A Multi-Hop Broadcast Routing Based On Real-Time Traffic Estimates For Vanet

Intelligent transport System (Intelligent Transport System, ITS) is the modern communication technology integration with network sensor technology, cloud and mobile computing technologies, collaborative awareness technology, intelligent terminal and network control technology and so on, which is applied to the whole traffic management system with the comprehensive information sharing among people, vehicles and road communication. ITS can apply real-time monitoring and intelligent control network to traffic system and committee to building an all-round, real-time, efficient and accurate comprehensive transportation and management system. The VANET (Vehicular Ad Hoc Network) has been proposed to provide communications support for the data transmission to achieve improved safety, productivity an environmental performance in ITS. The VANET which supports complete mobility and applications in dynamic, random, and multi-hop topology is one of the branches of MANET (Mobile Ad Hoc Network) in a special situation. The characteristics of VANETs can be summarized as highly dynamic network topology, limited link bandwidth, poor link quality and short distance of communication. Therefore, one of the key challenges in VANETs is to design efficient and reliable routing algorithm to support the information transmission.From the perspective of recent demand and the technical development of intelligent transportation, VANET routing protocol research mainly focus on satisfy traffic safety warning and real-time traffic sharing. So to design efficient and reliable multihop broadcast routing is essential for ITS practicality. Several main patterns of routing algorithms used in VANETs have been proposed, but it is, generally, we still haven’t found a multiple hops broadcast routing algorithm which can to fulfill the requirements of safety broadcast messages transmission. In view of this, our multi-hop routing algorithm apply the advantage of real-time traffic estimation algorithm to mobility prediction, and design a comprehensive weighted utility function(WUF) based on the prediction, such as speed of the vehicles, density, vehicle flow, and headway, to assign the rebroadcast priority according to the WUF value. In addition, we also design the timeout retransmission mechanism to further improve the reliability of multi_hops broadcast routing algorithm. Theoretical and simulation results demonstrate the effectiveness of the proposed algorithm in terms of the packet delay, data redundancy, effective permeability and network robustness, when compared with classical M-Flood and Slotted algorithms. Thus, our algorithm can effectively guarantee the broadcast of traffic warning message in emergency circumstances.