Ciena Corporation

Steffen D Koehler

Victor Mizrahi

Loudon Thomas Blair

Kevin S Meagher

Steven W Cornelius

A WDM ring transmission system is provided having two hubs. Identical groups of optical signals for transmission along the ring are input to both hubs, but one of the hubs includes optical switches for selectively passing one of the groups of optical signals to the WDM ring. Accordingly, if a fault occurs in one of the network-hub connections or one of the hubs becomes defective, the switches couple optical signals from the operational hub to the WDM ring. In addition, optical signals emitted by nodes coupled to the WDM ring are output from both hubs, thereby insuring that signals can be output from, and input to, the ring even if one of the hubs fails.

WDM ring transmission system having two hubs

A method for monitoring a plurality of components associated with a communications network node. A diagnostic service signal is generated at an intra-node component and transmitted along a first optical path to another intra-node component where the presence or absence of the signal is detected. In this manner, optical paths defined between intra-nodal components can be monitored using a diagnostic service signal.

Intra-node diagnostic signal

A WDM ring configuration having reduced adjacent channel cross-talk is disclosed. In the WDM ring, an add/drop element having a filter for selecting an optical signal at a desired wavelength is spaced from another add/drop element having a filter adding an optical signal at an adjacent wavelength within a channel plan by at least one add/drop element that adds/drops an optical signal at a wavelength which is not next to either the optical signal at the desired wavelength or the adjacent wavelength.

Growing community of inventors

Annapolis, MD, United States of America

Steffen D Koehler