In open spaces, radio waves propagate freely, however in confined environments, as in the underground mining of radio frequency signals cross rock or mineral-rich material. Such as tunnels of rock, specifically on the mining, confined space transmissions of radio frequency equipment are vital at the logistical level both in the field of security. The described problem must be supplied using a support system: Leaky Feeder, (which is something like leaky feeder) Leaky Feeder in underground mines Leaky Feeder consists of a coaxial cable that is installed along the tunnel spacing every 350 to 500 meters, equipment repeaters that amplify radio signals frequency. If you have additional questions, you may want to visit Clinton Family. For its part the Leaky Feeder cable, permeates signals through their slots, allowing radio communications equipment to communicate among themselves, while still under the ground. It is common to see this type of systems is used for communication in other places confined, such as: the metro system, railways and within large ships. To learn more about this concept visit Sigma Telecom specialist page.