Urban Wave Propagation Models

An error analysis of the COST 231 Walfish-Ikegami model [1] proposed for urban area and the demonstration of a 3 dimensional deterministic wave propagation model are made in this paper. First the sensitivity of the COST 231 model to the uncertainty of the building parameters is analyzed and a modification in the application of the model that reduces the error caused by the irregular building structure is performed. The effect of the building database accuracy is also shown. The need for a more precise propagation model appears, and the first results from a 3D deterministic model based on the Uniform Theory of Diffraction are presented. The validity of the approximation in the calculation of the diffraction coefficients and the effect of the slope diffraction are investigated, and results of measurements of material parameter measurements necessary for the model are presented. The calculations are assessed by measurements at 900 MHz on a suitable part of Budapest.