A Radio Propagation Model for Wireless Underground Sensor Networks

Abstract

An accurate and simple radio propagation model for underground low-power devices such as wireless sensor nodes is introduced and its performance is evaluated by real wireless sensor nodes. The proposed model describes underground radio signal propagation that is proportional to e- <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2ap</sup> /ρ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> where p represents the distance and α represents the attenuation con- stant reflecting the soil properties. To evaluate the proposed underground radio propagation model, experiments measuring the radio signal strength with underground sensor nodes were conducted in various sub-surface conditions. Comparing the theoretical estimations of the underground radio propagation and the measured data, the theoretical model fits the measured data well within a 3.45dBm deviation or with an accuracy of 96.33% on average.