Study On Data Transmission Method Of GPS Based Probe Vehicle System

Probe vehicle technology is one of the typical applications in Intelligent Transportation System. For a perfect traffic data collection of GPS based probe vehicle system, reliable data transmission technology is very important, and it can improve ITS' performance. It is also a key problem on how to choose the data transmission method of GPS based probe vehicle system by using major factors: the network performance indexes that affect traffic data transmission, the data sampling frequency and the transmission cost.Some problems on data transmission method of GPS based probe vehicle system are discussed in this thesis. The key technologies include GPS, GIS-T and probe vehicle technology. The Drive Test technology is used to study on the data transmission technology of GPS based probe vehicle system, and some mobile communication network performance indexes (including transmission delay, error rate and network coverage) are tested by Pilot Pioneer.Other factors that affect the choice of data transmission method are data sampling frequency and transmission cost. The accuracy of traffic parameter estimation is influenced by the data sampling frequency, and the transmission cost is connected with the data sampling frequency and the probe penetration. So we put emphases on the data sampling frequency, the transmission cost and the probe penetration. The micro traffic simulation software—FlowSim is used to simulate the probe penetration. During the study on the data sampling frequency, transmission cost is analyzed and calculated in detail, and the effect on traffic parameter estimation by data sampling frequency are simulated and analyzed from the relevant data in the test of Huanchengbeilu in Hangzhou.Under the preceding analyses, we use the analytic hierarchy process to analysis the factors of choosing data transmission method. In this way, not only the accuracy of traffic parameter estimation, but also the economic benefit are guaranteed. It applies an auxiliary decision on the choice of data transmission method in GPS based probe vehicle system.