Abstract
Recently, the public transportation system of a city in Taiwan has been well developed, the bus lines are well distributed over important buildings by the comprehensive city planning. Bus network is an extension of VANET with the backbone which is based on public transportation systems. By installing wireless devices on buses and bus stops, we can serve most of vehicles and people in city by WIFI-enable buses and stops. Bus network has strong characteristics of delay-tolerant network due to the slow driving speed of buses and the low density of buses in city. In previous approaches, there are three types of ways to route data in bus network: bus-bus, bus-stop and bus-assisted. In previous studies, the performance of bus-stop is better than bus-bus, hence we choose bus-stop to route data in bus network. Our goal is to route data to the moving vehicles in the shortest time by bus-stop routing method, and the feasibility of bus network will be discussed. We generate the trajectories of buses with exponential distribution, and exploit those trajectories to simulate the actual arrival time of buses with unexpected traffic conditions. The results have shown that the performance of bus network is strongly affected by the intervals between buses, but we can reach acceptable results under an appropriate bus interval by increasing candidate path size. In the conclusion, bus network is an appropriate way to assist VANET.