Patents by Inventor Naresh Chand
Naresh Chand 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: 20070153772Abstract: A method, system and apparatus are provided for measuring the quality of voice (QOV) in a communication network. A time-stamped voice data packet is received. The time stamped on the voice data packet indicates the time at which the voice data packet arrives at intermediate devices. In an embodiment of the invention, the intermediate devices at each hop stamp the time. Thereafter, the voice data packets are analyzed to measure the quality of voice in the communication network.Type: ApplicationFiled: January 5, 2006Publication date: July 5, 2007Applicant: Cisco Technology, Inc.Inventors: Shiva Shankar J, Ottalingam Satyanarayan, Srinivas Muktevi, Naresh Chand
-
Patent number: 7068936Abstract: Methods and apparatus for providing a time slot switch which performs switching in the optical domain without the need for O-E-O conversion is described. The time slot switching device of the present invention may be part of a large switching device capable of performing switching and other function on WDM, TDM and WDM signals which are time division multiplexed. An optical time slot switch implemented using a time slot demultiplexer, optical cross-connect, variable delay lines and time slot multiplexer are described. Frequency conversion may be performed on a per time slot basis in cases where time slot signals are switched between lines using different wavelengths. Wave division demultiplexers and multiplexers can be added to the basic time slot switch to provide support for WDM switching and switching of TDM signals which are transmitted using wave division multiplexing.Type: GrantFiled: June 3, 2002Date of Patent: June 27, 2006Assignee: Agere Systems Inc.Inventors: Stanley Pau, Jianjun Yu, Keisuke Kojima, Naresh Chand
-
Publication number: 20040208555Abstract: Methods and apparatus for providing a time slot switch which performs switching in the optical domain without the need for O-E-O conversion is described. The time slot switching device of the present invention may be part of a large switching device capable of performing switching and other function on WDM, TDM and WDM signals which are time division multiplexed. An optical time slot switch implemented using a time slot demultiplexer, optical cross-connect, variable delay lines and time slot multiplexer are described. Frequency conversion may be performed on a per time slot basis in cases where time slot signals are switched between lines using different wavelengths. Wave division demultiplexers and multiplexers can be added to the basic time slot switch to provide support for WDM switching and switching of TDM signals which are transmitted using wave division multiplexing.Type: ApplicationFiled: June 3, 2002Publication date: October 21, 2004Inventors: Stanley Pau, Jianjun Yu, Keisuke Kojima, Naresh Chand
-
Publication number: 20040138146Abstract: Disclosed are methods of preventing or treating cardiac arrhythmia comprising administering to a mammal in need thereof, such as a human, an effective amount of vanoxerine (GBR 12909) or a pharmaceutically acceptable salt, derivative or metabolite thereof.Type: ApplicationFiled: December 23, 2003Publication date: July 15, 2004Applicants: ChanTest, Inc., Government of the United States of AmericaInventors: Arthur M. Brown, Naresh Chand
-
Patent number: 6763193Abstract: This invention is a new communication system in which multichannel broadcast digital services are distributed to each user with the broadcast services signal riding in the passband above a digital baseband signal. The system can deliver more than 1 Gbps additional bandwidth to each subscriber. The passband bandwidth will accommodate growth in downstream services including video on demand, higher speed web downloads including improved streaming audio and video, HDTV, interactive video, and personalized video. The invention requires only a single fiber path and a single optical receiver for each user or group of users. A single fiber, single optical receiver system is much less expensive than two systems, one transmitting baseband and the other passband. A single receiver is greatly cost beneficial to achieving economical fiber to the home.Type: GrantFiled: November 29, 1999Date of Patent: July 13, 2004Assignee: Lucent Technologies Inc.Inventors: Naresh Chand, Thomas Henry Daugherty, Wouterus Muys, Yong-Kwan Park, Venkataraman Swaminathan
-
Patent number: 6743797Abstract: Disclosed are methods of preventing or treating cardiac arrhythmia comprising administering to a mammal in need thereof, such as a human, an effective amount of vanoxerine (GBR 12909) or a pharmaceutically acceptable salt, derivative or metabolite thereof.Type: GrantFiled: February 22, 2002Date of Patent: June 1, 2004Assignees: ChanTest, Inc., United States of AmericaInventors: Arthur M. Brown, Naresh Chand
-
Patent number: 6727901Abstract: A system generates a smoothed curve from a noisily drawn, multi-segmented curve by minimizing an energy function for a smoothed curve which fits between end-points of the drawn curve. The energy function has three components: a distortion component, a smoothing component and a shrink component. Numerical analysis methods are applied to evaluate the energy function and to identify the smoothed curve with the lowest energy. The transposed curve with the lowest energy value is selected as the smoothed curve.Type: GrantFiled: August 7, 2002Date of Patent: April 27, 2004Assignee: Adobe Systems IncorporatedInventor: Naresh Chand Gupta
-
Publication number: 20030235227Abstract: A transmit optical subassembly (TOSA) includes a spot-size-converted (SSC) semiconductor laser coupled to an optical fiber without a lens or isolator. The spot-size-converted semiconductor laser includes an active region and an expander region that expands the spot size of the laser while maintaining efficient active laser performance. The SSC laser is coupled to a submount and passively aligned to an optical fiber positioned within a V-shaped groove formed within the submount. The SSC laser includes a narrow far field advantageous for providing a high coupling efficiency and high quality data transmission. The SSC laser is resistant to back reflection and produces a 1.3 or 1.55 micron optical wavelength and a data rate ranging from 1 to 10 Gbps. The TOSA provides high coupled power due to narrow far field, with potential extra reflection resistance due to absorption and mode transfer losses in coupling reflections through the expander back into the active region.Type: ApplicationFiled: June 19, 2002Publication date: December 25, 2003Inventors: Naresh Chand, Julie Eng, Martin Christian Fischer, Philip Anthony Kiely, David J. Klotzkin, Keisuke Kojima, Genji Tohmon, Yan Xu
-
Patent number: 6617288Abstract: This invention relates to an aqueous composition comprising water, a surfactant or thickener, and at least one metal-free thiophosphorus acid ester, at least one amine salt of the thiophosphorus acid ester, or a mixture thereof, wherein the thiophosphorus acid ester contains at least one hydrocarbyl terminated oxyalkylene group, at least one hydrocarbyl terminated polyoxyalkylene group, or a mixture thereof. The aqueous compositions have improved antiwear/extreme pressure properties and improved antioxidation properties. In these compositions, the thiophosphorus acid esters and their salts act as antiwear agents and rust inhibitors.Type: GrantFiled: May 8, 1998Date of Patent: September 9, 2003Assignee: The Lubrizol CorporationInventors: Naresh Chand Mathur, Edward J. Konzman
-
Publication number: 20030165285Abstract: Methods and apparatus for providing improving optical signal transmission results over standard mode fiber using a combination of negative chirp, low extinction ratio, and self-phase modulation transmission techniques in combination are described. The use of pre-transmission signal distortion in combinations with one or more of the other transmission techniques is also described. Pre-transmission signal distortion may be introduced by controlling a modulator with a large symmetric AC signal which causes the modulator to operation in a non-linear region or, alternatively, by using a relatively small non-symmetric AC signal to drive the modulator. Use of the small non-symmetric signal has the advantage of reduced power requirements. The pre-transmission distortion acts to counter some of the distortion introduced by the transmission of the signal over an optic fiber.Type: ApplicationFiled: August 9, 2002Publication date: September 4, 2003Inventors: Jianjun Yu, Keisuke Kojima, Naresh Chand
-
Publication number: 20030043431Abstract: Simultaneous demultiplexing and clock recovery of high-speed (e.g., 80 Gbps or 160 Gbps) optical time division multiplexing (OTDM) signals is achieved using a tandem electro-absorption modulator (TEAM). The TEAM has a monolithically integrated SOA to compensate the insertion loss and two EAMs to reduce the switching window. The demultiplexing and clock recovery may be performed by a single TEAM, or by two or more TEAMs. A fiber Raman amplifier may be used to boost the intensity of the OTDM signals during transmission.Type: ApplicationFiled: January 30, 2002Publication date: March 6, 2003Inventors: Naresh Chand, Keisuke Kojima, Thomas Gordon Beck Mason, Jianjun Yu, Rolando Espindola
-
Publication number: 20030025697Abstract: A system generates a smoothed curve from a noisily drawn, multi-segmented curve by minimizing an energy function for a smoothed curve which fits between end-points of the drawn curve. The energy function has three components: a distortion component, a smoothing component and a shrink component. Numerical analysis methods are applied to evaluate the energy function and to identify the smoothed curve with the lowest energy. The transposed curve with the lowest energy value is selected as the smoothed curve.Type: ApplicationFiled: August 7, 2002Publication date: February 6, 2003Applicant: Adobe Systems Incorporated, a Delaware CorporationInventor: Naresh Chand Gupta
-
Publication number: 20020163705Abstract: An optical transmitter for digitally modulated RF sub-carriers comprising an electroabsorption modulator integrated distributed feedback laser for transmitting the digitally modulated RF sub-carriers in the sub-octave frequency range. The negative bias is optimized for maximum carrier signal to noise ratio (CNR) which occurs when the composite triple beat (CTB) non-linear distortion is minimum that allows higher modulation index without causing any in-band distortion. A higher CNR increases the receiver sensitivity and thus more users can be served from a single transmitter or the transmitting signal can be modulated with higher order of digital modulation.Type: ApplicationFiled: April 6, 2001Publication date: November 7, 2002Inventors: Laurens Bakker, Naresh Chand, Doutje Tjitske van Veen
-
Patent number: 6462739Abstract: A system generates a smoothed curve from a noisily drawn, multi-segmented curve by minimizing an energy function for a smoothed curve which fits between end-points of the drawn curve. The energy function has three components: a distortion component, a smoothing component and a shrink component. Numerical analysis methods are applied to evaluate the energy function and to identify the smoothed curve with the lowest energy. The transposed curve with the lowest energy value is selected as the smoothed curve.Type: GrantFiled: March 18, 1999Date of Patent: October 8, 2002Assignee: Abode Systems IncorporatedInventor: Naresh Chand Gupta
-
Patent number: 6459521Abstract: An optical transmitter for digitally modulated RF sub-carriers comprising an electroabsorption modulator integrated distributed feedback laser for transmitting the digitally modulated RF sub-carriers in the sub-octave frequency range. The negative bias is optimized for maximum carrier signal to noise ratio (CNR) which occurs when the composite triple beat (CTB) non-linear distortion is minimum that allows higher modulation index without causing any in-band distortion. A higher CNR increases the receiver sensitivity and thus more users can be served from a single transmitter or the transmitting signal can be modulated with higher order of digital modulation.Type: GrantFiled: April 6, 2001Date of Patent: October 1, 2002Assignee: Agere Systems Guardian Corp.Inventors: Laurens Bakker, Naresh Chand, Doutje Tjitske van Veen
-
Patent number: 5968880Abstract: This invention relates to a lubricating composition comprising a major amount of an oil of lubricating viscosity and at least one metal-free thiophosphorus acid ester, at least one amine salt of the thiophosphorus acid ester, or a mixture thereof, wherein the thiophosphorus acid ester contains at least one hydrocarbyl terminated oxyalkylene group, at least one hydrocarbyl terminated polyoxyalkylene group, or a mixture thereof. In one embodiment, the thiophosphorus acid ester is a thiophosphorus acid ester represented by the following formula ##STR1## wherein X.sub.1, X.sub.2, and X.sub.3 are oxygen or sulfur, provided that at least one of X.sub.1, X.sub.2, and X.sub.3 is sulfur; R.sub.1 is a hydrocarbyl group; R.sub.2 is an alkylene group; R.sub.3 is hydrogen or a hydrocarbyl group; x is a number from 1 to about 40; and a is 0, 1, or 2, or at least one salt of the thiophosphorus acid ester.Type: GrantFiled: October 23, 1997Date of Patent: October 19, 1999Assignee: The Lubrizol CorporationInventors: Naresh Chand Mathur, Mary Galic Raguz
-
Patent number: 5773318Abstract: The specification describes techniques for cleaving crystal bodies, e.g. semiconductor laser bars, using thermostatic cleaving tools. Use of such tools allows the cleaving process to occur in an ultra high vacuum chamber without the use of mechanical devices activated from the exterior of the chamber. Cleaving occurs automatically and controllably by locally heating the cleaving tools, thereby deflecting the thermostatic element against the laser bar and causing fracture.Type: GrantFiled: October 30, 1996Date of Patent: June 30, 1998Assignee: Lucent Technologies Inc.Inventors: Naresh Chand, Robert Alan Hamm
-
Patent number: 5665637Abstract: Provision of a novel passivation layer can result in improved reliability of semiconductor lasers having a laser cavity defined by 2 laser facets. In a preferred embodiment, the passivation layer is a zinc selenide layer (e.g., 5 nm), formed on an essentially contamination-free laser facet. More generally, the passivation layer comprises at least one of Mg, Zn, Cd and Hg, and at least one of S, Se and Te. Typically, the facets are formed by cleaving in vacuum, immediately followed by in-situ deposition of the novel passivation layer material on the facets.Type: GrantFiled: November 17, 1995Date of Patent: September 9, 1997Assignee: Lucent Technologies Inc.Inventor: Naresh Chand
-
Patent number: 5629233Abstract: The disclosed novel method of making III/V semiconductor lasers involves cleaving of the wafer along predetermined cleavage planes. A cleavage plane is defined by means of aligned non-continuous depressions. The depressions are spaced from the laser contact regions, and typically are V-grooves produced by photolithography and anisotropic etching. A further surface feature, typically a precisely positioned scribe mark, facilitates cleavage initiation. When carried out in vacuum the novel method can provide high quality, accurately positioned cleavage surfaces, and consequently can facilitate increased yield of high power lasers.Type: GrantFiled: April 4, 1996Date of Patent: May 13, 1997Assignee: Lucent Technologies Inc.Inventors: Naresh Chand, Sung-Nee G. Chu, Alexei V. Syrbu
-
Patent number: 5440575Abstract: Disclosed are high reliability semiconductor lasers that need not be maintained inside a hermetic enclosure. Such lasers can advantageously be used in a variety of applications, e.g., in optical fiber telecommunications, and in compact disc players. Such "non-hermetic" lasers comprise facet coatings that comprise a dielectric layer that has very low water saturation value. In preferred embodiments this dielectric layer is SiO.sub.x (1.ltoreq.x<2), deposited by a molecular beam method. Deposition conditions are selected to result in a dense material that is largely free of particulates and blisters, and is substantially impermeable to moisture. Among the deposition conditions is substantially normal beam incidence, and a relatively low deposition rate. Deposition is advantageously carried out under relatively high vacuum conditions. A quantitative method of determining the water level in a SiO.sub.x film is disclosed.Type: GrantFiled: April 6, 1994Date of Patent: August 8, 1995Assignee: AT&T Corp.Inventors: Naresh Chand, Robert B. Comizzoli, John W. Osenbach, Charles B. Roxlo, Won-Tien Tsang