Monitoring Patents (Class 398/33)
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Patent number: 7567758Abstract: A transceiver module having intergrated eye diagram opening functionality for reducing jitter is describe. The transceiver module may transmitter eye opener and a receiver eye opener integrated in a single circuit. The transceiver module may also include serial control and various other integrated components. Other functionalities that may be integrated on the transceiver module include loopback modes, bypass features, bit error rate testing, and power down mode.Type: GrantFiled: July 28, 2003Date of Patent: July 28, 2009Assignee: Finisar CorporationInventors: Lewis B. Aronson, Rudy Hofmeister, Christopher Madden, Mark Farley, Dan Case, Tom Lenosky
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Patent number: 7565079Abstract: A system and method are presented for demarcating an optical network. The system comprises an optical monitor that receives a portion of an outbound signal from an optical network and generates a switch control signal based on the intensity of the outbound signal. Generally, the switch control signal is active when the intensity of the outbound signal falls below a threshold value. Alternatively, the system comprises an override switch, and the switch control signal is active when the override signal is activated or the outbound signal falls below a threshold value. An optical switch receives the switch control signal, and selectively isolates the network generating the outbound signal from the rest of the network when the switch control signal is active.Type: GrantFiled: September 6, 2006Date of Patent: July 21, 2009Assignee: Westell Technologies, Inc.Inventors: Christopher F. Simanonis, Daniel Wynard
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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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Patent number: 7561796Abstract: An optical transmission system for transmitting optical signals in which signals at different bit rates coexist, includes an optical sending apparatus for, when one or more faults are detected in a signal for transmission, generating a fault information signal with one frequency set in advance in accordance with the faults, converting the fault information signal into an optical signal, and sending out the optical signal, an optical transmission line for transmitting the optical signal sent out from the optical sending apparatus, and an optical receiving apparatus for receiving the optical signal transmitted through the optical transmission line, converting the received optical signal into an electric signal, detecting the fault information signal from the electric signal, and halting output of the electric signal to the outside.Type: GrantFiled: June 30, 2006Date of Patent: July 14, 2009Assignee: NEC CorporationInventor: Makoto Ishiguro
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Patent number: 7558479Abstract: An optical communications system has a plurality of spans between a transmitter and a receiver. The receiver has optical to electrical conversion circuitry for converting the received optical signal to an electric signal, analogue to digital conversion circuitry and digital signal processing means for analysing the electrical digital signal. The digital signal processing means derives information concerning characteristics of individual spans from the electrical digital signal. This enables parameters such as per-span variations in provisioned power, local dispersion and span loss to be measured. In-service measurements of system characteristics can be used to enable optimisation of the network operation.Type: GrantFiled: April 15, 2004Date of Patent: July 7, 2009Assignee: Nortel Networks LimitedInventor: Alan Robinson
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Patent number: 7551857Abstract: An optical amplifier may be quickly returned from a shutdown state to a regular state after getting recovery information of a fault. Gain setting by ASE is conducted to the repeaters on the up-stream side during the shutdown state, by outputting ASE light with the same intensity as the WDM signal. Accordingly, before realizing the recovery of shutdown, the gain setting is completed with the light whose intensity is within the safe criterion. After realizing the recovery of shutdown, the optical transmission system can be returned quickly to the regular operating state after recovery of shutdown state.Type: GrantFiled: July 11, 2005Date of Patent: June 23, 2009Assignee: Fujitsu LimitedInventors: Tougo Fukushi, Hideaki Sugiya, Akira Yamamoto, Masanori Kondoh
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Patent number: 7551852Abstract: A method and apparatus configured to transmit module data between optic modules over a primary communication channel, such as an optic fiber configured to carry network data or outgoing data. A control center may send the module data, such as any type of DDMI data, over the optic fiber to control one or more aspects of the optic module system. The optic module may also be configured to send module data regarding any aspect of module status or operation, to a control center, via the optic fiber. Use of the primary communication channel, normally reserved for only network data, allow for module to module communication or module to control center communication without need of cumbersome two wire interface or supplement channels. Optic module data communication may occur concurrent with network data transmission. Optic module data back-up may occur via the optic channel to provide rapid re-load of important optic module data.Type: GrantFiled: July 15, 2005Date of Patent: June 23, 2009Assignee: Mindspeed Technologies, Inc.Inventors: Maurice M. Reintjes, Daniel Draper, Gilberto I. Sada
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Patent number: 7548696Abstract: A fiber-to-the-home (FTTH) system transmits forward and reverse optical signals, such as video, voice, and data signals, via optical fiber, and includes a plurality of home network units. The home network units include an optical receiver for receiving at least one of the video, voice, and data signals. Included is a plurality of gain stages that are distributed throughout the optical receiver. The gain stages include a preamplifier stage, two interstage amplifiers, and a postamplifier stage. Two gain control circuits automatically adjust the gain of the video signal based upon the input power level to the FTTH optical receiver. Additionally, a tilt network performs level compensation for externally located coaxial cable. A signal is then provided to a device located within a home via the coaxial cable at the proper RF level having low noise signals.Type: GrantFiled: February 15, 2006Date of Patent: June 16, 2009Assignee: Scientific-Atlanta, Inc.Inventor: Robert R. Riggsby
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Patent number: 7546035Abstract: The invention relates to a method for conveying management information in a WDM system from a number of wavelength converters to a central management unit, wherein a management information signal is superimposed on the WDM signal from the respective wavelength converter. A fraction of the optical signal in the common optical transmission line is tapped off to a detector and the different management information signals are recovered by a receiver unit which is connected to the detector. The invention also relates to a WDM system and a pluggable WDM wavelength converter.Type: GrantFiled: May 11, 2004Date of Patent: June 9, 2009Assignee: Transmode Systems ABInventors: Gunnar Forsberg, Johan Sandell
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Publication number: 20090142053Abstract: The present invention is directed toward systems for conducting laser range and enabling optical communication between a plurality of entities and to the application of such systems in a secure covert combat identification system. In one embodiment, the present invention uses a novel laser system that generates high pulse rates, as required for optical communications, while concurrently generating sufficiently high power levels, as required by laser range finding operations. One application of the present invention is in enabling secure covert communications between a plurality of parties. Another application of the present invention is in tracking and identifying the movement of objects.Type: ApplicationFiled: December 10, 2008Publication date: June 4, 2009Applicant: Cubic CorporationInventors: Deepak Varshneya, John Roes
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Patent number: 7542674Abstract: Systems and methods for verifying performance at an intermediate point in an optical link are provided by virtue of one embodiment of the present invention. One application is locating a fault along a long optical link while minimizing the need for trained personnel to inspect and monitor the link at numerous widely separated locations. At an intermediate point in the link, a portion of the optical signal present is tapped off and demodulated. By use of error correction decoding techniques on the demodulated data, the performance of the link up until that intermediate point may be verified.Type: GrantFiled: May 24, 2001Date of Patent: June 2, 2009Assignee: Cisco Technology, Inc.Inventors: Gianpaolo Barozzi, Mauro Macchi, Andrea Marchio
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Patent number: 7539413Abstract: The present invention discloses a submarine observation system in which a plurality of carrier lights assigned to each submarine observation equipment is transmitted from a land terminal apparatus to an optical submarine cable (down-going) by using a WDM transmission. In the submarine observation equipment, only a prescribed carrier light is demultiplexed by an optical demultiplexer, an observation signal indicating an observation result is generated by an observation device, intensity of the carrier light demultiplexed by the optical demultiplexer is modulated by an optical amplifier based on an observation signal, and the modulated carrier light is multiplexed by an optical multiplexer. The multiplexed carrier light is output to the optical submarine cable (up-going) to be returned to the land terminal apparatus being the transmission station.Type: GrantFiled: March 14, 2005Date of Patent: May 26, 2009Assignees: Mitsubishi Denki Kabushiki Kaisha, Independent Administrative Institution, Japan Agency for Marine-Earth Science and TechnologyInventors: Hiroaki Munehira, Junichi Nakagawa, Toshiyuki Tokura, Kenichi Asakawa, Hitoshi Mikada, Katsuyoshi Kawaguchi
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Patent number: 7526200Abstract: An optical transmission apparatus includes optical transmitters for transmitting optical signals and first monitor units for monitoring optical signals from the optical transmitters. A multiplexer is provided for multiplexing the optical signals from the optical transmitters into a multiplexed signal. A second monitor unit is provided for monitoring each optical signal which is multiplexed in the multiplexed signal from the multiplexer. A processing unit is provided for comparing a first number of optical signals detected by the first monitor units and a second number of optical signals detected by the second monitor unit.Type: GrantFiled: August 29, 2005Date of Patent: April 28, 2009Assignee: Hitachi Communication Technologies, Ltd.Inventors: Hiroyuki Nakano, Yasuyuki Fukashiro
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Patent number: 7526199Abstract: An optical transmission apparatus includes a demultiplexer for separating wavelength-division multiplexing light received from a first optical transmission line into signals of different wavelengths to transmit the signals to an outside and a multiplexer for multiplexing signals of different wavelengths received from the outside to transmit multiplexed signals to a second optical transmission line. An input check unit is provided for monitoring a power level of a signal separated by the demultiplexer and for providing an output indicative thereof. An output adjuster is provided for intercepting a signal from the outside so as to inhibit receipt of the signal from the outside by the multiplexer depending on the output of the input check unit.Type: GrantFiled: July 20, 2005Date of Patent: April 28, 2009Assignee: Hitachi Communication Technologies, Ltd.Inventors: Kenro Sekine, Junya Kosaka, Tadashi Matsuoka
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Patent number: 7522842Abstract: A commercially viable All-Raman system, is implemented by removing the dispersion compensating Fiber (DCF) and two stage amplifier at each span, and including a transmission path dispersion compensator which performs dispersion compensation on a transmission path basis. For example, by pre-compensating for the accumulated dispersion in the electrical domain at the transmitter, the gain of the Raman pumps at each span amplifier need only compensate for the loss within the span, without needing to compensate for the loss of a DCF. In addition there is provided a low-cost method for implementing a bidirectional Service Channel by modulating/demodulating low-rate data on the Raman pump. For example, a Raman amplifier can include an information source for producing a service channel signal which includes information to be communicated; and a modulator for modulating the Raman pump signal with the service channel signal.Type: GrantFiled: September 30, 2005Date of Patent: April 21, 2009Assignee: Nortel Networks LimitedInventors: John McNicol, Kuang Tsan Wu
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Patent number: 7522845Abstract: A transmitter (11) emits a single wavelength optical signal and transmits this as a wavelength channel (13) in a compound multiplex signal through the WDM network. The receiver (12) selects the single wavelength optical signal (21) from the compound multiplex signal using a band-pass filter. A wavelength fit detector (15) determines a feedback signal by correlating variations of the amplitude of the received signal with variations of the traffic density. This feedback signal is then returned to the transmitter (11) via a back channel (16) and serves to tune the wavelength of the single wavelength optical signal.Type: GrantFiled: July 14, 2005Date of Patent: April 21, 2009Assignee: AlcatelInventor: Wolfram Lautenschläger
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Patent number: 7509047Abstract: Apparatus and method for transmitting a supervisory signal for optical network applications. The apparatus includes a subcarrier transmission system configured to receive a first supervisory signal and output a second supervisory signal, and an electrical-to-optical conversion system configured to receive the second supervisory signal and a data signal and output an optical signal. The second supervisory signal is associated with a subcarrier frequency. The data signal is associated with a data bandwidth, and the data bandwidth includes a data frequency. At the data frequency, a power density of the data signal is substantially equal to zero. A ratio of the subcarrier frequency to the data frequency ranges from 0.8 to 1, and the subcarrier frequency ranges from 2.4 GHz to 2.483 GHz.Type: GrantFiled: March 2, 2005Date of Patent: March 24, 2009Assignee: FutureWei Technologies, Inc.Inventor: Yu Sheng Bai
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Patent number: 7509438Abstract: Methods and apparatus for enabling a protection path within a network to be monitored are disclosed. According to one aspect of the present invention, a method for sending traffic on a path within an optical network system that has a plurality of nodes and a plurality of fibers includes identifying a circuit path within the optical network system which is associated with a first node and includes at least one fiber. The method also includes sending a signal that includes embedded path trace information on the circuit path from the first node on the fiber, and determining when the signal is received from the first node by a second node over the fiber. Finally, the method includes broadcasting path trace information to the plurality of nodes when it is determined that the signal is not received by the second node over the fiber.Type: GrantFiled: February 14, 2003Date of Patent: March 24, 2009Assignee: Cisco Technology, Inc.Inventors: Chenchuan Lu, Philippe Daniel
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Patent number: 7502565Abstract: A laser filter circuit includes an input terminal configured to receive an input laser signal and a first filter chain configured to generate a filtered signal. The first filter chain is coupled to the input terminal and has one or more filters connected in series. Each filter includes one or more adjustable capacitor networks. An adjustable capacitor controller generates one or more capacitor switch control signals based on an operating frequency of the input laser signal. The one or more control signals are for adjusting the capacitance of the one or more adjustable capacitor networks in the first filter chain. A plurality of output terminal output the filtered signal from the first filter chain.Type: GrantFiled: March 4, 2005Date of Patent: March 10, 2009Assignee: Finisar CorporationInventor: Timothy G. Moran
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Patent number: 7493040Abstract: A method and apparatus for securing an optical communication link includes the step of identifying a profile of the link by measuring, at the transmitter, optical back-reflections from optical pulses forwarded to a receiver. The profile is stored at the transmitter. Periodically during operation, such as during key exchange, more optical pulses are forwarded to the receiver, and the back reflections are collected as periodic profiles. The periodic profiles are compared against the stored profiles. Eavesdroppers, such as those who cut the fiber, tap the fiber, or implement a man in the middle attack, may be easily identified because the losses caused by their interference with the fiber will be evident in the periodic profiles.Type: GrantFiled: July 15, 2004Date of Patent: February 17, 2009Assignee: Nortel Networks LimitedInventors: Bruce Schofield, Franco Travostino, Indermohan Monga, Victor Firoiu
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Patent number: 7489865Abstract: The present invention is directed toward systems for conducting laser range and enabling optical communication between a plurality of entities and to the application of such systems in a secure covert combat identification system. In one embodiment, the present invention uses a novel laser system that generates high pulse rates, as required for optical communications, while concurrently generating sufficiently high power levels, as required by laser range finding operations. One application of the present invention is in enabling secure covert communications between a plurality of parties. Another application of the present invention is in tracking and identifying the movement of objects.Type: GrantFiled: June 13, 2003Date of Patent: February 10, 2009Assignee: Cubic CorporationInventors: Deepak Varshneya, John Roes
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Publication number: 20090034967Abstract: I branch is provided with a first interferometer, a first balanced optical detector, and a first data recovery circuit. Q branch is provided with a second interferometer, a second balanced optical detector and a second data recovery circuit. In I branch, a mixer multiples input signal of the first data recovery circuit with output signal of the second recovery circuit. An averaging circuit averages output signal of the mixer. In Q branch, a mixer multiples input signal of the second data recovery circuit with output signal of the first recovery circuit. An averaging circuit averages output signal of the mixer. A first phase control apparatus controls the phase of a phase shifter comprised in the first interferometer based on the output signal of the averaging circuit. A second phase control apparatus, in the same manner, controls the phase of a phase shifter comprised in the second interferometer.Type: ApplicationFiled: July 7, 2006Publication date: February 5, 2009Inventors: Zhenning Tao, Jens C. Rasmussen, Akihiko Isomura
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Patent number: 7486889Abstract: A transceiver test module and method for testing an optical transceiver. An optical wrap interconnects the optical transmitter and optical receiver of an optical transceiver. A processor system reads information from an optical transceiver; provides a signal to the optical transceiver to operate the optical transceiver to transmit a signal at the optical transmitter, which is received via the optical wrap; detects diagnostic information from the optical transceiver for errors of the optical transceiver; and determines the rated speed of the optical transceiver from the read information. Operation of the optical transceiver at the rated speed is verified by the diagnostic information.Type: GrantFiled: June 23, 2006Date of Patent: February 3, 2009Assignee: International Business Machines CorporationInventors: Jonathan Wade Ain, Craig Anthony Klein
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Patent number: 7486893Abstract: The disclosed technology provides a dynamic interconnection system which allows to couple a pair of optical beams carrying modulation information. In accordance with the disclosed technology, two optical beams emanate from transceivers at two different locations. Each beam may not see the other beam point of origin (non-line-of-sight link), but both beams can see a third platform that contains the system of the disclosed technology. Each beam incident on the interconnection system is directed into the reverse direction of the other, so that each transceiver will detect the beam which emanated from the other transceiver. The system dynamically compensates for propagation distortions preferably using closed-loop optical devices, while preserving the information encoded on each beam.Type: GrantFiled: August 15, 2005Date of Patent: February 3, 2009Assignee: HRL Laboratories, LLCInventors: David M. Pepper, Richard P. Berg
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Publication number: 20090022490Abstract: A method for data-flow protection of an optical interface in data communication equipment includes: receiving an optical-signal from a source-neighboring device, then duplicating the received optical signal into two duplicated optical signals. One of the optical signals is sent to a protected device for processing. According to the protected device working status, either the optical signal having been processed by the protected device or the second duplicated optical signal is selected and sent to a destination-neighboring device. The device includes a first optical-signal duplicating unit and an optical-signal selecting unit. The first optical-signal duplicating unit is used for duplicating an optical signal, and the optical-signal selecting unit is used as a selector. The method and device proposed by the disclosure are independent to network topology and can protect data-flow reliably.Type: ApplicationFiled: September 26, 2008Publication date: January 22, 2009Applicant: HUAWEI TECHNOLOGIES CO., LTD.Inventors: Chongyang Wang, Zhichun Zhang, Shuyou Dong
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Patent number: 7477847Abstract: Optical transceivers have loopback and pass-through paths for diagnosing transceiver components and optical networks connected to the optical transceiver or for routing data out of the transceiver in a pass-through mode. The loopback paths are selectively configured so that a selected number of the components in the transceiver are included in the loopback path. Where more than one loopback path is present, a network administrator can select which components will be included in a particular test so that, depending on whether a signal is returned on the loopback path as intended, the network administrator can determine which components are operating correctly and which are faulty. The loopbacks can be configured to run on the electrical side of the transceiver from input port to output port or on the optical side from receiver to transmitter. The pass-through paths can be used to connect the transceiver to other devices.Type: GrantFiled: July 25, 2003Date of Patent: January 13, 2009Assignee: Finisar CorporationInventors: Rudolf J. Hofmeister, Greta Light
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Publication number: 20090010644Abstract: The present invention is directed toward systems for conducting laser range and enabling optical communication between a plurality of entities and to the application of such systems in a secure covert combat identification system. In one embodiment, the present invention uses a novel laser system that generates high pulse rates, as required for optical communications, while concurrently generating sufficiently high power levels, as required by laser range finding operations. One application of the present invention is in enabling secure covert communications between a plurality of parties. Another application of the present invention is in tracking and identifying the movement of objects.Type: ApplicationFiled: June 13, 2003Publication date: January 8, 2009Inventors: Deepak Varshneya, John Roes
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Patent number: 7474852Abstract: A system for communication of signals between remote devices and monitoring and control devices via fiber. The system in accordance with one aspect of the invention includes a plurality of remote interface units each coupled to a corresponding one of the remote devices, a base unit coupled to one or more monitoring devices and one or more control devices, and a central hub coupled between the base unit and the plurality of remote interface units. The central hub is coupled to the base unit by a first fiber optic link, and is coupled to the remote interface units by additional fiber optic links.Type: GrantFiled: February 11, 2005Date of Patent: January 6, 2009Assignee: Multidyne Electronics Inc.Inventors: Vincent Jachetta, Brian C. Moore, James G. Jachetta, Francis P. Jachetta
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Patent number: 7471898Abstract: Disclosed is a device and method for optical supervisory channel framing in an optical transport network system including at least one of an optical transmission section, an optical multiplex section, and an optical channel section. A maintenance signal is generated according to a first LOS (Loss OF Signal) signal generated from at least one of the optical transmission section, the optical multiplex section, and the optical channel section. The maintenance signal and a frame-related channel such as a message communication channel are multiplexed to generate an optical supervisory channel frame. The optical supervisory channel frame is output to another device including a repeater and a terminal system through a single supervisory channel.Type: GrantFiled: April 29, 2004Date of Patent: December 30, 2008Assignee: Electronics and Telecommunications Research InstituteInventors: Jong-Yoon Shin, Ji-Sung Jung, Yool Kwon, Je-Soo Ko
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Publication number: 20080317463Abstract: An optical transmitter system supplies a plurality of different wavelength optical radiation components to a transmission element which, in operation, is connected to the transmitter system for conveying the different wavelength radiation components to a respective receiver. The supply of the wavelength components is interrupted, preferably in response to a loss of the wavelength components at the respective receiver. A timer provides respective restart times which differ one to another for the wavelength radiation components. The supply of the wavelength components is restarted, following an interruption, at the respective restart times provided by the timer.Type: ApplicationFiled: August 25, 2008Publication date: December 25, 2008Inventors: Andrew James Barker, Phillip Andrew Arnold
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Patent number: 7469102Abstract: Various methods, systems, and apparatuses is described in which a passive-opticalnetwork includes a first multiplexer/demultiplexer, a second multiplexer/demultiplexer, a wavelength tracking component, and a transmission wavelength controller. The first multiplexer/demultiplexer is located in a first location. The second multiplexer/demultiplexer is located in a second location remote from the first location. The wavelength tracking component determines the difference between the transmission band of wavelengths of the first multiplexer/demultiplexer and the second multiplexer/demultiplexer to provide a control signal to match the transmission band of wavelengths of the first multiplexer/demultiplexer and the second multiplexer/demultiplexer. The transmission wavelength controller alters an operating parameter of the first multiplexer/demultiplexer based on the control signal to control the transmission band of wavelengths of the first multiplexer/demultiplexer.Type: GrantFiled: April 18, 2003Date of Patent: December 23, 2008Assignee: Novera Optics, Inc.Inventors: Chang-Hee Lee, Kwang-Uk Chu
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Patent number: 7466921Abstract: Disclosed is a drop-and-continue device (84), provided between a signal converter (85) which supplies a signal to an end user and a wavelength-division multiplexing device (83) which comprises an optical demultiplexer (831) for separating an optical signal of a desired wavelength from an optical signal supplied from a head end station (82) and an optical multiplexer (832) for supplying an optical signal to a wavelength-division multiplexing device at a subsequent stage, comprising: an optical receiver (841) which converts the optical signal separated by the optical demultiplexer into an electrical signal; a transmitter (844) which transmits the electrical signal to the end user via the signal converter (85); an optical transmitter (845) which supplies an optical signal to the optical multiplexer (832); and a loopback processor (842) which loops the electrical signal output from the optical receiver back to the optical transmitter, thereby providing a drop-and-continue device that can easily add capabilities bType: GrantFiled: July 19, 2005Date of Patent: December 16, 2008Assignee: Fujitsu LimitedInventor: Hatsumi Haishima
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Patent number: 7466923Abstract: Methods and systems for PMD compensation in an optical communication system are implemented by transmitting multiple optical signals through a common optical conduit to an optical compensator that adjustably rotates the polarization states of the multiple optical signals and transmits the rotated optical signals to an optical receiver. The receiver, upon sensing an excessive error condition, commands the optical compensator to change the polarization state of rotation, which changes the PMD profile of the received optical signals.Type: GrantFiled: October 3, 2007Date of Patent: December 16, 2008Assignee: AT&T Corp.Inventors: Michael Herbert Eiselt, Jonathan A. Nagel
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Patent number: 7460790Abstract: Systems and methods for compensating transitions in a data stream to account for jitter including laser jitter. Transitions in the data stream are delayed or advanced depending on the laser jitter and/or whether the previous transition is a rising or falling transition. The compensation of transitions is non-linear such that compensation applied to a rising transition is not necessarily the same as compensation applied to a falling transition. A history of more than one or more bits or transitions of the data stream can be used to further adjust the compensation of transitions in the data stream. When a transition is detected, the bit following the detected transition is peaked either positively or negatively such that the following transition is accordingly delayed or advanced.Type: GrantFiled: January 24, 2005Date of Patent: December 2, 2008Assignee: Finisar CorporationInventors: Juergen Hauenschild, Thelinh Nguyen
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Patent number: 7460785Abstract: An optical performance monitor (OPM), e.g., for use in an optical network. The OPM may be configured to characterize one or more impairments in an optical signal modulated with data. The OPM has an optical autocorrelator configured to sample the autocorrelation function of the optical signal, e.g., using two-photon absorption. Autocorrelation points at various bit delays independently or in combination with average optical power may be used to detect and/or quantify one or more of the following: loss of data modulation, signal contrast, pulse broadening, peak power fluctuations, timing jitter, and deviations from the pseudo-random character of data. In addition, the OPM may be configured to perform Fourier transformation based on the autocorrelation points to obtain corresponding spectral components. The spectral components may be used to detect and/or quantify one or more of chromatic dispersion, polarization mode dispersion, and misalignment of a pulse carver and data modulator.Type: GrantFiled: March 28, 2002Date of Patent: December 2, 2008Assignee: Lucent Technologies Inc.Inventors: Mihaela Dinu, Hernando Garcia, Daniel Kilper, Wayne H. Knox, Howard R. Stuart, Chunhui Xu
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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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Publication number: 20080292312Abstract: A method and apparatus of determining attenuation of an optical path between two optical networks may include using a communications traffic signal without interrupting service or requiring additional external test equipment. A transmit optical network node is configured to measure the transmit power of a transmitted optical signal. A receive optical network node is configured to measure the transmit power of the same transmitted optical signal. A calculation unit calculates the power differential of a transmit and receive optical power. A determination unit is configured to determine optical path attenuation as a function of the optical path distance between the transmit and receive optical network nodes. A reporting unit reports data indicative of the optical path attenuation. The optical path attenuation may be monitored periodically, on demand, on an event basis and may report an alert if the attenuation measurement exceeds a preconfigured threshold.Type: ApplicationFiled: May 21, 2007Publication date: November 27, 2008Applicant: Tellabs Petaluma, Inc.Inventors: Moshe Oron, Muneer Zuhdi
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Patent number: 7457549Abstract: A sub signal modulation apparatus, with the intention of stabilized transmission of a sub signal superimposed on main signal light irrespective of the intensity of the main signal light when used in a general-purpose main signal transmitter, including a sub signal outputting unit; a variable optical attenuator for variably attenuating main signal light, into which the main signal has been modulated, at a response speed lower than ½ of a speed of the main signal; an attenuation determining unit for determining, in accordance with the sub signal output from the sub signal outputting unit, an attenuation of the variable optical attenuator for the main signal light; and a stabilizing controller for controlling the attenuation determining unit such that an amplitude of the attenuation of the variable optical attenuator is stabilized to have a constant ratio to a mean intensity of the main signal light.Type: GrantFiled: August 26, 2005Date of Patent: November 25, 2008Assignee: Fujitsu LimitedInventor: Youhei Koganei
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Patent number: 7457538Abstract: A digital performance monitoring method and system for an optical communications system utilizes a channel monitor and a digital signal processor (DSP). The channel monitor is designed to monitor a respective channel signal of the optical communications system, and includes: a sample memory adapted to store sample data including a set of sequential N-bit (where N?1) samples generated by an Analog-to-Digital (A/D) converter at a timing of a predetermined sample clock during a predetermined time interval; and a controller adapted to control storage of the sample data to the sample memory. The digital signal processor (DSP) is designed to calculate at least one performance parameter of the optical communications system based on the sample data.Type: GrantFiled: May 15, 2002Date of Patent: November 25, 2008Assignee: Nortel Networks LimitedInventors: Leo Strawczynski, Kim B. Roberts
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Patent number: 7457542Abstract: An optical access network system having a function of correcting upstream signal waveform distortions occurring in the PON section, wherein a central office side apparatus comprises a main controller to notify each subscriber connection apparatus of a transmission grant period, an equalizer of a tap gain adaptive control type to correct waveform distortions of signals received from the subscriber connection apparatuses, an equalizer controller, and a parameter table for storing, for each subscriber connection apparatus, the initial values of tap gains to be set for the equalizer. The main controller issues a switchover request for switching the equalization characteristic to the equalizer controller each time notifying a subscriber connection apparatus of a transmission grant period, and the equalizer controller retrieves the initial values of the tap gains for the subscriber connection apparatus from the parameter table in response to the switchover request, and sets these values to the equalizer.Type: GrantFiled: January 20, 2006Date of Patent: November 25, 2008Assignee: Hitachi Communication Technologies, Ltd.Inventors: Kenro Sekine, Nobuaki Tajimi
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Patent number: 7447424Abstract: An optical communication system includes a first optical device including a transmission optical switch and a controller coupled to the transmission optical switch, and a second optical device coupled to the first optical device via each of a first fiber and a second fiber. The transmission optical switch is configured to operate in one of a first mode associated with the first fiber and a second mode associated with the second fiber based on control signals generated by the controller. Moreover, the controller is configured to perform a non-revertive switching operation on the transmission optical switch based on the satisfaction or the non-satisfaction of a predetermined condition or a plurality of predetermined conditions.Type: GrantFiled: November 4, 2005Date of Patent: November 4, 2008Inventors: Karen Hovakimyan, Danzhu Wu
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Patent number: 7447437Abstract: An interface arrangement for opto-electronic data transfer which has an electrical plug connection part which includes at least one electrical contact used by a connected plug-in transceiver to provide information related to the data transfer rate at which the connected plug-in transceiver is able to transmit optical signals. An electrical control apparatus connected to this contact is used to set the data transfer rate of signals transferred from an electrical chip to a connected plug-in transceiver, the control apparatus taking several specified data transfer rates and setting that data transfer rate on the electrical chip which is the maximum at which a connected plug-in transceiver is able to transfer, provided that this data transfer rate is lower than the data transfer rate which has been set internally on the electrical chip. An opto-electronic transceiver which can be connected to an interface arrangement in plug-in fashion is also disclosed.Type: GrantFiled: January 26, 2005Date of Patent: November 4, 2008Assignee: Infineon Technologies Fiber Optics GmbHInventor: Nikolaus Schunk
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Patent number: 7447430Abstract: Disclosed is an optical cross connect apparatus that is applicable to an end office node and relay node in a path. The optical cross connect apparatus includes an optical switch for generating plural optical output signals from plural optical input signals; an optical level monitor section for detecting the optical levels of the optical input signals; and a control section that is connected to the optical switch and the optical level monitor section, includes a path switching management section for retaining a path switching management table, references the path switching management table when the optical input signals detected by the optical level monitor section are found to be OFF, and judges whether the optical switch should be operated.Type: GrantFiled: July 20, 2005Date of Patent: November 4, 2008Assignee: Hitachi Communications Technologies, Ltd.Inventors: Yoshio Nogi, Tomohiro Mori, Yasuyuki Fukashiro, Hideaki Tsushima
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Patent number: 7447431Abstract: An optical information transmission system comprises a plurality of optical transmitters and receivers, each having ports for exchangeable waveguides. Each transmitter has an input for receiving an enable signal assigned to it, and is adapted to generate or not to generate an optical information signal according to the status of the enable signal. A signal generator generates the enable signal whose status indicates whether the receiver is connected via a waveguide to a transmitter or not. Each signal generator is connected to one enable input by an enable control line wired separately from the waveguides and is adapted to generate the enable signal only after a test signal specific for each receiver has been received at its waveguide port. A description of the specific test signal of a receiver is transmitted to the associated transmitter.Type: GrantFiled: October 6, 2003Date of Patent: November 4, 2008Assignee: Ericsson ABInventors: Jurgen Fischer, Willi Wolf
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Patent number: 7447432Abstract: There is provided a method of, and apparatus for, regulating radiation component (wavelength channel) power in a wavelength division multiplexed (WDM) optical communications system (10). The system (10) comprises a plurality of nodes (20) interconnected through optical waveguides (30, 40) (optical fibers). The method is characterised by: passing one or more tokens (300) around the system from node to node; adjusting nodal settings (150, 170), such as optical attenuation, applied at each node to regulate the power of WDM radiation components at the node in response to receiving one or more tokens; and repeating the method until WDM radiation component power within the system is substantially regulated.Type: GrantFiled: February 12, 2002Date of Patent: November 4, 2008Assignee: Ericsson ABInventors: John Richard Fielding, Graham Ronald French
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Publication number: 20080267623Abstract: An optical medium, whether inside or outside an internet/telecommunications backbone, is managed using a management signal at a wavelength which is distinct from wavelengths of service signals. A multiplexer multiplexes the management signal onto the optical medium, after which a demultiplexer demultiplexes the management signal for analysis. Performance of customer channels may be inferred from performance of the management signal.Type: ApplicationFiled: May 27, 2008Publication date: October 30, 2008Inventor: Robert H. Manifold
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Patent number: 7444077Abstract: An optical transmission system includes an optical signal transmitter to output optical signal, a monitoring light transmitter to generate monitoring light, an optical multiplexer to output a multiplexed signal light by multiplexing the optical signal and monitoring light, an optical relay transmission path to amplify the multiplexed signal light by using a Raman amplification effect, an optical demultiplexer to demultiplex the multiplexed signal light, a monitoring light receiver to receive the monitoring light output from the optical demultiplexer, and a pumping light source stopping device to continuously monitor a transmission state of the monitoring light and, when the transmission of the monitoring light is interrupted, to stop emission of the pumping light from the pumping light source to be used for distributed Raman amplification.Type: GrantFiled: June 23, 2005Date of Patent: October 28, 2008Assignee: NEC CorporationInventor: Hideki Okuno
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Patent number: 7437083Abstract: A wavelength converter for binary optical signals includes an interferometer structure (110) for generating an output signal by modulating a received local signal (LS) according to the modulation of a fUrther received first input signal (IS 1). When such interferometer structures (110) are operated in a standard mode it is known in the art to control the power of the input signal such that the extinction ratio of the output signal is kept minimal. The invention also controls the power of the input signals to achieve the minimal extinction ratio when the wavelength converter and in particular the interferometer structure (110) is operated in a differential mode receiving two input signals.Type: GrantFiled: September 10, 2004Date of Patent: October 14, 2008Assignee: ALCATELInventors: Bruno Lavigne, Olivier Leclerc, Jean-Luc Moncelet, Alex Bombrun, Jean-Baptiste Pomet, Fabien Seyfert
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Patent number: 7437069Abstract: The present invention provides an automatic power restoring method capable of reliably detecting continuity by the dissolution of a line fault, to restore the optical power, even in a structure including an optical amplification medium on an optical transmission path and an optical communication system using the method. To this end, in an optical communication system to which the automatic power restoring method of the invention is applied, a pilot signal having a low transmission rate, a wavelength of which is set based on loss wavelength characteristics obtained by combining loss wavelength characteristics of an optical fiber used for the optical transmission path and loss wavelength characteristics of the optical amplification medium on the optical transmission path, is transmitted and received between an optical transmitting station and an optical receiving station when a line fault occurs, and a detection of continuity is thus performed.Type: GrantFiled: March 5, 2004Date of Patent: October 14, 2008Assignee: Fujitsu LimitedInventors: Hiroyuki Deguchi, Shinichirou Harasawa, Hideki Maeda, Akira Naka, Gentaro Funatsu
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Patent number: 7437070Abstract: In each of a plurality of submarine observation apparatus (1 to n), a branching unit (63) branches fixed-wavelength light (?1) from an incoming wavelength-multiplexed light signal. An observation signal modulating unit (64) modulates the intensity of the branched fixed-wavelength light (?1) with observation information multiplexed by an observation signal multiplex unit (61). A combining unit (65) combines light signals (?2) to (?n) passing through the branching unit (63) and the fixed-wavelength light (?1a) modulated by the observation signal modulating unit (64) into a composite light signal, and outputs it to an optical fiber (12a). Therefore, in each of the plurality of submarine observation apparatus (1 to n), there is no necessity for providing a wavelength-division-multiplexing-transmission optical transmitter which requires high wavelength stability.Type: GrantFiled: February 18, 2005Date of Patent: October 14, 2008Assignees: Mitsubishi Denki Kabushiki Kaisha, Japan Agency for Marine-Earth Science and TechnologyInventors: Tasuku Fujieda, Hideki Goto, Kenichi Asakawa, Hitoshi Mikada, Katsuyoshi Kawaguchi