A group of South Korean researchers at the Electronics and Telecommunications Research Institute (ETRI) has successfully created a new underground wireless networking technology capable of penetrating as much as 100 meters below the Earth's surface. As published in the IEEE Xplore journal, this new method takes advantage of magnetic induction to provide clear communication with devices underground and avoids signal attenuation and degradation that would occur with traditional radio-frequency methods.
The test equipment consists of a (relatively) small transmitter loop antenna measuring 0.9 by 0.9 square meters and a small magnetic field receiving sensor, all connected to a wireless communication system using quadrature phase-shift keying modulation to transmit data, albeit at an incredibly limited 2 Kb/s. The testing was conducted in a limestone bedrock environment known for blocking radio signals effectively.
