Optical redundant switching method of optical wavelength multiplex system

摘要

An optical redundant switching method in an optical wavelength multiplex system has the steps of carrying out validity check of standby systems in a normal operation mode of operating systems with emitting optical outputs of the standby systems continuously; and reducing a gain of an optical amplifying repeater (29a-29n) while at least one of the operating systems is faulty, and the operating channel (1a-4a) associated with the faulty operating system is connected to one of the standby optical terminal units (25a). This makes it possible to prevent an adverse effect on transmission characteristics due to changes in the number of wavelengths involved in redundant switching by a conventional optical redundant switching method in an optical wavelength multiplex transmission system.