ONE DIRECTION CHANGEOVER APPARATUS OF OPTICAL CHANNEL LAYER TO WAVELENGTH DIVISION MULTIPLEX OPTICAL TRANSMISSION SYSTEM

摘要

PURPOSE: One direction changeover apparatus of optical channel layer to wavelength division multiplex optical transmission system is provided to perform continuously communication service by recovering obstruction of multi-channel WDM(Wave-length Division Multiplex) optical transmission system rapidly. CONSTITUTION: An optical splitter is located at optical channel section and transmits an optical signal to relay station signals dividing the multi-channel which is inputted into two optical signal with same wave-length. An optical switch part is located at optical channel section of reception side and select optical signal of normal state among the two optical signal(A signal, B signal) with same wave-length translated from the relay station. A first photo diode sense obstruction state of the optical signal A. A second photo diode sense obstruction state of the optical signal B. A selection controller output optical switch control signal to select one of the two optical signals according to the obstruction state of the two optical signal. An optical switch(24) output one of the two optical signals according to optical switch control signal which is output by the selection controller(23). A logical OR gate input obstruction state of the optical signal A and reset signal. An input board and S board input obstruction state signal of the signal A. Former optical switch control signal is inputted to input board. A selector outputs to select one of the two input boards according to signal level of the board S. A D-flipflop outputs output-signal of the selector according to clock inputted into the clock board and reset by output signal of the logical OR gate.