TUNNEL VOICE

Wireless extension systems for tunnels, namely, distributed antenna systems comprising base interface units to connect to base radios, in-tunnel network signal boosters, in-tunnel cabling and tunnel network antenna; distributed antenna systems, namely, interface units to connect to base radios, network boosters, repeaters, and signal antennas specifically for railroad and mass transit, that extends two way wireless voice signals in zones that are normally shielded from coverage by conventional wireless systems; amplifiers, namely, amplifiers for radio communications; amplifiers, namely, sound projectors and amplifiers for locomotive radio dispatch; amplifiers, namely, sound projectors and amplifiers for two way voice communication radios