Parabolic equation technique in vegetation and urban environments

The radio channel gives limitations for wireless communication systems regardless of the propagation environment. Therefore, it is important to model the propagation properly. F0I has developed a promising model using a two dimensional parabolic equation (PE) technique. This model is intended for irregular forest-covered terrain and shows good results. By this report we study if this technique is useful also for urban environments, since operations in urbanized environment are gaining importance in the scenarios of the armed forces. Urbanized environment differs very much from forest environment. The lack of line-of-sight propagation forces the radio waves to diffract over rooftops and around comers. This might result in significant multi-path propagation and back scattering, which usually makes the PE technique unsuitable to use in urban areas. Still some attempts have been made to use 2D PE models in such environments and a few papers on this topic are reviewed. Propagation in urban environments usually requires modelling in 3D and approaches using 3D PE technique for built-up areas are described. 31) PE is a promising technique for the future, but still not fully mature for practical use in built-up areas. At present, we do not find it worthwile for FOI to engage in 3D PE development.