Radiowave Propagation Prediction in Vegetated Residential Environments

Abstract

This paper proposes a propagation prediction model in vegetated residential areas. The goal is to model the attenuation caused by the tree canopies in vegetated residential areas in a simplified manner. The model is based on the Torrico-Bertoni-Lang model. It describes a vegetated residential area where rows of houses and trees are lying between an elevated transmitting antenna and the receiving antenna that is located at street level. In this scenario, the receiving antenna does not have a direct line of sight (LoS) from the transmitting antenna. Since the transmitting antenna has comparable height to the houses, propagation takes place over the top of the houses. From this viewpoint, the propagation loss is computed by using multiscreen diffraction, where the houses are modeled as absorbing screens, and the trees are modeled as phase screens. Using this approach, the total propagation loss is broken into three components, namely, free-space loss, multiscreen diffraction loss, and rooftop-to-street diffraction loss. In this paper, two main contributions are provided. The first is that a simplified analytical model is proposed to compute the multiscreen diffraction loss in a vegetated residential environment. The second contribution is to include in a simplified manner the effects of vegetation on the rooftop-to-street diffraction loss via the scattering theory of Foldy-Lax. To verify the proposed model, cross-season measurement campaigns at 800 and 3500 MHz were conducted in vegetated residential areas in the north of Germany. The model serves as an important extension of the Walfisch-Bertoni urban model and the COST-231 Walfisch-Ikegami model for applications in vegetated residential areas. The model is valid at the UHF frequency band between 0.5 and 3.5 GHz.