Design of Urban Public Transportation Positioning System Based on Overlay Network

In this paper, A Urban public transportation positioning system is designed based on overlay network. and its Network topology structure and system framework are also shown, based on the postioning system, it decribles the hardware model of GPRS accessing internet and control programe. and then gives the Transceiver circuit of RF model and control programe. According to the characteristics of buses which is large number points and fluidness, it proposes the combination method of polling scheduling and delay retreating, it improves the reliability of the RF networking.