Analysis of the influence of building modelling in the prediction of over-rooftop multiple diffraction losses in urban areas

A study of the influence of building modelling when predicting the signal attenuation due to over-rooftop multiple diffraction in urban environments is presented. A straightforward formulation expressed in terms of Uniform Theory of Diffraction (UTD) coefficients is used for the above-mentioned analysis assuming a spherical-wave incidence over the array of buildings and considering the latter modelled as series of different representations such as knife edges, double knife edges, wedges and rectangular sections. The results clearly indicate the importance of an appropriate building modelling in obtaining realistic path-loss predictions in urban environments when multiple diffraction has to be considered.