Patent attributes
In a WDM optical communication network composed of a transmitter, an optical switching device (an optical cross-connect, an optical router, etc.) and a receiver, when transmitting switching information to the optical switching device, the transmitter suspends the transmission of a main signal by a wavelength for switching of a WDM optical signal and transmits switching information instead. Upon receipt of this switching information, the optical switching device switches a route, re-starts the transmission of a main signal after the switching is completed and transfers the main signal through the switched route. The signal speed of switching information is sufficiently lower than the modulation speed of the main signals with other wavelengths. By designing the receiving device so that the receiving device of switching information reacts only to this low modulation speed, the receiving device can extract only switching information even when receiving the entire WDM optical signal including the main signals with other wavelengths.
