Patents by Inventor David Dal Farra
David Dal Farra 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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Publication number: 20240106557Abstract: An optical transmission device configured to: receive an input of signal interruption information from a second optical transmission device that detects a signal interruption of signal light on a transmission path, and to receive an input of ASE light after the signal interruption, has a wavelength selective switch configured to drop and/or add signal light; a memory; and a processor coupled to the memory. The processor is configured to: switch, based on the input of the signal interruption information from the second optical transmission device, control of output of the wavelength selective switch from a constant level control of the output, to a constant level control of attenuation for holding an amount of the attenuation of the signal light constant; and return the constant level control of the attenuation to the constant level control of the output, after the input of the ASE light.Type: ApplicationFiled: September 28, 2022Publication date: March 28, 2024Applicant: FUJITSU LIMITEDInventors: Akihiro MUKAI, Yoshito Kachita, David Dal Farra
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Publication number: 20230147398Abstract: A method may include sending a first machine learning model to one or more optical systems in which the first machine learning model is configured to predict span losses in the optical systems. Each respective optical system may be configured to identify the span losses associated with the respective optical system and locally train the first machine learning model according to the respective identified span losses to obtain a respective local first machine learning model that includes one or more respective local model parameters. The method may include obtaining the respective local model parameters from each respective optical system without obtaining the corresponding respective locally trained first machine learning model. The method may also include generating a second machine learning model based on the obtained local model parameters. The second machine learning model may be used to predict occurrences of span losses corresponding to a given optical system.Type: ApplicationFiled: November 5, 2021Publication date: May 11, 2023Applicant: FUJITSU LIMITEDInventors: Qiong ZHANG, Naga Raghavendra Anudeep TUNGALA, Calvin WAN, David DAL FARRA, Paparao PALACHARLA
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Patent number: 10903931Abstract: An optical system including a ROADM including previously in-service channels; a SDN computing module in communication with the ROADM over a DCN, the SDN computing module providing an instruction to place in-service an additional channel at the ROADM; an optical controller included by the ROADM and configured to, in response to the instruction to place in-service the additional channel at the ROADM: obtain optical power targets for each in-service channel including the previously in-service channels and the additional in-service channel; equalize a transmit power for each in-service channel of the ROADM, including: identify the transmit power of each in-service channel; transition each in-service channel to a power mode; adjust the transmit power of each in-service channel based on, for each in-service channel, the optical power target for the in-service channel and the identified transmit power for the in-service channel; and transition each in-service channel to a steady state mode.Type: GrantFiled: August 23, 2019Date of Patent: January 26, 2021Assignee: Fujitsu LimitedInventor: David Dal Farra
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Patent number: 6408070Abstract: The invention relates to an acoustic echo canceller particularly well suited for use in a hands-free terminal or teleconference system. The echo canceller is designed to assess the inherent signal attenuation occurring in the analog loop that connects the terminal to the switch mechanism of the PSTN domain or the PBX domain. The echo canceller is then adjusted in accordance with the degree of signal attenuation manifested by the loop. For high signal attenuation levels, the degree of echo control at the terminal is reduced since the signal attenuation occurring in the loop itself will compensate for the reduction, allowing to reach the echo control target at the far end of the loop (switch side). This feature avoids overly attenuating the echo at the terminal by taking advantage of the inherent echo control provided by the local loop conductors.Type: GrantFiled: April 30, 1998Date of Patent: June 18, 2002Assignee: Nortel Networks LimitedInventor: David Dal Farra
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Publication number: 20010043701Abstract: The invention relates to an acoustic echo canceller particularly well suited for use in a hands-free terminal or teleconference system. The echo canceller is designed to assess the inherent signal attenuation occurring in the analog loop that connects the terminal to the switch mechanism of the PSTN domain or the PBX domain. The echo canceller is then adjusted in accordance with the degree of signal attenuation manifested by the loop. For high signal attenuation levels, the degree of echo control at the terminal is reduced since the signal attenuation occurring in the loop itself will compensate for the reduction, allowing to reach the echo control target at the far end of the loop (switch side). This feature avoids overly attenuating the echo at the terminal by taking advantage of the inherent echo control provided by the local loop conductors.Type: ApplicationFiled: April 30, 1998Publication date: November 22, 2001Inventor: DAVID DAL FARRA
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Patent number: 6201873Abstract: The invention is an audio compression system for reducing distortion arising primarily from excessive loudspeaker excursion. For a given input audio signal, the maximum signal magnitude (or envelope, energy or power) level above which the loudspeaker will begin to distort is dependent upon the frequency content of the signal. In this invention, the input audio signal is filtered and the magnitude (or envelope, energy or power) level of the filtered signal is compared to a single, constant threshold level. The input audio signal is subsequently compressed only if the magnitude (or envelope, energy or power) level of the filtered audio signal exceeds the threshold value. In one embodiment, the filter has a frequency response which models the excursion response of the loudspeaker in question, and which can be obtained analytically for various types of loudspeakers.Type: GrantFiled: June 8, 1998Date of Patent: March 13, 2001Assignee: Nortel Networks LimitedInventor: David Dal Farra
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Patent number: 6178162Abstract: An improved echo canceller capable of reducing a magnitude of an echo signal propagating in a return channel of a communication device. The echo canceller includes an adaptive filter that models the echo path to generate an estimate of the echo. That estimate is subtracted from the echo-corrupted signal. The residual echo signal (error-signal) is then attenuated in a switching loss device. The switching loss device manifests a variable attenuation level selected in accordance with certain characteristics of the residual echo signal. These characteristics are the strength of the residual echo signal and its duration. For residual echo signals of very short duration, the attenuation level is set lower because those signals are perceived by the human ear as being weaker. For signals having a longer duration, the attenuation level is raised to inhibit the residual echo to acceptable levels.Type: GrantFiled: December 19, 1997Date of Patent: January 23, 2001Assignee: Nortel Networks CorporationInventors: David Dal Farra, Heping Ding
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Patent number: 5796818Abstract: A system and method for dynamically optimizing the analog gain for a microphone in a telephone terminal operable in handsfree mode. The system makes use of a process whereby a relatively inexpensive analog to digital converter is used to meet gain requirements so as to accommodate the loudest echo through transmit path while maintaining an acceptable signal to noise ratio for the quietest talker. The system digital signal processor in conjunction with speech activity detection means is used to provide an optimum microphone gain under all circumstances.Type: GrantFiled: August 8, 1996Date of Patent: August 18, 1998Assignee: Northern Telecom LimitedInventors: Scott McClennon, Heping Ding, David Dal Farra