Wavelength Patents (Class 398/48)
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Publication number: 20090238565Abstract: An optical intensity control system for use with an optical switch providing individual signal paths between input and output ports. The system has a optical splitters connectable to output multiplexers of the switch and also has variable optical intensity controllers (VOICs) for insertion into the individual signal paths. The VOICs individually control the intensity of optical signals present in the signal paths in accordance with intensity control signals. An equalizer is connected to the splitters and to the VOICs, for producing an estimate of the optical power of each individual switched optical signal and generating the intensity control signals. The equalizer is adapted to controllably isolate individual switched optical signals.Type: ApplicationFiled: June 2, 2009Publication date: September 24, 2009Applicant: Nortel Networks LimitedInventors: Alan Frank Graves, John G. Gruber, Andrew John Bryant
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Patent number: 7593637Abstract: The invention pertains to optical fiber transmission systems, and is particularly relevant to transmission of high volume of data and voice traffic among different locations. In particular, the improvement teaches the use of a single optical transport system for both metropolitan area transport and long haul transport of data and voice traffic.Type: GrantFiled: April 30, 2003Date of Patent: September 22, 2009Inventors: Angela Chiu, Michael Herbert Eiselt, Jay Martin Wiesenfeld, Lara Denise Garrett, Mark Shtaif
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Patent number: 7590102Abstract: In general, in one aspect, the disclosure describes a multi-stage switch having at least one ingress switch module to receive data and to generate frames that are transmitted as a wavelength division multiplexed signal. The multi-stage switch further includes a core switch module operatively connected to receive the wavelength division multiplexed signal from the at least one ingress switch module and to switch the frames. The multi-stage switch additionally includes at least one egress switch module to receive the wavelength division multiplexed signal from the core switch module and to transmit data.Type: GrantFiled: January 27, 2005Date of Patent: September 15, 2009Assignee: Intel CorporationInventor: Anujan Varma
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Patent number: 7590109Abstract: Methods and apparatus for scheduling transfer of data bursts in a network comprising electronic edge nodes interconnected by bufferless core nodes are disclosed. Each edge node comprises a source node and a sink node, and each core node comprises several bufferless space switches operating in parallel. Each space switch has a master controller and one of the master controllers in a core node functions as a core-node controller. Each master controller has a burst scheduler for computing a schedule for transfer of data bursts, received from source nodes, to respective destination sink nodes. A core-node controller receives requests for bitrate allocations from source nodes and assigns each request to one of the master controllers of the core node. In one embodiment, a scheduler determines schedules for concatenated reconfiguration periods. In another embodiment, parallel schedulers determine schedules for overlapping reconfiguration periods.Type: GrantFiled: April 4, 2007Date of Patent: September 15, 2009Assignee: Nortel Networks LimitedInventors: Maged E. Beshai, Bilel N. Jamoussi
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Publication number: 20090226168Abstract: Optical networks are increasingly employing optical network nodes having multiple interfaces to allow a node to direct optical signals received at any interface to any other interface connected to the node. Constructing a larger wavelength selective switching (WSS) module used in such a node can be complex and expensive. A method an apparatus for constructing a large WSS using parallelism is provided. In example embodiments, a larger WSS may include multiple parallel non-cascaded smaller WSSs and an optical coupler configured to optically couple the multiple parallel, non-cascaded smaller WSSs. This technique may be used to construct both N×1 and 1×N WSSs. Because the technique employs multiple parallel, non-cascaded WSSs, all inputs of a larger N×1 WSS and all outputs of a larger 1×N WSS are available receive or transmit external signals rather than being rather than being unavailable due to, for example, cascading smaller WSS devices together.Type: ApplicationFiled: March 4, 2009Publication date: September 10, 2009Applicant: Tellabs Operations, Inc.Inventor: Mark E. Boduch
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Publication number: 20090226169Abstract: A programmable optical network architecture and associated components employing a two-level orthogonal frequency division multiplexing (OFDM)/wavelength division multiplexed (WDM) mechanisms for bandwith virtualization.Type: ApplicationFiled: February 12, 2009Publication date: September 10, 2009Applicant: NEC Laboratories America, Inc.Inventors: Wei Wei, Junqiang Hu, Lei Zong, Dayou Qian, Ting Wang
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Publication number: 20090220228Abstract: Optical devices extending the free spectral range and tunability of, and enabling hitless switching of, integrated optical filters suitable for add-drop filters.Type: ApplicationFiled: July 25, 2006Publication date: September 3, 2009Applicant: Massachusetts Institute of TechnologyInventor: Milos Popovic
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Patent number: 7580636Abstract: An optical switch is provided with: an optical matrix switch; and an optical path decision section which divides input light into two branches, supplies the input light of one divided branch to the optical matrix switch, demultiplexes the input light of the other divided branch into the light of individual wavelengths, subjects the demultiplexed optical signals to photoelectric conversion and generates electric signals corresponding to individual wavelengths, outputs connection request signals to SW connection request adjustment circuits for O1 to O4 which are set beforehand for individual wavelengths by receiving the generated electric signals, supplies, to the optical matrix switch, input port information JP corresponding to connection request transmitters from which the connection request signals are output, and decides optical paths in the optical matrix switch.Type: GrantFiled: January 4, 2006Date of Patent: August 25, 2009Assignee: Hitachi Communication Technologies, Ltd.Inventor: Yoshio Nogi
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Publication number: 20090185804Abstract: In an optical access network system in which a relay station receives a wavelength multiplexed and time-division multiplexed optical signal (WDM optical signal) from an optical network, and the relay station transmits optical signals having specified wavelengths to subscriber units, the relay station demultiplexes the WDM optical signal into a plurality of groups with one group having a plurality of optical signals having a fixed wavelength interval between signals, then divides the optical signals of each group into k branches (k is the number of subscriber units) and inputs the signals to optical switches, and by turning ON/OFF the optical switches such that they are spaced in time, inputs the branched optical signals to the respective specified subscribers units.Type: ApplicationFiled: November 17, 2008Publication date: July 23, 2009Applicant: FUJITSU LIMITEDInventors: Yutaka Kai, Yasuhiko Aoki
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Patent number: 7561799Abstract: An optical path switching device includes compact and unpackaged components; the components are mounted onto a single platform; and the components are coupled by luminous flux. Connection between optical fibers is negated. In particular the optical path switching device includes an optical input, an optical output, an optical branching device and an optical signal detection device. At least two of the optical input, the optical output, the optical branching device and the optical signal detective device are mounted onto a single platform.Type: GrantFiled: March 8, 2005Date of Patent: July 14, 2009Assignee: Nabtesco CorporationInventors: Masayuki Togawa, Morio Kobayashi
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Publication number: 20090175620Abstract: The present invention provides a wavelength-switched reconfigurable optical add-drop multiplexer (R-OADM) with wavelength broadcasting capability, such that asymmetric video signal distribution and the like can be performed without sacrificing with respect to component complexity and expense. The present invention utilizes an optical splitting and combining device with the wavelength-switched R-OADM to allow the R-OADM to support network-wide wavelength broadcasts without requiring external regeneration and extra optical transceiver equipment.Type: ApplicationFiled: January 8, 2008Publication date: July 9, 2009Inventors: Vipul Bhatnagar, Balakrishnan Sridhar
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Publication number: 20090162059Abstract: A wavelength division multiplexing transmission system in which a first channel using an intensity modulation scheme and a second channel using a phase modulation scheme are present includes a polarization scrambler inserted into a signal path of either one of the first channel and the second channel to perform polarization scrambling, and a drive unit configured to drive the polarization scrambler at frequency greater than or equal to a value defined as: (bit rate of phase modulated signal)/(error correction frame length)×2.Type: ApplicationFiled: December 18, 2008Publication date: June 25, 2009Applicant: FUJITSU LIMITEDInventor: Hiroshi NAKAMOTO
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Publication number: 20090154923Abstract: Provided is a wavelength selective switch (WSS), and more particularly, a wavelength selective switch for electrically switching a wavelength without physical displacement. The wavelength selective switch includes an optical demultiplexer for dividing an input optical signal into signals having wavelengths corresponding to respective channels, selecting either the optical signal of each channel obtained by dividing the input optical signal or an optical signal input via an add port, and outputting the selected optical signal; and an optical multiplexer including an optical deflecting unit for individually deflecting the optical signals of the respective channels received from the optical demultiplexer according to supplied current or applied voltage, wherein the optical signal of each channel deflected by the optical deflecting unit is output to a specific output port.Type: ApplicationFiled: September 11, 2008Publication date: June 18, 2009Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTEInventors: Oh Kee KWON, Yong Soon Baek, Jang Uk Shin, Young Tak Han, Dong Hun Lee, Chul Wook Lee, Eun Deok Sim, Jong Hoi Kim, Sang Pil Han, Sang Ho Park
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Publication number: 20090148162Abstract: A method for providing multi-wavelength switching. The method comprising receiving a plurality of signals through at least one input port, and separating the plurality of said signals into at least one wavelength signal set based on wavelengths, wherein a first wavelength signal set of said at least one wavelength signal sets corresponds to a first wavelength. The method further comprises providing a plurality of output lanes to at least one output port, and determining if two signals from said first wavelength signal set traveling on said first wavelength are scheduled output from an output port during an overlapping time period through said plurality of output lanes.Type: ApplicationFiled: November 10, 2008Publication date: June 11, 2009Applicant: University of HoustonInventors: Wenjing Tang, Yuhua Chen
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Patent number: 7539418Abstract: A system that facilitates optical multiplexing and demultiplexing. The system includes an optical transmitter which is structured in the following way. A wavelength-splitting mechanism is coupled to the optical transmitter, which separates the wavelengths of light onto an array of input-optical-waveguide busses within the optical transmitter. An array of ring modulators within the optical transmitter is coupled to each optical-waveguide bus, wherein the input-end of a given ring modulator is coupled to a corresponding input-optical-waveguide bus. Output-optical-waveguide busses within the optical transmitter are coupled to the array of ring modulators, wherein the output-end of each ring modulator is coupled to a corresponding output-optical-waveguide bus. When a modulation signal is applied to a given ring modulator within the array of ring modulators, a specific wavelength of light is directed to the corresponding output-optical-waveguide bus.Type: GrantFiled: September 16, 2005Date of Patent: May 26, 2009Assignee: Sun Microsystems, Inc.Inventors: Ashok V. Krishnamoorthy, John E. Cunningham
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Publication number: 20090129776Abstract: A wavelength multiplex signal (WDM1, WDM2) having a plurality of channels is supplied to a wavelength-selective switch (WSS1, WSS2) which has a tunable, optical band rejection filter (TUF1, TUF2) at least one input or output. In addition, a controller is provided which is designed such that before a switching operation by the switch (WSS1, WSS2) a channel to be switched is locked by means of the band rejection filter (TUF1, TUF2), the switching operation is performed and then the channel is unlocked.Type: ApplicationFiled: March 8, 2007Publication date: May 21, 2009Inventor: Robert Schimpe
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Publication number: 20090116835Abstract: A wavelength selective switch is provided. The wavelength selective switch according to the present invention comprises: an optical demultiplexer for separating an incident light with a plurality of wavelengths multiplexed into a plurality of wavelength lights and outputting the separated wavelength lights; an optical amplifier for selectively amplifying or absorbing the separated wavelength lights; an optical deflector for selectively deflecting outputs of the optical amplifier; and an optical multiplexer for multiplexing the selectively deflected lights and outputting the multiplexed lights.Type: ApplicationFiled: August 19, 2008Publication date: May 7, 2009Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTEInventors: Oh Kee KWON, Yongsoon Baek, Dong Hun Lee, Chul Wook Lee, Eundeok Sim, Jonghoi Kim
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Publication number: 20090116833Abstract: Each network device holds as a database parameters relating to the size of a factor of signal degradation of the device, and relays the parameters according to a path through which a signal passes. When each network device receives a relayed parameter, it accumulates the parameter of the device to the received parameter value, and transmits the result to the network device at the next stage. The network device on the terminating side of the path estimates the size of the degradation of the signals in the entire path using the received parameter, thereby determining the reachability as to whether or not a signal can be transmitted through the path.Type: ApplicationFiled: September 30, 2008Publication date: May 7, 2009Applicant: FUJITSU LIMITEDInventors: Takayuki SHIMIZU, Hideaki Sugiya, Taichi Ueki
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Patent number: 7529441Abstract: An optical switch for routing arbitrary wavelengths between optical fibers in optical networks. The optical switch may include a highly wavelength dispersive element together with a spatially dispersive element to separate the wavelengths. Broadband switch inputs and outputs may be provided for adding and dropping arbitrary wavelengths at each node of the network. Fiber demultiplexers and multiplexers may also be used to reduce the impact of mirror array yield on switch functionality.Type: GrantFiled: July 2, 2007Date of Patent: May 5, 2009Assignee: Calient Networks, Inc.Inventors: Roger Jonathan Helkey, Shifu Yuan, Xuezhe Zheng
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Publication number: 20090110395Abstract: A network component comprising at least one processor configured to implement a method comprising transmitting a request to compute a routing assignment, a wavelength assignment, or both, wherein the request comprises a lightpath constraint indicator is disclosed. Also disclosed is an apparatus comprising a Path Computation Client (PCC) configured to transmit a request to and receive a reply from a Path Computation Element (PCE), wherein the request comprises a lightpath constraint, and wherein the reply comprises a routing assignment, a wavelength assignment, an error message, a no-path indication, or combinations thereof. Included is a method comprising receiving a request comprising a request parameter (RP) object comprising a lightpath constraint, sending a reply comprising a routing assignment, a wavelength assignment, an error message, a no-path indicator, or combinations thereof, wherein the request is received and the reply is sent using path computation element protocol (PCEP).Type: ApplicationFiled: July 16, 2008Publication date: April 30, 2009Applicant: Futurewei Technologies, Inc.Inventors: Young Lee, Greg Bernstein
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Publication number: 20090110396Abstract: A method is provided for routing optical signals in an optical transport network. The method includes: separating an incoming optical multiplexed signal having a plurality of wavelength-channels embodied therein into two or more channel groups, where each channel group has a subset of the wavelength-channels and channels to be routed hitlessly in a given channel group are adjacent to a channel free region; providing a wavelength selective element for each wavelength-channel to be routed hitlessly; and routing a given wavelength-channel by tuning the corresponding wavelength selective element to either the given wavelength-channel or a channel free region adjacent to the given wavelength-channel. Providing a channel free region next to each channel to be routed allows the use of inexpensive tunable elements, which typically cause hits as they tune, to effect hitless routing.Type: ApplicationFiled: October 25, 2007Publication date: April 30, 2009Inventors: Daniel Levner, Francois Boudreault, Hanan Anis
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Publication number: 20090103919Abstract: A system and method are described for integrating a fiber optic fixed access network and a fiber optic radio access network. At least one radio unit transmits and receives communications with at least one mobile unit. A first multiplexer transmits and receives the communications with the at least one radio unit and fixed access communications with at least one fixed access subscriber. The first multiplexer is connected to each of the at least one radio unit and to each of the at least one fixed access subscriber using fiber optic connections. Each of the at least one radio unit transmits and receives the communications with the first multiplexer using a wavelength that is different for each of the at least one radio unit and different from that used to transmit and receive the fixed access communications from the at least one fixed access subscriber.Type: ApplicationFiled: January 12, 2007Publication date: April 23, 2009Inventors: Hans Mickelsson, Torbjorn Cagenius
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Patent number: 7522837Abstract: An optical communication system is constructed which enables highly reliable and flexible connection to communication nodes connected to a path establishment circuit, by utilizing wavelength-routing characteristics of a path establishment circuit such as an arrayed waveguide grating. The optical communication system has multiple communication nodes having a signal output port and signal input port pair, and a path establishment circuit having multiple optical input ports and multiple optical output ports which are set so that optical signals input from the respective optical input ports are output to predetermined optical output ports corresponding to the wavelengths of the optical signals.Type: GrantFiled: November 19, 2003Date of Patent: April 21, 2009Assignee: Nippon Telegraph and Telephone CorporationInventors: Hiromasa Tanobe, Akira Okada, Morito Matsuoka, Kazuto Noguchi, Takashi Sakamoto, Osamu Moriwaki
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Patent number: 7522836Abstract: A switching element capable of being used in an optical processing device includes an optical signal separator operable to separate a multiple wavelength optical signal into one or more optical signal wavelengths. The switching element further includes a plurality of semiconductor optical amplifiers located on a single semiconductor substrate. The plurality of semiconductor optical amplifiers operable to perform an optical switching operation on at least one of the optical signal wavelengths. The switching element also includes a controller operable to generate a control signal that affects the optical switching operation performed by one or more of the plurality of semiconductor optical amplifiers.Type: GrantFiled: November 30, 2006Date of Patent: April 21, 2009Assignee: Cheetah Omni, LLCInventor: Mohammed N. Islam
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Patent number: 7512340Abstract: An optical network system capable of directly routing optical signals without entailing multiple reception of identical wavelengths. A set wavelength output unit outputs a set wavelength. An Nk-axis filter receives an Nk-axis signal propagated through a ring of an Nk-axis direction and an Nk?1-axis signal split inside the local node, and performs filtering by removing a wavelength identical with that of the Nk?1-axis signal from the Nk-axis signal and adding the wavelength of the Nk?1-axis signal to the Nk-axis signal. An Nk-axis splitter splits the Nk-axis signal into two, one being output to outside through the ring of the Nk-axis direction while the other being output, if k<n, to a confluence with an Nk+1-axis signal, and, if k=n, to a wavelength separation filter. The filter separates a desired wavelength from the Nk-axis signal. Optical transmission media connect nodes so as to constitute an n-dimensional torus network.Type: GrantFiled: July 9, 2008Date of Patent: March 31, 2009Assignee: Fujitsu LimitedInventors: Kyousuke Sone, Yasuhiko Aoki
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Publication number: 20090080886Abstract: A network component comprising at least one processor configured to implement a method comprising transmitting a request to compute a routing assignment, a wavelength assignment, or both for a signal in a wavelength switched optical network, wherein the request comprises a lightpath constraint and wherein the request is transmitted using a path computation element protocol. Also disclosed is a network comprising a first path computation element (PCE) and a path computation client (PCC) in communication with the PCE, wherein the PCC is configured to send a request to and receive a reply from the PCE using a PCE protocol, wherein the request comprises a lightpath constraint. Included is a method comprising sending a discovery advertisement to the at least one PCE that calculates a wavelength assignment, receiving a response comprising a PCE capability information from the PCE, wherein the request and the reply are communicated via a PCE protocol.Type: ApplicationFiled: June 12, 2008Publication date: March 26, 2009Applicant: FUTUREWEI TECHNOLOGIES, INC.Inventors: Young Lee, Greg Bernstein
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Publication number: 20090080885Abstract: An optical network scheduling device (10) including a plurality of schedulers (16) each corresponding to a respective channel in the optical burst switch network and configured to maintain a transmission schedule for the respective channel; and a controller (12) configured to receive a burst transmission request and to select at least one of the schedulers as a selected scheduler schedule a burst transmission.Type: ApplicationFiled: May 27, 2005Publication date: March 26, 2009Applicant: Research Triangel InstituteInventors: Pronita Mehrotra, Dan Stevenson, Mark Cassada, Wayne Dettloff
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Publication number: 20090074409Abstract: A packet-switched WDMA ring network has an architecture utilizing packet stacking and unstacking for enabling nodes to access the entire link capacity by transmitting and receiving packets on available wavelengths. Packets are added and dropped from the ring by optical switches. A flexible credit-based MAC protocol along with an admission algorithm enhance the network throughput capacity.Type: ApplicationFiled: November 10, 2008Publication date: March 19, 2009Inventors: MIKHAIL BORODITSKY, Nicholas J. Frigo, Aleksandra Smiljanic
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Patent number: 7505686Abstract: 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×N cyclic arrayed waveguide grating (AWG); a middle stage includes N tuner modules, and a second N×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.Type: GrantFiled: September 1, 2005Date of Patent: March 17, 2009Assignee: Alcatel-Lucent USA Inc.Inventor: Jean Gerardus Leonardus Jennen
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Publication number: 20090060503Abstract: An optical line terminal (OLT), network and method include input and output switching modules configured to switch between input and output channels. A transmission module is configured for physical layer transmission using at least one of a plurality of transmission technologies to provide multiple uses of an existing transmission line. A dynamic resource module is configured to allocate network resources dynamically to one or more storage area networks (SAN) based on storage resource requests. A service differentiation module is configured to determine and implement different service levels for SAN users. An existing network infrastructure is enabled to provide custom SAN services without a dedicated line and without interfering with existing services.Type: ApplicationFiled: March 7, 2008Publication date: March 5, 2009Applicant: NEC LABORATORIES AMERICA, INC.Inventors: Si Yin, Yuanqiu Luo, Lei Zong, Stephen Rago
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Publication number: 20090060505Abstract: An apparatus, comprising a first node configured to communicate with a second node to generate a wavelength assignment, wherein the first node is configured to send a wavelength availability information to the second node. Included is a network component comprising at least one processor configured to implement a method, comprising receiving a wavelength availability information, and updating the wavelength availability information using a local wavelength availability information. Also included is a method, comprising acquiring a local wavelength assignment information, calculating a local wavelength availability information, and transmitting the local wavelength availability information to a subsequent network element on a lightpath.Type: ApplicationFiled: July 22, 2008Publication date: March 5, 2009Applicant: FUTUREWEI TECHNOLOGIES, INC.Inventors: Greg Bernstein, Young Lee
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Publication number: 20090060504Abstract: An apparatus and method for protection switching of an optical channel at each node in an optical network based on wavelength division multiplexing optical transmission technology are provided. The method can be applied to any node having at least two optical fiber inputs and outputs. The apparatus includes: a splitter receiving an electrical signal and splitting the received electrical signal into a plurality of electrical signals which are substantially identical to the received electrical signal; an output switching unit selecting output paths of the electrical signals split by the splitter according to an optical channel path control command of the optical network; and a plurality of optical transponders being assigned to the respective output paths of the electrical signals, converting the electrical signal input by the selection of the output switching unit to an optical signal, and transmitting the converted optical signal to another node of the optical network.Type: ApplicationFiled: March 21, 2008Publication date: March 5, 2009Applicant: Electronics & Telecommunications Research InstituteInventors: Sun-hyok Chang, Hwan-seok Chung, Sang-soo Lee, Kwang-joon Kim
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Patent number: 7499652Abstract: Consistent with the present invention, tunable demultiplexers are provided in WSS-based add/drop multiplexer. The tunable demultiplexers are modular and thus allow the add/drop multiplexer to be readily expandable, and facilitate flexible add/drop capabilities whereby a channel present on any input line to the WSS can be dropped and supplied to one or more desired outputs of the tunable demultiplexer. Similar flexibility can be achieved on the add-side of the WSS. Moreover, the demultiplexers and the WSS are remotely configurable, thus obviating the need to manually disconnect and connect demultiplexers to a router. In a particular embodiment, multicast switches are provided that permit the same channel, for example, to be provided to one or more outputs of the add/drop multiplexer, such that copy of the channel can carry working traffic while the other copy carries protection traffic. As a result, 1+1 and 1:N optical layer protection can be achieved.Type: GrantFiled: September 14, 2007Date of Patent: March 3, 2009Assignee: Ciena CorporationInventors: Shan Zhong, Charles Haggans
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Publication number: 20090052893Abstract: An optical transmission system comprises a metropolitan core network operated in a wavelength division multiplexing mode and connected via metro connection devices to access connections to optical network terminals connected by means of a passive optical splitter. The metro connection devices contain regenerators and wavelength converters, so that data regeneration takes place between the network terminals and the central management and switching unit. This makes it possible to cover distances around 100 km.Type: ApplicationFiled: March 6, 2006Publication date: February 26, 2009Applicant: Siemens Networks GmbH & Co KGInventors: Stephan Beer, Ansgar Dirkmann, Thomas Nagel
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Publication number: 20090034971Abstract: Methods and apparatuses for multiple redundancy schemes in an optical network are described herein. In one embodiment, an exemplary method includes receiving a demand for allocating a first protection path that meets a first set of disjointness constraints with respect to a first working path according to a first protection scheme having a first priority, in response to the demand, locating a second protection path that meets a second set of disjointness constraints with respect to a second working path according to a second protection scheme having a second priority, and assigning the second protection path as a protection path to the first working path if the first priority of the first protection scheme is higher than the second priority of the second protection scheme. Other methods and apparatuses are also described.Type: ApplicationFiled: February 17, 2004Publication date: February 5, 2009Inventor: Santosh Kumar Sadanada
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Patent number: 7483631Abstract: A method and apparatus for scheduling data burst transmission in a wavelength-division-multiplexing photonic burst-switched network is disclosed. In one embodiment, a scheduler determines a set of weighting factors at each wavelength for each of the lightpath segments among all the network nodes. These weighting factors may be used to calculate a set of coarse-grained bandwidth allocation factors, one for each potential lightpath formed from the available lightpath segments between an ingress node and an egress node. The scheduler may schedule the transmission of the data burst on one of the lightpaths that has a coarse-grained bandwidth allocation factor which indicates that it can support the requested bandwidth. The scheduler may periodically update the set of weighting factors at each wavelength for each of the lightpath segments.Type: GrantFiled: December 24, 2002Date of Patent: January 27, 2009Assignee: Intel CorporationInventors: Shlomo Ovadia, Christian Maciocco
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Publication number: 20080304827Abstract: It is an object of the present invention to provide an FSK demodulator which can be used in the optical information and telecommunications and the like, and which can appropriately demodulate an FSK signal by compensating a delay of an optical FSK modulated signal due to dispersion and the like of an optical fiber. The above mentioned problem is solved by a frequency shift keying (FSK) demodulator (1) composed of a branching filyer (2) for branching an optical signal according to wavelengths thereof; a delay adjusting apparutus (3) for adjusting a delay time of two lights branched by the branching filter; a first photodetector (4) for detecting one optical signal branched by the branching filter; a second photodetector (5) for detecting a remaing optical signal branched by the branching filter; and a means (6) for calculating a difference between an output signal of the first photodetector and an output signal of the second photodetector.Type: ApplicationFiled: July 19, 2005Publication date: December 11, 2008Applicants: ADMINISTRATIVE AGENCYInventors: Tetsuya Kawanishi, Masayuki Izutsu
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Publication number: 20080298805Abstract: A network component comprising at least one processor configured to implement a method comprising collecting wavelength availability information associated with a wavelength switched optical network (WSON), receiving a path computation request to transport a signal through the WSON, calculating at least one route through the WSON for the signal, and assigning at least one wavelength for the signal to use along the route. Also disclosed is a network comprising a first path computation element (PCE) configured to compute at least one route for a signal between a source and a destination, and a second PCE in communication with the first PCE, wherein the second PCE is configured to receive the route from the first PCE and assign at least one wavelength to the route.Type: ApplicationFiled: March 5, 2008Publication date: December 4, 2008Applicant: FUTUREWEI TECHNOLOGIES, INC.Inventors: Young LEE, Greg BERNSTEIN
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Patent number: 7460783Abstract: Method and apparatus for dynamic provisioning of reliable connections in the presence of multiple failures in optical networks are described. One embodiment is a method for allocation of protection paths after a failure in an optical network. The method comprises, responsive to a failure in an active lightpath, switching traffic on the active lightpath to a protection path; subsequent to the switching, identifying all active lightpaths in the network that no longer have an available protection path; and attempting to allocate a protection path to each of the identified active lightpaths.Type: GrantFiled: October 2, 2003Date of Patent: December 2, 2008Assignee: Alcatel LucentInventors: Andrea Fumagalli, Sandeep Darisala, Parthasarathy Kothandaraman, Marco Tacca, Luca Valcarenghi, Maher Ali, David Eli-Dit-Cosaque
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Patent number: 7457539Abstract: A 2×2 optical switch routs each light signal received from input ports to selected output. The optical switch has an adjustable light signal steering element, a fixed light signal steering element, and a steering element actuator. The adjustable light signal steering element is repositioned by the steering element actuator to selectively place one light signal received from the input ports such that the light signal is transferred from the input port to a selected output port. The fixed light signal steering element is placed in the path of each light signal such the light signals from the input ports is transferred to of mirrors, prisms, and light waveguides, default output ports, when the adjustable light steering element is removed from the path of each light signal.Type: GrantFiled: May 10, 2004Date of Patent: November 25, 2008Assignee: LIGHTech Fiberoptics, Inc.Inventor: Jimmy Ko
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Publication number: 20080247753Abstract: An optical switch assembly is provided having a plurality of optoelectronic switching nodes. Each node is a three terminal optical device having a first optical input, a second optical input and an optical output. Each node can be electrically activated or deactivated via an electrical control input. Each node has a transmittance between its second optical input and its optical output. This transmittance depends on the signal at the first optical input if the node is activated, and is independent of the first optical input if the node is deactivated. Thus modulation at the first optical input can be selectively imposed on the optical output. The switch includes at least two chains of nodes, each chain having two or more nodes connected in series such that each pair of adjacent nodes is connected from optical output to second optical input. Switches according to the invention can be configured as optical crossbar switches or optical routers.Type: ApplicationFiled: January 19, 2006Publication date: October 9, 2008Inventors: Hilml Volkan Demir, David A.B. Miller, Vijit Ashok Sabnis
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Patent number: 7433594Abstract: An optical wavelength division multiplexing network has a multi-level structure where a plurality of optical network units (ONUs) are connected to a lowest-level network. A node apparatus connected to networks other than the lowest-level network includes (a) passive optical components to branch optical signals from a higher-level network to a lower-level network, and couple optical signals from the lower-level network to the higher-level network, and (b) optical amplifiers for the optical signals. A node apparatus connected to the lowest-level network includes (a) an optical multiplexer/de-multiplexer to de-multiplex optical signals from the higher-level network, selectively output an optical signal to each ONU, and multiplex wave-length specific optical signals from the ONUs into a multiplexed optical signal, and (b) optical amplifiers for the optical signals.Type: GrantFiled: October 12, 2006Date of Patent: October 7, 2008Assignee: Nippon Telegraph and Telephone CorporationInventors: Noboru Takachio, Katsumi Iwatsuki, Hitoshi Obara
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Patent number: 7434249Abstract: A fiber to the home (FTTH) system based on a passive optical network (PON) includes an optical line terminal (OLT) block, an optical network terminal (ONT) block, and an optical distribution network (ODN). The ONT block includes a video-optical line terminal (V-OLT) and an OLT to output optical signals of the V-OLT and the OLT by multiplexing the optical signals. The V-OLT receives cable TV (CATV), master antenna (MATV), and satellite broadcasting (SB) optical signals inputted from a broadcasting service network to output received signals as a first optical signal having a predetermined wavelength band. The ONT block includes a video-optical network terminal (V-ONT) and an (ONT) to split multiplexed data communications signals, and CATV broadcasting, MATV broadcasting, and (SB) optical signals. The V-ONT processes the split CATV broadcasting, MATV, and (SB) optical signals to provide subscribers with the split cable CATV, MATV and SB optical signals.Type: GrantFiled: May 24, 2004Date of Patent: October 7, 2008Assignee: Samsung Electronics Co., Ltd.Inventors: Se-Hong Park, Seong-Ha Kim, Gil-Yong Park, Tae-Sung Park
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Publication number: 20080232738Abstract: Systems and methods to reduce passband side-lobes associated with WSS-based ROADMs by applying a filter on each channel are provided. In an exemplary embodiment, a comb filter, such as a thin film filter or an interleaver, is utilized. Additionally, the present invention provides systems and methods to adaptively control amplifier target power and per wavelength target power to maintain signal launching power as per design in networks with WSS-based ROADMs. Accordingly, signal OSNR does not collapse faster than other similar configured system without WSS-based ROADM. In order to correct amplifier target power, the present invention utilizes system information about side-lobe size and OSNR at each amplifier.Type: ApplicationFiled: October 31, 2007Publication date: September 25, 2008Inventors: Xiaohui Yang, Zhonghua Zhu
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Publication number: 20080232800Abstract: An example embodiment of the present invention is a non-blocking wavelength switching architecture that enables graceful scaling of a network wavelength switching node from small to large fiber counts using fixed size bidirectional 1×N Wavelength Selective Switches (WSS). The architecture uses an intermediate broadcast and select layer implemented using optical splitters and WSSs to eliminate wavelength blocking.Type: ApplicationFiled: March 11, 2008Publication date: September 25, 2008Applicant: Polatis Photonics, Inc.Inventor: Richard A. Jensen
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Patent number: 7428383Abstract: An intelligent photonic burst switched (PBS) network includes edge nodes and switching nodes. The PBS edge node includes a flow classifier, flow manager, and ingress/egress PBS MAC layer components. The flow classifier classifies information received from outside the PBS network into forward-equivalent classes. The flow manager determines whether the information is to be sent over the PBS network or elsewhere. Information to be sent over the PBS network is processed by the ingress PBS MAC layer component, which assembles the information into data bursts, schedules the transmission of the data burst, builds a control burst, and frames the data and control bursts, which are to be optically transmitted over the PBS network. The egress PBS MAC layer component receives control bursts and the corresponding data bursts, de-frames the data bursts, and appropriately assembles the data. The data is then classified and transmitted to the intended destination.Type: GrantFiled: February 28, 2003Date of Patent: September 23, 2008Assignee: Intel CorporationInventors: Christian Maciocco, Shlomo Ovadia
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Patent number: 7428384Abstract: According the invention, a multiplexed light composed of a signal light of a signal wavelength, and a first route control light of a first route control wavelength different from the signal wavelength or a second route control light of a second route control wavelength different from the signal light and the first route control wavelength is incident to a demultiplexer. The demultiplexer demultiplexes the signal light of the signal wavelength, the first route control light, and the second route control light from the multiplexed light. An interferometer optical switch outputs the signal light from first output port according to the first route control light, and outputs the signal light from second output port according to the second route control light.Type: GrantFiled: December 28, 2004Date of Patent: September 23, 2008Assignee: National Institute of Information and Communications Technology Incorporated Administrative AgencyInventor: Tetsuya Miyazaki
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Publication number: 20080226292Abstract: Disclosed is a method for transmitting Ethernet service signals in a Wavelength Division Multiplexing (WDM) network, including: a Center receiving Ethernet service signals and transmitting the signals to a transmission channel; a receiving station receives the Ethernet service signals, performs a space-division cross operation upon the received signals, duplicates the signals into two copies, where one is locally downloaded while the other is returned to the transmission channel. Three devices for processing the Ethernet service signals in the WDM network are provided. With the present invention, the broadcast of the Ethernet service signals with large granularity is implemented, therefore decreasing the delay for broadcast the real-time services; besides, it is not necessary anymore to construct a overlapped network with three layers of devices, i.e. a WDM system, a Synchronous Digital Hierarchy (SDH) system and a data device, so the network structure is simplified and management is convenient.Type: ApplicationFiled: March 9, 2006Publication date: September 18, 2008Applicant: Huawei Technology Co., Ltd.Inventors: Weishi Li, Qianjin Xiong, Jianmei Zhang, Dianjun Xiao
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Patent number: 7426347Abstract: An apparatus for shared optical performance monitoring (OPM) is provided. A wavelength sensitive device receives light at an input port and routes it wavelength selectively to a set of output ports. To perform optical performance monitoring on the output ports, a monitoring component of each output signal is extracted, and these monitoring components are then combined. A single OPM function is then performed on the combined signal. However, with knowledge of the wavelengths that were included in each output signal, a virtual OPM function can be realized for each output port. The per port functionality can include total power per port, power per wavelength per port, variable optical attentuation, dynamic gain equalization, the latter two examples requiring feedback.Type: GrantFiled: July 15, 2005Date of Patent: September 16, 2008Assignee: JDS Uniphase CorporationInventors: Alan Hnatiw, Sheldon Walklin, Thomas Ducellier
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Publication number: 20080219662Abstract: A reconfigurable optical add-drop mulitplexer comprises a first waveguide layer having formed therein a first multiplexer-demultiplexer, a second multiplexer-demultiplexer, and a plurality of optical switches. The reconfigurable optical add-drop multiplexer further comprises a second waveguide layer optically coupled to the first waveguide and having a second effective index of refraction, said second waveguide layer having an optical amplifier formed therein. An input signal is amplified by the optical amplifier and communicated to the first optical multiplexer-demultiplexer where the signal is demultiplexed into a plurality individual wavelength signals. The second optical multiplexer-demultiplexer is adapted to receive a multiplexed add signal and to demultiplex the add signal into component wavelength signals. The individual wavelength signals are received at the optical switches and selectively routed to either an optical detector or toward the first multiplexer-demultiplexer.Type: ApplicationFiled: October 26, 2007Publication date: September 11, 2008Applicant: The Trustees Of Princeton UniversityInventors: Shashank S. Agashe, Kuen-Ting R. Shiu, Stephen R. Forrest