Alcatel Cit

Societe Anonyme Dite: Alcatel Cit

Philippe Perrier

Paul Vinel

Luc Berthelon

Marc Dieudonne

Herve Fevrier

Olivier Gautheron

Christian Coeurjolly

Herv&eacute; Fevrier

Jean-Marc Delavaux

St&eacute;phane Ruggeri

Alain Noury

An extract-and-insert optical wavelength division multiplexer includes a broadcaster (D,) for applying an incoming multiplex signal to N outputs, a combiner-diffuser (D,) for broadcasting the multiplex to be inserted (MI) on N outputs, a first set of N tunable filters (FIT, . . . , FNT) for selecting the carriers of the signals which are to be used for modulating the carriers of the outgoing multiplex (MS), a second set of N tunable filters (F,E, . . . , FNE) for selecting the carriers which are to constitute the extracted multiplex (MT), N wavelength converter devices (CL,, . . . , CLN) suitable for supplying N carriers of the outgoing multiplex (MS), and N two-input, two-output optical switches (SW,, . . . , SWN) enabling each output of the broadcasters (D,, D,) to be selectively connected to the input of a filter of the first set and/or to the input of a filter of the second set, and/or to transmit the carriers of the multiplex to be inserted (MI) to a filter of the first set and/or a filter of the second set. The multiplexer is particularly applicable to optical transmission networks implementing a synchronous digital hierarchy.

Optical spectral multiplexer for inserting and extracting

Bidirectional optical link, and device for amplifying such link

A simple implementation of a high-capacity switching matrix includes four input functional modules each having one input and four outputs and four output functional modules each having four inputs and one output. A broadcast network has 16 inputs connected to the 16 outputs of the input functional modules and 16 outputs connected to the 16 inputs of the output functional modules to broadcast four signals from each input functional module simultaneously to each output functional module. The broadcast network includes four send subsystems each sending four optical carriers at four different wavelengths .lambda..sub.1, . . . .lambda..sub.4 and four receive subsystems each receiving four optical carriers at these respective wavelengths. The broadcast network further includes four optical buses each connected to a respective input of a receive subsystem and to a respective send subsystem so that the jth bus for j=1 through 4 receives from the kth send subsystem the carriers at the wavelengths .lambda..sub.1-k(modulo 4), . . . .lambda..sub.4-k(modulo 4). Applications include switching equipment.

High capacity switching matrix

An add-drop optical spectrum-division multiplexer for dropping a drop multiplex from an incoming multiplex signal and for adding an add multiplex into an outgoing multiplex signal. The multiplexer includes a demultiplexing device for separating a number of optical carriers from the incoming multiplex signal and for selecting drop carriers which constitute the drop multiplex as well as through carriers which are to be output as the outgoing multiplex signal. The multiplexer further includes an apparatus for selecting a certain number of add carriers from the total number of carriers of the add multiplex, and a coupling device and wavelength converter for allocating fixed wavelengths to the signals which modulate the through carriers and the add carriers.

Add-drop optical spectrum-division multiplexer

An optical connection system for connecting customer premises networks to a switching center of a telecommunication network providing interactive and non-interactive services includes a switching center comprising central office termination equipments, a connection network, a control unit, an optical distribution network and customer premises networks. Non-interactive services are connected to the control central office termination equipment so that non-interactive service signals are sent to all customer premises networks on standby at the control central office termination equipment wavelength. These customer premises networks can therefore use these services without having to set up a call individually and so without having to busy a central office termination equipment for each customer premises network. Each customer premises network which requests a non-interactive service during an interactive call retains the same wavelength and the same central office termination equipment assigned to it for the interactive call. The system finds an application in broadband telecommunication networks.

Optical system for connecting customer premises networks to a switching

An automatically configurable optical connection system for connecting customer premises networks to a switching center of a telecommunication network includes an optical distribution network connecting all central office termination equipment optical senders to all customer premises network optical receivers and connecting all customer premises network optical senders to all central office termination equipment optical receivers. A control unit assigns a different wavelength to each customer premises network communicating at a given time, this wavelength representing an available central office termination equipment which is not the control central office termination equipment. To enable automatic system configuration each central office termination equipment sends cyclically an identification message and each inactive customer premises network listens out cyclically at each wavelength available to the central office termination equipments and memorizes the relationship between the wavelengths and the central office termination equipment identities, marking the control central office termination equipment wavelength. The system is for use in broadband telecommunication networks.

Automatically configurable optical system for connecting customer

This bidirectional transmission system, especially one using optical fiber, between a source terminal and a user terminal employing a single carrier for both transmission directions obtained from a source in the source terminal characterized in that it comprises for each transmission direction means for modulating one parameter of said carrier, this parameter being intensity for the two directions and subject in all cases to the condition that the modulation applied first for transmission in the downward direction from the source terminal to the user terminal the depth of modulation is sufficiently high to leave sufficient power for application of the second modulation to which that applied second can be applied for transmission in the upward direction from the user terminal to the source terminal.

Growing community of inventors

Velizy-Villacoublay, France

Philippe Perrier