Channel modelling for ad-hoc communication in an underground sensor network

Wireless underground sensor network is an emerging area of research that can enable efficient communication between underground sensors. Underground sensor networks can be used for many applications like monitoring of soil properties in sports fields, in agricultural lands, in land slide prediction etc. Attenuation of radio wave in the soil is the main challenge prevailing in the communication medium. So the characteristics of the radio wave should be properly selected so as to make the attenuation at its minimum. Hence the characteristics of the soil should be thoroughly examined to make necessary changes in the properties of radio wave. In this paper, underground channel characteristics are discussed and are used to derive a path loss model for the underground communication. For deriving the path loss model, the channel characteristics and propagation effects are considered. For the derivation of path loss model, the soil has been considered as a mixture of sand, silt, clay and moisture. Propagation effects like reflection, refraction, absorption and scattering are also considered. Since we have included the attenuation of path loss due to silt content and attenuation due to scattering of radio waves at higher order frequencies, the results will be more close to practical results. The characteristics of the channel are simulated using MAT LAB and graphs are plotted which helps to analyze the properties of the soil very well.