Lucent Technologies Inc.

Alcatel-lucent USA Inc.

Jean Gerardus Leonardus Jennen

Jan Willem Hellenthal

Christopher Richard Doerr

Alexei Ashikhmin

Adriaan J De Lind Van Wijngaarden

Philip Alfred Whiting

Carl Robert Posthuma

Hungkei Keith Chow

Gerhard Guenter Theodor Kramer

Miroslav Zivkovic

Harmanus Van Tellingen

Kyriakos Vlachos

A multi-channel processing module is arranged in series with multiple channels of a communication system. The processing module synchronizes downstream symbols among the channels, and synchronizes downstream symbols for at least a given one of the channels with upstream symbols for that channel. The synchronization of downstream symbols among the channels and the synchronization of downstream symbols for at least the given channel with upstream symbols for that channel are collectively achieved by adjusting downstream and upstream adjustable delay elements associated with respective downlink and uplink signal paths in the multi-channel processing module. The channels may comprise respective subscriber lines of a DSL communication system.

Methods and apparatus for providing synchronization in a multi-channel communication system

The present invention provides a method and an apparatus for scheduling a flow on an output link among a plurality of flows of incoming packet traffic at a network device associated with a data network. A scheduler comprises scheduler logic that uses a credit counter per flow to keep track of the service difference received between two or more flows and selects the flow for service next that has the maximum credit value. The scheduler logic updates an amount of credit value in a counter of the next flow with the front-end packet currently being served among the first and second flows with a value that substantially equals a packet size value divided by a flow weight value of the front-end packet currently being served. The scheduler logic further updates an amount of credit value in the first and second counters of the first and second flows having packets waiting with a value that substantially equals the size of the front-end packet currently being served.

Scheduling incoming packet traffic on an output link of a network device associated with a data network

Highly Scalable Multi-granular Node Architecture based upon strictly non-blocking waveband switch constructed around cyclic arrayed waveguide grating (AWG) routers. In one implementation, the invention includes a first N&#xd7;N cyclic arrayed waveguide grating (AWG); a middle stage includes N tuner modules, and a second N&#xd7;N cyclic AWG for routing information from a plurality of different optical networks. Another implementation of the invention further provides an add/drop switch, and a shuffler for performing add/drop functions and preserving the wavelength order.

Highly scalable multi-granular node architecture

An optical switching architecture utilizing a multiple stage configuration of wavelength division multiplexed (WDM) component wavelength converters and cyclic arrayed waveguide grating (AWG) router.

Non-blocking cyclic AWG-based node architectures

A method and system for increasing the spectral efficiency of binary coded signals includes encoding an input binary bit sequence such that the input binary bit sequence is converted into a series of rectangular pulses having varying repetition rates. A continuous wave carrier signal is then modulated via a control signal representative of the encoded signal. The modulated optical signal is filtered by a narrow band optical filter to generate a minimum shift keying (MSK) encoded optical signal. In accordance with the present invention, an input binary bit sequence is encoded via a minimum shift keying (MSK) modulation format to improve the spectral efficiency of a binary coded digital signal and to contemporaneously limit distortion of the optical signal induced by optical nonlinear effects during transmission in an optical transmission system.

Method and system for increasing the spectral efficiency of binary coded digital signals

An optical device extracts an information bearing sideband such as an FSK or SCM signal (label) from a composite signal that includes the sideband and an orthogonally modulated signal such as an intensity modulated signal (payload) by employing polarization beam splitting and polarization transformation. Polarization transformation is accomplished by splicing the optical signal into a polarization maintaining fiber at a desired angle so that it is separated into two orthogonal polarizations that experience differential group delay in the fiber. The fiber is characterized by a beat length Land the fiber is designed to have a length substantially equal to (L&#xd7;f)/2&#x3b4;f, wherein the sidebands of the composite signal are separated by a wavelength difference &#x3b4;f and fis the nominal center frequency of the composite signal. This device has been shown to be useful for extracting GMPLS LSC level wavelength labels from either an FSK/IM composite signal or an SCM/IM composite signal.

Optical device for extracting a sideband signal from a composite signal including orthogonally modulated signals

A reconfigurable optical add/drop multiplexer (ROADM) includes a first optical dynamic gain equalization filter (DGEF) having a first input for receiving an initial wavelength division multiplexed (WDM) signal, a first output for sending a phase shifted WDM signal, and a second output connected to a demultiplexer for demultiplexing a WDM drop signal thereby producing a plurality of drop channels. A second DGEF having a first input for receiving the phase shifted WDM signal, a second input connected to a multiplexer, for multiplexing a plurality of add channels to produce thereby a wavelength division multiplexed (WDM) add signal, and an output for sending a second adjusted WDM signal. The ROADM allows for the channels from the initial WDM signal to be dropped, added and equalized.

Reconfigurable optical add/drop multiplexer

An optical device extracts an information bearing sideband such as an FSK or SCM signal (label) from a composite signal that includes the sideband and an orthogonally modulated signal such as an intensity modulated signal (payload) by splicing the composite signal into a polarization maintaining fiber at a desired angle so that the composite signal is separated into two orthogonal polarizations that experience differential group delay in the fiber. The polarized output signals from the fiber are then coupled to a polarization beam splitter at an equivalent or complementary angle to the desired angle so that one sideband of the composite signal appears at a first output of the beam splitter while another sideband appears at a second output of the beam splitter. The sidebands can then be converted to an electrical data signal by using an appropriate receiver, such as a balanced receiver for FSK signals. In one embodiment of the present invention, an input polarization beam splitter is coupled to the polarization maintaining fiber which, in turn, is coupled to an output polarization beam splitter. The coupling at each end of the fiber is made at approximately 45&#xb0; to one polarization axis of the fiber. The fiber is characterized by a beat length Land the fiber is designed to have a length substantially equal to (L&#xd7;f)/2&#x3b4;f, wherein the sidebands of the composite signal are separated by a wavelength difference &#x3b4;f and fis the nominal center frequency of the composite signal. This device has been shown to be useful for extracting GMPLS LSC level wavelength labels from either an FSK/IM composite signal or an SCM/IM composite signal.

Growing community of inventors

Huizen, Netherlands

Jean Gerardus Leonardus Jennen