A global ray-tube tracing method to determine signal variations in urban areas for mobile communications

The ray tracing method has been applied successfully to predict wave propagation for wireless communications but it is not computationally efficient. This paper presents a new method, called the global ray-tube tracing method, to trace the global wave tubes instead of many individual rays for simulating GSM signal propagation in urban areas. Therefore, simulation efficiency can be improved significantly so that site-specific signal distributions in cities may be determined more easily and practically. Field measurements on streets in Taipei city were performed, and the results are compared with those obtained from the global ray-tube tracing program. To find the scattering objects, building exterior geometries were extracted from 1:1000 digital city maps. Good agreement between simulations and measurements are obtained.