Communication System
The Metro communication system consists of ten sub-systems integrated over the transmission system. The ten sub-systems include: Automated Telephone System, Direct Line System, e-Mail System, Closed Circuit Television (CCTV), Radio System, Public Addressing System (PA), Train Communications System, Time Synchronization System, Fiber-Optic Transmission System, and Communications Multi function Terminal.
System Components
- Automated Telephone System：The telephone system is made up of automated exchanges and phones. These are used for internal operations within the Metro network, communication between maintenance personnel, and external communications.
- Direct Line System：The direct line system is separate from the automated telephone system. It is used by for emergency station, track and train communications, and for direct communication by operations personnel.
- e-Mail System：Used in conjunction with office automation to support general administration, meeting management and e-mails within the Metro network.
- Digital Radio System：TETRA digital radio system is used for radio communications by operations, maintenance, train drivers and train communications within the Metro network.
- Public Addressing System (PA)：Schedule broadcasts for stations or trains for live or pre recorded broadcasts asrequired for that day’s schedul
- Train Communications System：Passenger services provided by the Train Communications System include emergency intercom, PA system, as well as train destination and arrival displays.
- Time Synchronization System：Primary clock provides a standard time signal for synchronizing electrical-mechanical systems within the Metro network. Secondary clocks are installed at stations for passenger use.
- Fiber-Optic Transmission System：The fiber-optic transmission system serves as the communications backbone for all core electrical mechanical systems. Advanced communications technologies including SDH, PTN and GE networks are used to connect the operations center, stations, and depot substations for transmitting voice, video, data, alerts and control signals.
- Communications Multi-function Terminal：The Communications Multi-function Terminal (CMFT) is an integrated human-machine interface workstation whose details are described in CMFT.
