Method and Apparatus for Detecting a Disconnected Optic Fiber Line and a Location of Disconnection in Ring Optical Network System

Disconnection and disconnection position detecting method for a ring network structure of the optical communication network system, discloses an optical communication network system using them. According to this embodiment, a method of detecting a disconnection position in affairs within the device (Central Office Terminal) and an optical ring network (ring network) WDM (Wavelength Division Multiplexing) is connected to the structure a plurality of remote devices (Remote Terminal) optical network system a process of generating the disconnection monitoring signal having a desired monitoring disconnection frame for the National History in the apparatus; The process of converting the disconnection supervisory signal into an optical signal through an optical element of the apparatus the digital characters affairs; The process of the above affairs within the device transmits the disconnection supervisory signal converted into an optical signal in both directions through the optical line in the optical ring network; And to analyze the frame of the optical signal which the affairs within the device that is received in both directions through the optical line of the optical ring network provides the disconnection position detecting method comprising the step of calculating the disconnection position.