Bit Error Rate Patents (Class 398/27)
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Patent number: 8244127Abstract: A method and apparatus for implementing optical network quality using bit error rate and chromatic dispersion. According to one embodiment of the invention, a method includes the provision of quality of service in a wavelength division multiplexing optical network that supports a plurality of bit rates. As part of this method, the cumulative noise and cumulative chromatic dispersion for each available path as a whole is determined, where an available path is a series of two or more nodes each connected by an optical link on which a set of wavelengths is available for establishing a lightpath. In addition, different grades of path quality are distinguished based on bit error rate (BER), where BER is based on cumulative noise and bit rate. Furthermore, a minimum path quality is required based on chromatic dispersion decibel penalty, where chromatic dispersion decibel penalty is based on cumulative chromatic dispersion and bit rate.Type: GrantFiled: June 6, 2006Date of Patent: August 14, 2012Assignee: Dynamic Method Enterprises LimitedInventors: Santosh Kumar Sadananda, Christopher M. Look, Jeffery J. Maki
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Patent number: 8229679Abstract: A system assesses a column of gas in an atmosphere. The system includes an optical transmitter for transmitting (a) an online signal tuned to an online wavelength of gas, (b) an offline signal tuned to an offline wavelength of the gas, and (c) an optical signal for providing altimetry data. A modulator is included for modulating the online signal with a first stepped chirp waveform and modulating the offline signal with a second stepped chirp waveform. A processor assesses the column of gas, after receiving a returned online signal, a returned offline signal and a returned optical signal. A lock-in amplifier is included for (a) multiplying a returned signal with the first stepped chirp waveform to obtain a detected online signal, and (b) multiplying the returned signal with the second stepped chirp waveform to obtain a detected offline signal. The processor is configured to remove ground reflections from the optical signal to obtain scattered noise, and assess the column of gas based on the scattered noise.Type: GrantFiled: September 14, 2009Date of Patent: July 24, 2012Assignee: Exelis, Inc.Inventor: Grant Matthews
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Patent number: 8218969Abstract: OFDM (Orthogonal Frequency Division Multiplexing) has been proposed for processing signals over WDM channels in an optical network. The number of OFDM sub-carrier channels utilized in transmitting optical signals from a transmitting node to a remote is adapted to the quality of transmission in a WDM channel. Responsive to control signals from the remote node, the number of used sub-carrier channels is set to optimize optical performance of the WDM channel.Type: GrantFiled: March 18, 2009Date of Patent: July 10, 2012Assignee: Cisco Technology, Inc.Inventors: Fabrizio Forghieri, Marco Croci, Luca Della Chiesa
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Patent number: 8208814Abstract: An optical transceiver calibration system and manufacturing method to fabricate a dual closed loop control transceiver are provided. The calibration system and method includes measuring an operating temperature and determining operational parameters based upon the operating temperature. The operational parameters may include, for example, a target power for transmitting a digital one, a target power for transmitting a digital zero, a modulation current, and a bias current. A bias may be added to the temperature to account for the difference between the temperature at the temperature sensor and the optical equipment. The operational parameters are preferably calculated independently of each other and are used as initial values during operating modes and allow the control loop to converge more quickly. The optics data is may be scanned electronically via bar code or some other electronic format prior to test. The software residing on the module then calibrates and configures the transceiver.Type: GrantFiled: April 24, 2008Date of Patent: June 26, 2012Assignee: IPhotonixs, LLCInventors: Samir Sheth, Andy James Filtness
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Publication number: 20120155862Abstract: An optical packet switching system includes: an optical packet switching device configured to route and output an input optical packet signal; an optical amplifier device provided in a stage subsequent to the optical packet switching device; and a control signal generation unit configured to superimpose a noise component on the optical packet signal by inducing cross talk in the optical packet switch.Type: ApplicationFiled: December 20, 2011Publication date: June 21, 2012Inventor: Reiko Sato
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Publication number: 20120141116Abstract: A method for recovering an OTUk frame includes: receiving an optical signal sent by using a method of multi-lane distribution from the OTUk frame to an interface of an optical module; converting the optical signal into an electrical signal, performing electrical equalization and demodulation on the electrical signal, and recovering multi-lane data from the demodulated signal; aligning and rearranging the data on each lane, according to a lane sequence identifier included in an overhead frame header of the data on each lane; and recovering the OTUk frame according to the aligned and rearranged data. According to the present invention, lane rearrangement is performed by detecting the lane sequence identifier, and the recovery of the OTUk frame is achieved. Therefore, a training sequence overhead does not need to be additionally introduced, and the influence on the system performance is avoided.Type: ApplicationFiled: January 11, 2012Publication date: June 7, 2012Applicant: Huawei Technologies Co., Ltd.Inventors: Li Zeng, Chan Zhao, Changsong Xie
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Publication number: 20120093502Abstract: A method for data processing in an optical network element is provided. An event of a forthcoming mode-hop of a tunable laser is detected. Furthermore, a corresponding optical network element and an optical communication system with at least one such optical network element are described.Type: ApplicationFiled: June 22, 2009Publication date: April 19, 2012Applicant: Nokia Siemens Networks OyInventors: Erich Gottwald, Harald Rohde, Thomas Treyer
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Patent number: 8155519Abstract: The disclosure relates to optical fiber transmission systems, and in particular, pertains to the transceiver cards in an optical fiber transport system. In particular the disclosure teaches an improved transceiver card architecture that allows high density, flexibility and interchangeability of functionality.Type: GrantFiled: April 21, 2010Date of Patent: April 10, 2012Assignee: Pivotal Decisions LLCInventors: Samir Satish Sheth, Marvin R. Young, Jeffrey Lloyd Cox, John W. Ayres, III
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Publication number: 20120063773Abstract: A customized bit error rate tester that characterizes data transmission through a free space optical channel that overcomes the limitations of commercial based bit error rate testers by providing visibility into packet based channel capacity by measuring bit-level statistics not dominated by fades. In this manner, fade characteristics can be measured and a relationship between fade time and data packet lengths can be developed. Further, analog outputs provide visual real-time data link statistics.Type: ApplicationFiled: March 11, 2011Publication date: March 15, 2012Inventors: Joseph E. Sluz, James L. Riggins, II, Juan C. Juarez, David W. Young
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Patent number: 8131151Abstract: An optical node may include a plurality of optical input components operable to receive a plurality of signals communicated in an optical network and a plurality of optical output components operable to transmit a plurality of signals to be communicated in the optical network.Type: GrantFiled: October 9, 2009Date of Patent: March 6, 2012Assignee: Fujitsu LimitedInventor: Paparao Palacharla
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Patent number: 8111988Abstract: A method for monitoring wavelength-division multiplexed (WDM) signal for detecting signal drift of objective signals, including generation of one or more objective signals and a guard signal. The guard signal has a wavelength that is within a range defined by a guard channel. The first and second objective signals and the guard signal are wavelength-division multiplexed to generate a wavelength-division multiplexed signal. The first objective signal, the second objective signal, and the guard signal are assigned to a first multiplexed objective channel, a second multiplexed objective channel, and a multiplexed guard channel, respectively. The wavelength-division multiplexed signal is received by a monitor and then the error rate of the multiplexed guard channel is determined.Type: GrantFiled: June 10, 2008Date of Patent: February 7, 2012Assignee: Lockheed Martin CorporationInventors: Howard J. Schantz, Brian L. Uhlhorn
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Publication number: 20120020661Abstract: An optical communication device comprises a variable dispersion compensator, a photoelectric converter, and a processor. The variable dispersion compensator compensates an amount of wavelength dispersion of an optical signal received from an optical transmission line. The photoelectric converter converts the compensated optical signal into an electrical signal. The processor is operative to extract a frequency of the converted electrical signal, and to discriminate bit information of the electrical signal based on the frequency extracted using a decision phase and a decision threshold. The processor is operative to detect bit error information that is information related to an error of the discriminated bit information, and to control the amount of wavelength dispersion based on the detected bit error information.Type: ApplicationFiled: September 28, 2011Publication date: January 26, 2012Applicant: FUJITSU LIMITEDInventors: Kenichi Kaburagi, Noriaki Mizuguchi
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Publication number: 20120008940Abstract: In a passive optical network, a downstream transmission rate from an OLT to multiple ONTs can be optimized by matching a transmission scheme for frames addressed to a channel to the downstream transmission characteristics of the channel. An FEC coding can be made channel dependent so that channels with low error rates can use minimal protection, and therefore minimal overhead, while channels with high input bit error rates can use the level of FEC coding required to produce a desired output bit error rate.Type: ApplicationFiled: September 20, 2011Publication date: January 12, 2012Applicant: Alcatel-Lucent USA Inc.Inventor: Adriaan J. de Lind van Wijngaarden
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Publication number: 20120002961Abstract: In a passive optical network, an upstream transmission rate from an ONT to an OLT can be optimized by matching a transmission scheme for a channel to the upstream transmission characteristics of the channel. An FEC coding can be made channel dependent so that channels with low error rates can use minimal protection, and therefore minimal overhead, while channels with high input bit error rates can use the level of FEC coding required to produce a desired output bit error rate.Type: ApplicationFiled: September 12, 2011Publication date: January 5, 2012Applicant: ALCATEL-LUCENT USA INC.Inventor: Adriaan J. de Lind van Wijngaarden
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Publication number: 20110286739Abstract: An optical receiver module includes an optical receiver that receives and converts a plurality of optical signals depending on different polarized states into a plurality of electric signals, a bit error detector that detects a plurality of bit error rates from electric signals, a maximum value detector that detects a maximum bit error rate among bit error rates, a dispersion compensating controller that calculates a dispersion compensating value based on the maximum bit error rate, and a variable dispersion compensator that performs dispersion compensation against waveform degradation of received optical signals. Thus, it is possible to accurately search for an optimum dispersion compensating value in a transmission line susceptible to polarized dispersion. This makes it possible to stabilize dispersion compensating control on the optical receiver.Type: ApplicationFiled: May 23, 2011Publication date: November 24, 2011Inventor: MORIHIKO OTA
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Publication number: 20110286740Abstract: An optical receiver includes a first interferometer having a plurality of arms. The optical receiver further includes first tunable optical filters connected in series with the arms of the first interferometer, where each first tunable optical filter is tuned to filter a region of overlap in the optical frequency spectrum between adjacent optical channels.Type: ApplicationFiled: August 4, 2011Publication date: November 24, 2011Applicant: VERIZON PATENT AND LICENSING INC.Inventors: David Zhi CHEN, E. Evert BASCH
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Patent number: 8064780Abstract: A demodulating unit demodulates a differential M-phase shift keying signal light by causing delay and interference. A phase-error detecting unit detects an error of a control phase amount of the delay and the interference caused by the demodulating unit. A control unit adjusts the control phase amount to a predetermined phase amount based on the error. A data processing unit monitors an error state of data signal that is demodulated by the demodulating unit. The control unit changes the control phase amount from the predetermined amount when the error state is in a predetermined state, and determines a reception state of the differential M-phase shift keying signal light based on an error that is detected after the control phase amount is changed.Type: GrantFiled: November 26, 2007Date of Patent: November 22, 2011Assignee: Fujitsu LimitedInventors: Takahiro Makimoto, Noriaki Mizuguchi
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Patent number: 8059539Abstract: An apparatus and communication method that provide for communicating information on a standardized link compliant with a published standard and communicating information on a private link capable of operation at a throughput higher than maximum throughput of the published standard. The apparatus and method further provide for monitoring private link performance and increasing information throughput on the private link above the maximum standard throughput by an amount determined by the monitored private link performance.Type: GrantFiled: December 29, 2004Date of Patent: November 15, 2011Assignee: Hewlett-Packard Development Company, L.P.Inventor: Robert A. Cochran
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Patent number: 8055128Abstract: The present invention provides methods and systems for efficiently computing optimal optical launch powers for meshed optical networks. The present invention can be utilized to find optimal launch powers for multiple wavelengths in a meshed dense-wave division multiplexed (DWDM) system. Generally, the present invention ensures Q exceeds a threshold for OSNR, and then the launch powers are optimized based on nonlinear penalties. If Q is below the threshold, DWDM equipment changes/additions are incorporated to provide adequate OSNR. The present invention provides a computationally efficient mechanism to optimize launch powers in 10 Gb/s, 40 Gb/s, 100 Gb/s, etc. highly-meshed optical networks.Type: GrantFiled: April 7, 2008Date of Patent: November 8, 2011Assignee: Ciena CorporationInventor: Sandra F. Feldman
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Patent number: 8055138Abstract: The subject matter disclosed herein relates to determining a photosensor operating point.Type: GrantFiled: January 31, 2008Date of Patent: November 8, 2011Assignee: Applied Optoelectronics, Inc.Inventor: Wangsheng Zhang
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Patent number: 8045852Abstract: An algorithm is disclosed for performing channel balancing on channels between optical network elements within an optic-fiber communications system. The algorithm groups at least a portion of the channels into channel pairs, differentially adjusts the transmitter output power level of each of the channel pairs until the bit error ratio (BER) of at least one channel in each of the channel pairs exceeds a threshold, and records a respective power margin for each of the channels as the difference between the initial and final power levels. From the recorded power margins, a mean power margin is determined that is used to shift the transmitter output power level of each of the channels.Type: GrantFiled: April 23, 2008Date of Patent: October 25, 2011Assignee: Alcatel LucentInventors: David Butler, Carlton Brown
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Publication number: 20110255865Abstract: For an apparatus which communicates data of a number of virtual lanes over a number of physical lanes, where the number of virtual lanes is different than the number of physical lanes and where a mapping between the virtual lanes and the physical lanes is not fixed, a method is provided for ascertaining the mapping between the virtual lanes and the physical lanes. The method includes: applying an impairment to a communication capability of one of the physical lanes so as to increase bit errors for data communicated via said one physical lane; determining a test bit error rate for each of the plurality of virtual lanes while the impairment is applied to the communication capability of the one physical lane; and ascertaining from the test bit error rates which of the virtual lanes is/are mapped to the one physical lane whose communication capability was impaired.Type: ApplicationFiled: April 7, 2011Publication date: October 20, 2011Applicant: JDSU DEUTSCHLAND GMBHInventors: Paul BROOKS, Reiner SCHNIZLER, Bernhard MAYER
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Patent number: 8023430Abstract: A regenerative relay method includes the steps of: i) calculating an error rate of a transmission path between the first half apparatus and a main apparatus; ii) calculating an error rate of a transmission path between the main apparatus and the latter apparatus; iii) adding the error rates; iv) selecting the error correction code and data before the error is corrected in the main apparatus so as to be supplied to the latter apparatus if the added error rates are lower than a designated error correction threshold; and v) selecting data after the error is corrected in the main apparatus and the other error correction code generated from the data so as to be supplied to the latter apparatus if the added error rates are higher than the designated error correction threshold.Type: GrantFiled: November 19, 2010Date of Patent: September 20, 2011Assignee: Fujitsu LimitedInventor: Takeshi Ono
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Patent number: 8014670Abstract: Some optical communications networks include one ingress fiber, an n-way signal coupler, and n egress fibers, where each fiber may carry signals in one or both directions. A method and apparatus for testing and monitoring data communications immediately before and after the coupler is provided. Benefits include improved ability to identify and locate system faults, and improved ability to monitor data quality and content.Type: GrantFiled: March 17, 2008Date of Patent: September 6, 2011Assignee: Bigbangwidth Inc.Inventors: Brian Moore, Stuart John Lomas
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Patent number: 7995917Abstract: A system for measuring properties of a medium includes an electromagnetic generator for forming a CW carrier, a digital encoder for forming a digital message, and a modulator for modulating the CW carrier with the digital message to form a digitally modulated CW carrier. The medium provides a channel for propagating the digitally modulated CW carrier. The system further includes a receiver configured to receive the propagated, digitally modulated CW carrier, and a processor for measuring at least one property of the medium. The medium may be disposed within a gaseous atmosphere, a body of water, or a cell of a laboratory.Type: GrantFiled: September 24, 2009Date of Patent: August 9, 2011Assignee: ITT Manufacturing Enterprises, Inc.Inventors: Scott Nelson Mendenhall, Michael E. Dobbs, Benjamin R. Neff, James Alexander McAdoo
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Patent number: 7995918Abstract: A method and apparatus for a monitoring technique for the rate of change of polarization state and of the polarization mode dispersion is proposed. This technique is used for performance monitoring and fault correlation as well as for the verification of commitments to customers with respect to the transmission system's tolerance to polarization mode dispersion.Type: GrantFiled: October 31, 2006Date of Patent: August 9, 2011Assignee: Alcatel LucentInventors: Lutz Raddatz, David Stahl
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Publication number: 20110188852Abstract: Having a fast method to perform impairment evaluation is useful for many networks. A method or corresponding apparatus according to an example embodiment of the present invention maintains a traffic engineering database of values representing characteristics of links in the network through storage of integer values representing advertised optical signal capabilities of links between the multiple optical nodes. The example embodiment determines a path through the network for optical wavelengths to be supported by the links represented in the database as a function of evaluating optical signal characteristics at each link along a possible path using the advertised optical signal capabilities and provides a selected path meeting an acceptable integrity of the optical wavelengths to a path establishment module to establish the path through the optical network. Example embodiments significantly reduce computational complexity associated with impairment evaluation and path selection in an optical network.Type: ApplicationFiled: March 2, 2010Publication date: August 4, 2011Applicant: Tellabs Operations, Inc.Inventors: Kevin C. Stodola, Steven D. Schwager
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Patent number: 7986878Abstract: Techniques, apparatus and systems to provide adjustable bit rate optical transmission using programmable signal modulation in optical communication systems.Type: GrantFiled: February 5, 2008Date of Patent: July 26, 2011Assignee: Opnext Subsystems, Inc.Inventors: Ross Alexander Saunders, Roberto Marcoccia, Steven Keck, Theodore J. Schmidt, Christian Malouin
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Patent number: 7978973Abstract: A wavelength division multiplexing transmission system, the system comprising: a plurality of channels at different wavelengths, each channel comprising a transmitter, a receiver, and one or more amplifiers, the system further comprising an encoder for encoding data with a coding, and; a decoder for decoding transmitted data; prioritizing means for prioritizing the data on each channel; monitoring means for monitoring directly or indirectly, raw (uncorrected) bit errors on each channel; power adjusting means for, varying the power on a channel in response to the bit error rate.Type: GrantFiled: April 28, 2009Date of Patent: July 12, 2011Assignee: Xtera Communications Ltd.Inventors: Martin Chown, Stuart Barnes, Stephen M. Webb, David C. Winterburn
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Patent number: 7957642Abstract: Transport network interfaces operate to transport for Optical Transport Unit frames over an Optical Transport Network. Besides FEC bits for the Optical Transport Unit frames, the transmitting transport network interface provides sequences of error-determining bits for the Optical Transport Unit frames sent on working and protection communications channels. There is at least one sequence for each Optical Transport Unit frame, the number of bits in the at least one sequence much smaller than the number of bits in the Optical Transport Unit frame. The receiving transport network interface determines the bit error rates for the working and protection channels from the sequences of error-determining bits without decoding said Forward Error Correction bits and can select the working and protection channels accordingly.Type: GrantFiled: April 26, 2007Date of Patent: June 7, 2011Assignee: Cisco Technology, Inc.Inventor: Gilberto Loprieno
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Publication number: 20110129214Abstract: An extender box (EB) includes: a downlink data sending module configured to send downlink data to first passive optical network (PON) devices; at least two uplink data receiving modules configured to receive uplink data sent from a corresponding first PON device respectively; and a duplexer configured to convert the data transmission mode used by the downlink data sending module and the uplink data receiving modules from dual-fiber transmission to single-fiber transmission to implement single-fiber bidirectional transceiving. The uplink data receiving modules have ports corresponding to uplink ports of the first PON devices on a one-to-one basis. Optical fibers of the uplink data receiving modules that are connected with the uplink ports of the first PON devices are separated from optical fiber of the downlink data sending module, where the optical fiber is connected with downlink ports of the first PON devices. A data transmission method and a PON system are also disclosed.Type: ApplicationFiled: December 30, 2010Publication date: June 2, 2011Applicant: HUAWEI TECHNOLOGIES CO., LTD.Inventor: Ruobin Zheng
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Patent number: 7945161Abstract: An iterative method for power pre-emphasis of N optical channels in a Wavelength Division Multiplex (WDM) signal in an optical communication systems in accordance with which representative Xi characteristics are defined for the channels with among the characteristics there being included at least one characteristic that is a function of the Bit Error Rate (BER).Type: GrantFiled: July 22, 2005Date of Patent: May 17, 2011Assignee: Ericsson ABInventors: Ernesto Ciaramella, Fabio Cavaliere, Luca Giorgi
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Patent number: 7929861Abstract: The path selection and wavelength assignment to a selected path are performed by mapping the wavelength reach to the demand distribution (agile reach) resulting in a 50-60% increase in the network reach. The network reach is further increased (about 2.2 times) when on-line measured performance data are used for path selection and wavelength assignment. The connections may be engineered/upgraded individually, by optimizing the parameters of the entire path or of a regenerator section of the respective path. The upgrades include changing the wavelength, adjusting the parameters of the regenerator section, controlling the launch powers, mapping a certain transmitter and/or receiver to the respective wavelength, selecting the wavelengths on a certain link so as to reduce cross-talk, increasing wavelength spacing, etc.Type: GrantFiled: March 30, 2010Date of Patent: April 19, 2011Assignee: Alcatel-Lucent USA Inc.Inventors: Alan Glen Solheim, Peter David Roorda, Kevan Peter Jones, Greg Peter Friesen
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Publication number: 20110085797Abstract: Methods and systems for receiving an optical signal using cascaded frequency offset estimation. Coherently detecting an optical signal includes compensating for a coarse laser frequency offset between a transmitting laser and a local oscillator laser by determining a maximum phase error (MPE) in the optical signal, compensating for a residual laser frequency offset between the transmitting laser and the local oscillator laser, and decoding data stored in the optical signal.Type: ApplicationFiled: October 12, 2010Publication date: April 14, 2011Applicant: NEC Laboratories America, Inc.Inventors: Lei Xu, Shaoliang Zhang, Jianjun Yu, Ting Wang
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Patent number: 7925156Abstract: Apparatus and method to measure the quality of burst signals and to perform optical line diagnostics in and optical passive optical network (PON). Statistical information about phase noise (jitter), signal distortion, clock distortions, and any other effects present in burst signals is generated. The statistics are based on phase and bit-length distortions, direction and length of the effect as detected by a phase error detector integrated in a burst mode clock and data recovery (BCDR) circuit. The invention can be further adapted to perform optical line diagnostics to detect the root cause performance degradation and failures in the PON, thereby providing an optical layer supervision tool for monitoring the PON. The statistical information can be used to estimate the quality of service (QoS) per customer connected to the PON. In addition, the generated statistic information can be used to calibrate transmission parameters of optical network unit (ONU) transmitters.Type: GrantFiled: December 20, 2007Date of Patent: April 12, 2011Assignee: Broadlight, Ltd.Inventors: Raviv Weber, Amiad Dvir, Eli Elmoalem, Alex Goldstein, Igor Elkanovich, David Avishai
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Patent number: 7903982Abstract: An optical divider divides an optical input signal into a plurality of paths. A plurality of optical-to-electrical converters respectively converts the divided optical input signals into electrical signals. A plurality of discriminators respectively outputs discrimination results by discriminating the electrical signals output from the optical-to-electrical converters based on predetermined thresholds. An operational circuit performs a predetermined logical operation with the discrimination results output from the discriminators.Type: GrantFiled: April 15, 2004Date of Patent: March 8, 2011Assignee: Mitsubishi Electric CorporationInventors: Jun'ichi Abe, Takashi Sugihara, Katsuhiro Shimizu
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Patent number: 7899324Abstract: Monitoring an optical signal comprises sampling the optical signal from two or more distinct tap points to retrieve a sample set. Multiple such sample sets are obtained over time. A joint probability distribution or phase portrait of the sample sets is assessed for indications of optical signal quality. The tap distinction can be polarization, for example to determine OSNR, or frequency. The tap distinction can be a time delay, which can enable diagnostic differentiation between multiple impairments, such as OSNR, dispersion, PMD, jitter, Q, and the like. Machine learning algorithms are particularly suitable for such diagnosis, particularly when provided a two dimensional histogram of sample density in the phase portrait.Type: GrantFiled: October 13, 2006Date of Patent: March 1, 2011Assignee: Nicta IPR Pty LimitedInventors: Trevor Anderson, Sarah Dods, Adam Kowalczyk, Justin Bedo, Kenneth Paul Clarke
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Patent number: 7899158Abstract: A method and apparatus for measurement of service disruption interval is described. The apparatus may include may included a setting component, a generating component, a first output component, a receiving component, a service disruption start time designator, a settling start time designator, a settling period designator, a service disruption end time designator, a service disruption interval designator, a second output component, and a memory component. In general, a test set consistent with the described embodiments may continuously send test traffic through a network under test (“NUT”) and monitor the traffic output from the NUT. The test set may be configured to detect the start of a service disruption and to detect when the service disruption has been cleared. Based on these two pieces of information, the test set may determine and report a service disruption interval.Type: GrantFiled: August 22, 2006Date of Patent: March 1, 2011Assignees: Verizon Services Organization Inc., Verizon Services Corp.Inventors: Muzaffer Kanaan, Stanley Y. Lee
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Patent number: 7885541Abstract: According to one aspect of the invention, an optical network including multiple optical network devices, or nodes, is provided. At each node, an optical performance monitor analyzes dispersion while a dispersion compensation module reduces the amount of dispersion in the signals. Information about the dispersion and the amount of compensation performed by the dispersion compensation module is generated by the optical performance monitor and stored in a memory. If the bit error rate of a particular path between nodes becomes too high, a new path is used. A monitoring computer then accesses the information about the dispersion stored in at least one node of the old path. The information allows a user to determine where along the path the greatest amount of dispersion is occurring.Type: GrantFiled: February 22, 2005Date of Patent: February 8, 2011Assignee: Dynamic Method Enterprises LimitedInventor: Christopher M. Look
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Publication number: 20110026918Abstract: A visible light communication apparatus of the present invention includes: a target signal receiver filtering only a signal having a target wavelength from a visible light received signal received from a transmitting terminal; a signal generator judging a reception quality of the visible light received signal by using characteristics of the signal having the target wavelength and generating a visible signal by using at least one light source having a wavelength different from the target wavelength in accordance with the reception quality; and an optical signal transmitter transmitting the signal having the target wavelength for transmitting data together with the visible signal and changing a light emitting color of a visible light transmitted signal.Type: ApplicationFiled: July 29, 2010Publication date: February 3, 2011Applicant: Electronics and Telecommunications Research InstituteInventors: Dae-Ho KIM, Tae-Gyu Kang, Sang-Kyu Lim, II-Soon Jang
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Publication number: 20110004802Abstract: Consistent with the present disclosure, circuitry may be provided in an optical receiver that can determine a bit error rate (BER) associated with an incoming signal by dividing the number of errored bits in a frame alignment signals (FAS) by the number of bits in the FAS. Accordingly, although an optical signal may be severely degraded and forward error correction (FEC) cannot be performed, a BER may be obtained if the FAS can be identified. The BER can then be used in a feedback loop to control various optical or electrical components in the receiver to improve or reduce the BER to a level, for example, at which FEC can be performed.Type: ApplicationFiled: July 1, 2009Publication date: January 6, 2011Inventors: JAN BIALKOWSKI, Satish K. Sridharan, Ting-Kuang Chiang
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Patent number: 7853837Abstract: A system, among other embodiments, includes a memory controller having an integrated BER circuit and a plurality of memory devices. The memory controller also includes a control circuit and an interface having at least one transmit circuit to provide write data to at least one of the memory devices and at least one receive circuit to receive read data from at least one of the memory devices. The BER circuit includes a request generator circuit that outputs a request for a memory transaction. A request multiplexer selectively outputs a memory request to the interface from the request generator circuit or the control circuit. A data generator circuit outputs corresponding write data. A first write multiplexer selectively outputs the write data to the interface from the data generator circuit or the control circuit. A read multiplexer selectively receives read data from the receive circuit. The data generator circuit also outputs corresponding write data to a comparator circuit via a second write multiplexer.Type: GrantFiled: February 22, 2007Date of Patent: December 14, 2010Assignee: Rambus Inc.Inventors: Richard E. Perego, Christopher J. Madden
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Publication number: 20100290780Abstract: A data transmission method for transmitting a digital optical signal over an optical transmission link includes creating a digital optical signal defining at least two service levels, each service level transporting information via a modulation scheme comprising at least three different modulation symbols. The data transmission method also includes transmitting the digital optical signal over the transmission link and receiving the transmitted digital optical signal at a remote end of the transmission link by demodulating the received signal and extracting the information of the at least two service levels. In case that the transmission performance is below a given threshold due to increased constraints of the transmission link a compensating action is taken to drop at least one of the service levels from the optical signal or to determine parameters associated with the transmission so as to increase one of the service levels to a predetermined quality level.Type: ApplicationFiled: May 12, 2010Publication date: November 18, 2010Inventor: Brian Teipen
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Patent number: 7826740Abstract: A system and method for an Avalanche photo-diode (“APD”) optical receiver and laser system to adjust its performance during system operation without disturbing network traffic. Very small changes may be adaptively applied to some key portions of the system by controlling a set of main system parameters including Q-factor; Bit Error Rate (BER); histograms of “1” and “0” levels; input optical power; and laser output power. This adaptive routine may be performed during operation of the system to keep the main system parameters close to their optimum value. During adjustment, the system may be divided into separate portions. The adjustment of each portion may be independent of the other portions of the system. For the optical network system, optimization and priority of different portions may be assigned based on network channel architecture.Type: GrantFiled: April 19, 2007Date of Patent: November 2, 2010Assignee: Allied Telesis Inc.Inventors: Nikolai Fediakine, Shinkyo Kaku, Vitali Tikhonov
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Publication number: 20100239245Abstract: Systems, devices and techniques for generating and analyzing states of polarization in light using multiple adjustable polarization rotators having different discrete polarization rotation states in various applications.Type: ApplicationFiled: March 22, 2010Publication date: September 23, 2010Applicant: GENERAL PHOTONICS CORPORATIONInventor: Xiaotian Steve Yao
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Patent number: 7788547Abstract: A method is provided for generating fault information associated with a communication channel. In the method, a time-varying error value associated with the communication channel is received. If the error value exceeds a first threshold, a first time value associated with the error value exceeding the first threshold is stored. If the error value then falls and remains below the first threshold for a first minimum time period before the error value exceeds and remains above a second threshold that is higher than the first threshold for a second minimum time period, the first time value is deleted; otherwise, a second time value associated with the error value exceeding the second threshold is stored. The fault information comprises the first time value and the second time value.Type: GrantFiled: May 13, 2008Date of Patent: August 31, 2010Assignee: Sprint Communications Company L.P.Inventors: Stephen A. Oliva, Douglas L. Richards
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Patent number: 7783935Abstract: In a preferred embodiment, the invention provides a circuit for reducing bit error rates. A data recovery circuit recovers data from a first HSS link to differential bit pair inputs. Data from the differential bit pair outputs of the data recovery circuit drive differential bit pair inputs to a plurality of FIFOs. The data is then driven from a parallel output of the plurality of FIFOs to the parallel input of a synchronizer. The data is then driven from the parallel output of the synchronizer to the parallel input of a serializer. The serializer, through different bit pair outputs, drives a second serial HSS link.Type: GrantFiled: June 2, 2006Date of Patent: August 24, 2010Assignee: Hewlett-Packard Development Company, L.P.Inventor: Larry J. Thayer
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Patent number: 7747172Abstract: An optical communication system combines strong electrical pre-filtering of data at the transmitter and digital feedback equalization (DFE) at the receiver to enhance spectral efficiency. The system can be applied to optical networking and digital communication systems, including binary modulated systems optical network systems.Type: GrantFiled: May 4, 2007Date of Patent: June 29, 2010Inventors: M. Imran Hayee, Rami J. Haddad
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Patent number: 7734173Abstract: Error detection and recovery of an optical network element are described herein. In one embodiment, an exemplary process includes, but is not limited to, transmitting from a transmitting module of the optical network element a first packet of data to a receiving module of the optical network element, and the transmitting module transmitting a first value representing a number of bits of the first packet having a predetermined logical value to the receiving module, wherein the first value is used by the receiving module to verify an integrity of the first packet in order to determine whether the packet has been transmitted successfully. Other methods and apparatuses are also described.Type: GrantFiled: February 16, 2006Date of Patent: June 8, 2010Assignee: Dynamic Method Enterprises LimitedInventor: Douglas A. Gilligan
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Patent number: 7715717Abstract: The present invention proposes a method whereby during a specified/specifiable observation period (Ttotal) , the polarization states of optical transmission system and/or the optical signals transmitted by the optical transmission system are changed by applying a targeted intervention in at least one position of the transmission line, and at a second position which is interposed at least one place downstream from the first position of the optical transmission line, a specified/specifiable signal characteristic (BER) is qualitatively measured and checked for adherence to a specified/specifiable threshold condition (BERth) and the PMD-induced outage probability of the optical transmission system is calculated on the basis of the ratio between the length of that share of the time (Tout), during which the measured signal characteristic fails to meet the threshold condition (BERth), to the length of the observation period (Ttotal).Type: GrantFiled: September 3, 2004Date of Patent: May 11, 2010Assignees: Deutsche Telekom AG, Nippon Telegraph and Telephone CorporationInventors: Werner Weiershausen, Arnold Mattheus, Ralph Leppla, Yutaka Miyamoto, Akira Hirano, Yoshiaki Kisaka