Wave propagation communication models for Wireless Underground Sensor Networks

Wireless Underground Sensor Networks (WUSNs) can be used to monitor a variety of conditions in both underground and above ground environments. Sensor nodes in WUSNs are usually buried underground and this posses the biggest challenge in as far as implementing WUSNs is concerned. Sensors in WUSNs are expected to communicate through dense substances such as soil or rock. This paper first discusses wave propagation attenuation modeling for wireless communication in underground channels and then proposes an enhanced model based on the CRIM-Fresnel, the modified Friis model and other models. The proposed model considers most of the characteristics comprising the underground wireless channel that would affect the communication efficiency in this environment. In particular, the underground communication channel is modeled by considering not only the propagation attenuation due to dielectric properties of the soil, but also other factors such as reflection, phase shifting, refraction, and the distance between sensor nodes. The proposed model shows through simulations that with lower frequencies and shorter distances underground communication with EM waves is possible with minimal attenuation.