Adva Optical Networking Se

Adtran Networks Se

Sorin Tibuleac

Steven Searcy

Mohammad Alfiad

Thomas Richter

Christophe Meyer

J David Portier

Sergey Burtsev

Mark Filer

Cornelius Fuerst

Paul Morkel

Cornelius Fürst

Fuerst Cornelius

Ted Rabenko

Roy Bowcutt

Jie Pan

David Portier

A method for providing a maximum channel capacity per optical channel in an optical wavelength division multiplexing, WDM, transmission system is described. The WDM transmission system includes transceivers using multiple optical channels in a WDM channel grid to transport optical signals modulated with a modulation format with a signal symbol rate, SR, via an optical transmission link, OTL, along an optical path from a transmitting transceiver to a receiving transceiver. A channel capacity of the optical channel is maximized while a calculated channel margin, CM, is maintained above a preset minimal channel margin value.

Method and system for providing a maximum channel capacity in a wavelength division multiplexing transmission system

The present invention relates to a method for optimizing performance of a multi-span optical fiber network. Each span has an associated optical transmission fiber connected to an associated optical amplifier. Gain and output power of the associated optical amplifier are respectively controlled independently. An amplifier noise figure respectively depends on the gain of the associated optical amplifier, with each associated optical amplifier further connected to launch optical signals into a remainder of a corresponding optical transmission line. The method includes the steps of for each span, computing the amplifier noise figure and a non-linear noise generated in the span based on information about the span and using the computed amplifier noise figure and the computed non-linear noise to compute an optimum launch power, and optimizing performance of the multi-span optical fiber network based on the computed optimum launch powers of all spans.

Method and network control device for optimizing performance of a multi-span optical fiber network

An apparatus for automatic amplifier gain setting of an optical amplifier, said apparatus comprising an optical channel counter, OCC, unit configured to detect a number of channels present in an optical transmission spectrum; a determination unit configured to determine an average power per channel calculated by dividing a measured total power of a signal input and/or signal output of the optical amplifier by the number of channels detected by said optical channel counter, OCC, unit and a gain adjustment unit configured to adjust the amplifier gain of said optical amplifier automatically depending on a calculated power difference between a predetermined desired power per channel and the determined average power per channel provided by said determination unit.

Method and apparatus for automatic signal gain setting

A method for determining a maximum transmission capacity, TCAP-OL, of an optical link, OL, within an optical network includes loading an optical transmission spectrum of the optical link, OL, being partially occupied by at least one data traffic carrying channel, CH, with amplified spontaneous emission, ASE, noise spectrally shaped such that the transmission performance of the optical transmission spectrum fully occupied with data traffic carrying channels, CHs, is matched. The method further includes determining the maximum transmission capacity, TCAP-OL, of the optical link, OL, on the basis of measured link data transported through the optical link, OL, via the at least one data traffic carrying channel, CH.

Method and apparatus for determining a maximum transmission capacity within an optical network

A wavelength division multiplexed telecommunication system with automatic compensation of chromatic dispersion in a predetermined wavelength band, said WDM telecommunication system comprising a probe signal detection unit at a receiver side adapted to detect amplitude modulated probe signals generated by a probe signal generation unit at a transmitter side with a predetermined relative phase difference and transmitted through an optical link to said receiver side; and a chromatic dispersion compensation unit adapted to compensate the chromatic dispersion in response to a relative phase difference of the amplitude modulated probe signals detected by said probe signal detection unit at the receiver side.

Wavelength division multiplexed telecommunication system with automatic compensation of chromatic dispersion

A method for establishing bidirectional communication links includes: supplying, to at least two optical transceiver modules at each side of at least two optical paths, a multiplexed optical CW signal comprising at least two optical CW signals having the same differing wavelengths, and modulating the multiplexed optical CW signal according to modulation signals; creating, at each side of the optical paths, at least two first and second optical transmit signals by optically filtering the modulated optical signals so that only a single wavelength remains, and routing pairs of a first and second optical transmit signal to the optical paths, wherein the optical transmit signals of each pair have differing wavelengths and wherein the optical transmit signals transmitted in the same direction over the same optical paths have differing wavelengths; receiving each optical transmit signals at a dedicated optical transceiver module by mixing it with the multiplexed optical CW signal.

Method and system for establishing at least two bidirectional communication links using coherent detection

A wavelength division multiplexing, WDM, network comprising an apparatus adapted to manage a frequency spectrum in the wavelength division multiplexing, WDM, network, the apparatus comprising an adjustment unit adapted to adjust a frequency offset between carriers for each individual carrier depending on performance characteristics of the individual carriers.

Method and apparatus for managing a frequency spectrum in a wavelength division multiplexing network

A chromatic dispersion compensation apparatus for automatic compensation of chromatic dispersion of signals transmitted via an optical link at predetermined wavelengths of WDM channels within a predetermined band. A tapping unit taps optical signals received by the chromatic dispersion compensation apparatus via the optical link at predetermined wavelengths and supply them to an optical coherent receiver adapted to tune its local oscillator to WDM channels to generate corresponding analog electrical signals of the WDM channels which are sampled by an analog digital converter to provide digital signal samples of WDM channels processed by a digital signal processor of the chromatic dispersion compensation apparatus to calculate an estimate residual chromatic dispersion value of the received optical signals. A tuneable dispersion compensation module is set to perform optical compensation of a residual chromatic dispersion of the received optical signals depending on calculated estimate residual chromatic dispersion value of the received optical signals.

Method and apparatus for automatic compensation of chromatic dispersion

A method and apparatus for automatic determination of a fiber type of at least one optical fiber span used in a link of an optical network, the method comprising the steps of measuring a length of said optical fiber span; measuring a chromatic dispersion of said optical fiber span; determining a fiber dispersion profile of said optical fiber span on the basis of the measured length and the measured fiber chromatic dispersion; and determining a fiber category and/or a specific fiber type of said optical fiber span depending on the determined fiber dispersion profile.

Method and apparatus for automatic determination of a fiber type

A hybrid wavelength division multiplexing system wherein one or more intensity modulated signals generated by optical amplitude modulators are co-propagated with one or more phase modulated signals generated by optical phase modulators, wherein a drive voltage of said optical amplitude modulator is adapted to reduce an extinction ratio of the intensity modulated signal to minimize a cross-phase modulation impact on the co-propagating phase modulated signals.

Method and apparatus for increasing a transmission performance of a hybrid wavelength division multiplexing system

A transmitter with at least one optical modulator adapted to modulate the optical signal output by a laser source to generate a modulated optical signal, wherein the optical signal output by the laser source is tapped and supplied to a monitoring circuit comprising an optical front end configured to select signal components of the tapped modulated optical signal and to convert the selected signal components of the tapped modulated optical signal into analog signals, and comprising at least one analog-to-digital converter, ADC, adapted to perform equivalent-time sampling of the analog signals to provide digital signals processed by a processing unit to monitor signal quality of the modulated optical signal.

Apparatus and method for monitoring signal quality of a modulated optical signal

A method and apparatus for performing an automatic power adjustment wherein a signal power level of an optical signal transmitted by an optical transceiver via an optical span to a far-end device is adjusted automatically in response to a determined span loss of the optical span to achieve a predetermined desired receive signal power level of the optical signal at the far-end device.

Method and apparatus for performing an automatic power adjustment for an optical signal

The length of the optical fiber section under tension expands by a certain amount that is proportional to the level of tension applied to it. Monitoring the variations in the phase of the arriving signal allows to discover a fiber that is subject to a certain level of mechanical tension. With the method and apparatus according to the present invention it is possible to protect optical communication channels against failures in an optical transmission fiber that are caused by any kind of mechanical disturbances.

Method and apparatus for monitoring mechanical fiber stress of optical fiber spans

An optical fiber transmission system adapted to provide a remote passive identification of components deployed in said transmission system, wherein each component comprises an associated passive optical identification unit adapted to provide identification of a component type of the respective component on the basis of a received optical identification signature carried in an optical identification signal to said component.

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Johns Creek, GA, United States of America

Sorin Tibuleac