Propagation model for microcellular communications applied to path loss measurements in Ottawa city streets

A new three-dimensional uniform theory of diffraction (UTD) microcellular communications propagation model is presented, using multiple-image theory and a ray launching technique, applicable to a general city scene with various distributions of buildings, streets and open areas. The model includes contributions to the received signal from all possible propagation paths, including ground and wall reflections from diffracted and specularly reflected signals both in the line-of-sight (LOS) and out-of-sight (OOS) regions. Within the scope of the UTD model, the accuracy of the UTD model is limited mainly by the assumptions of characterizing the tall building walls as “smoothed-out” flat surfaces with average relative permittivity ε_r and conductivity σ. The building corners are modeled as conducting wedges characterized by ε_r and σ. Comparison between present calculations and published measurements for a side street and a parallel street in Ottawa shows good results