Research Of Real-time Trafic Flow Data Transmission System Based On GPRS

Intelligent transportation system (ITS) is a transportation service system based on the modern electronic information technology which has been played a significant role in improving road traffic and traffic safety. Real-time traffic information system is an important field of ITS, which have combined GPS technology and communication technology so that it could obtain real-time traffic flow data and release traffic information effectively. But the traffic information release is based on the Internet, users download maps and update traffic information regularly which makes the update time is too long and the real-time performance is so poor, In this paper, a system is researched which could obtain real-time and accurate traffic information. Works and results of the research were as follows:1. Based on the GPRS technology, embedded technology and GPS technology, a real-time traffic flow data providing system was proposed, which is constructed by data processing center, vehicle terminal and wireless communication network. The GPS module in the vehicle terminal has been used to collect traffic flow data, and ARM processor to extract and parse the effective positioning data(including latitude, longitude, speed and so on).The positioning data would be send to the data processing center through wireless communication network. In data processing center, the traffic flow data (including the average speed and the average traffic flow, etc.) would be worked out according to the positioning information on each vehicle and the relevant mathematical model. Finally, the traffic flow data would be send to the vehicle terminal for displaying through the wireless communication network.2. It is low cost and easy deployment by using GPRS communication network to transmit traffic flow data. The traffic parameters and the code of road traffic information are transmited through the GPRS communication network, rather than images and other information of large amount of data, which is the small amount of data and burst transmission, namely strong real-time.3. The Columbus V800+GPS receiver was used in this paper, which has high gain active antenna, channel sixty-six, and advanced Enhanced Positioning System (EPS) technology, so that positioning accuracy up to two meters. The Transmission Control Protocol (TCP) is data transmission protocol of the reliable, the confirmation mechanism and flow control mechanism to guarantee the correctness of data transmission, which can provide accurate traffic information.