Bit Error Rate Patents (Class 398/27)
  • Patent number: 8244127
    Abstract: 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: Grant
    Filed: June 6, 2006
    Date of Patent: August 14, 2012
    Assignee: Dynamic Method Enterprises Limited
    Inventors: Santosh Kumar Sadananda, Christopher M. Look, Jeffery J. Maki
  • Patent number: 8229679
    Abstract: 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: Grant
    Filed: September 14, 2009
    Date of Patent: July 24, 2012
    Assignee: Exelis, Inc.
    Inventor: Grant Matthews
  • Patent number: 8218969
    Abstract: 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: Grant
    Filed: March 18, 2009
    Date of Patent: July 10, 2012
    Assignee: Cisco Technology, Inc.
    Inventors: Fabrizio Forghieri, Marco Croci, Luca Della Chiesa
  • Patent number: 8208814
    Abstract: 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: Grant
    Filed: April 24, 2008
    Date of Patent: June 26, 2012
    Assignee: IPhotonixs, LLC
    Inventors: Samir Sheth, Andy James Filtness
  • Publication number: 20120155862
    Abstract: 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: Application
    Filed: December 20, 2011
    Publication date: June 21, 2012
    Inventor: Reiko Sato
  • Publication number: 20120141116
    Abstract: 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: Application
    Filed: January 11, 2012
    Publication date: June 7, 2012
    Applicant: Huawei Technologies Co., Ltd.
    Inventors: Li Zeng, Chan Zhao, Changsong Xie
  • Publication number: 20120093502
    Abstract: 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: Application
    Filed: June 22, 2009
    Publication date: April 19, 2012
    Applicant: Nokia Siemens Networks Oy
    Inventors: Erich Gottwald, Harald Rohde, Thomas Treyer
  • Patent number: 8155519
    Abstract: 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: Grant
    Filed: April 21, 2010
    Date of Patent: April 10, 2012
    Assignee: Pivotal Decisions LLC
    Inventors: Samir Satish Sheth, Marvin R. Young, Jeffrey Lloyd Cox, John W. Ayres, III
  • Publication number: 20120063773
    Abstract: 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: Application
    Filed: March 11, 2011
    Publication date: March 15, 2012
    Inventors: Joseph E. Sluz, James L. Riggins, II, Juan C. Juarez, David W. Young
  • Patent number: 8131151
    Abstract: 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: Grant
    Filed: October 9, 2009
    Date of Patent: March 6, 2012
    Assignee: Fujitsu Limited
    Inventor: Paparao Palacharla
  • Patent number: 8111988
    Abstract: 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: Grant
    Filed: June 10, 2008
    Date of Patent: February 7, 2012
    Assignee: Lockheed Martin Corporation
    Inventors: Howard J. Schantz, Brian L. Uhlhorn
  • Publication number: 20120020661
    Abstract: 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: Application
    Filed: September 28, 2011
    Publication date: January 26, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Kenichi Kaburagi, Noriaki Mizuguchi
  • Publication number: 20120008940
    Abstract: 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: Application
    Filed: September 20, 2011
    Publication date: January 12, 2012
    Applicant: Alcatel-Lucent USA Inc.
    Inventor: Adriaan J. de Lind van Wijngaarden
  • Publication number: 20120002961
    Abstract: 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: Application
    Filed: September 12, 2011
    Publication date: January 5, 2012
    Applicant: ALCATEL-LUCENT USA INC.
    Inventor: Adriaan J. de Lind van Wijngaarden
  • Publication number: 20110286739
    Abstract: 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: Application
    Filed: May 23, 2011
    Publication date: November 24, 2011
    Inventor: MORIHIKO OTA
  • Publication number: 20110286740
    Abstract: 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: Application
    Filed: August 4, 2011
    Publication date: November 24, 2011
    Applicant: VERIZON PATENT AND LICENSING INC.
    Inventors: David Zhi CHEN, E. Evert BASCH
  • Patent number: 8064780
    Abstract: 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: Grant
    Filed: November 26, 2007
    Date of Patent: November 22, 2011
    Assignee: Fujitsu Limited
    Inventors: Takahiro Makimoto, Noriaki Mizuguchi
  • Patent number: 8059539
    Abstract: 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: Grant
    Filed: December 29, 2004
    Date of Patent: November 15, 2011
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Robert A. Cochran
  • Patent number: 8055128
    Abstract: 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: Grant
    Filed: April 7, 2008
    Date of Patent: November 8, 2011
    Assignee: Ciena Corporation
    Inventor: Sandra F. Feldman
  • Patent number: 8055138
    Abstract: The subject matter disclosed herein relates to determining a photosensor operating point.
    Type: Grant
    Filed: January 31, 2008
    Date of Patent: November 8, 2011
    Assignee: Applied Optoelectronics, Inc.
    Inventor: Wangsheng Zhang
  • Patent number: 8045852
    Abstract: 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: Grant
    Filed: April 23, 2008
    Date of Patent: October 25, 2011
    Assignee: Alcatel Lucent
    Inventors: David Butler, Carlton Brown
  • Publication number: 20110255865
    Abstract: 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: Application
    Filed: April 7, 2011
    Publication date: October 20, 2011
    Applicant: JDSU DEUTSCHLAND GMBH
    Inventors: Paul BROOKS, Reiner SCHNIZLER, Bernhard MAYER
  • Patent number: 8023430
    Abstract: 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: Grant
    Filed: November 19, 2010
    Date of Patent: September 20, 2011
    Assignee: Fujitsu Limited
    Inventor: Takeshi Ono
  • Patent number: 8014670
    Abstract: 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: Grant
    Filed: March 17, 2008
    Date of Patent: September 6, 2011
    Assignee: Bigbangwidth Inc.
    Inventors: Brian Moore, Stuart John Lomas
  • Patent number: 7995917
    Abstract: 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: Grant
    Filed: September 24, 2009
    Date of Patent: August 9, 2011
    Assignee: ITT Manufacturing Enterprises, Inc.
    Inventors: Scott Nelson Mendenhall, Michael E. Dobbs, Benjamin R. Neff, James Alexander McAdoo
  • Patent number: 7995918
    Abstract: 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: Grant
    Filed: October 31, 2006
    Date of Patent: August 9, 2011
    Assignee: Alcatel Lucent
    Inventors: Lutz Raddatz, David Stahl
  • Publication number: 20110188852
    Abstract: 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: Application
    Filed: March 2, 2010
    Publication date: August 4, 2011
    Applicant: Tellabs Operations, Inc.
    Inventors: Kevin C. Stodola, Steven D. Schwager
  • Patent number: 7986878
    Abstract: Techniques, apparatus and systems to provide adjustable bit rate optical transmission using programmable signal modulation in optical communication systems.
    Type: Grant
    Filed: February 5, 2008
    Date of Patent: July 26, 2011
    Assignee: Opnext Subsystems, Inc.
    Inventors: Ross Alexander Saunders, Roberto Marcoccia, Steven Keck, Theodore J. Schmidt, Christian Malouin
  • Patent number: 7978973
    Abstract: 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: Grant
    Filed: April 28, 2009
    Date of Patent: July 12, 2011
    Assignee: Xtera Communications Ltd.
    Inventors: Martin Chown, Stuart Barnes, Stephen M. Webb, David C. Winterburn
  • Patent number: 7957642
    Abstract: 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: Grant
    Filed: April 26, 2007
    Date of Patent: June 7, 2011
    Assignee: Cisco Technology, Inc.
    Inventor: Gilberto Loprieno
  • Publication number: 20110129214
    Abstract: 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: Application
    Filed: December 30, 2010
    Publication date: June 2, 2011
    Applicant: HUAWEI TECHNOLOGIES CO., LTD.
    Inventor: Ruobin Zheng
  • Patent number: 7945161
    Abstract: 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: Grant
    Filed: July 22, 2005
    Date of Patent: May 17, 2011
    Assignee: Ericsson AB
    Inventors: Ernesto Ciaramella, Fabio Cavaliere, Luca Giorgi
  • Patent number: 7929861
    Abstract: 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: Grant
    Filed: March 30, 2010
    Date of Patent: April 19, 2011
    Assignee: Alcatel-Lucent USA Inc.
    Inventors: Alan Glen Solheim, Peter David Roorda, Kevan Peter Jones, Greg Peter Friesen
  • Publication number: 20110085797
    Abstract: 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: Application
    Filed: October 12, 2010
    Publication date: April 14, 2011
    Applicant: NEC Laboratories America, Inc.
    Inventors: Lei Xu, Shaoliang Zhang, Jianjun Yu, Ting Wang
  • Patent number: 7925156
    Abstract: 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: Grant
    Filed: December 20, 2007
    Date of Patent: April 12, 2011
    Assignee: Broadlight, Ltd.
    Inventors: Raviv Weber, Amiad Dvir, Eli Elmoalem, Alex Goldstein, Igor Elkanovich, David Avishai
  • Patent number: 7903982
    Abstract: 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: Grant
    Filed: April 15, 2004
    Date of Patent: March 8, 2011
    Assignee: Mitsubishi Electric Corporation
    Inventors: Jun'ichi Abe, Takashi Sugihara, Katsuhiro Shimizu
  • Patent number: 7899324
    Abstract: 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: Grant
    Filed: October 13, 2006
    Date of Patent: March 1, 2011
    Assignee: Nicta IPR Pty Limited
    Inventors: Trevor Anderson, Sarah Dods, Adam Kowalczyk, Justin Bedo, Kenneth Paul Clarke
  • Patent number: 7899158
    Abstract: 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: Grant
    Filed: August 22, 2006
    Date of Patent: March 1, 2011
    Assignees: Verizon Services Organization Inc., Verizon Services Corp.
    Inventors: Muzaffer Kanaan, Stanley Y. Lee
  • Patent number: 7885541
    Abstract: 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: Grant
    Filed: February 22, 2005
    Date of Patent: February 8, 2011
    Assignee: Dynamic Method Enterprises Limited
    Inventor: Christopher M. Look
  • Publication number: 20110026918
    Abstract: 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: Application
    Filed: July 29, 2010
    Publication date: February 3, 2011
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Dae-Ho KIM, Tae-Gyu Kang, Sang-Kyu Lim, II-Soon Jang
  • Publication number: 20110004802
    Abstract: 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: Application
    Filed: July 1, 2009
    Publication date: January 6, 2011
    Inventors: JAN BIALKOWSKI, Satish K. Sridharan, Ting-Kuang Chiang
  • Patent number: 7853837
    Abstract: 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: Grant
    Filed: February 22, 2007
    Date of Patent: December 14, 2010
    Assignee: Rambus Inc.
    Inventors: Richard E. Perego, Christopher J. Madden
  • Publication number: 20100290780
    Abstract: 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: Application
    Filed: May 12, 2010
    Publication date: November 18, 2010
    Inventor: Brian Teipen
  • Patent number: 7826740
    Abstract: 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: Grant
    Filed: April 19, 2007
    Date of Patent: November 2, 2010
    Assignee: Allied Telesis Inc.
    Inventors: Nikolai Fediakine, Shinkyo Kaku, Vitali Tikhonov
  • Publication number: 20100239245
    Abstract: 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: Application
    Filed: March 22, 2010
    Publication date: September 23, 2010
    Applicant: GENERAL PHOTONICS CORPORATION
    Inventor: Xiaotian Steve Yao
  • Patent number: 7788547
    Abstract: 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: Grant
    Filed: May 13, 2008
    Date of Patent: August 31, 2010
    Assignee: Sprint Communications Company L.P.
    Inventors: Stephen A. Oliva, Douglas L. Richards
  • Patent number: 7783935
    Abstract: 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: Grant
    Filed: June 2, 2006
    Date of Patent: August 24, 2010
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Larry J. Thayer
  • Patent number: 7747172
    Abstract: 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: Grant
    Filed: May 4, 2007
    Date of Patent: June 29, 2010
    Inventors: M. Imran Hayee, Rami J. Haddad
  • Patent number: 7734173
    Abstract: 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: Grant
    Filed: February 16, 2006
    Date of Patent: June 8, 2010
    Assignee: Dynamic Method Enterprises Limited
    Inventor: Douglas A. Gilligan
  • Patent number: 7715717
    Abstract: 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: Grant
    Filed: September 3, 2004
    Date of Patent: May 11, 2010
    Assignees: Deutsche Telekom AG, Nippon Telegraph and Telephone Corporation
    Inventors: Werner Weiershausen, Arnold Mattheus, Ralph Leppla, Yutaka Miyamoto, Akira Hirano, Yoshiaki Kisaka