Tyco Telecommunications (us) Inc.

Tyco Submarine Systems Ltd.

Robert L Lynch

Georg Heinrich Mohs

Ekaterina A Golovchenko

Franklin Webb Kerfoot, Iii

Howard D Kidorf

Stuart M Abbott

Michael Vaa

Bamdad Bakhshi

Cleo D Anderson

Robert F Gleason

Richard L Maybach

Francis C Bekampis

David Gunderson

Joel Schesser

An apparatus and method directed to testing and optimizing performance of an optical transmission system is disclosed, including at least one broadband dispersion compensation unit (DCU) or at least one depolarization device. The depolarization device may be used alone or in combination with the at least one broadband DCU. A method for optimizing performance of data channels in initial loading (IL) and full loading (FL) configurations of the optical transmission system is also disclosed.

Apparatus and method for commissioning an optical transmission system

A method of repairing a slope-matched cable system that leaves the net chromatic dispersion of the system nominally unchanged comprises removing a portion of the slope-matched cable system that is faulted, either the cable or a repeater, and constructing a replacement cable portion from two N-P cable lengths having negative dispersion fibers and positive dispersion fibers and a P cable length having positive dispersion fibers. The N-P cable lengths are coupled on each side of the P cable length and the replacement cable portion is connected to the slope-matched cable where the faulted cable was removed. The method also accounts for the extra cable that necessarily has to be added during the repair and for the replacement of a faulted repeater. A cable repair can be made in a regular cable section or in a compensation cable section, in which case the replacement cable portion can also include a repair repeater with LBOs to leave the gain shape of the transmission spectrum nominally unchanged and allows for replacement of a gain equalizer if one was removed during the repair. Similarly, when a faulted repeater is removed the replacement portion can include a replacement repeater, as well as a repair repeater, to leave the gain shape of the transmission spectrum nominally unchanged.

Method of repairing a slope-matched cable system and replacement cable portion for use therein

A powering arrangement for an undersea cable system provides that each branch of the system is supplied with a current equal to half of the current in the trunk. By coupling both branches to the trunk, the current adds at the branching unit. Upon occurrence of a power path fault in any branch, a virtual ground moves to the site of the fault. In addition, an image virtual ground moves to a similar point in the branch that does not have the cable fault. As a result of this implementation, the cable power system is able to tolerate at least one fault in a branch without necessitating repair, and can tolerate some multiple branch faults depending upon their location. In contrast to the operation of existing power-switched branching units, the fault-tolerant branching unit does not require down-powering and re-powering in order in order to change the power configuration, e.g., to allow a virtual ground to be re-located at shunt fault sites that occur in either trunk or branches. Moreover, even with a branch shunt fault or cable break, the fault-tolerant branching unit allows for power to be removed from the faulted branch for repair without having to first power down the other two legs. And finally, at the completion of a branch repair, power to the repaired branch can be restored without first powering down the other two legs.

Method and apparatus for operating cabled-fiber undersea network, and fault-tolerant branching unit for use therein

An OTDR provides both in-service and out-of-service measurement information for an optical transmission system with multiple repeaters. The repeaters include an optical high-loss loop back (HLLB) path and an OTDR path. The OTDR is coupled to the input lines of the optical transmission system via an optical coupler so that both traffic signals and test signals from the OTDR can be transmitted simultaneously. When the OTDR is providing in-service measurement information, test signals in the form of side-tone pulses are transmitted on the transmission system. The wavelengths of the test signals are sufficiently offset from the wavelength of the traffic signal so there is minimal interference between them. The level of the test signals is low relative to the traffic signal to also minimize interference. The OTDR filters out the traffic signal from the returned signal. The HLLB path through the amplifier pairs of each repeater is distinguishable in the filtered returned signal. When the OTDR is providing out-of-service measurement information, the level of the side-tone pulses is increased because interference with traffic signal is no longer a concern. Both the HLLB path and the OTDR path are distinguishable in the filtered returned signal when the higher level out-of-service test pulses are transmitted.

Side-tone OTDR for in-service optical cable monitoring

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Colts Neck, NJ, United States of America

Robert L Lynch