An optical-path supervisory scheme for optical cross-connects using pilot-tones

All-optical WDMA transport networks depend critically on the functioning of the optical cross-connects (OXCs) that are responsible for routing wavelength channels to their respective destinations. Failure of the optical switches in OXCs will route the channels to the wrong destinations, degrading the network performance. Fault detection in channel add-drop and routing is thus of vital significance. We propose an optical-path supervisory scheme for OXCs by imposing pilot tones onto input wavelength channels as channel identifications (IDs).