Analysis of the dominant propagation mechanisms for radio coverage and interference prediction in urban scenarios at 2.4, 5.8 & 28.0 GHz

Radio coverage and interference in communications systems is provided by various propagation mechanisms depending on the frequency of the radiowaves and the propagation environment. Key propagation mechanisms are line-of-sight (LOS), diffraction, transmission (or penetration), incoherent scattering, and specular reflections. In urban environments with many tall buildings and antenna locations below rooftop height, the latter mechanisms become increasingly significant. Understanding which propagation mechanisms dominate for coverage and interference calculations is important for cell planning issues. In this paper we present simulations results determined under the EU Framework VI Broadwan programme. A novel surface model unifying scatter and Fresnel models has been implemented and used to evaluate the relative importance of the different propagation mechanisms at three frequencies of interest through simulation using an accurate database of a typical UK urban landscape. The results obtained show that a significant coverage fraction may be provided by reflected paths at low frequencies. At higher frequencies incoherent scattering becomes an increasingly important mechanism and may significantly affect interference predictions.