Monitoring Patents (Class 398/177)
  • Patent number: 8391707
    Abstract: First and second switching device are connected by a number of signal paths. The first switching device receives an instruction to switch from a first one of the signal paths to a second one of the signal paths. The first switching device performs, in response to the received instruction, a first switching operation to connect the first path, at an input of the first switching device, to the second path, at an output of the first switching device. The second switching device receives the instruction to switch from the first path to the second path and detects a loss of signal on the first path as a result of the first switching operation performed by the first switching device. The second device performs, in response to detecting the loss of signal on the first path, a second switching operation to connect the first path, at an output of the second switching device, to the second path, at an input of the second switching device.
    Type: Grant
    Filed: November 13, 2009
    Date of Patent: March 5, 2013
    Assignee: Verizon Patent and Licensing Inc.
    Inventors: Glenn A Wellbrock, Tiejun J Xia
  • Patent number: 8380061
    Abstract: A method, system and device for protecting a Long Reach Passive Optical Network (LR-PON) system are provided. The Electrical Relay (E-R) device receives the optical signal transmitted on two fiber transmission paths by the Optical Line Terminal (OLT) or Optical Network Unit (ONU) on one side, performs optical-to-electrical (O/E) conversion, signal regeneration, and electrical-to-optical (E/O) conversion for the optical signal, and sends the signal to the ONU or the OLT on the other side through the two fiber transmission paths. Through backup of the fiber transmission path, an LR-PON system protection method is provided to improve the reliability of the LR-PON system. The method, system, and device for protecting the LR-PON system under the present invention all support and are compatible with the existing functions of all devices in the existing LR-PON system.
    Type: Grant
    Filed: January 18, 2010
    Date of Patent: February 19, 2013
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Jianlin Zhou, Shimin Zou
  • Patent number: 8364033
    Abstract: Changes in a signal are detected. The signal is repeatedly sampled in a synchronous manner during a predetermined interval to generate a captured eye diagram. At least one of a positive differential eye diagram or a negative differential eye diagram is generated from the captured eye diagram and a baseline eye diagram. The at least one positive or negative differential eye diagram is analyzed to determine whether a change in signal conditions is present.
    Type: Grant
    Filed: December 8, 2009
    Date of Patent: January 29, 2013
    Assignee: Telcordia Technologies, Inc.
    Inventors: Ronald A. Skoog, Marcus Pang, Paul Toliver
  • Patent number: 8355631
    Abstract: A system for transmitting a plurality of data channels and an optical service channel through an optical fiber link of a Wavelength Division Multiplexed (WDM) optical communications system. The system comprises a first transmitter at a first end of the optical fiber link, for transmitting the data channels as a wavelength division multiplexed optical signal through the optical fiber link in a first direction. A second transmitter is connected at a second end of the optical fiber link, for transmitting the optical service channel through the optical fiber link in a second direction opposite to the first direction.
    Type: Grant
    Filed: January 29, 2010
    Date of Patent: January 15, 2013
    Assignee: Ciena Corporation
    Inventors: Maurice O'Sullivan, Jamie Gaudette, Roger Carroll
  • Patent number: 8351797
    Abstract: A repeater is disclosed that transmits an optical signal using wave division multiplexing. The repeater includes a demultiplexing unit that separates plural channels contained in the optical signal, an adjusting unit that adjusts at least optical power of each of the channels according to a control signal, a multiplexing unit that outputs a multiple wavelength signal in which the channels are multiplexed, and a monitoring unit that determines a modulation scheme and a bit rate of the optical signal for each of the channels so as to generate the control signal.
    Type: Grant
    Filed: January 27, 2010
    Date of Patent: January 8, 2013
    Assignee: Fujitsu Limited
    Inventors: Hisao Nakashima, Takeshi Hoshida
  • Patent number: 8339698
    Abstract: A pumping unit supplies pumping light to a fiber connecting medium; a light monitoring unit detects light power of multiple-wavelength light; and a control unit controls the pumping light based on light power detected by the light monitoring unit and connecting medium information indicating optical characteristics in the connecting medium. The connecting medium information includes information indicating a fiber type of the fiber connecting medium, information indicating a length of the fiber connecting medium, an average fiber loss coefficient of the fiber connecting medium and an intra-station loss value.
    Type: Grant
    Filed: September 1, 2010
    Date of Patent: December 25, 2012
    Assignee: Fujitsu Limited
    Inventors: Maki Hiraizumi, Yoshio Shimano, Masao Nakata
  • Patent number: 8290365
    Abstract: An optical communication apparatus that includes multiple optically communicative components positioned optically in series. Some of the optically communicative components may be optical fiber segments of perhaps different types. The optical channel represented by the series of optically communicative components and approximates a transfer function of an optical channel of a longer optical fiber. Accordingly, rather than deal with a lengthy optical fiber, an apparatus having a shorter optical channel may be used instead. The construction of the optical communicative components may be calculating an input transfer function. The construction would include an ordering of discrete optically communicative components that, when placed optically in series, simulates an estimation of a particular transfer function. Testing may then occur by actually passing an optical signal through the series construction of optically communicative components, rather than through the longer optical fiber.
    Type: Grant
    Filed: August 20, 2008
    Date of Patent: October 16, 2012
    Assignee: Finisar Corporation
    Inventors: Gayle L. Noble, Lucy G. Hosking, Luke M. Ekkizogloy
  • Patent number: 8285138
    Abstract: An optical correlation apparatus is described which forms first and second parallel optical signals in response to a serial input data stream. The first parallel optical signal is arranged to have bright pulses represent binary 1 and the second parallel optical signal is arranged to have bright pulses represent binary 0. A channel select means, such as an optical switch or amplitude modulator, deselects or blocks channels in the first parallel optical signal which correspond to binary 1 in a reference data string and also deselects or blocks channels in the second parallel optical signal which correspond to binary 0 in the reference data string. The remaining optical signals are combined at one or more detectors. Where the input data matches the reference data string each bright pulse in the first and second parallel optical signals is deselected and the detector registers zero intensity. However when there is any mismatch at least one channel will pass a bright pulse to the detector.
    Type: Grant
    Filed: December 17, 2007
    Date of Patent: October 9, 2012
    Assignee: Qinetiq Limited
    Inventors: Andrew Charles Lewin, David Arthur Orchard, Martin James Cooper
  • Patent number: 8275269
    Abstract: The distributed Raman amplifier monitors an OSNR of each channel in a WDM light which has been propagated through a transmission path to be Raman amplified, and thereafter, is amplified by an optical amplifier in an optical repeating node; judges whether a monitor value of the OSNR is larger or smaller than a previously set target value thereof; and feedback controls a driving state of a pumping light source which supplies a Raman pumping light to the transmission path, based on the judgment result. The optical communication system comprises the above distributed Raman amplifier in each repeating span thereof, and performs a pumping light control of the distributed Raman amplifier corresponding to the repeating span selected based on the OSNR in each distributed Raman amplifier and the monitor result of span loss. As a result, it becomes possible to effectively improve the OSNR of each channel in the WDM light, and also, to reduce the power consumption.
    Type: Grant
    Filed: November 12, 2009
    Date of Patent: September 25, 2012
    Assignee: Fujitsu Limited
    Inventor: Miki Onaka
  • Patent number: 8275010
    Abstract: The pulse light source according to the present invention comprises: a seed pulse generator 1 for outputting an input pulse 10 as a seed pulse; a pulse amplifier 2; and a dispersion compensator 3 for dispersion compensating a light pulse output from the pulse amplifier 2. Moreover, the pulse amplifier 2 comprises a normal dispersion medium (DCF 4) and an amplification medium (EDF 5) that are multistage-connected alternately, for changing the input pulse 10 to a light pulse having a linear chirp and outputting the light pulse. Furthermore, an absolute value of the dispersion of the DCF 4 becomes to be larger than the absolute value of the dispersion of the EDF 5.
    Type: Grant
    Filed: June 10, 2008
    Date of Patent: September 25, 2012
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Atsushi Oguri, Shunichi Matsushita
  • Patent number: 8265485
    Abstract: An optical transmission system including an optical transmission path for transmitting WDM signals multiplexed different wavelength optical signals, the WDM signals including different bit rate optical signals or different modulation format optical signals; a repeater arranged in the optical transmission path, the repeater including a chromatic dispersion compensation unit for compensating chromatic dispersion compensation for the WDM signals; and a network management system including processes of determining a dispersion compensation ratio indicating the ratio with respect to the dispersion compensation amount at which the residual dispersion of the WDM signals are zero after transmission via the optical transmission path, on the bases of the mixture ratio of different optical signals included in the WDM signals, and variably setting the dispersion compensation amount for the in-line repeater according to the dispersion compensation ratio.
    Type: Grant
    Filed: March 17, 2009
    Date of Patent: September 11, 2012
    Assignee: Fujitsu Limited
    Inventors: Kantaro Nakamura, Hiroki Ooi, George Ishikawa
  • Patent number: 8223795
    Abstract: A computer system and method for transmitting LAN signals over transport systems. LAN signals are generated in any client LAN compliant interface. A transceiver receives the client LAN signal in the LAN format. The client LAN signals are not converted to a SONET transmission format at any time before reaching the transceiver. The transceiver then converts the client LAN signal to an internal electrical LAN signal before re-clocking the internal electrical LAN signal. The re-clocked internal electrical LAN signal is then re-modulated into a second LAN signal. The second LAN signal is then transmitted to a transport system.
    Type: Grant
    Filed: February 25, 2005
    Date of Patent: July 17, 2012
    Assignee: Pivotal Decisions LLC
    Inventors: Jeffrey Lloyd Cox, Samir Satish Sheth
  • Patent number: 8213078
    Abstract: A pumping unit supplies pumping light to a fiber connecting medium; a light monitoring unit detects light power of multiple-wavelength light; and a control unit controls the pumping light based on light power detected by the light monitoring unit and connecting medium information indicating optical characteristics in the connecting medium. The connecting medium information includes information indicating a fiber type of the fiber connecting medium, information indicating a length of the fiber connecting medium, an average fiber loss coefficient of the fiber connecting medium and an intra-station loss value.
    Type: Grant
    Filed: August 31, 2010
    Date of Patent: July 3, 2012
    Assignee: Fujitsu Limited
    Inventor: Maki Hiraizumi
  • Patent number: 8213805
    Abstract: According to halt of a Raman pumping light source, a transmitting light power of a first light which is subject to receive a Raman gain is controlled to increase. In this state, a first input/output light power for a first light of an optical transmission line is measured, the first input/output light power being used for determining a reference of loss characteristic of the optical transmission line. A second input/output light power for a second light of the optical transmission line is measured, the second light not being subject to receive the Raman gain, the second input/output light power being used for determining a fluctuation of the reference.
    Type: Grant
    Filed: March 28, 2009
    Date of Patent: July 3, 2012
    Assignee: Fujitsu Limited
    Inventor: Takeshi Sakamoto
  • Patent number: 8200098
    Abstract: A system which comprises point-to-multipoint connections and in which a portion of a downstream signal is extracted at a point located between a central network unit and a plurality of user network units, a header of the downstream signal is read and analyzed, and the header data obtained in this manner is used for controlling a regenerator provided in the upstream path for the data burst signals. The header data contains the beginning and end of the burst of the data burst signals, thus making it possible to reliably generate a temporal triggering signal for the regenerator.
    Type: Grant
    Filed: November 8, 2007
    Date of Patent: June 12, 2012
    Assignee: Nokia Siemens Networks GmbH & Co. KG
    Inventor: Andreas Stadler
  • Patent number: 8190023
    Abstract: An input of a command to stop optical output or a command to reduce optical output by a main signal transmitting section is received from the outside. When the input of the optical output stop command or optical output reduction command is received, an inter-device control signal communication section transmits the optical output stop command or optical output reduction command. Based on the input optical output stop command or optical output reduction command, an output of optical signals from the main signal transmitting section is stopped, or else the output level is reduced to less than the output level during normal operation.
    Type: Grant
    Filed: July 29, 2009
    Date of Patent: May 29, 2012
    Assignee: NEC Corporation
    Inventor: Masaru Nishino
  • Patent number: 8184987
    Abstract: A method, a device, and a system for realizing data transmission extension in a passive optical network (PON) are provided. Between a burst-mode clock and data recovery (BCDR) module and an electrical-optical (E/O) amplification module, the device includes a delimiter matching module and a preamble buffering and compensating module. The delimiter matching module is adapted to receive a data frame sent by the BCDR module and determine a location of a delimiter in the data frame. An optical-electrical (O/E) amplification module performs O/E conversion, amplification, and shaping on the data frame. The BCDR module then performs clock and data recovery processing on the data frame.
    Type: Grant
    Filed: January 8, 2010
    Date of Patent: May 22, 2012
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Juan Chen, Shimin Zou, Jianlin Zhou
  • Patent number: 8165136
    Abstract: Methods and apparatus for performing SPAN for a virtual port are disclosed. Specifically, a frame is received from a first port. The frame or a copy thereof is transmitted to a second port, where the second port is identified in a header of the frame. At least one of the first port and the second port is a virtual port. The frame or a copy thereof is also transmitted to a third port, thereby enabling an analyzer coupled to the third port to analyze traffic received by the third port.
    Type: Grant
    Filed: April 25, 2005
    Date of Patent: April 24, 2012
    Assignee: Cisco Technology, Inc.
    Inventors: Samar Sharma, Sanjaya Kumar, Srinivas Avasarala, Gaurav Rastogi, Jeevan Kamisetty
  • Patent number: 8145056
    Abstract: A network component comprising at least one processor configured to implement a method comprising obtaining a wavelength availability information for a path, determining whether to implement a wavelength assignment based on the wavelength availability information, updating the wavelength availability information when the wavelength assignment is to be implemented, and forwarding the wavelength availability information. Also included is a method comprising obtaining a wavelength availability information, comparing a number of wavelengths in the wavelength availability information to a threshold, determining whether to implement wavelength conversion along a path when the number of available wavelengths is less than or about equal to the threshold, and resetting the wavelength availability information when wavelength conversion is to be implemented.
    Type: Grant
    Filed: July 15, 2008
    Date of Patent: March 27, 2012
    Assignee: Futurewei Technologies, Inc.
    Inventors: Greg Bernstein, Young Lee
  • Patent number: 8121491
    Abstract: A method and apparatus for compensating for channel depletion of a multi-channel signal in an optical link or optical network comprising a chain of optical amplifiers. The method comprises determining channel depletion for each amplifier from the power of the input signal to the optical amplifier and the power of the output signal from the previous amplifier. Each amplifier is then controlled to amplify the signal to a level equal to the nominal (ideal) power plus the calculated channel depletion for that amplifier.
    Type: Grant
    Filed: October 6, 2006
    Date of Patent: February 21, 2012
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Gianmarco Bruno, Fabio Cavaliere
  • Patent number: 8121486
    Abstract: An optical transmission apparatus is arranged by: means for demultiplexing monitoring light for received wavelength-multiplexed signal light so as to detect optical intensity of the monitoring light; means for detecting optical intensity of wavelength-multiplexed signal light after the monitoring light has been demultiplexed therefrom; a gain controlling type optical amplifier for amplifying the wavelength-multiplexed signal light; an optical attenuating unit for adjusting optical intensity of the amplified wavelength-multiplexed signal light; and a monitoring control unit for controlling the gain controlling type optical amplifier in such a manner that the gain of the optical amplifier becomes constant, and for controlling an attenuating amount of the optical attenuating unit in such a manner that the optical intensity of the wavelength-multiplexed signal light becomes a predetermined target value.
    Type: Grant
    Filed: February 7, 2008
    Date of Patent: February 21, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Tetsuya Uda, Hiroshi Takeuchi
  • Patent number: 8111985
    Abstract: An apparatus for performing an optical line analysis of continuous data signals. The apparatus comprise a phase position processor for computing a phase early/late indicator; a phase control code processor for computing a difference phase indicator; a frequency extractor for computing a low frequency jitter indicator; and a statistical calculator for computing a plurality of statistical measures regarding frequency and amplitude components of a jitter of an input continuous data signal, wherein the statistical measures are computed based on one of the phase early/late information indicator, the difference phase indicator, or the low frequency jitter indicator.
    Type: Grant
    Filed: May 1, 2009
    Date of Patent: February 7, 2012
    Assignee: Broadlight, Ltd.
    Inventors: Amiad Dvir, Alex Goldstein, David Avishai
  • Patent number: 8068735
    Abstract: An optically amplified wavelength division multiplexing network has the functionality to add/drop channels at the optical add/drop multiplexing (OADM) nodes. The OADM node includes a receiver amplifier, an OADM module, and a transmitter amplifier. Once the OADM node detects a loss of signal (LOS) due to a fiber cut or network element failure upstream, the receiver amplifier is kept in operation as a noise source. The output of the receiver amplifier is immediately raised by increasing pump power to compensate for the LOS. The noise power received at the transmitter amplifier from the receiver amplifier is substantially equal to the signal power expected before LOS. The transient effect of downstream optical amplifiers is therefore completely suppressed and the inter-channel stimulated Raman scattering (SRS) induced spectrum tilt does not change. After the noise power is raised, the receiver amplifier may be shut down at a speed much slower than the speed of downstream amplifier control circuitry.
    Type: Grant
    Filed: October 8, 2010
    Date of Patent: November 29, 2011
    Assignee: AT&T Intellectual Property II, LP
    Inventors: Joseph T. Stango, Guodong Zhang
  • Patent number: 8055127
    Abstract: A wavelength division multiplex optical ring network comprises optical fibre (1-4) arranged in a ring configuration and a plurality of doped fibre optical amplifiers (17-20) arranged in the ring. The spectral response in the ring is configured such in use amplified spontaneous emission (ASE) noise circulates around the ring in a lasing mode to clamp the gain of each doped fibre optical amplifier. Each optical amplifier (17-20) includes respective control means (28) which in use control the optical amplifier to produce a substantially constant output power or to maintain a substantially constant pump power. In the event of loss of the lasing peak, detection means switches the doped fibre optical amplifiers to a different mode of gain control, for example, a mode to produce constant gain at the value before the loss of the lasing peak. Optionally, after a predetermined delay, the optical amplifiers may revert to constant output power or pump power mode.
    Type: Grant
    Filed: November 22, 2004
    Date of Patent: November 8, 2011
    Assignee: Ericsson AB
    Inventors: Roberto Magri, Cornelius Furst
  • Patent number: 8045860
    Abstract: An optical transceiver stores an output A/D value which is A/D-converted from reference voltage in an EEPROM as correction data in preparing the optical transceiver. The optical transceiver, receiving a request for outputting a monitored value from an external device connected therewith, calculates a variation based on difference between the output A/D value which is A/D-converted from the reference voltage at the timing when the request for outputting the monitored value is received and the correction data stored in the EEPROM. Then, the optical transceiver uses the calculated variation to convert current of light-input power which is input thereinto into voltage, amplify the voltage, and A/D-convert the voltage to thereby correct the output A/D value. The optical transceiver outputs the corrected A/D value to the connected external device as the monitored value.
    Type: Grant
    Filed: December 30, 2008
    Date of Patent: October 25, 2011
    Assignee: Fujitsu Limited
    Inventors: Kensuke Matsui, Takahiro Fujimoto
  • Patent number: 8041231
    Abstract: The present invention aims at providing a technique capable of supervising and controlling optical repeaters, without affecting transmission characteristics and wavelength bands of signal lights, by utilizing the Raman effect. To this end, the present invention provides a supervisory controlling system of an optical repeater, in an optical amplifying-and-repeating transmission system for amplifying and repeatingly transmitting signal light propagated through an optical transmission path by the optical repeater, wherein the supervisory control signal light is amplified due to the Raman effect by the signal light acting as excitation light in an optical transmission path (Raman amplifying medium), to thereby supervise and control the optical repeater in accordance with the thus Raman amplified supervisory control signal light.
    Type: Grant
    Filed: January 19, 2010
    Date of Patent: October 18, 2011
    Assignee: Fujitsu Limited
    Inventor: Kenji Ohta
  • Patent number: 8036538
    Abstract: A method for laser safety protection in an optical communication system includes: a downstream station detecting whether an identification signal loaded by an upstream station on a main optical channel in a direction from the upstream station to the downstream station, exist on the main optical channel; if the identification signal is not detected, the downstream station executing a scheduled safety protection procedure. Methods for loading an identification signal on a main optical channel in an optical communication system and an optical amplifier of laser safety protection, which implement loading the identification signal by controlling the change of pump light of optical amplifier or the wave motion of signal light of main optical channel, are also provided. The solution makes it possible to reliably detect a fiber failure when RAMAN amplifiers or remotely-pumped amplifiers exist, thereby implementing laser safety protection.
    Type: Grant
    Filed: November 30, 2007
    Date of Patent: October 11, 2011
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Hao Wang, Yiquan Lu, Congqi Li
  • Patent number: 8036526
    Abstract: A method and apparatus for restoration of operating conditions of a WDM optical ring network comprising a plurality of amplifiers linked together in a ring after a break or fault has occurred in the network. The method comprises in response to repair of the break or other fault, increasing output power or/and pump power of an amplifier in the network such that the output power or/and pump power increases substantially in accordance with a ramp function.
    Type: Grant
    Filed: May 26, 2006
    Date of Patent: October 11, 2011
    Assignee: Ericsson AB
    Inventors: Antonella Bogoni, Roberto Magri, Riccardo Ceccatelli
  • Patent number: 8027585
    Abstract: The present invention relates to controlling wavelength switching in a plurality of nodes that are provided to increase the distance of signal transmission in inverse MUX transmission in which a high-speed line is divided into a plurality of low-speed lines for transmission. A maximum skew occurring between adjacent nodes is measured, and switching of wavelength channels is performed in one or a plurality of nodes on the basis of the measured maximum skew to keep the skew of the entire inverse MUX transmission system at or below a prescribed value. The optical communication device is provided with an NNI functional block to which high-speed lines on the transmission channel side are connected, and a UNI functional block to which low-speed lines on the client side are connected.
    Type: Grant
    Filed: March 31, 2006
    Date of Patent: September 27, 2011
    Assignee: NEC Corporation
    Inventor: Yoshitaka Yokoyama
  • 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: 8005358
    Abstract: A system and method for suppressing beat noise in line monitoring equipment. A wavelength dither generator wavelength modulates a carrier wavelength of a test signal laser transmitter. A test code is modulated on the dithered carrier wavelength to provide a test signal output of the line monitoring equipment.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: August 23, 2011
    Assignee: Tyco Electronics Subsea Communications LLC
    Inventors: Hongbin Zhang, Ralph Brian Jander, Ram M. Engira
  • Patent number: 8000606
    Abstract: A method for processing overheads in an optical communication system and a signal processing device are disclosed. The method includes: in a receiving direction, conduct an O/E and S/P conversion for the received optical signal, extract overheads necessary for overheads processing; transmit the overheads in serial; conduct an S/P conversion of the overheads, add fixed reserved overheads, and revert the parallel overheads for overheads processing; in a transmitting direction, generate parallel overheads, extract overheads necessary for overheads processing; transmit the overheads in serial; conduct an S/P conversion of the overheads, revert the overheads, synthesize the overheads with the payload data before the P/S and E/O conversion, and generate and transmit the optical signal. In accordance with the disclosed method and device, a serial bus is employed to transmit overheads, which reduces the number of buses on the motherboard and lowers the complexity of system design.
    Type: Grant
    Filed: December 14, 2004
    Date of Patent: August 16, 2011
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Xinhua Xiao, Chengyu Huang
  • Patent number: 7953321
    Abstract: An optical transmission equipment includes an optical amplifier that is coupled to an optical transmission path and amplifies a first optical signal which is received from the optical transmission path, a first controller that controls the optical amplifier depending on a first optical power of output light from the optical amplifier and a second optical power of reflecting light to the optical amplifier, an optical coupler that branches a second optical signal from the optical amplifier into a first output and a second output, an optical demultiplexer that demultiplexes the first output of the optical coupler, an optical switch or attenuator that receives the second output of the optical coupler, and a second controller that controls the optical switch or attenuator depending on a third optical power of output light from the optical switch or attenuator and a fourth optical power of reflecting light to the optical switch or attenuator.
    Type: Grant
    Filed: March 16, 2010
    Date of Patent: May 31, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Yasuhiro Uchiyama, Hiroyuki Nakano
  • Patent number: 7941048
    Abstract: An apparatus and a method for accurately detecting Loss of Optical Power (LOS) by noise power cancellation effect and optical power is measured at two output ports of an athermal periodic filter, wherein one output port in the optical frequency domain, is aligned with the signal channels of an input WDM signal (on-grid port), whereas the second output port is aligned complementary to the first output port (off-grid port). In a preferred embodiment, the apparatus computes the ratio of the measured optical powers at the two output ports of the periodic filter, and comparing them to a threshold value that is determined from the overall common-mode rejection ratio (CMRR) of the detection apparatus. In an alternative embodiment, the apparatus additionally compares the optical power measured at the on-grid port to a threshold power that is determined from system design parameters.
    Type: Grant
    Filed: June 29, 2007
    Date of Patent: May 10, 2011
    Assignee: Alcatel-Lucent USA Inc.
    Inventors: Daniel Fishman, Alan Gnauck, Yuan-Hua Kao, Xiang Liu
  • Patent number: 7912370
    Abstract: An apparatus provides measurement of power of an optical signal transmitted in a wavelength multiplexing scheme, based on the optical spectrum and the information on the optical signal. A method provides measuring the power of an optical signal transmitted in a wavelength multiplexing scheme based on the optical spectrum of the optical signal and information acquired on the optical signal.
    Type: Grant
    Filed: November 15, 2007
    Date of Patent: March 22, 2011
    Assignee: Fujitsu Limited
    Inventor: Kentaro Nakamura
  • Patent number: 7912382
    Abstract: An optical-electrical transmitting device for transmitting a signal includes an electrical signal transmitting circuit which divides a transmission signal into a first transmission signal and a second transmission signal, a switching device which is electrically connected to receive and converts the first signal into an identification signal for determining the transmission signal to be one of a fast signal and a slow signal, and a selector which is electrically connected to receive the second transmission signal and the identification signal and outputs the second transmission signal to an optical waveguide when the transmission signal is determined to be the fast signal and an electrical wiring when the transmission signal is determined to be the slow signal, the optical waveguide optically connecting the electrical signal transmitting circuit to an electrical signal receiving circuit, the electrical wiring electrically connecting the electrical signal transmitting circuit to the electrical signal receiving
    Type: Grant
    Filed: September 19, 2007
    Date of Patent: March 22, 2011
    Assignee: Ibiden Co., Ltd.
    Inventors: Zhenhua Shao, Xu Huang, Masataka Ito, Dongdong Wang
  • 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: 7844185
    Abstract: Apparatuses and methods are provided which suppress a surge component occurring at an optical amplifier on an optical path through which an optical burst signal is transmitted. An optical amplifier may experience a surge due to the power variation of the optical burst signal that is fed to the optical amplifier. To suppress such a surge component, a power corresponding to a number of wavelengths of an optical burst signal to be input is calculated. The optical amplifier is instructed to generate an optical signal with a power corresponding to a difference between a set value and the calculated power. The generated optical signal and the optical burst signal to be input are coupled and output according to the instruction. Thus, the optical amplifier can receive the optical signal with the constant power and the surge component at the optical amplifier can be suppressed.
    Type: Grant
    Filed: November 2, 2005
    Date of Patent: November 30, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Keun-joo Park, Hyun-chin Kim, June-koo Rhee, Young-kwang Seo, Chun-ju Youn
  • Patent number: 7826746
    Abstract: An optically amplified wavelength division multiplexing network has the functionality to add/drop channels at the optical add/drop multiplexing (OADM) nodes. The OADM node includes a receiver amplifier, an OADM module, and a transmitter amplifier. Once the OADM node detects a loss of signal (LOS) due to a fiber cut or network element failure upstream, the receiver amplifier is kept in operation as a noise source. The output of the receiver amplifier is immediately raised by increasing pump power to compensate for the LOS. The noise power received at the transmitter amplifier from the receiver amplifier is substantially equal to the signal power expected before LOS. The transient effect of downstream optical amplifiers is therefore completely suppressed and the inter-channel stimulated Raman scattering (SRS) induced spectrum tilt does not change. After the noise power is raised, the receiver amplifier may be shut down at a speed much slower than the speed of downstream amplifier control circuitry.
    Type: Grant
    Filed: October 28, 2008
    Date of Patent: November 2, 2010
    Assignee: AT&T Intellectual Property II, L.P.
    Inventors: Joseph T. Stango, Guodong Zhang
  • Patent number: 7822341
    Abstract: In one embodiment, a control method, according to which a cascade of control messages is propagated between nodes of an optically transparent network, with each message being sent from a node to an adjacent downstream node to inform the latter about a control operation scheduled to be performed at the message-sending node and/or an upstream node that impacts an optical communication signal received at that downstream node. The cascade of control messages effectively creates an ad hoc control domain, in which control operations performed at various nodes of that domain can be coordinated to reduce unfavorable interactions between those control operations. By repeatedly propagating appropriate cascades of control messages through the network, control domains can be changed dynamically and adaptively to reflect any changes to the network topology, equipment, and/or traffic distribution.
    Type: Grant
    Filed: September 28, 2006
    Date of Patent: October 26, 2010
    Assignee: Alcatel-Lucent USA Inc.
    Inventors: Robert D. Feldman, Daniel C. Kilper, Thomas A. Skrobala, Christopher A. White, Lili Yu
  • Patent number: 7817921
    Abstract: In a method for determining a power of an amplified spontaneous emission in an optical fiber amplifier for a WDM signal, wherein the optical fiber amplifier includes at least a first amplifier stage having a predetermined output power set for a measured input power, a first mean inversion is determined for the first amplifier stage. A first output power of the amplified spontaneous emission is determined at an output of the first amplifier stage by reference to tabulated values which depend on the first mean inversion.
    Type: Grant
    Filed: September 26, 2005
    Date of Patent: October 19, 2010
    Assignee: Nokia Siemens Networks GmbH & Co. KG
    Inventors: Lutz Rapp, Wolfgang Peisl
  • Patent number: 7809279
    Abstract: A system and method using differential loop gain for fault analysis in line monitoring equipment. Differential loop gain data is calculated from loop gain data, and fault analysis is conducted using differential loop gain data, e.g. by comparing the differential loop gain data to predefined fault signatures.
    Type: Grant
    Filed: July 27, 2007
    Date of Patent: October 5, 2010
    Assignee: Tyco Electronics Subsea Communications LLC
    Inventors: Hongbin Zhang, Ralph Brian Jander
  • Publication number: 20100247111
    Abstract: An optical relay system is provided, which includes a first optical signal distribution device (101), a phase detection device (103), an amplitude regeneration device (102), and a phase regeneration and load device (104). An optical relay method is further provided, which includes the following steps. A received input signal is divided into two paths; phase information of one path of the input signal is extracted, and is converted to an amplitude modulated signal; an amplitude of the other path of the input signal is restored, so as to generate an amplitude regenerated signal; a phase is loaded on the amplitude regenerated signal by using the amplitude modulated signal, so as to generate a phase regenerated signal. The system and method eliminate a phase noise of the signal in a transmission process, improve a transmission performance of the signal, and realize a simple implementation method.
    Type: Application
    Filed: June 14, 2010
    Publication date: September 30, 2010
    Inventors: Lijun Li, Qianjin Xiong
  • Patent number: 7801443
    Abstract: An automatic circulation collection type data system is constructed by connecting a monitoring device and data collecting modules disposed at respective places through optical cables. The monitoring device transmits a trigger pulse for data collection through the optical cable to each data collecting module. An identification code is given to each data collecting module, and each data collecting module has an automatic circulation mechanism comprising first and second optical switches, a data collecting unit, and a controller 6 for performing various kinds of control for data collection. When receiving the trigger pulse from the monitoring device, the automatic circulation mechanism turns on the third switch and transmits the collected data through the optical cable to the monitoring device together with the identification code, and also transmits a trigger pulse through the optical cable to a next data collecting module.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: September 21, 2010
    Assignees: National Institute of Advanced Industrial Science and Technology, Dainichiseika Color & Chemicals Mgf. Co., Ltd., Spacecreation Co., Ltd., Inter Energy Co., Ltd.
    Inventors: Takashi Hiraga, Ichiro Ueno, Noritaka Yamamoto, Toshiko Mizokuro, Nobutaka Tanigaki, Norio Tanaka, Kuniaki Aoki, Hirofumi Watanabe, Shiro Futaki
  • Patent number: 7787777
    Abstract: An optical packet network system of a ring type, capable of preventing degradation of an optical signal, can be implemented by providing a mechanism relatively simple in structure, capable of erasing light noise if the optical packet signal does not exists. In the optical packet network system made up by interconnecting respective nodes adjacent to each other, and connecting a sending source of an optical packet signal to a ring, a light noise removal function block is provided between the respective nodes adjacent to each other.
    Type: Grant
    Filed: August 11, 2006
    Date of Patent: August 31, 2010
    Assignee: Yokogawa Electric Corporation
    Inventors: Shinji Iio, Masayuki Suehiro, Katsuya Ikezawa, Akira Miura, Sadaharu Oka, Chie Sato, Mamoru Hihara, Tsuyoshi Yakihara, Shin-ichi Nakajima, Morio Wada, Daisuke Hayashi, Shinji Kobayashi, Yoshiyuki Asano
  • Patent number: 7787765
    Abstract: A method and apparatus for initializing an end-to-end link in a fiber optic communications system in which a pair of nodes interconnect a pair of end devices. A first node, upon initializing a device link segment with an end device to which the node is coupled, sends a signal to the other node over a network link segment indicating that the sending node has initialized its device link segment. The first node completes initialization of the end-to-end link upon receiving a signal from the other node over the network link segment indicating that the other node has initialized its device link segment. In an alternative initialization scheme, a node momentarily operates its data channel in a loopback mode to allow its end device to initialize the device link segment in accordance with a predetermined protocol before returning to a transparent mode.
    Type: Grant
    Filed: December 21, 2005
    Date of Patent: August 31, 2010
    Assignee: International Business Machines Corporation
    Inventors: Casimer M. DeCusatis, Thomas A. Gregg
  • Patent number: 7783201
    Abstract: An optical repeater device of the present invention comprises: a preamble compensating circuit 53, for taking out a normal data signal from burst signals propagating through a communication transmission path, and for adding a preamble signal before and/or after the data signal. Furthermore, the preamble compensating circuit 53 comprises: a detector circuit 53a, for inputting the burst signal, and for outputting only the normal data signal; a buffer circuit 53b, for storing the data signal output from the detector circuit 53a, and for outputting thereof; a preamble signal generation circuit 53d, for outputting at least one type of the preamble signal; and an data output select circuit 53e, for outputting the data signal at the time of the data signal input from the buffer circuit 53b, and for outputting the preamble signal from the preamble signal generation circuit 53d at any other time thereof.
    Type: Grant
    Filed: March 11, 2008
    Date of Patent: August 24, 2010
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Masayuki Miura, Kunio Odaka, Fuyuki Takeuchi
  • Patent number: 7773886
    Abstract: In an optical fiber communication system, the input power to an all-optical nonlinear device in an optical regenerator is monitored and adjusted such that the regenerator operates at an optimized operation point.
    Type: Grant
    Filed: June 30, 2003
    Date of Patent: August 10, 2010
    Assignee: Fujitsu Limited
    Inventors: Rainer Hainberger, Shigeki Watanabe
  • Patent number: 7756422
    Abstract: During initial start-up of an optical communication system, an ASE reference span loss is calculated based on transmitting power and received power of ASE light generated by an optical amplifier, and an OSC reference span loss is calculated based on the transmitting power and the received power of OSC light. During normal operation of the optical communication system, a span loss is calculated using the OSC light, and an amount of change in the span loss representing a difference between the span loss and the OSC reference span loss is calculated. A current span loss between a transmitting station and a receiving station is calculated by adding the amount of change in the span loss to the ASE reference span loss.
    Type: Grant
    Filed: August 11, 2006
    Date of Patent: July 13, 2010
    Assignee: Fujitsu Limited
    Inventors: Takeshi Sakamoto, Kosuke Komaki, Yuji Shimada, Takuji Maeda
  • Patent number: RE42095
    Abstract: The control of the transmission of useful optical signals on different line paths of an optical transmission device is accomplished via at least one of the following features: using signal sources and signal sinks, the useful optical signals are coupled into the line paths, or are coupled out of them; at least one portion of the optical line paths is configured as normal line paths having coupling nodes via which a switchover to an alternative line path can be undertaken if a normal line path is disturbed; in addition to the useful optical signals, test signals, whose evaluation is used for the switchover between the line paths, are transmitted bidirectionally section-by-section; at least two types of test signals can be transmitted, of which a first type is used as an indicator for an intact line path and a second type as an indicator for a disturbed line path; and any switchover to an alternative line path is only undertaken if, before the detection of the disturbance, a test signal of the first type has be
    Type: Grant
    Filed: September 30, 1998
    Date of Patent: February 1, 2011
    Assignee: Nola Semiconductor LLC
    Inventors: Jan Koeppen, Guenter Neumann, Helmut Tiltmann