True Wireless Communications In Underground Environments and Other Non-Line-of Sight Applications

In previous modeling of the effect of soil properties on radio-frequency (RF) electromagnetic communications, SARA, Inc. has shown a drop-off of electric-field strength versus distance through the ground at a nearly billion-fold reduction. Even average ground properties shield the electromagnetic source so thoroughly that there is little hope of using a wireless RF communications network sensitive enough to be able to communicate from and into buried structures, as the attenuation of electromagnetic fields underground is simply too great to consider their utility for wireless communications. What is required is a wireless method of communication that can effectively and consistently communicate to and from underground structures through hundreds of feet of earth, rock and even concrete. SARA, Inc. proposes here that magnetic-based communications appears practical for wireless communications in the challenging environments under consideration. SARA, Inc. has developed a way to effectively and consistently sense signals to and from underground structures using a magnetic source of reasonable power to penetrate a barrier with the ability to recognize the broadcast magnetic signal in the presence of background electromagnetic noise. As far as the magnetic transmitter is concerned, the existence of the soil is almost completely transparent to its ability to communicate to above ground sites. Furthermore, the attenuation of the magnetic source. These previous and ongoing efforts have validated the abilities of magnetic fields as new communication devices through the ground to desired ranges where standard RF communications fail.