Alcatel Cit

Alcatel

Alcatel Lucent

Luc Berthelon

Philippe Perrier

Ludovic Noirie

Arnaud Bisson

Herve Fevrier

Christian Coeurjolly

St&eacute;phane Ruggeri

Alain Noury

Herv&eacute; Fevrier

A method is disclosed of reconfiguring a ring optical network made using a single optical fiber ( ). A traffic concentrator ( ) and stations ( ) are optically connected to the fiber. The concentrator sends a light signal to and receives a light signal from both ends of the fiber using two groups of wavelengths ( ) in order to be able to communicate with all the stations. When the network is established, a virtual break ( ) is created between two stations. If a real break is detected in the optical fiber, then the virtual break is shifted until it coincides with the real break, thereby enabling traffic to be re-established between the concentrator and the stations. Each station is equipped with a three-state optical switch ( ) for changing the direction of the light signals.

Method and a system for protecting data transmitted on an optical ring formed of a single optical fiber

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

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

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Palaiseau, France

Luc Berthelon