Tellabs Operations, Inc.

International Business Machines Corporation

Nortel Networks Corporation

Xros, Inc.

Other

Rockstar Consortium US LP

Coriant Operations, Inc.

Rajiv R Ramaswami

Ornan A Gerstel

Robert R Ward

Galen H Sasaki

William Eric Hall

Armand P Neukermans

John C Carrick

Marc R Schuman

Steven M Clark

Frank J Janniello

Mark I Oppenheimer

Chung-Sheng Li

Timothy G Slater

Karen Liu

Franklin F Tong

Jack D Foster

Sam Calmes

Humair Raza

James P Downing

Babu O Narayanan

Jeff Kenneth Kravitz

Paul Eliot Green, Jr

Michael M Choy

John S Forker

Gregory A Reznick

Tyler L Baughman

Osama S Aboul-Magd

John F Heanue

Asit Dan

Brian Tremaine

Dinkar Sitaram

Robert William Keys

Frederic J Simard

Vasant Sahay

David G Steinberg

David Park

Adrian Segall

Chaoyu Yue

Kent Erickson

Subhashini Kaligotia

Steven T Tabaska

A wavelength division multiplexed optical communication system includes a plurality of optical line terminals which may be part of separate in service networks, each having a line interface and an all-optical pass-through interface including a plurality of pass-through optical ports, and each also including a plurality of local optical ports which are connectable to client equipment and an optical multiplexer/demultiplexer for multiplexing/demultiplexing optical wavelengths. The optical multiplexer/demultiplexer may include one or more stages for inputting/outputting individual wavelengths or bands of a predetermined number of wavelengths, or a combination of bands and individual wavelengths. At least one of the pass-through optical ports of an optical line terminal of one network may be connected to at least one of the pass-through optical ports of an optical line terminal of another network to form an optical path from the line interface of the optical line terminal of the one network to the line interface of the optical line terminal of the another network to form a merged network. The use of such optical line terminals allows the upgrading and merging of the separate networks while in service.

Optical line terminal arrangement, apparatus and methods

Automatic discovery and verification of optical communication links as well as isolation of link failures in an optical communication system.

Link discovery, verification, and failure isolation in an optical communication system

A ring communication network according to an embodiment of the present invention includes a plurality of nodes in which a single one of the nodes is configured for full channel conversion and the remaining nodes, other than the single node, are configured for no channel conversion. Links with no more than W channels couple the nodes. The ring communication network also may include N nodes and links connecting the nodes for carrying data in W channels such that N&#x2267;2 logW&#x2212;1 where W is a power of 2. Each of the N nodes includes switches connected such that each channel of a first one of the links adjacent to any one of the N nodes can be switched to no more than W&#x2212;1 channels of another one of the links adjacent any one node.

Multichannel ring and star networks with limited channel conversion

A ring communication network according to an embodiment of the present invention includes a plurality of nodes in which a single one of the nodes is configured for full channel conversion and the remaining nodes, other than the single node, are configured for no channel conversion. Links with no more than W channels couple the nodes. The ring communication network may include N nodes and links connecting the nodes for carrying data in W channels such that N&#x2267;2 logW&#x2212;1, where W is a power of 2. Each of the N nodes includes switches connected such that each channel of a first one of the links adjacent to any one of the N nodes can be switched to no more than W&#x2212;1 channels of another one of the links adjacent to any one node.

Methods and apparatus for managing an optical network using pilot tones are provided. One method includes selecting an optical path having a plurality of nodes from a database defining an expected optical network. A detected list of pilot tones associated with each node of the selected optical path is generated. An expected list of pilot tones associated with each node of the selected optical path is generated. The detected and expected lists are compared to identify any mismatched nodes.

Methods and apparatus for optical network management using pilot tones

A wavelength division multiplexed optical communication system including a first optical line interface optically coupled to a first transponder and an optical demultiplexer through which the first optical line interface is not optically coupled to the first transponder. The system also includes a second optical line interface and at least one switch. The switch is operable to optically couple the second optical line interface to (a) the first optical line interface through at least the optical demultiplexer, and alternatively (b) the second transponder. A method for an optical add/drop multiplexing system also is provided.

A way of testing a wavelength division multiplexed (WDM) system without requiring connection to data source/sink equipment. A test signal is introduced onto a light path of interest in the system, and the test signal is monitored downstream for signal integrity. Lack of signal integrity is used to identify a fault in the lightpath. Alternatively, optical loopbacks may be used to localize and identify a fault in the lightpath. The lightpath includes a source optical node connected to a sink optical node via intermediate optical nodes. An optical signal introduced at the source node with a destination at the sink node may be looped back at any one of the intermediate nodes or the sink node to localize and identify a fault in the lightpath.

Optical network connection test apparatus and methods

Methods and apparatus for managing an optical network using pilot tones are provided. One method includes generating a list of pilot tones contributed by a selected node to each of its target nodes. Network pilot tone sources are re-configured so that a pilot tone source of any optical path incorporating one of the target nodes has a value distinct from the listed pilot tones. The selected node can then be added to the network. Another method includes generating a list including all selected network nodes to be incorporated into a new optical path and nodes adjacent to the selected network nodes. Network pilot tone sources are re-configured until a pilot tone source associated with the new optical path has a pilot tone distinct from that of any listed node. The new optical path can then be added to the network.

Apparatus and methods are disclosed for alignment of an input mirror and an output mirror in a photonic cross-connect.

Alignment laser for use in cross-connects

Methods and apparatus for managing static and dynamic optical network configurations to enable mapping an actual optical network or validating an expected optical network are provided. In one embodiment a validation method includes the step of selecting an optical path having a plurality of nodes from a database defining an expected optical network. A list of detected pilot tones from each node associated with the selected optical path is generated. An expected list of pilot tones associated with each node of the selected optical path is generated. Comparison of the expected and detected lists identifies any mismatched nodes. Another method includes the step of setting a first pilot tone source to have a first pilot tone value. All other network pilot tone sources are set to have another pilot tone value. An optical path associated with the first pilot tone source is then mapped by identifying each node of the network having the first pilot tone value. Extraneous information can be applied to provide greater assurances as to likelihood of possible actual optical paths during the mapping process. Methods of re-configuring network pilot tone sources to preserve mapping and validation abilities when adding nodes, adding optical paths, or even adding another network to a pre-existing network are also provided.

A star communication network including a hub node () and links (E) couple to the hub node for carrying data along routes in W channels. The hub node has switches connecting each channel of a first one of the links to various channels of a second one of the links through the hub node.

One aspect is a method for controllably attenuating the beam of light () coupled between incoming and outgoing optical fibers () by misaligning minor surfaces () included of an optical switching module (). Misalignment of the mirror surfaces (and) causes only a portion of the beam of light () propagating along the incoming optical fiber (), which is less than when the light beam deflectors' mirror surfaces () are precisely aligned, to propagate along the outgoing optical fiber (). Thus, the optical switching module () controllably attenuates the beam of light () coupled between the incoming and the outgoing optical fibers (). Another aspect is a variable-optical-attenuator ('VOA') () that includes an optically reflective membrane () upon which the beam of light () impinges. Application of an electrostatic field between an adjacent electrode () and the membrane () deforms the membrane () thereby attenuating an impinging beam of light ().

Variable attenuation of free-space light beams

Methods, apparatus and systems for regenerating, monitoring and bridging optical signals through an optical cross-connect switch to provide increased reliability. A self testing method, apparatus and system for an optical cross-connect switch. An optical-to-electrical-to-optical converter (O/E/O) is provided in an optical cross-connect switch to provide optical-electrical-optical conversion. I/O port cards having an optical-to-electrical-to-optical converter are referred to as smart port cards while I/O port cards without an optical-to-electrical-to-optical converter are referred to as passive port cards. Test port/monitor cards are also provided for testing optical cross-connect switches. Methods, apparatus and systems for performing bridging, test access, and supporting redundant optical switch fabrics are also disclosed.

Signals and methods for increasing reliability in optical network equipment

Method and apparatus for regenerating optical signals in an all-optical cross-connect switch

Growing community of inventors

Yorktown Heights, NY, United States of America

Rajiv R Ramaswami