SoilComm: A miniaturized through-soil wireless data transmission system

Abstract

Wireless underground sensor networks (WUSN), are emerging Internet-of-things (IoT) technologies, that can benefit numerous applications including geotechnical data acquisition for online infrastructural health monitoring and automated agricultural systems. State-of-the-art approaches to wireless underground sensor communications have employed, as their data carrier, electromagnetic waves, characterized by: their extreme signal path losses in soil due to absorption and scattering, the challenges they impose on transceiver miniaturization, and the power/energy efficiency constraints they suffer from during battery-based operation. Acoustic waves can resolve many of these challenges, benefiting from lower levels of absorption and scattering losses at target frequencies, and from looser size limitations, resulting in smaller form factor, power-efficient transceivers. In this work, biologically inspired, and afterwards motivated by the physical properties of acoustic propagation in soil, a scheme for wireless data communication through soil employing acoustic waves is presented. Experimental results illustrate the system capability of sending application-specific data, ranging from sensor readings to low-resolution images, over distances exceeding 30 m through soil.