Fujitsu Corporation

Sprint Communications Comapny L.p.

Hok Yong Pua

Kumar Vijay Peddanarappagari

Ron Hui

Ken Demarest

Chris Allen

Paparao Palacharla

Emir Catovic

Hal V Kauffeldt

Xiaojun Fang

Harbhajan Vridee

A method for optical supervisory signaling includes determining a wavelength channel status (WCS) value, a wavelength channel failure (WCF) value, and a wavelength channel lit (WCL) value for each one of multiple data channels services by an optical communication node. The method further includes communicating the values to a second optical communication node.

Optical signaling to share active channel information

An optical add/drop multiplexing unit () includes a demultiplexer () which optically isolates component signals of an optical input signal from an optical input terminal (). A plurality of switching units () can optically couple either of two outputs to either of two inputs. One input of each switching unit receives a respective component signal from the demultiplexer, and the other is coupled to a respective protection input terminal () of the multiplexing unit. One of the output terminals of each switching unit is coupled to a respective protection output terminal (), and the other is coupled to a respective input of a multiplexer (). The multiplexer has an output coupled to an optical output terminal () of the multiplexing unit, and optically combines the signals at its inputs into an optical signal for its output. The multiplexing unit is operable to cause one of the component signals from the input signal to be routed to the further terminal, or to cause a component signal present at the further terminal to be included in the optical signal at the optical output terminal.

Method and apparatus for optical channel switching in an optical add/drop multiplexer

A polarization scrambler and a polarization mode dispersion (PMD) compensation system compensate for PMD on an active optic fiber. The polarization scrambler scrambles a state of polarization of an optical signal that carries user information. The PMD compensation system then receives the optical signal over the active optic fiber. The PMD compensation system measuring a differential group delay and principal states of polarization of the PMD in the active optic fiber. The PMD compensation system then determines a modification of the optical signal based on the differential group delay and the principal states of polarization of the PMD. The PMD compensation system modifies the optical signal in the active optic fiber to compensate for PMD based on the determination of the modification. The PMD compensation system then transmits the optical signal. By measuring the differential group delay and the principal states of polarization, the PMD compensation system adapts to changes in the PMD in the active optic fiber.

Method and apparatus to compensate for polarization mode dispersion

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Plano, TX, United States of America

Hok Yong Pua