Abstract: A switching apparatus for switching an optical channel overhead in an optical supervisory channel is disclosed. The switching apparatus can suppress a terminated optical channel defect occurred by a defect of upper layers of the optical channel or a defect of the optical channel transmitter and also can maintain the corresponding optical channel at the wavelength converted optical transport network system. Furthermore, an apparatus for forwarding an optical channel maintenance signal is disclosed too. The apparatus includes the switching apparatus and transmits only an add and drop optical channel maintenance signal information to the CPU and generate the LOS suppression signal with respect to the optical channel according to the occurrence of malfunction, thus directly transmitting the suppression signal to the corresponding optical channel unit.

Abstract: An apparatus for synchronizing a clock using a source synchronous clock is disclosed. The apparatus includes: channel receivers for receiving a source synchronous channel; divider for dividing the source synchronous clock to a low frequency clock; selectors for selecting one of the divided source synchronous clock and a system clock as a reference clock; detectors for generating a phase difference signal; phase difference signal selectors for selecting a phase difference signal from the detectors and a phase difference signal from an internal logic; and voltage oscillators for transmitting a clock synchronized to a source synchronous channel to the external optical transmission system by generating a predetermined synchronous frequency according to the selected phase difference signal.

Abstract: An apparatus for synchronizing a clock using a source synchronous clock is disclosed. The apparatus includes: channel receivers for receiving a source synchronous channel; divider for dividing the source synchronous clock to a low frequency clock; selectors for selecting one of the divided source synchronous clock and a system clock as a reference clock; detectors for generating a phase difference signal; phase difference signal selectors for selecting a phase difference signal from the detectors and a phase difference signal from an internal logic; and voltage oscillators for transmitting a clock synchronized to a source synchronous channel to the external optical transmission system by generating a predetermined synchronous frequency according to the selected phase difference signal.

Abstract: A switching apparatus for switching an optical channel overhead in an optical supervisory channel is disclosed. The switching apparatus can suppress a terminated optical channel defect occurred by a defect of upper layers of the optical channel or a defect of the optical channel transmitter and also can maintain the corresponding optical channel at the wavelength converted optical transport network system. Furthermore, an apparatus for forwarding an optical channel maintenance signal is disclosed too. The apparatus includes the switching apparatus and transmits only an add and drop optical channel maintenance signal information to the CPU and generate the LOS suppression signal with respect to the optical channel according to the occurrence of malfunction, thus directly transmitting the suppression signal to the corresponding optical channel unit.

Abstract: Disclosed is a device and method for optical supervisory channel framing in an optical transport network system including at least one of an optical transmission section, an optical multiplex section, and an optical channel section. A maintenance signal is generated according to a first LOS (Loss OF Signal) signal generated from at least one of the optical transmission section, the optical multiplex section, and the optical channel section. The maintenance signal and a frame-related channel such as a message communication channel are multiplexed to generate an optical supervisory channel frame. The optical supervisory channel frame is output to another device including a repeater and a terminal system through a single supervisory channel.