Comparison of radio path loss models for wireless sensor networks in orchard environments

Abstract

In this paper, radio propagation within a plum orchard was investigated using ZigBee devices operating within the 2.4 GHz band. Measurements were performed to estimate the power attenuation due to the presence of trees and their foliage. An approach was carried out to characterize empirical data by means of established vegetation-attenuation models. The most accurate model for the particular orchard layout was the parametric exponential decay model using parameters best fitted to the measurements, whereas the second-best was the standard Weissberg exponential decay model, which doesn’t require any parameter fitting. Also, several standard foliage exponential decay models can be used as conservative upper bounds of path loss, at least for the particular orchard.