An improved propagation model for wireless communications

When a radiowave propagates through vegetated areas, the received power fluctuates substantially due to scattering and absorption. This fluctuation has been shown to be influenced by density, shape, and site of the vegetation. This paper examines the propagation loss in the presence of scattering objects, such as trees, where electromagnetic waves could reach the receiver via direct, reflected, and scattered paths. A propagation model which incorporates the scattering effects caused by vegetation is developed in this study. The developed model is utilized in the study of effects of tree trunks and branches in radiowave propagation. Model predictions show the scattered power increases as the trunk size (diameter) increases, and the presence of trunk scattering may cause signal fluctuation in excess of 10 dB at the receiver