in the transit environment typically include systems such as but not limited to radio, CCTV, intercom, public address, security, and copper and fiber optic data transmission systems. The systems may be standalone or integrated with one or more other systems, depending on the operational needs of each transit system.
Surface radio systems
are used to communicate above ground with maintenance vehicles and other nonrevenue vehicles. The surface vehicle radio system is used to communicate between the vehicle operators and the control center. Many transit systems use these systems for both voice and data for use with the fleet management. Subway radio systems are used to communicate to vehicles and personnel below ground and are usually VHF or UHF conventional radio systems that utilize radiating antenna cable in stations and tunnels. Outdoor areas use traditional antennas. Cab-mounted mobile radios are installed in the vehicles and operating and maintenance staff will carry portable radios. Maintenance and emergency agencies may have some point-to-point channels.
The telephone service
includes emergency, maintenance and a
dministrative telephones, and passenger assistance intercom at passenger stations, waysides and yards. Typically all telephone lines in a control center are recorded on a voice recorder.