Design Of Vehicle Ad-hoc Network Application Layer Program And Implementation Of Safety Applications Based On WAVE Protocol

In recent years,with the increase of car ownership,traffic congestion and traffic accidents occur frequently.At the same time,with the rapid development of mobile Internet technology and electronic information technology,people want to use the advanced communication technology,computer technology and sensor technology to improve transportation efficiency,reduce traffic accidents and improve the driving experience.In order to solve this problem,the ITS(Intelligent Transportation System)and VANET(Vehicular Ad-hoc Networking)has attracted wide attention,has become a new research hotspot.The wireless communication technology used in VANET should be able to adapt to the complex road environment and the rapid mobility of vehicles.However,the traditional communication technology can not meet the requirements of wireless communication in the vehicle environment,such as access speed,transmission delay and communication distance.In order to provide safe,timely and reliable wireless communication in the vehicle environment,IEEE completed the WAVE(Wireless Access in Vehicular Environment)protocol stack in 2013.WAVE protocol stack is specially used for vehicle communication,which is composed of IEEE 802.11 p protocol,IEEE 1609 protocols and SAE J2735 standard.At present,although there are some companies has launched modules based on PHY layer,link layer and network layer of WAVE protocol,but there is no system-level products on the market.However,the design of a mature application layer based on the WAVE protocol stack is an important part of the secure and efficient vehicle communication.We have completed the application programming based on the WAVE protocol stack and implemented the "intersection collision warning" and "emergency brake warning" safety-applications.The main work is as follows:1.Analysis of the composition of the WAVE protocol stack,described the process of establishing the communication connection of WAVE devices and the transmission process of various types of messages in detail.2.Through the analysis and understanding of the WAVE protocol stack,we put forward a set of practical system design scheme which includes the overall topology of the system,the deployment of the RSU(Road Side Unit),the channel allocation scheme and the "cell" channel switching.3.On the basis of understanding how the WAVE protocol stack establishes communication connection and transmission message,we have designed the application layer program of WAVE device which includes time synchronization module,sub application,task manager and so on.4 We designed two kinds of safety applications based on the SAE J2735 standard,and programmed the PC simulation program.5.Conducted simulation test and road test for the the application layer program and safety applications.The results show that the safety applications run sccessfully in the simulation environment,and application layer program requirements of VANET in transmission performance and time-delay.