Repeater Patents (Class 398/97)
  • Patent number: 9882649
    Abstract: Provided are transmitting, receiving and communication systems of an optical network and a method for modulating a signal. The transmitting system includes: first Passive Optical Network (PON) equipment, configured to output a binary digital signal; and an M-order digital modulator, configured to modulate the binary digital signal into an M-order digital signal, and output the M-order digital signal, wherein each transmission symbol in the M-order digital signal carries information of N=log2M bits, where N is a natural number greater than 1 and M is a natural number. By the disclosure, the problems in the related art is solved, the bandwidths required by transmission are further reduced, and the actual cost of the optical transceiver modules is lowered.
    Type: Grant
    Filed: August 14, 2013
    Date of Patent: January 30, 2018
    Assignee: XI'AN ZHONGXING NEW SOFTWARE CO. LTD.
    Inventors: Songlin Zhu, Yong Guo, Yongjia Yin, Yang Gao, Guanjun Zeng, Dezhi Zhang, Weifeng Tong
  • Patent number: 9509412
    Abstract: An optical communication system includes an optical transmitter that sends an optical signal; and an optical receiver that receives the optical signal. The optical transmitter controls a transmission rate of the optical signal to a first transmission rate corresponding to first reception light power lower than target reception light power of the optical receiver in response to transmission light power control for the optical signal corresponding to the target reception light power.
    Type: Grant
    Filed: November 12, 2014
    Date of Patent: November 29, 2016
    Assignee: FUJITSU LIMITED
    Inventors: Toshiki Tanaka, Tomoo Takahara
  • Patent number: 9036995
    Abstract: An optical communication system includes an optical-signal transmission unit transmitting an existing optical signal and a low-rate-signal superimposition unit superimposing a low-rate signal on the existing optical signal by intensity modulation. It further includes: a low-rate-signal extraction unit that extracts the low-rate signal from the existing optical signal on which the low-rate signal is superimposed and converts the extracted low-rate signal into a low-rate electric signal; an add-on optical-signal transmission unit that transmits an add-on optical signal; a low-rate-signal superimposition unit that superimposes a low-rate signal on the add-on optical signal by the intensity modulation based on the low-rate electric signal; and a repeater that repeats the add-on optical signal on which the low-rate signal is superimposed, to a transmission destination.
    Type: Grant
    Filed: September 3, 2010
    Date of Patent: May 19, 2015
    Assignee: Mitsubishi Electric Corporation
    Inventors: Toshiyuki Tokura, Kazuyuki Ishida, Takashi Mizuochi
  • Patent number: 8942565
    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: August 13, 2013
    Date of Patent: January 27, 2015
    Assignee: Alcatel Lucent
    Inventors: Alan Glen Solheim, Peter David Roorda, Kevan Peter Jones, Greg Peter Friesen
  • Patent number: 8873956
    Abstract: Optical regenerators and amplifiers are expensive to implement and maintain. A method or corresponding apparatus in an example embodiment of the present invention relates to an optical planning tool that plans an optical network configuration by determining a plurality of costs for maintaining signal strength in corresponding network configurations including (i) a configuration of regenerators, (ii) a configuration of pre-or post-amplifiers, and (iii) a configuration of pre- and post-amplifiers in candidate locations and regenerator modules. The candidate locations for placing pre-or post-amplifiers are determined based on loss in each span, expected traffic patterns, and proposed regeneration locations along paths of expected traffic. The regeneration modules are located in locations determined based on the candidate locations. The example embodiment selects a configuration from among the network configurations as a function of the plurality of costs, helping reduce the cost of network deployment.
    Type: Grant
    Filed: April 27, 2009
    Date of Patent: October 28, 2014
    Assignee: Tellabs Operations, Inc.
    Inventor: Dion Kwun Kit Leung
  • Publication number: 20140294378
    Abstract: A transmission apparatus includes: an amplifier controller configured to determine a target value for an average optical input power of a transmitting amplifier in a transmitting-side apparatus, based on an index based on a quality of transmission from an output of the transmitting amplifier to an output of a receiving amplifier in a receiving-side apparatus; and a pre-emphasis controller configured to determine amounts of adjustment of transmission optical powers for respective wavelengths, based on the target value and per-wavelength reception optical powers at the output of the receiving amplifier.
    Type: Application
    Filed: January 13, 2014
    Publication date: October 2, 2014
    Applicant: FUJITSU LIMITED
    Inventors: Yoshinobu Matsukawa, Norifumi Shukunami, Kosuke Komaki
  • Publication number: 20140269784
    Abstract: A relay device includes: a first port, a plurality of second ports, a splitter configured to branch first optical signals input from the first port into the plurality of second ports; and a plurality of optical modulators configured to modulate shared carrier light by multiplexing the carrier light with a plurality of second optical signals with different frequencies input from the plurality of second ports and by inputting the multiplexed carrier light into a plurality of nonlinear optical mediums, and to transmit the carrier light to the first port.
    Type: Application
    Filed: December 19, 2013
    Publication date: September 18, 2014
    Applicant: FUJITSU LIMITED
    Inventors: Tomoyuki Kato, Shigeki Watanabe
  • Patent number: 8787763
    Abstract: Embodiments of the present invention provide a repeater, including a local unit and a remote unit. The local unit includes a base station interface unit, multiple local basic units and a controller. The remote unit includes multiple remote basic units. The controller is configured to generate, according to a down-tilt angle and/or azimuth angle of a downlink signal instructed by a control instruction, a downlink signal phase for each remote basic unit. The multiple local basic units each are configured to perform, according to the downlink signal phase generated by the controller for a corresponding remote basic unit, phase adjustment on the downlink signal sent by the base station interface unit. The multiple remote basic units each are configured to receive the downlink signal sent by a corresponding local basic unit and to send the downlink signal.
    Type: Grant
    Filed: April 25, 2013
    Date of Patent: July 22, 2014
    Assignee: Huawei Technologies Co., Ltd.
    Inventor: Lanping Gong
  • Publication number: 20140186043
    Abstract: Provided are a passive optical network reach extender based on a wavelength tunable optical module and a method thereof. According to an embodiment of the invention, a passive optical network reach extender includes a first optical splitter configured to receive an optical signal from an optical line terminal and split the signal into optical signals having a multiplexed wavelength, a wavelength tunable remote relay configured to receive the optical signals split from the first optical splitter, and select and control an available wavelength for each port, a wavelength multiplexer configured to multiplex a wavelength of the optical signal output from the wavelength tunable remote relay, and a second optical splitter configured to split the optical signal multiplexed by the wavelength multiplexer into a plurality of optical network units.
    Type: Application
    Filed: August 23, 2013
    Publication date: July 3, 2014
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Kwang-Ok KIM, Sang-Soo LEE, Jong-Hyun Lee
  • Patent number: 8731404
    Abstract: An optical transmission system is provided. The optical transmission system includes a user side optical repeater device (ORD), a central office side ORD, and wavelength multiplexing and wavelength de-multiplexing functions (MUX/DEMUX). The user side optical repeater device (ORD) is to be connected with a user side optical network unit (ONU), transmits data in two ways, and is used for wavelength division multiplexing (WDM). The central office side ORD is to be connected with a central office side optical line terminal (OLT), transmits data in two ways, and is used for WDM. The wavelength multiplexing and a wavelength de-multiplexing functions (MUX/DEMUX), are used for relaying between the user side ORD and the central office side ORD.
    Type: Grant
    Filed: November 30, 2012
    Date of Patent: May 20, 2014
    Assignee: Furukawa Electric Co., Ltd.
    Inventor: Masayuki Miura
  • Patent number: 8718475
    Abstract: A system and method for sizing transponder pools in a dynamic wavelength division multiplexing optical network having selected nodes designated to have a shared transponder pool is presented.
    Type: Grant
    Filed: March 16, 2011
    Date of Patent: May 6, 2014
    Assignee: Telcordia Technologies, Inc.
    Inventors: Ronald A. Skoog, Brian J. Wilson
  • Patent number: 8676059
    Abstract: In an optical signal processing apparatus, carrier light propagates through a nonlinear optical medium. An optical combiner optically combines output control light for generating idler light of the carrier light with the carrier light. An optical splitter splits the idler light from the carrier light. A receiver acquires a signal multiplexed on the carrier light from the idler light split by the optical splitter.
    Type: Grant
    Filed: April 13, 2012
    Date of Patent: March 18, 2014
    Assignee: Fujitsu Limited
    Inventor: Shigeki Watanabe
  • Patent number: 8620160
    Abstract: An optical transmission apparatus includes a reception part for receiving a wavelength division multiplexed (WDM) signal reached via optical amplifiers; a measuring part for measuring an optical power level of each wavelength of the WDM signal received by the reception part; a determination part for determining whether an amount of tilt of the WDM signal calculated based on measurement results of the measuring part is suitable or not; an operation part for calculating the tilt correction amount to be applied to tilt correction processing performed by the optical amplifiers if the amount of tilt of the WDM signal is not suitable; and a notification part for notifying the optical amplifiers of the tilt correction amount.
    Type: Grant
    Filed: July 8, 2008
    Date of Patent: December 31, 2013
    Assignee: Fujitsu Limited
    Inventor: Miki Onaka
  • Patent number: 8577222
    Abstract: The present invention relates to an optical relay system for transmitting multi-band frequency signals with limited bands by using optical lines. According to the present invention, a plurality of band-limited signals are band-combined into one signal by using a combiner, and the signals are transmitted through multiple outputs by using a distributor, and thus a multi-stage filter is not necessary. In addition, the present invention is capable of effectively solving various problems such as damage to the original signals caused by the band combination of the multi-stage filter, and there is no need to precisely connect each of the band-limited signals to the determined ports of the combiner and the signals can be connected to random ports, thereby improving convenience of use.
    Type: Grant
    Filed: December 23, 2009
    Date of Patent: November 5, 2013
    Assignee: Solid Technologies Inc.
    Inventors: Kyung Eun Han, Yeong Shin Yeo, Ki Chul Cho
  • Patent number: 8526812
    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: June 8, 2012
    Date of Patent: September 3, 2013
    Assignee: Alcatel Lucent
    Inventors: Alan Glen Solheim, Peter David Roorda, Kevan Peter Jones, Greg Peter Friesen
  • Patent number: 8520685
    Abstract: A ROADM device generates link information including a virtual link in which a first link that is used by a node apparatus for transmitting a signal and a second link of a ROADM device that is capable of branching a signal transmitted via the first link when the signal is transmitted via a WDM network are virtually connected each other, and transmits the generated link information.
    Type: Grant
    Filed: January 31, 2007
    Date of Patent: August 27, 2013
    Assignee: Fujitsu Limited
    Inventors: Akira Nagata, Keiji Miyazaki, Shinya Kano, Yasuki Fujii
  • Patent number: 8488977
    Abstract: Provided is a time division multiple access over wavelength division multiplexed passive optical network (TDM-over-WDM-PON) system. According to the TDM-over-WDM-PON system, a downstream optical signal is separated according to a wavelength in a remote node, transmitted to an optical amplifying device located in subscriber equipment, amplified in the optical amplifying device, transmitted back to the remote node, and then transmitted to the subscriber equipment. Also, an upstream optical signal is transmitted to a wavelength converting device located in the subscriber equipment from the remote node, wavelength-converted in the wavelength converting device, returned back to the remote node, and then transmitted to a central office.
    Type: Grant
    Filed: August 14, 2008
    Date of Patent: July 16, 2013
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Byoung Whi Kim, Han Hyub Lee, Bong Tae Kim
  • Patent number: 8463135
    Abstract: A relay apparatus including: a first interface 11 that branches an optical signal that is input in a first direction from one side of the optical transmission line, and directs the optical signal to a first path and a second path, the first path being a processing path of an optical signal having a first transmission speed, the second path being a processing path of an optical signal having a second transmission speed that is different from the first transmission speed; a processing section 12 that executes processing on an optical signal propagating through each of the paths in accordance with a corresponding transmission speed; and a second interface 13 that binds the first path and the second path of the optical signal on which the processing is executed by the processing section, by means of wavelength multiplexing and directs to the other end of the optical transmission line.
    Type: Grant
    Filed: April 5, 2010
    Date of Patent: June 11, 2013
    Assignee: Fujitsu Limited
    Inventors: Kyosuke Sone, Yutaka Kai, George Ishikawa, Susumu Kinoshita
  • Publication number: 20130129356
    Abstract: An optical communication system includes an optical-signal transmission unit transmitting an existing optical signal and a low-rate-signal superimposition unit superimposing a low-rate signal on the existing optical signal by intensity modulation. It further includes: a low-rate-signal extraction unit that extracts the low-rate signal from the existing optical signal on which the low-rate signal is superimposed and converts the extracted low-rate signal into a low-rate electric signal; an add-on optical-signal transmission unit that transmits an add-on optical signal; a low-rate-signal superimposition unit that superimposes a low-rate signal on the add-on optical signal by the intensity modulation based on the low-rate electric signal; and a repeater that repeats the add-on optical signal on which the low-rate signal is superimposed, to a transmission destination.
    Type: Application
    Filed: September 3, 2010
    Publication date: May 23, 2013
    Applicant: Mitsubishi Electric Corporation
    Inventors: Toshiyuki Tokura, Kazuyuki Ishida, Takashi Mizuochi
  • Patent number: 8447184
    Abstract: A system and method for Raman amplification of optical signals in a wavelength division multiplexing (WDM) optical transmission system includes transmitting optical signals within a transmission band via an optical waveguide between a transmitter and a receiver, Raman-amplifying the optical signals with at least one pump so as to distort an amplification profile of the Raman amplification within the transmission band, and rectifying the distorted amplification profile so as to compensate for the distortion.
    Type: Grant
    Filed: June 3, 2006
    Date of Patent: May 21, 2013
    Assignee: Deutsche Telekom AG
    Inventors: Matthias Gunkel, Ralph Leppla, Malte Schneiders, Sascha Vorbeck, Werner Weiershausen, Michael Bousonville
  • Patent number: 8428462
    Abstract: A device may include a component, a first switch, a repeater, and a second switch. The component may configure optical paths between ports. The component may comprise a first pair of optical ports connected to a first pair of optical fibers, and a second pair of optical ports connected to a second pair of optical fibers. The first switch may be configured to output one of two optical signals received by the first pair of optical ports from the first pair of optical fibers. The repeater may reshape or amplify the outputted optical signal. The second switch may be configured to direct the reshaped or amplified signal to one of the second pair of optical ports.
    Type: Grant
    Filed: June 18, 2009
    Date of Patent: April 23, 2013
    Assignee: Verizon Patent and Licensing Inc.
    Inventors: Glenn A. Wellbrock, Tiejun J. Xia
  • Patent number: 8428463
    Abstract: Consistent with the present disclosure, a method and apparatus for providing a uniform spectral gain of an optical amplifier is provided. Namely, a “balancing” step is carried out in which an optical channel having the lowest power level input to an optical circuit, such as an dynamic gain equalizer (DGE), is assigned a zero “attenuation error” and is substantially un-attenuated by the DGE. The lowest power level optical signal does not require further attenuation and effectively serves as a reference power level, which the power levels of the remaining optical signals are set to. For example, remaining optical signals are assigned either positive or negative attenuation errors relative to the zero attenuation error based on optical signal input powers to the DGE and accumulated DGE attenuations over time. Those optical signals having a negative attenuation error are substantially unattenuated by the DGE, because such optical signals are adequately attenuated and do not require further attenuation.
    Type: Grant
    Filed: May 10, 2010
    Date of Patent: April 23, 2013
    Assignee: Infinera Corporation
    Inventors: Benjamin A. Warren, Saurabh Kumar, Abhijeet D. Deore, Brian B. Shia, Ganesh Sundaresan
  • 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: 8340521
    Abstract: An optical transmission system is provided. The optical transmission system includes a user side optical repeater device, a central office side optical repeater device, and wavelength multiplexing and wavelength de-multiplexing functions. The user side optical repeater device is to be connected with a user side optical network unit, transmits data in two ways, and is used for wavelength division multiplexing. The central office side optical repeater device is to be connected with a central office side optical line terminal, transmits data in two ways, and is used for wavelength division multiplexing. The wavelength multiplexing and wavelength de-multiplexing functions are used for relaying between the user side optical repeater device and the central office side optical repeater device.
    Type: Grant
    Filed: April 14, 2010
    Date of Patent: December 25, 2012
    Assignee: Furukawa Electric Co., Ltd.
    Inventor: Masayuki Miura
  • Patent number: 8306424
    Abstract: The present invention provides a remodulating channel selector for a wavelength division multiplexed optical communication system. The remodulating selector receives a WDM input signal, selects a particular optical channel from the WDM signal and places the information from the selected signal onto a newly-generated optical output signal. The wavelength of the output optical signal can be the same as or different from one of the optical channels which comprises the WDM input signal. When used in a WDM optical communication system with remodulators at the transmission input, the remodulating selectors provide complete control over the interfaces with optical transmitters and receivers, permitting use with a broad range of optical equipment.
    Type: Grant
    Filed: August 24, 2010
    Date of Patent: November 6, 2012
    Assignee: Ciena Corporation
    Inventors: Stephen B. Alexander, Steve W. Chaddick, Roy C. Litz, Cecil D. Smith
  • Patent number: 8306427
    Abstract: There is provided a WDM transmission apparatus including a calculator being operable to calculate an optical signal level of a wavelength after wavelength demultiplexing based on information of OSNR, an amplifier controller being operable to compensate for the optical signal levels of all the wavelengths after wavelength demultiplexing to become a target level based on an optical signal level calculated by the calculator, and an deviation corrector being operable to correct a deviation of an optical signal level between each wavelength based on the optical signal level calculated by the calculator.
    Type: Grant
    Filed: December 17, 2009
    Date of Patent: November 6, 2012
    Assignee: Fujitsu Limited
    Inventors: Ryosuke Goto, Takehiro Fujita
  • Patent number: 8265481
    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 10, 2011
    Date of Patent: September 11, 2012
    Assignee: Alcatel Lucent
    Inventors: Alan Glen Solheim, Peter David Roorda, Kevan Peter Jones, Greg Peter Friesen
  • 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: 8208812
    Abstract: A control-target-value setting unit sets a control target value corresponding to the number of multiplexed wavelengths measured by a number-of-multiplexed-wavelengths measuring unit. A controller controls the variable optical attenuator based on the control target value. An optical amplifier performs an optical amplification with a constant gain regardless of power of a wavelength-multiplexed light. The controller performs feedback control of the variable optical attenuator such that a result of measurement of the total power of the wavelength-multiplexed light coincides with the control target value.
    Type: Grant
    Filed: May 25, 2006
    Date of Patent: June 26, 2012
    Assignee: Mitsubishi Electric Corporation
    Inventors: Toshiyuki Tokura, Katsuhiro Shimizu, Kazuyuki Ishida, Kuniaki Motoshima
  • Patent number: 8204379
    Abstract: An optical network node for an n-channel dense wavelength division multiplexing (DWDM) optical communications network, includes an add path for adding an n-channel wavelength multiplex onto the network. The add path has an n-channel signal combiner for combining the n signal channels. An optical amplifier amplifies an output of the signal combiner. A multichannel wavelength selective filter with variable-per-channel attenuation filters out noise from the amplifier on a channel which carries no content to be added to the network, and controls amplitude of signals in channels to be added to the network. An add coupler couples the add path to the network.
    Type: Grant
    Filed: November 17, 2010
    Date of Patent: June 19, 2012
    Assignee: Ericsson AB
    Inventors: Harry Richard Claringburn, Michael Sharratt
  • Publication number: 20120106971
    Abstract: An optical transmission device includes: an optical signal generator to generate and transmit an optical signal that transmits data; a detector to detect a number of active clients; and a processor to determine transmission rate of the optical signal according to the number of active clients and quality of the optical signal at an optical receiver.
    Type: Application
    Filed: July 28, 2011
    Publication date: May 3, 2012
    Applicant: FUJITSU LIMITED
    Inventor: Yasushi SUGAYA
  • Patent number: 8165467
    Abstract: Where an integrated monitoring and controlling unit is to control an optical add-drop unit so as to cause transmit signals from the optical transceiver of a first optical node to be received by the optical transceivers of plural different optical nodes, this purpose can be achieved by an optical transmission system provided with an alarm inhibiting device that can inhibit the optical transceiver, which is a source of transmission, from issuing any unexpected alarm.
    Type: Grant
    Filed: November 21, 2008
    Date of Patent: April 24, 2012
    Assignee: Hitachi, Ltd.
    Inventor: Yasuyuki Fukashiro
  • Publication number: 20120087670
    Abstract: The present invention relates to an optical relay system that transmits a band-limited multi-band frequency signal via an optical line. According to an embodiment of the present invention, since a remote unit includes a multiplexer that fixes a power flow direction to combine wireless signals of various bands and outputs the combined signals to a mobile terminal, or distributes wireless signals wireless signals received from the mobile terminal and fixes a power flow direction to output the distributed wireless signals, even if frequency bands of signals combined by the multiplexer overlap or are adjacent, power delivery in a direction opposite to the power delivery direction of a signal during a signal combining process can be prevented, reducing signal distortion, and thus improving efficiency in combining a number of signals.
    Type: Application
    Filed: December 23, 2009
    Publication date: April 12, 2012
    Applicant: SOLID TECHNOLOGIES INC.
    Inventors: Kyung Eun Han, Yeong Shin Yeo, Ki Chul Cho
  • 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
  • Publication number: 20120002963
    Abstract: Provided is an optical relay system (10) which is capable of suppressing wasteful power consumption of an entire system to a low level. The optical relay system (10) includes a plurality of relay devices (30) and a network control device (20). The network control device (20) causes an optical signal to be regenerated by a regenerative repeater (35) within the relay device (30) existing at an upstream of the relay device (30) reporting that the optical signal has deteriorated by a degree exceeding a predetermined level. Further, the network control device (20) causes the regenerative repeater (35) to stop regenerating the signal in a case where deterioration of the signal remains within an allowable range even when the regenerative repeater (35) stops regenerating the signal.
    Type: Application
    Filed: June 6, 2011
    Publication date: January 5, 2012
    Inventors: Takuya Iwasawa, Kenta Noda, Takayuki Suzuki
  • Patent number: 8086106
    Abstract: In the WDM optical transmission system, when performing a correction of a control target value of the total light intensity per one channel of the WDM light in each node on a transmission path, a correction value calculation section of each node determines the type of its own node, and if it corresponds to a node (for example, OADM node) that demultiplexes the WDM light into individual channels and performs a predetermined processing, performs correction of the control target value of the total light intensity according to a calculation expression with use of a noise cut ratio. The noise cut ratio is defined according to a filtering characteristic for when demultiplexing the WDM light into individual channels, so that the influence due to removal of the noise components distributed across the intermediate region of each channel due to filtering is reflected in the correction processing of the control target value of the total light intensity.
    Type: Grant
    Filed: April 28, 2009
    Date of Patent: December 27, 2011
    Assignee: Fujitsu Limited
    Inventor: Kentaro Nakamura
  • 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
  • Publication number: 20110274433
    Abstract: The invention relates to improvements in or relating to modulation in an Optical Network, and to an apparatus, a method and a communications network for modulation in an Optical Network. An apparatus is arranged to receive a modulated optical signal comprising a carrier wavelength and first data. The apparatus is arranged to substantially erase the first data from the optical signal by performing an inversion operation on the modulated optical signal. The apparatus is arranged to receive second data and to modulate the carrier wavelength with the second data for onward transmission of the second data. The inversion operation comprises applying a signal comprising an inverse of the first data to at least a portion of the modulated optical signal. The signal may further comprise the second data such that the modulation of the carrier wavelength and erasure of the first data is performed in a single operation.
    Type: Application
    Filed: October 7, 2008
    Publication date: November 10, 2011
    Inventors: Marco Presi, Ernesto Ciaramella, Fabio Cavaliere
  • 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
  • Publication number: 20110110667
    Abstract: An optical network and an optical signal modulation method thereof are provided. The optical network includes an optical fiber and a remote node (RN). The RN receives a continuous carrier wave from the optical fiber and modulates the continuous carrier wave to generate a first frequency offset carrier wave The frequency of the first frequency offset carrier wave is different from that of the continuous carrier wave. A first user device re-modulates and loads data to the first frequency offset carrier wave to generate a first upstream signal. The frequency of the first upstream signal is the same as that of the first frequency offset carrier wave. The RN inputs the first upstream signal into the optical fiber.
    Type: Application
    Filed: December 22, 2009
    Publication date: May 12, 2011
    Applicant: INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE
    Inventors: Chien-Hung Yeh, Chi-Wai Chow
  • 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: 7899331
    Abstract: According to a WDM optical transmission system of the present invention, wavelength numbers information of a WDM signal light output from an upstream side optical amplifying unit to a transmission path fiber, and signal output level information thereof are transmitted to a downstream side optical amplifying unit utilizing a supervisory control light. In the downstream side optical amplifying unit, a loss (span loss) in the transmission path fiber is computed using the upstream side signal output level information and downstream side signal input level information, so that a gain to be set for a downstream side optical amplifier is calculated based on the computed loss, and also, the gain is corrected based on a difference between a target value of the signal output level computed using the wavelength numbers information and an actual measurement value thereof, so that the optical amplifier is controlled in accordance with the post-corrected gain.
    Type: Grant
    Filed: July 30, 2007
    Date of Patent: March 1, 2011
    Assignee: Fujitsu Limited
    Inventors: Hiroyuki Itoh, Kosuke Komaki
  • Publication number: 20110008042
    Abstract: A communication system for providing downlink and uplink communication between Service Providers, and users located in RF remotely located isolated areas, includes the sequential series connection of Service Provider signal sectors to Radio Interface Modules (RIM's), Service Combiner Units (SCU's), Fiber Transceiver Units (FTU's), Optical Multiplexer Units (OMU's), and Remote Fiber Nodes (RFN's), with only the RFN's being located in the RF isolated areas. The RIM's provide level control of RF signals bidirectional flowing between the Service Providers and SCU's. The SCU's both multiplex and split received downlink RF signals for inputting to the FTU's, and also combine and split RF uplink signals received from the FTU's for feed to the RIM's. The FTU's convert downlink RF signals into optical signals, and split the optical signals for connection to the OMU's. The FTU's also convert uplink optical signals received from the OMU's into uplink RF signals for connection to the SCU's.
    Type: Application
    Filed: July 7, 2009
    Publication date: January 13, 2011
    Inventor: James N. Stewart
  • Patent number: 7860396
    Abstract: The add path of a dense wavelength division multiplexing (DWDM) add/drop node comprises an n:1 coupler for combining n signal sources. The combined signal is amplified and then demultiplexed. Each output of the demultiplexer is passed through a variable optical attenuator (VOA) and the VOA outputs multiplexed to form the add signal. Channels carrying no add signal and not used to control the added signals are attenuated to zero to remove a broadband noise contribution from those channels. The signal sources are run at maximum power and the signals of those channels are attenuated by the respective VOAs to control their amplitude and optimize the optical signal to noise ratio of the add signal.
    Type: Grant
    Filed: December 17, 2002
    Date of Patent: December 28, 2010
    Assignee: Ericsson AB
    Inventors: Harry Richard Claringburn, Michael Sharratt
  • 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: 7809263
    Abstract: An optical transmission apparatus comprising a first detector for detecting the power of the supervisory signal light separated from received wavelength-division multiplexed signal lights; a second detector for detecting the power of the wavelength-division multiplexed signal lights after the separation of the supervisory signal light; a gain-controlled type optical amplifier for amplifying the wavelength-division multiplexed signal lights; an optical attenuator coupled to the amplifier; and a control unit for controlling the optical amplifier and the optical attenuator so as to keep the output level of the wavelength-division multiplexed signal lights to a predetermined target value, wherein the control unit restrains automatic output level control by the optical attenuator when the supervisory signal light power fluctuates within its permissible range and fluctuations in the signal light power have deviated from its permissible range.
    Type: Grant
    Filed: November 25, 2008
    Date of Patent: October 5, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Tetsuya Uda, Kenta Noda, Yasuhiro Uchiyama, Hiroshi Masuda, Hiroyuki Nakano
  • 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: 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
  • Publication number: 20100166426
    Abstract: An optical signal processing device includes a waveform width widening unit configured to widen a waveform width of an optical signal; and an optical limiter circuit, to which the optical signal the waveform width of which is widened is input, configured to suppress an intensity of the optical signal in a region where an input intensity and an output intensity are not proportional.
    Type: Application
    Filed: November 12, 2009
    Publication date: July 1, 2010
    Applicant: FUJITSU LIMITED
    Inventor: Shigeki WATANABE