Lucent Technologies Inc.

Alcatel-lucent USA Inc.

Robert D Feldman

Thomas Huntington Wood

William A Thompson

Gordon Cook Wilson

David A Sadler

Mahan Movassaghi

Clinton R Giles

Martin C Nuss

Christopher Alan White

Kang-Yih Liou

Daniel Charles Kilper

Carl A Caroli

Luc Boivin

Janet M Greenberg

Singanallur R Thangavelu

Scott D Young

Mile Radovanovic

Thomas A Skrobala

John A Stiles

Lili Yu

A method and apparatus for controlling the power level of an optical signal includes detecting the loss of a supervisory signal counter-propagating in an optical fiber.

Method and apparatus for automatically controlling optical signal power in optical transmission systems

In one embodiment, a control method, according to which a cascade of control messages is propagated between nodes of an optically transparent network, with each message being sent from a node to an adjacent downstream node to inform the latter about a control operation scheduled to be performed at the message-sending node and/or an upstream node that impacts an optical communication signal received at that downstream node. The cascade of control messages effectively creates an ad hoc control domain, in which control operations performed at various nodes of that domain can be coordinated to reduce unfavorable interactions between those control operations. By repeatedly propagating appropriate cascades of control messages through the network, control domains can be changed dynamically and adaptively to reflect any changes to the network topology, equipment, and/or traffic distribution.

Coordination of control operations in an optical network

A method and apparatus for controlling transients in an optical signal propagating along an optical fiber path interconnecting a plurality of network elements employs a power threshold to determine an appropriate response given a change in optical signal power.

Method and apparatus for controlling power transients in an optical communication system

Optical signal power levels for selected optical channels processed within an add/drop node in a wavelength division multiplexed (WDM) system are adjusted as a function of variations in signal power in an incoming WDM signal caused by gain ripple. In particular, a &ldquo;ripple fitting&rdquo; method is described whereby the optical signal power of individual optical channels being added at the add/drop node are adjusted to levels that correspond to the ripple profile of other optical channels being routed through the add/drop node. In this manner, the gain ripple in the WDM signal being output from the add/drop node approximately corresponds to the gain ripple in the incoming WDM signal at the node.

Method of controlling optical signal power at an add/drop node in a WDM optical communication system

A method for identifying faults in a branched optical network having a central office optically connected to a plurality of optical network units by a plurality of optical paths. The method involves transmitting an optical signal from the central office to the optical network units reflecting a portion of the transmitted optical signal back to the central office. This reflected signal is then used to determine whether a fault exists in the branched optical network.

Method for identifying faults in a branched optical network

A passive optical network is provided that integrates signals carrying broadcast CATV services into a FTTH/C network that also provides high-speed Internet access and telephony. Essentially all residential telecommunications services are provided in a single network, based on a single fiber and a single simple transceiver in an optical network unit. Multiple services (e.g., analog video, digital video, cable-modem based Internet access) are multiplexed using separate rf subcarriers (subcarrier multiplexing or SCM) and the delivered signals are compatible with existing consumer appliances (e.g., TVs, VCRs, cable modems, etc.). The system and method combines a bi-directional network with dedicated upstream and downstream networks so that the most expensive and extensive portion of the network (the bi-directional outside plant infrastructure) need not be duplicated for each direction, while the use of two separate dedicated upstream and downstream networks further upstream facilitates flexible provisioning of bandwidth for each direction independently.

Subcarrier modulation fiber-to-the-home/curb (FTTH/C) access system providing broadband communications

A method and apparatus for substantially reducing OBI on optical networks in which a number of source lasers operate simultaneously and the output from the lasers is subsequently combined in the network. The method involves operating the laser in burst mode such that the laser is operational only during transmission periods.

Broadband communications method and apparatus for reducing optical beat

Low-noise, bidirectional communications in a fiber optic cable is achieved by coupling a first end of the cable to an optical power source having an inherently broad spectral width. A second end of the cable is coupled to an optical detector having a detector bandwidth, such that the bandwidth of the optical power source is greater than the detector bandwidth. When the bandwidth of the optical power source is large compared to the bandwidth of the detector, the beat frequencies resulting from coherent Rayleigh noise fall outside the bandwidth of the detector and are not detected.

Suppression of coherent rayleigh noise in bidirectional communication

A passive optical network for the downstream dense wavelength division multiplexing communication of data between a host terminal complex (HTC) and a plurality of optical network units (ONUs), and for the upstream communication of data from the ONUs to the HTC. The network includes a routing device for distributing downstream data signals contained in a common frequency band among a plurality of fiber drop lines for providing a corresponding wavelength to a corresponding ONU. The routing device also combines upstream data signals contained in a frequency band other than the downstream common frequency band, which are input to the routing device on the plurality of fiber drop lines, to a multi-wavelength signal which is provided to the HTC. In a preferred embodiment, the upstream data signals are output by the routing device to a broadcast port.

Passive optical network for dense WDM downstream data transmission and

A lightwave communication system includes an optical distribution system for routing optical signals and a plurality of optical transmitters coupled to the optical distribution system. At least one of the optical transmitters has an amplified light emitting diode for generating an optical spectrum. At least one optical receiver is optically coupled to the optical distribution system.

Growing community of inventors

Middletown, NJ, United States of America

Robert D Feldman