Design And Implementation Of GPS Vehicle Terminal Access Gateway

With a large-scale civilian use of the vehicle, the demand for the vehicle’s positioninginformation service is becoming bigger and bigger, at the same time, in order to enrich thesystem function, more and more data and application are added to the vehicle control system. Asystem platform which can manage the communication of a variety of data arises. But thetraditional vehicle positioning equipment can’t access to the new platform due to thecompatibility problem, which greatly influences the application of the vehicle equipment. Inorder to solve the problem, the thesis designs a kind of GPS vehicle terminal access gateway,which has improved the ability of the access and extended the application of the device.First this paper reviews the research statue of intelligent transportation system at home andabroad and then analyses the features of vechile positioning, introduces the TCP protocol and thesession initialization protocol SIP, studys the features of the operating system Linux and relatedtechnologies, lays a theoretical foundation for the design of the access gateway.Secondly, this paper designs the overall structure of the access gateway. First the paperintroduces the GPS on-board equipment and the server, and analyses the SIP communicationprotocol of the server. Depending on the problem in the system, the thesis proceeds the demandanalysis and completes the function design of the access gateway. At last, the paper uses thehierarchical modular manners to realize the function of the whole gateway, and analyses thenetwork system structure and analyses the specific function of each level of the gateway.At last, according to the requirement of the concurrency of the gateway, the paper comparesthe concurrent processing mechanism under the Linux server environment by experiments tochoose the proper mechanism to achieve the goal basing on the experimental data and thefunction demand. After realizing the concurrency of multiple devices’ connection, the paperdesigns and realizes the TCP communication between device and gateway and the SIP communication between gateway and server to finally establish the communication betweendevice and server. Meanwhile, the thesis realizes the mutual conversion of the device data andthe server data to complete the data transporting. After the test, the server can receive the datafrom the vechile device, displaying the position on the web, realizing the access of the vechileequipment to the system platform.