A propagation prediction tool for urban mobile radio systems

This paper presents a propagation prediction tool (PPT), developed mainly to facilitate the path loss computation in urban environments. Based on analytical methods-geometrical optics (GOs), physical optics (POs), and uniform theory of diffraction (UTD)-the tool incorporates an empirical factor, the path loss factor n, used in all unobstructed paths between two points to remedy the deficiencies of the analytical models. Ray tracing techniques were used to model the flow of electromagnetic energy from the transmitter to the receiver. The received field strength is computed by complex vector addition of the fields arriving at the receiver by any of the mechanisms utilized. Path loss results are given for line-of-sight (LOS) and non-line-of-sight (NLOS) cases, indicating the contribution from each mechanism. Finally, comparisons with measured data for DECT systems in urban sites are presented, in order to validate the prediction tool.