology to realize the reliable multi-hop transmission in vehicle networks,and it has become one of the research hotspots of VANET.Opportunistic routing is a path that does not require a full routing path between the source and destination nodes.With the mechanism of “Storage-CarryingForwarding",using the meeting chance of mobile node to realize the transmission of message data,it can meet the characteristics of VANET communication well,and effectively improve the transmission stability and scalability of VANET.This paper focuses on the current problems of VANET opportunistic routing and conducts a series of studies.The main work of this paper is as follows:(1)Aiming at the characteristics of urban road environment and the different communication opportunities brought by the location change of neighboring nodes,this paper proposes a Geographic and State-based Opportunistic Routing for VANET(GSOR).The routing protocol is divided into different message forwarding modes according to the location of neighboring nodes: restricted greedy forwarding mode,peripheral forwarding mode,cooperative forwarding mode and carrying forwarding mode.Different routing strategies are used in different modes,and vehicle location information and node state information are used to select a more successful forwarding node.The simulation results show that compared with other routing protocols,the performance of GSOR routing protocol is improved.(2)Aiming at the problem of large distributed area and uneven environment of vehicle nodes and the decrease of network performance due to blind flood forwarding in multiple copies routing,this paper presents a Multi-Copy and Utility-based Opportunistic Routing for VANET(MUOR).The MUOR routing protocol is divided into two forwarding modes based on the number of message copies: In the multi-copy forwarding mode,the MUOR routing protocol selects the best next hop forwarding node through the node utility function,considering the multiple attribute parameters of the node,and uses the analytic hierarchy process to determine the weight value of each parameter.In the single-copy forwarding mode,the MUOR routing protocol takes the form of direct delivery,in which messages are forwarded only when the destination node is encountered.The simulation results show that the performance of MUOR routing protocol is superior to other similar routing protocols.