Patents by Inventor Cechan Tian

Cechan Tian has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20050095001
    Abstract: An optical network includes an optical ring operable to communicate optical traffic and a plurality of nodes coupled to the optical ring. Each node is operable to passively add and drop one or more traffic streams to and from the optical ring. Each traffic stream comprises at least one channel. The plurality of nodes comprise a hub node operable to selectively pass or terminate a plurality of individual sub-bands of the optical traffic and a plurality of sub-band nodes each operable to terminate a respective sub-band of the optical traffic.
    Type: Application
    Filed: October 29, 2003
    Publication date: May 5, 2005
    Inventors: Cechan Tian, Yasuhiko Aoki, Susumu Kinoshita
  • Publication number: 20050045810
    Abstract: A method for controlling an amplifier in an optical network includes determining primary pump power information for a primary amplifier and communicating the primary pump power information to a secondary amplifier coupled to the primary amplifier. The method also includes generating secondary pump control information for the secondary amplifier based on the primary pump power information and amplifying a first optical signal at the secondary amplifier based on the secondary pump control information.
    Type: Application
    Filed: August 26, 2003
    Publication date: March 3, 2005
    Inventors: Cechan Tian, Susumu Kinoshita
  • Publication number: 20050008363
    Abstract: A method for management of directly connected optical components includes receiving a source optical signal for communication to an optical network. The source optical signal comprises one or more source channels. The method includes monitoring optical traffic communicated on the optical network to determine one or more network channels of the optical traffic and determining network channel information of the one or more network channels. The method also includes communicating to the optical network channels of the one or more source channels that do not interfere with any of the one or more network channels.
    Type: Application
    Filed: July 8, 2003
    Publication date: January 13, 2005
    Inventors: Cechan Tian, Yasuhiko Aoki, Susumu Kinoshita
  • Publication number: 20040240040
    Abstract: A method for determining gain for an optical signal includes measuring a first power level that is an output power level of an optical signal at a first optical node, communicating the optical signal to a second optical node, and communicating the first power level to the second optical node in an optical supervisory channel of the optical signal. The method further includes receiving the optical signal at the second optical node, measuring a second power level of the optical signal at the second optical node, and determining a gain for the optical signal based on the first and second power levels.
    Type: Application
    Filed: May 29, 2003
    Publication date: December 2, 2004
    Applicant: Fujitsu Limited
    Inventors: Cechan Tian, Susumu Kinoshita
  • Publication number: 20040240041
    Abstract: A method for correcting power tilt in an optical signal includes tapping off a representative portion of an optical signal and separating the representative portion into a first signal and a second signal. The first signal includes a first wavelength band and the second signal includes a second wavelength band different from the first wavelength band, wherein each wavelength band includes more than one channel. The method also includes detecting a power level of the first signal, detecting a power level of the second signal, and comparing the power levels of the first and second signals. The method further includes determining a power tilt for the optical signal based on the comparison and adjusting an amplifier gain based on the power tilt.
    Type: Application
    Filed: May 29, 2003
    Publication date: December 2, 2004
    Applicant: Fujitsu Limited
    Inventors: Cechan Tian, Susumu Kinoshita
  • Publication number: 20040208576
    Abstract: An add/drop node for an optical network comprises a passive splitter to split an ingress signal from the network into a first ingress signal and a second ingress signal. A first amplified splitter stages module is operable to passively split and amplify the first ingress signal into a plurality of drop signals. A filter module is operable to filter the second ingress signal to provide a filtered pass-through signal. A second amplified splitter stages module is operable to passively combine a plurality of add signals into a combined add signal and to combine the combined add signal with the filtered pass-through signal to create an egress signal forwardable to the network.
    Type: Application
    Filed: May 30, 2002
    Publication date: October 21, 2004
    Inventors: Susumu Kinoshita, Remi Pecqueur, Cechan Tian
  • Publication number: 20040208561
    Abstract: A method and system for control signaling in an open ring optical network includes transmitting traffic in an optical ring. At each of a plurality of nodes along the ring, local traffic is passively added to and passively dropped from the connected ring. At each node, an ingress optical supervisory channel (OSC) signal is dropped from the ring to a managing element. An egress OSC signal is added to the ring from the managing element. The OSC signals may be in-band signal or out-of-band signals.
    Type: Application
    Filed: March 27, 2002
    Publication date: October 21, 2004
    Inventors: Susumu Kinoshita, Koji Takeguchi, Satoru Odate, Cechan Tian
  • Publication number: 20040208506
    Abstract: A flexible open ring optical network includes a plurality of nodes connected by twin or other suitable optical rings. Each node is operable to passively add and passively drop traffic from the rings. The nodes may include a transport element for each ring. The transport elements include an optical splitter element and an optical combiner element. The optical splitter element is operable to passively combine an add signal including local add traffic and a first transport signal including ingress traffic from a coupled optical ring to generate a second transport signal including egress traffic for transmission on the coupled optical ring. The optical combiner element is coupled to the optical splitter element and is operable to passively split a third transport signal including the ingress traffic to generate a drop signal including local drop traffic and a fourth transport signal including the ingress traffic.
    Type: Application
    Filed: March 28, 2002
    Publication date: October 21, 2004
    Inventors: Susumu Kinoshita, Koji Takeguchi, Satoru Odate, Cechan Tian
  • Publication number: 20040208505
    Abstract: The method and system for testing during operation of an open ring network includes opening a ring of the network at the node. Traffic circulating on the ring is dropped in the node to a monitoring element prior to or at the opening of the ring in the node. At the monitoring element, a signal received from the ring is tested. During tested and while the ring is open, traffic continues to be communicated between each node on at least one of the ring or a second ring each connecting the nodes of the network.
    Type: Application
    Filed: March 27, 2002
    Publication date: October 21, 2004
    Inventors: Susumu Kinoshita, Koji Takeguchi, Satoru Odate, Cechan Tian
  • Publication number: 20040114215
    Abstract: A method and system for controlling the gain of the amplification of an optical signal is provided that includes both electrical feedforward and feedback. In a feedforward portion of an optical amplifier, the method includes receiving an optical signal and measuring an input power. Based on the measured input power and a desired gain, a feedforward pump power is determined. The pump power is adjusted based on the determined pump power. In a feedback portion of an optical amplifier, an output power is measured and gain is determined based on the output power and the measured input power. The measured gain is compared to a desired gain and the pump power is adjusted based on that comparison.
    Type: Application
    Filed: December 1, 2003
    Publication date: June 17, 2004
    Applicant: Fujitsu Network Communications, Inc., a California corporation
    Inventors: Cechan Tian, Susumu Kinoshita, Joseph R. Rodriguez
  • Publication number: 20040052530
    Abstract: A node for an optical network includes a first transport element operable to be coupled to an optical ring and to transport traffic in a first direction and a second transport element operable to be coupled to the optical ring and to transport traffic in a second, disparate direction. The first and second transport elements each include an optical splitter element operable to split an ingress signal into an intermediate signal and a drop signal. A filter in each node is operable to reject a first sub-band of the network from the intermediate signal to generate a passthrough signal including a plurality of disparate sub-bands of the network. Each node further includes an add element operable to add local traffic in the first sub-band to the passthrough signal for transport in the network.
    Type: Application
    Filed: September 17, 2002
    Publication date: March 18, 2004
    Inventors: Cechan Tian, Koji Takeguchi, Yasuhiko Aoki, Susumu Kinoshita
  • Patent number: 6690508
    Abstract: A method and system for controlling the gain of the amplification of an optical signal is provided that includes both electrical feedforward and feedback. In a feedforward portion of an optical amplifier, the method includes receiving an optical signal and measuring an input power. Based on the measured input power and a desired gain, a feedforward pump power is determined. The pump power is adjusted based on the determined pump power. In a feedback portion of an optical amplifier, an output power is measured and gain is determined based on the output power and the measured input power. The measured gain is compared to a desired gain and the pump power is adjusted based on that comparison.
    Type: Grant
    Filed: March 26, 2002
    Date of Patent: February 10, 2004
    Assignee: Fujitsu Network Communications, Inc.
    Inventors: Cechan Tian, Susumu Kinoshita, Joseph R. Rodriguez
  • Publication number: 20030223104
    Abstract: A system for distributing optical signals comprises a plurality of optical splitter stages. The optical splitter stages are each operable to passively split each of one or more optical signals provided to the stage into a plurality of optical signals. At least one of the optional splitter stages comprises an amplification stage, with the amplification stage including a plurality of gain media. The gain media are each operable to amplify an optical signal with pump power.
    Type: Application
    Filed: May 30, 2002
    Publication date: December 4, 2003
    Inventors: Susumu Kinoshita, Remi Pecqueur, Cechan Tian
  • Publication number: 20030184851
    Abstract: A method and system for controlling the gain of the amplification of an optical signal is provided that includes both electrical feedforward and feedback. In a feedforward portion of an optical amplifier, the method includes receiving an optical signal and measuring an input power. Based on the measured input power and a desired gain, a feedforward pump power is determined. The pump power is adjusted based on the determined pump power. In a feedback portion of an optical amplifier, an output power is measured and gain is determined based on the output power and the measured input power. The measured gain is compared to a desired gain and the pump power is adjusted based on that comparison.
    Type: Application
    Filed: March 26, 2002
    Publication date: October 2, 2003
    Applicant: Fujitsu Network Communications, Inc.
    Inventors: Cechan Tian, Susumu Kinoshita, Joseph R. Rodriguez