Through-The-Earth (TTE) Communications for Underground Mines

The communication needs for rescue op-erations of trapped miners has recently motivated thecreation of through-the-earth communication systems,which are also envisaged for enabling autonomous mi-ning operations. Because of the large attenuation of ra-dio frequency waves in this propagation medium, thesesystems usually employ transmission through magneticinduction using very low frequencies. In this paperwe present an overview of the possible applicationsbut also of the technical hurdles faced in this type ofcommunications system. We present a model of a TTEtransmission system and discuss some modulation anddigital transmission approaches for this medium.