Patents by Inventor Nandakumar Ramanujam
Nandakumar Ramanujam 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).
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Patent number: 7340185Abstract: An optical receiver including a plurality of time delay elements and threshold decision elements configured to receive a signal representative of an optical signal. Each of the time delay elements is configured to impart an associated time delay to the signal. Each of the threshold decision elements is configured to compare the signal to a plurality of threshold levels. Each decision element outputs a signal indicative of a probability that a particular pulse of the received signal is a binary one at its associated sampling time. An optical communication system and a method of detecting a received data signal in an optical communication system are also provided.Type: GrantFiled: April 22, 2002Date of Patent: March 4, 2008Assignee: Tyco Telecommunications (US) Inc.Inventors: Nandakumar Ramanujam, Andrej B. Puc
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Patent number: 7032154Abstract: A method and apparatus for performing error correction is described. A stream of data is encoded using concatenated error correcting codes. The encoded data is communicated over a transmission system. The encoded data is decoded using the codes and three levels of decoding.Type: GrantFiled: March 25, 2002Date of Patent: April 18, 2006Assignee: Tyco Telecommunications (US) Inc.Inventors: Howard D. Kidorf, Franklin W. Kerfoot, III, Nandakumar Ramanujam, Bo Pedersen
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Patent number: 6937389Abstract: An optical system including an optical amplifier having an optical coupler adapted for receiving and coupling pump radiation from a plurality of pump radiation sources. The gain profile of the amplifier being modified to employ optical couplers that are periodic in radiation wavelength with a period ??.Type: GrantFiled: December 13, 2002Date of Patent: August 30, 2005Assignee: Corvis CorporationInventor: Nandakumar Ramanujam
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Patent number: 6934469Abstract: A collapsed ring fiber optic system includes a service path and a protection path provides at a shallow water portion of the fiber optic system, to deal with any fiber cuts that may occur at the shallow water portion without loss of main trunk bandwidth. The service and protection paths meet at a branch point, which is preferably located at a deep water portion of the fiber optic system. A passive combiner or a 1×2 switch is provided at the branch unit, along with a detector and a processor, to determine whether any signals are being received from the service path, and if not, to reconfigure the system to accept signals from the protection path. At another shallow water portion of the fiber optic system, nearby where a destination is located, the signal provided on the optical path over the deep water portion is split into a service path and a protection path, to provide redundancy to deal with any fiber cuts that may occur.Type: GrantFiled: March 27, 2003Date of Patent: August 23, 2005Assignee: Dorsal Networks, Inc.Inventors: Lee Daniel Feinberg, Bo Pedersen, Ronald Dale Esman, John Hagopian, Cathal Mahon, Brent Ashley Miller, M. Imran Hayee, Ronald E. Johnson, Nandakumar Ramanujam
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Publication number: 20050019039Abstract: A system and method for controlling the amplification of an optical data signal in an optical communication system having a plurality of optical fiber spans, each optical fiber span providing amplification to the optical data signal includes transmitting the optical data signal into a first optical fiber span at an input power level lower than a nominal power level. More than unity gain is provided to the optical data signal over each of at least a first group of the optical fiber spans such that the power level of the optical data signal after propagating through each of the plurality of optical fiber spans is higher than the nominal power level.Type: ApplicationFiled: June 14, 2004Publication date: January 27, 2005Inventor: Nandakumar Ramanujam
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Patent number: 6633712Abstract: A system and method of providing a transmission span that compensates for signal attenuation, dispersion, and nonlinearity of an optical signal communicated between two line units of a transmission link includes dividing the transmission span into a plurality of fiber segments and selecting a particular fiber for each of the segments. The fiber selection and arrangement of fibers within the span can be selected in accordance with the nonlinearity, dispersion conditions, and distributed gain conditions of the constituent fibers. In a three segment map, the first segment can provide low non linearity, the third segment can provide distributed gain, and the second segment can compensate for the dispersion of the first and third segments. The span can be used, e.g., for distributed Raman amplification. The span can alternatively include a two segment map, a four segment map, or a map with additional segments.Type: GrantFiled: March 16, 2001Date of Patent: October 14, 2003Assignee: Sowilo Networks, Inc.Inventors: Michael L. Dennis, M. Imran Hayee, Cathal Mahon, Bo Pedersen, Nandakumar Ramanujam, William Shieh
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Publication number: 20030185562Abstract: A collapsed ring fiber optic system includes a service path and a protection path provides at a shallow water portion of the fiber optic system, to deal with any fiber cuts that may occur at the shallow water portion without loss of main trunk bandwidth. The service and protection paths meet at a branch point, which is preferably located at a deep water portion of the fiber optic system. A passive combiner or a 1×2 switch is provided at the branch unit, along with a detector and a processor, to determine whether any signals are being received from the service path, and if not, to reconfigure the system to accept signals from the protection path. At another shallow water portion of the fiber optic system, nearby where a destination is located, the signal provided on the optical path over the deep water portion is split into a service path and a protection path, to provide redundancy to deal with any fiber cuts that may occur.Type: ApplicationFiled: March 27, 2003Publication date: October 2, 2003Applicant: Dorsal Networks, Inc.Inventors: Lee Daniel Feinberg, Bo Pedersen, Ronald Dale Esman, John Hagopian, Cathal Mahon, Brent Ashley Miller, M. Imran Hayee, Ronald E. Johnson, Nandakumar Ramanujam
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Patent number: 6622277Abstract: A method and apparatus to perform error correction is described. A stream of data is encoded using concatenated error correcting codes. The encoded data is communicated over a long-haul transmission system. The encoded data is decoded using the codes and three levels of decoding.Type: GrantFiled: June 7, 2000Date of Patent: September 16, 2003Assignee: Tyco Telecommunications(US)Inc.Inventors: Nandakumar Ramanujam, Bo Pedersen
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Patent number: 6556319Abstract: A collapsed ring fiber optic system includes a service path and a protection path provides at a shallow water portion of the fiber optic system, to deal with any fiber cuts that may occur at the shallow water portion without loss of main trunk bandwidth. The service and protection paths meet at a branch point, which is preferably located at a deep water portion of the fiber optic system. A passive combiner or a 1×2 switch is provided at the branch unit, along with a detector and a processor, to determine whether any signals are being received from the service path, and if not, to reconfigure the system to accept signals from the protection path. At another shallow water portion of the fiber optic system, nearby where a destination is located, the signal provided on the optical path over the deep water portion is split into a service path and a protection path, to provide redundancy to deal with any fiber cuts that may occur.Type: GrantFiled: May 8, 2001Date of Patent: April 29, 2003Assignee: Dorsal Networks, Inc.Inventors: Lee Daniel Feinberg, Bo Pedersen, Ronald Dale Esman, John Hagopian, Cathal Mahon, Brent Ashley Miller, M. Imran Hayee, Ronald E. Johnson, Nandakumar Ramanujam
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Publication number: 20030031440Abstract: A system and method of providing a transmission span that compensates for signal attenuation, dispersion, and nonlinearity of an optical signal communicated between two line units of a transmission link includes dividing the transmission span into a plurality of fiber segments and selecting a particular fiber for each of the segments. The fiber selection and arrangement of fibers within the span can be selected in accordance with the nonlinearity, dispersion conditions, and distributed gain conditions of the constituent fibers. In a three segment map, the first segment can provide low non linearity, the third segment can provide distributed gain, and the second segment can compensate for the dispersion of the first and third segments. The span can be used, e.g., for distributed Raman amplification. The span can alternatively include a two segment map, a four segment map, or a map with additional segments.Type: ApplicationFiled: March 16, 2001Publication date: February 13, 2003Inventors: Michael L. Dennis, M. Imran Hayee, Cathal Mahon, Bo Pedersen, Nandakumar Ramanujam, William Shieh
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Publication number: 20020167694Abstract: A collapsed ring fiber optic system includes a service path and a protection path provides at a shallow water portion of the fiber optic system, to deal with any fiber cuts that may occur at the shallow water portion without loss of main trunk bandwidth. The service and protection paths meet at a branch point, which is preferably located at a deep water portion of the fiber optic system. A passive combiner or a 1×2 switch is provided at the branch unit, along with a detector and a processor, to determine whether any signals are being received from the service path, and if not, to reconfigure the system to accept signals from the protection path. At another shallow water portion of the fiber optic system, nearby where a destination is located, the signal provided on the optical path over the deep water portion is split into a service path and a protection path, to provide redundancy to deal with any fiber cuts that may occur.Type: ApplicationFiled: May 8, 2001Publication date: November 14, 2002Inventors: Lee Daniel Feinberg, Bo Pedersen, Ronald Dale Esman, John Hagopian, Cathal Mahon, Brent Ashley Miller, M. Imran Hayee, Ronald E. Johnson, Nandakumar Ramanujam
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Publication number: 20020166091Abstract: A method and apparatus for performing error correction is described. A stream of data is encoded using concatenated error correcting codes. The encoded data is communicated over a transmission system. The encoded data is decoded using the codes and three levels of decoding.Type: ApplicationFiled: March 25, 2002Publication date: November 7, 2002Inventors: Howard D. Kidorf, Franklin W. Kerfoot, Nandakumar Ramanujam, Bo Pedersen
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Publication number: 20020056064Abstract: A method and apparatus for performing error correction. A stream of data is encoded using concatenated error correcting codes. The encoded data is communicated over a transmission system. The encoded data is decoded using the codes.Type: ApplicationFiled: November 14, 2001Publication date: May 9, 2002Applicant: TyCom (US) Inc.Inventors: Howard D. Kidorf, Franklin W. Kerfoot, Anderj B. Puc, Nandakumar Ramanujam