The Research Of Wireless Communication Network For Intelligent Transportation Systems

Along with the rapid economic and social development, our transportation system becomes overload, which leads to many road deaths and road congestion. Intelligent transportation systems (ITS) provide an answer for these transportation issues. The communication system of ITS, which the ITS based on, is one of the most important sub-system. This paper will be focus on this topic.The communication system of ITS can be divided into two parts: Road-Vehicle Communication (RVC) system and Inter-Vehicle Communication (IVC) system.Road-Vehicle Communication system has been researched carefully by ITS researchers. And it is reasonable to adopt communication system based on wireless base-station beside roads.Inter-Vehicle Communication system is more complex, because the topology might change quickly as the vehicle moving. To set up a communication network between moving nodes is the key to this problem. Mobile Ad Hoc Network has been introduced to solve this problem, in which each node can be sever as both terminal and router. So the matter of rapid changing topology has been solved.In order to solve the problem of how to distribute shared wireless medium fairly and effectively, the Dynamic-stayed-time algorithm according to collisions has been put forward to improve the Binary Exponential Backoff algorithm used in IEEE 802.11. And, we use OPNET to simulate the Dynamic-stayed-time algorithm, the experimental result shows that Comparing with the original algorithm, the performance such as the utilization of wireless medium and the throughput has obviously improved.Meanwhile, in this paper the routing algorithms of Mobile Ad Hoc Network have been researched. After fully analyzing and comparison, this paper has pointed out that AODV is more effective in Inter-Vehicle Communication system This conclusion has been supported by simulation result based on OPNET Modeler.