The Design Of Public Traffic Information System Based GPS-GPRS

With the development of economic,the condition of city traffic block becomes more and more aggravated, as a new method of resolving the traffic block called ITS,develops quickly in our country. The monitor system for car is the most important part of the ITS, for it can really master the condition of running car promptly and accurately the condition of the road block, and manage the running cars promptly to avoid the traffic block, and make the cars and roads in well working condition.so the research of ITS can make tremendous and benefic of society and economic.This paper analyses the designing and working principle of existing monitor system for car firstly. from these monitor system for car we can find that most the wireless transmission system of these monitor system for car use the GSM communication system,the business data communication rely on the GSM whose delay of transmission can be less than six seconds actually,so it can not satisfy the requirement of the system promptly. after the technical of GSM ,another new technical of GPRS appears, the GPRS was the technical of group exchange, the higher speed of transmission can be up to 171.2Kbps , with the lower expenditure.the GSM was the technical of circuit exchange , the shortage of GSM is that the transmission speed is lower, the utilization rate of resource is lower and the expenditure is higher , contrast to the shortage of GSM , the advantage of GPRS is obvious , so the usage the GPRS in the wireless transmission instead of GSM will be the development direction of monitor system for car. After the research of the theory of GPS satellite fixed position and the data of satellite, this paper puts forward of index smoothness and carrier wave smoothness, this method can raise processing precision higherly. on the basis of GPS fixed position system , ARM embedded system and the technical of GPRS wireless communication ,we can establish a new set of public traffic information system.this system was the winsocket technology to communicate, resolve the problem of communication net join , and use the subnet distribution to resolve the problem of distribution of monitor terminal.