Optical add/drop multiplexer has controlled group switch unit for connecting group multiplex signal of channel multiplexer unit to one or other optical group wavelength multiplexer/demultiplexer unit

摘要

The device has two optical group wavelength multiplexer/demultiplexer units with some optical group multiplex signal ports of each unit fed to the other unit and at least one channel multiplexer unit that multiplexes useful signals from optical transceiver units into an optical group multiplex signal. The group multiplex signal of the channel multiplexer unit can be connected to either unit by a group switch unit controlled by a control unit. The device (9) has first and second optical group wavelength multiplexer/demultiplexer units (3) with some optical group multiplex signal ports (3a,3b) of each unit fed to the other unit and at least one channel multiplexer unit that multiplexes the useful signals from optical transceiver units into an optical group multiplex signal. The group multiplex signal of the channel multiplexer unit can be connected to one or other unit by a group switch unit (13) controlled by a control unit. AN Independent claim is also included for the following: (a) a self-healing ring structure for optical messaging .