field
Metro communication system consists of two parts: privatecommunication system and public security communication system.
1) Private communication system
The metro private communication system provides reliable transmissionchannels for systems of metro operation.
It mainly includes 10 subsystems which are a transmissionsystem, public telephone system, private telephone system, wirelesscommunication system, video monitoring system, broadcasting system, clock system,power supply system and grounding, centralized alarm system, and an integratedwiring system.
2) Public security communicationsystem
Public securitycommunication system is a network platform for metro public security dispatch,passenger services and information transmission of public security department.It is an integrated service digital network which may transmit voice, digitaland image information with the features of reliable, extensible and flexiblenetworking. It can ensure the travel safety of passengers and the safeoperation of metros, and implement metro’s security task rapidly, accuratelyand high efficiently. The system mainly consists of four subsystems: computernetwork (including IP phone, optical cable), video surveillance, wirelesscommunication for public security and fire protection, power & grounding.
