The Research Of The Real-time Trafifc Information System Based On Vehicular Networks

In recent years, intelligent transportation system played a key role on improving trafficproblems. The concept of “Internet of Car” has been proposed, it provides a new direction ofdevelopment for the future of intelligent transportation. Vehicle communication technology hasattracted the attention of the traffic control department, auto companies and technical experts.As a new form of wireless network, vehicular Ad Hoc network has become a new hotresearch topic. Its purpose is to build a self-organizing inter-vehicle communication network,which is easy deployment, low cost and open architecture. At present, the traffic informationbased on the VANET has not formed a mature system. In VANET, nodes are in high speedmobile and network topology changes quickly. Due to these characteristics, there are someproblems, such as unstable data transmission, low-connectivity and so on. In this paper, VANETtechnology will be used for traffic information collection. And a new VANET traffic informationsystem will be proposed, which has no center and collects information by broadcasting andinquiries information by unicasting. It provides the basis for man-machine interactive distributedtraffic management control which based on vehicle networking.In this paper, several aspects of the key technologies were studied, such as real-timedynamic traffic information collection and distribution, road traffic identification algorithms andtraffic check. The main results of the work are presented as follows:(1) Mainstream traffic information acquisition methods cannot directly get the vehicle speedand traffic density. However, VANET-based traffic information system can collect both trafficflow parameters through the information broadcast. But in the urban scene, there is high densityof vehicles and it is easy to produce broadcast redundancy. In this paper, a traffic informationdistribution method based on the priority broadcast is proposed. In this method, trafficinformation broadcast is limited to specific section. It can reduce the redundant information ofthe broadcast and restrict broadcast storms.(2) Using the information collection and distribution methods, it can collect the average of the traffic speed and traffic density. The analysis of these two traffic parameter is needed toidentify the traffic conditions of the road. But because of the fuzzy traffic information, a roadtraffic identification method which based on fuzzy C-means clustering algorithm is proposed inthis paper. This method can achieve the traffic evaluation.(3) Summarize the current vehicular Ad Hoc networks routing protocols and analyze thedeficiency of these protocols in urban scenarios. In this paper, a new routing protocol used inurban scenes is proposed. Its name is Urban Roads-based and On-demand Routing Protocol. Thisprotocol using the information of urban roads, established a path with the on-demand thoughts.In this path, the protocol gives full consideration to the characteristics of the vehicle. In order toachieve the purpose to improve the efficiency of data forwarding, the protocol executes theoptimized greedy forwarding mechanism by using the neighbor list which have directionmessage.(4) The priority broadcast and UROR are simulated in this paper by using NCTUns which ishigh-fidelity, scalable, open-source and good for VANET simulation. And the funtion of trafficinformation collection and query is also simulated, the results show that using VANET detectreal-time traffic is valid.