Alcatel N.v.

Alcatel

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Alcatel Cit

Alcatel Cable

Alcatel Fibres Optiques

Alcatel Cable France

Alcatel Fibers Optiques

Olivier Audouin

Michel Sotom

Jean-Pierre Hamaide

Jean-Michel Gabriagues

Pascale Nouchi

Pierre Sansonetti

Denis Penninckx

Laurence Prigent

Dominique Chiaroni

Ludovic Noirie

Nicolas Le Sauze

Jose Chesnoy

Amaury Jourdan

Emmanuel Dotaro

Claude Artigue

Yann Frignac

Albert Benveniste

Frederic Cerou

Maria Manzanedo

Jean-Michael Gabriagues

Stéphanie Lanne

George Moustakides

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

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

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

Dispersion-shifted monomode optical fibers have an effective mode surface area greater than 65 &mgr;m by optimization of the geometrical characteristics that characterize the fibers.

Dispersion-shifted monomode optical fiber

Dispersion-shifted monomode optical fibers have an effective mode surface area greater than 65 .mu.m.sup.2 by optimization of the geometrical characteristics that characterize the fibers.

Light pulses carrying data in binary form to be transmitted are injected into a transoceanic line fiber in which they pass through amplifiers imparting Gordon-Haus jitter to them. In accordance with the invention, a compensation fiber is disposed at the output of the line fiber so as to apply negative chromatic dispersion to the pulses so as to compensate their jitter in part before they are processed in a receiver. The invention applies to telecommunications.

System and a method for performing soliton transmission

In an optical frequency marking method and a frequency channel communication network using this method, an optical reference frequency is scanned across a scanning band to produce frequency coincidences with a monitored frequency which constitutes the frequency to be marked. During each scanning half-cycle it effects a go path and a return path according to a known law to produce a go frequency coincidence and a return frequency coincidence. A marker interval is measured which is the time elapsed between said two coincidences. This interval marks the monitored frequency and enables said frequency to be locked by comparison with a set point interval. The invention finds a particular application in the marking and stabilization of carrier frequencies of a closely-spaced different frequency channel network.

Optical frequency marking method and different frequency channel

An optical communication link with correction of non-linear effects comprises an optical fiber transmission line subject to chromatic dispersion and non-linear effects and correction means for limiting the disadvantageous consequences of this dispersion and/or these non-linear effects. The correction means comprise at the output of the transmission line a dispersion compensator adapted to apply dispersion in the opposite direction to and of lower absolute value than the dispersion due to the transmission line.

Optical communication link with correction of non-linear effects and

According to the invention, messages to be transmitted between user terminals interconnected by a transmission network are classified into 'heavyweight' messages and 'lightweight' messages. The heavyweight messages, i.e. messages containing a large quantity of data, are transmitted over the network in message frequency channels attributed to respective heavyweight messages, while the lightweight messages are transmitted over a shared channel common to the lightweight messages.

Method and a network for transmitting messages in frequency channels

In a method of the invention an emission wave (F(2P-1)) which is to be positioned within the spectrum relative to an external wave (F(2P-2)B) is modulated. Said external wave is mixed with one of the side waves that results from said modulation (F(2P-1)A) and the emission wave is positioned in response to variations in the frequency of a beat signal (F(2P-2)BE) that results from said mixing. The invention applies in particular to implementing an optical fiber communications network.

Method and apparatus for relative positioning of a frequency, in

Calls are made in known manner between terminals in the form of information-carrying modulation applied to emission waves that travel along common transmission lines. An emission frequency (F(2P-1)) is allocated to each terminal for each call. According to the invention, a marking wave is supplied to all of the terminals while no call is yet being set up, thereby marking an emission frequency. When a new call is being set up, the marked frequency is allocated for the new call to at least one of the terminals that are to participate in the call. The invention is particularly applicable to communications by means of optical fibers.

Communications method and network with frequency allocation

The emission frequencies (F(1) . . . F(2P)) used for simultaneous communications form a stack extending from a fixed based frequency (F(0)) to a top of stack frequency (F(2P-1), F(2-P)). At the beginning of each call, the emission frequency (F(2P-1)) used for the call is at the top of the stack. During the call, said emission frequency is maintained by being servo-controlled to a predetermined spectrum distance (DF) beyond a lower support frequency (F(2P-2)) providing such a frequency can be detected. When such a frequency cannot be detected, the emission frequency is shifted progressively towards the base frequency. The invention is particularly applicable to communications between the peripherals of computer systems.

Communication method and network using optical fibers with frequency

In a long-haul optical communication line the fibers to be made into the line are grouped into pairs such that the two fibers in each pair have substantially symmetrical chromatic dispersion relative to a mean value of the chromatic dispersion of all the fibers of the line. These two fibers are thereafter connected consecutively into the line. The invention finds an application in telecommunications.

Growing community of inventors

Savigny sur Orge, France

Olivier Audouin