Through The Earth Mine Communications
Through-the-Earth (TTE) signalling is a type of radio signalling used in underground mines that uses low frequency waves to penetrate dirt and rock, which are opaque to higher-frequency conventional radio signals.
In mining these higher frequency signals can be relayed underground through various antennae, repeater or mesh configurations, but communication is restricted to line of sight to these antenna and repeaters systems.
Read more about Through The Earth Mine Communications: Overview, Personal Emergency Device, Development, See Also
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