A Fast Computational Method of Calculating Radio Propagation Path using 3 Dimensional Map for Ray Tracing Technique

Ray trace based radio propagation prediction in urban environments has been recognized as a remarkable method today. It provides a more accurate prediction than other methods such as empirical statistic models. But this method requires 3D city model database and it takes much time to execute simulation, so it is not easy to apply this method for large cities. This paper presents GIS (Geographical Information System) based radio propagation simulator using ray trace method. This system generates a 3D city model automatically from 2D digital maps stored in GIS. The generated city model is managed using hierarchical bounding volume to effective collision test between rays and buildings. Simulation results such as propagation paths and power levels of receivers are shown over the 3D city model. It helps users to analyze the simulation results and also to predict power delay profile. Based on the experimental results using an actual digital map, the effectiveness of this system is totally discussed from the viewpoint of practical usage.