Reliable communication underground is harder than it looks. Rock, changing tunnel geometry, equipment, distance, and branching entries can all interfere with ordinary radio coverage. A radio that works clearly near the portal may become unreliable once a crew moves deeper underground or around several turns. A tunnel radio leaky feeder system addresses that problem by extending radio coverage along the path workers actually travel. Instead of depending on a single antenna to send a signal through rock, the system uses radiating coaxial cable as a distributed antenna throughout the mine or tunnel.
Tunnel Radio Leaky Feeder Systems for Mine Safety