Research On Vehicle Navigation System Based On Wireless Mesh Networks

Wireless Mesh Networks (WMN) are the next generation wireless Internet and important component of the fourth-generation mobile communication system, which have good development and application prospects. Since WMN has many characteristics, such as the accurate positioning ability, the support of a high vehicle speed and a high data transmission rate, and etc., WMN has already had some successfull applications on Intelligent Transportation Systems. A new vehicle navigation system based on Wireless Mesh Networks is presented in this paper. Following is the main works:Firstly, the basic framework and work process of the vehicle navigation system based on Wireless Mesh Networks are given, and its merits and feasibility are also discussed.Secondly according to the characteristics of Wireless Mesh Networks and road nets, the vehicles positioning methods of integrated radio/DR/MM based on Wireless Mesh Networks and of single-fixed reference point are presented in the following. A method is also given to detect traffic parameters using WMN vehicle positioning methods.Thirdly based on center- decision path planning, rapid path planning methods are designed. In order to improve the speed of the Floyd all-sources shortest path algorithm, two optimization of Floyd algorithm are studied, one is the improved Floyd algorithm based on the strategy of grouping and numbering and the other is the improved Floyd algorithm based on the strategy of disconnexion. When the vehicles need to do paths re-planning, a method of Dijkstra single-source shortest path algorithm is also provided.Finally a modulation method of symbol spacing modulation is presented based on direct sequence spread spectrum technology. The method on how to use its modulation method to improve the performance, such as data transmission rate, power consumption and intersymbol interference of Wireless Mesh Networks is analyzed.