Alcatel

Other

Alcatel N.v.

Alcatel Lucent

Denis Penninckx

Dominique Chiaroni

Ludovic Noirie

Nicolas Le Sauze

Thierry Zami

Olivier Audouin

St&eacute;phanie Lanne

Patrick Brindel

Amaury Jourdan

Jean-Pierre Hamaide

Sabry Khalfallah

Olivia Rofidal

Gabriel Charlet

Jose Chesnoy

Emmanuel Desurvire

Emmanuel Dotaro

Olivier Leclerc

Alexandre Shen

Claude Artigue

Franck Bruyere

Yann Frignac

Arnaud Dupas

Bertrand Desthieux

Fran&ccedil;ois-Xavier Ollivier

Jean-Luc Beylat

Albert Benveniste

Frederic Cerou

Philippe Delansay

Stéphanie Lanne

George Moustakides

Maria Manzanedo

St&eacute;phanie Barre

Christophe Bridoux

Fabien Roy

To optimize the resources of an optical transmission network using wavelength division multiplexing, assigning carrier frequencies to signals to be transmitted consists in associating N sets of optical frequencies of the comb with N respective ranges of consecutive error rate values, each of the sets comprising frequencies generating a mean error rate in the associated range, defining a measured signal transmission constraint level that is a function of the transmission constraint parameter(s) and may take N distinct values referred to as constraint values, associating the N constraint values in increasing order respectively with the N sets of frequencies in decreasing order of the error rate values of the associated N ranges, assigning any signal to be transmitted a constraint value obtained by applying the measurement, and assigning the signal to be transmitted a carrier frequency belonging to one of the sets of frequencies that is associated with a constraint value at least equal to the constraint value assigned to the signal to be transmitted.

Method of assigning carrier frequencies in an optical transmission network

The field of the invention is that of switching optical signals with carrier wavelength conversion capacity, comprising a set of input ports (PE-PEn), a set of output ports (PS-PSn) functionally connected to the input ports so that an input signal presented to one of the input ports may be selectively routed to at least one of the output ports, and wavelength conversion means () providing a capacity for converting an input signal carrier wavelength to at least one other output port output wavelength. According to the invention the wavelength conversion capacity of said conversion means () is limited by at least one of the following three limitation means i) to iii):

Device and method for switching optical data for optical communication networks

The invention relates to a reconfigurable optical switching system for selectively coupling one or more frequencies of first and second input wavelength division multiplex signals (WDM, WDM) consisting of N channels to first and second output ports (O, O). The invention also relates to a variable and reconfigurable optical delay circuit comprising said optical switching system associated with an optical delay loop. The input frequency division multiplex optical spectra (WDM, WDM) are therefore divided by a first demultiplexer (Demux) to a plurality of interleaved stages of optical switches (D, C, A and B) which selectively feed a plurality of input ports (M) of a multiplexer (Mux), which then uses its routing properties to implement in particular the complex reconfigurable multiple 2&#xd7;2 frequency switching function.

Selective frequency switching system and a reconfigurable optical delay circuit incorporating it

The present invention relates to an optical communication network and to a network element for use in such a network. The network element comprises a plurality of receivers (-) for receiving optical communication signals, a plurality of transmitters (--) for transmitting optical communication signals, and a plurality of network connections, each network connection having an individual signal impairment characteristic. The pluralities of receivers (-) and transmitters (--) are adapted to employ a plurality of different modulation schemes (). Furthermore, the pluralities of receivers (-) and transmitters (--) are assigned to the network connections as a function of the individual signal impairment characteristics.

Network element for use in an optical communication network, in particular a DWDM communication network

The invention relates to a time division and wavelength division multiplex optical switching node for use in an optical communications network (), which node combines a set of time division multiplex packets (---i) into a wavelength division multiplex packet () to form a composite wavelength division multiplex packet, in particular by conferring on each time division multiplex packet (---I) a respective appropriate multiplexing wavelength (&#x3bb;, . . . , &#x3bb;i), for example a wavelength specific to each time division multiplex packet. The invention has applications in high bit rate optical networks in particular, in which it offers versatility and transparent use of the different multiplexing modes.

Time division multiplex and wavelength division multiplex optical switching node

A decision system for a modulated electrical signal delivered by a converter in response to a received modulated optical signal compares the amplitude of the electrical signal to a reference level, measures an average amplitude of the electrical signal, and generates the reference level as a function of the result of such measurements so that the 'reference level/average amplitude' ratio can be adjusted to a predetermined constant value different from 1. Applications include receivers for optical packet transmission systems.

Decision system for modulated electrical signals

A selective frequency extractor is disclosed which forwards one or more selected frequencies of a wavelength division multiplex input signal consisting of N channels to one output port and all the other frequencies to another output port. A reconfigurable frequency add and drop multiplexer is also disclosed. The input signal is divided up by a first demultiplexer and routed to a plurality of interleaved stages of optical switches for selectively feeding a plurality of input ports of a multiplexer, whose routing properties are then used for extracting one or more frequencies from the input signal or for reconfigurable frequency add and drop multiplexing.

Frequency extractor

An optical packet node for receiving and transmitting optical packets is disclosed. A multiwavelength band splitting device splits received optical packets transmitted via multiwavelength bands into at least three groups, each group including one multiwavelength band. A multiwavelength band combining device combine the three groups of multiwavelength bands. At least two optical packet add drop multiplexers are placed between the multiwavelength band splitting device and the multiwavelength band combining device. Each optical packet add drop multiplexer adds and drops at least one individual wavelength to a respective multiwavelength band group. A load balancing stage is connected to the optical packet add drop multiplexers to provide an interconnection between at least two wavelength bands.

Optical packet node and optical packet add drop multiplexer

Optical switching device and a method of controlling the device

A device for compensating the polarization dispersion suffered by an optical signal when it is transmitted by an optical line includes a polarization controller. It generates a differential time delay between two orthogonal polarization modes and controls the polarization controller so that it converts the signal transmitted by the line into a compensated optical signal. If the quality of the compensated optical signal remains below a reference quality the device modifies the state of polarization of the optical signal. Applications include long distance optical transmission via standard fibers.

Device for compensating polarization dispersion in an optical transmission system

To delay optical signals precisely and continuously in a very small dynamic range, a device for applying a time-delay to optical signals includes a first phase modulator to receive an input optical signal carried by an original center wavelength and to apply a first stage of phase modulation to the carrier wave of the input signal to supply a first intermediate signal carried by a modified center wavelength, a delaying dispersive member having chromatic dispersion to receive the first intermediate signal and to supply a second intermediate signal, and a second phase modulator to receive the second intermediate signal and to apply a second stage of phase modulation to the carrier wave of the second intermediate signal to supply an output signal carried by the original center wavelength. Applications include optical telecommunication systems, in particular converting wavelength division multiplexed signals into time division multiplexed signals and regenerating wavelength division multiplexed signals.

Device for applying time-delays to optical signals

Method of measuring the error rate of an optical transmission system and apparatus for implementing the method

To increase the bit rate at which and the distance over which data can be transmitted by optical fiber, polarization dispersion is compensated by means of a polarization controller, a system for generating a differential group delay between two orthogonal modes of polarization and a control unit of the polarization controller. A chromatic dispersion compensator applies compensation which is adjusted dynamically to optimize the quality of the received optical signal. Applications include long-haul optical transmission on standard fibers.

System for compensating polarization dispersion in an optical transmission system

The present invention is a device to increase the bit rate and distance at which data can be transmitted by optical fiber. The device compensates the polarization dispersion of the line by processing a received optical signal with the use of a polarization controller, the generation of a differential group delay between two orthogonal polarization modes and a control unit for the polarization controller. The data that is sent is redundant to enable detection of errors affecting the data received and the control unit is adapted to minimize the error rate calculated in real time by using the redundant data. The application of the device is to long-haul optical transmission, in particular over stranded fibers.

Known optical power equalizers receive an optical main input signal modulating between high and low input power levels. The optical power equalizers emit an equalized optical main output signal modulating between high and low output power levels, where at least one of the two sets of high and low power levels is equalized to one high or one low output power level. Such devices can comprise at least one gain-clamped semiconductor optical amplifier that operates about its saturation range. The optical power equalizer receives an amplifier input signal, which has one or more modulated portions, and emits a modulated amplifier output signal. According to the invention the dependence of the gain-clamped semiconductor optical amplifier's gain on the power of the amplifier input signal is adjusted such that the high input power levels of the amplifier input signal are equalized into the one high output power level of the amplifier output signal.

Optical power equalizer

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Nozay, France

Denis Penninckx