France Telecom

Orange

Other

Alcatel

Erwan Pincemin

Paulette Gavignet

Yann Loussouarn

Naveena Genay

Mengdi Song

Bing Han

S&eacute;bastien Bigo

Esther Le Rouzic

Benjamin Cuenot

Daniel Hui Bon Hoa

Christian Dourthe

Bertrand Le Guyader

Franck Payoux

Sylvain Capouilliet

Julie Karaki

René Coquille

Didier Grot

Abdul Rahman El Falou

Albert Luron

Sofiene Blouza

A system for sending data in an optical network comprising a plurality of source nodes and destination nodes is disclosed. In one aspect, a source node generates, in a spectral band that is associated with it, a multi-carrier optical data signal obtained by modulation of a source signal at a source wavelength and sends it in the form of single-band data bursts that can be associated with distinct source wavelengths. A single-band data burst comprises, in addition to payload data symbols (PL), a sequence of learning symbols (TS) composed of a plurality of learning symbols. A control unit belonging to the control plane of the optical network determines, for at least one of the source nodes, instants of sending of the single-band data bursts and source wavelengths to be used for sending these single-band data bursts, as a function of a path time of the data bursts between the source node and one of the destination nodes associated with the source wavelength. The control unit also determines the size of the sequence of learning symbols (TS) of the single-band data bursts.

Control plane for an optical network for transmitting multi-carrier data bursts with dynamic adaptation of learning sequence

A load-controlling device controlling load on an optical transmission line, the input of which is coupled to an emitting device for modulating with data and multiplexing a plurality of useful wavelengths into a useful optical signal to be transmitted over the transmission line. The load-controlling device includes elements for generating a filler optical signal composed of at least one filler wavelength that is not modulated by data, to be injected into the optical transmission line. The generating elements generate a source optical signal composed of a plurality of wavelengths corresponding to the plurality of wavelengths of the useful optical signal and selects the wavelength of the filler optical signal among the wavelengths of the source optical signal. A control module controls selection of the wavelength of the filler optical signal depending on information indicative of non-turn-on of a wavelength among the plurality of wavelengths of the useful optical signal.

Method and device for controlling the load of an optical transmission line with wavelength-division multiplexing

The invention relates to a system for sending data in an optical network comprising source nodes (-----), each capable of generating, in a spectral band that is associated with it, a multi-carrier optical data signal obtained by modulation of a source signal at a source wavelength and of sending this signal in the form of single-band data bursts (-----) that can be associated with distinct source wavelengths, and a combiner () for combining single-band data bursts, sent by the source nodes in the spectral bands that are associated with them, into multi-band data bursts (--) occupying a spectral band corresponding to a juxtaposition of the spectral bands associated with the source nodes. In this system, a unit for controlling an instant of sending of said single-band data bursts by the source nodes, implements a control plane taking account of a path time of the single-band data bursts sent by the source nodes to the combiner.

Optical signal comprising a succession of multi-band bursts of multi-carrier data signals, system and method of emission of such a signal, and corresponding optical transport network

A coherent optical receiver capable of receiving a multiple-wavelength optical signal comprising a series of single-band optical bursts is described. Each single-band optical burst is carried by one wavelength from among a plurality of wavelengths on a predetermined spectral band. The optical receiver can include optical generation means arranged to generate a local multiple-wavelength optical oscillator consisting of a plurality of optical lines at wavelengths corresponding to the wavelengths of the optical bursts, optical mixing means arranged to mix the optical oscillator and the optical signal in order to generate at least one mixed optical signal comprising a plurality of beats between at least one of the single-band optical bursts and the optical lines of the local multiple-wavelength optical oscillator, and a detection means to filter at least one beat between said single-band optical burst and one of the optical lines of the local multiple-wavelength optical oscillator.

Reception of multiple-wavelength optical signals consisting of single-band optical bursts

A method is provided for determining an optical signal to noise ratio of a dual polarization optical signal. The method includes: detecting, in the dual polarization optical signal, a modulation signal which modulates, at at least one low amplitude level that is approximately zero and at a high amplitude level, the dual polarization optical signal, and determining the optical signal to noise ratio from a measurement of the power of the modulation signal.

Determination of an optical signal to noise ratio of a dual-polarization optical signal

A method is provided for pre-distorting an optical signal, intended to be transmitted over an optical transmission line and including a plurality of frequency division multiplexed optical sub-carriers. The optical signal is obtained from an optical conversion of an electrical signal including a plurality of frequency division multiplexed sub-carriers. This method includes obtaining a plurality of corrective factors, corresponding to the electrical sub-carriers, as a function of a plurality of values, determined for the optical sub-carriers, of a first parameter dependent on the power of the sub-carriers, and application of the corrective factors to the amplitudes of the corresponding electrical sub-carriers, so as to equalize, at the output of the optical transmission line, the values of the first parameter for the sub-carriers of the optical signal.

Pre-distortion of an optical signal with frequency division multiplexed sub-carriers

A method is provided for receiving an optical signal including a step of coherently detecting the optical signal, outputting a multicarrier signal received, and a step of processing the received multicarrier signal, which includes a step of estimating a frequency offset affecting the received multicarrier signal relative to a corresponding multicarrier transmitter signal. The estimation step implements two sub-steps including: a sub-step of determining the entire portion of the frequency offset; and a sub-step of determining the fractional portion of the frequency offset. The sub-step of determining the entire portion implements a measurement, in the spectral range, of an offset between the position of at least one specific carrier of the multicarrier transmitter signal and the position of the corresponding specific carrier or carriers in the received multicarrier signal.

Frequency synchronization for an OFDM optical receiver

A method of calculating a series of control parameters to be applied to a polarization controller arranged so as to compensate for the modal dispersion of polarization affecting an optical signal passing through an optical link by calculating a plurality of polarization states of which the respective representations on a Poincar&#xe9; sphere are separated from one another by a distance greater than a minimum distance dependent on an acceptable threshold of bit error ratios and, for each state of polarization thus calculated, associating at least one control parameter to be applied to the polarization controller with the calculated state of polarization.

Compensation of modal dispersion of polarization by deterministic jamming of polarization

A device for inserting/extracting at least one optical subband into an optical channel consisting of a plurality of optical subbands. The device includes an extraction means that is capable of extracting a first optical subband belonging to the optical channel, a suppression means that is arranged so as to obtain a filtered optical channel from the optical channel wherein at least one second subband is suppressed, and a coupling means that is capable of inserting a replacement optical subband in place of the second subband in the filtered optical channel so as to obtain a modified optical channel. The device moreover relates to an optical insertion/extraction switcher, using one or more insertion/extraction devices, and to the corresponding insertion/extraction methods.

Method and device for inserting/extracting optical subband into multiband optical OFDM signal

A system and an associated method of bidirectional optical transmission between a central terminal () and a plurality of client terminals () via a passive optical network (PON) (), wherein the conversion of an OTDM signal into a WDM signal (respectively the conversion of a WDM signal into an OTDM signal) is effected by an optical converter () (respectively) by a soliton trapping effect during a downlink (respectively uplink) transmission stage.

Optical transmission between a central terminal and a plurality of client terminals via an optical network

The invention relates to a passive optical network comprising an optical exchange linked by at least one optical fiber to at least one line termination device of said network, able to transmit a downlink optical signal phase-modulated in NRZ-DPSK format and to receive an uplink optical signal. According to the invention, said line termination device comprises means of converting the transmitted downlink optical signal phase-modulated in NRZ-DPSK format into an optical data signal amplitude-modulated in duobinary modulation format and means of generating an uplink optical signal phase-modulated in NRZ-DPSK format from the downlink optical signal phase-modulated in NRZ-DPSK format. The optical exchange is able to convert the uplink optical signal phase-modulated in NRZ-DPSK format into an optical data signal amplitude-modulated in duobinary modulation format.

High bit rate bidirectional passive optical network, associated optical exchange and line termination device

The differential group delay is measured in an optical fiber connection for an optical signal undergoing a phase modulation BPSK or DPSK by a digital signal at a given rate. A polarization controller at an emerging end of the connection scans polarization states of the modulated optical signal. An emulator iteratively introduces an additional delay in the modulated optical signal emerging from the connection and combines the delayed modulated optical signal and the non delayed modulated optical signal which are both polarized along two orthogonal axes into a resulting optical signal. A polarization controller and a fixed polarizer select a polarization state in the resulting optical signal along one of bisecting lines of the orthogonal axes into a linearly polarized signal. An eye diagram or a spectrum of the polarized signal is acquired by a digital oscilloscope or an optical spectrum analyzer to determine the differential group delay.

Measuring differential group delay in an optical fiber connection

A passive optical network is provided, which includes an optical central office connected to a line termination device by a branch of the network including a passive amplification medium. The central office is adapted to send/receive a first data optical signal and has a first amplifier for sending a second amplification optical signal. The second signal exciting the amplification medium to amplify the optical power of an optical signal. The line termination device is adapted to receive the first optical signal, modulate the second amplification optical signal; and inject the modulated second signal into the network.

Long-reach passive optical network using remote modulation of an amplification optical signal

The apparatus includes a pulse emitter and at least one line fiber for conveying at least one pulse in the line fiber. A spreader module for linearly spreading pulses is provided including a propagation medium that is dispersive and linear. The propagation medium presents accumulated chromatic dispersion that is high enough to lower the peak power of the pulse to below a predetermined threshold, where a signal above the threshold is subjected to non-linear distortion in the line fiber. The spreader module is disposed between the emitter and the line fiber.

Apparatus and method for very high data rate optical transmission, and the use of said apparatus and said method

The invention concerns a device for temporal subsampling of an OTDM optical signal at a predetermined subsampling frequency, comprising a generator () for generating clock pulses transmitted at the predetermined subsampling frequency and at a conversion wavelength &#x3bb;and a wavelength converter device () adapted to receive at its input the OTDM optical signal and the clock pulses in order to deliver at its output a subsampled OTDM optical signal at the conversion wavelength. The converter device comprises a linear optical amplifier () adapted to receive the OTDM optical signal and the clock pulses propagating in the opposite direction, the maximum linear power of the conversion being adjusted so that it can be less than the peak power of the OTDM optical signal, and a converter () of phase modulation into amplitude modulation.

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Gommenec'h, France

Erwan Pincemin