CONCEPTS AND RESULTS FOR 3D DIGITAL TERRAIN-BASED WAVE-PROPAGATION MODELS - AN OVERVIEW

Mobile communication links are severely influenced by propagation effects. Wave propagation in the VHF/UHF frequency range over natural and man-made terrain is strongly dependent on topography and morphography. Propagation modeling is based on a ray-optical approach. Wave interactions, like diffraction and scattering, over the propagation path are described by the uniform theory of diffraction and physical optics. State-of-the-art propagation models for rural and urban areas are presented for 2D and 3D ray tracing. Near-range models apply for the corresponding areas in forest and urban sites. The fieldstrength delay spectrum describes ray contributions with deterministic amplitudes but statistical phases are used to derive time- and frequency-domain channel characteristics. Comparisons between measured and predicted data are presented.