Patents by Inventor De Fu Li
De Fu Li 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: 20240048941Abstract: Signals used to test for upstream signal leaks in a hybrid fiber-coaxial (HFC) network may be interleaved with client data and strategically timed to be received by a leak detection device with a one-hundred percent probability of intercept. A method includes receiving an indication that a user device is in proximity to a computing device. The method includes determining, based on the indication that the user device is in proximity to the computing device, signal information. The method includes causing, based on the signal information, the user device to output a signal. The method includes determining, based on an indication that the signal was received by the computing device, a location of a network leak.Type: ApplicationFiled: July 19, 2023Publication date: February 8, 2024Inventors: Daniel Rice, John Chrostowski, Benny Lewandowski, De Fu Li, Robert Gaydos
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Patent number: 11758362Abstract: Signals used to test for upstream signal leaks in a hybrid fiber-coaxial (HFC) network may be interleaved with client data and strategically timed to be received by a leak detection device with a one-hundred percent probability of intercept. A method includes receiving an indication that a user device is in proximity to a computing device. The method includes determining, based on the indication that the user device is in proximity to the computing device, signal information. The method includes causing, based on the signal information, the user device to output a signal. The method includes determining, based on an indication that the signal was received by the computing device, a location of a network leak.Type: GrantFiled: April 2, 2021Date of Patent: September 12, 2023Assignee: Comcast Cable Communications, LLCInventors: Daniel Rice, John Chrostowski, Benny Lewandowski, De Fu Li, Robert Gaydos
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Publication number: 20220322037Abstract: Signals used to test for upstream signal leaks in a hybrid fiber-coaxial (HFC) network may be interleaved with client data and strategically timed to be received by a leak detection device with a one-hundred percent probability of intercept. A method includes receiving an indication that a user device is in proximity to a computing device. The method includes determining, based on the indication that the user device is in proximity to the computing device, signal information. The method includes causing, based on the signal information, the user device to output a signal. The method includes determining, based on an indication that the signal was received by the computing device, a location of a network leak.Type: ApplicationFiled: April 2, 2021Publication date: October 6, 2022Inventors: Daniel Rice, John Chrostowski, Benny Lewandowski, De Fu Li, Robert Gaydos
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Patent number: 9503180Abstract: Presented herein are techniques for detection and avoidance of interference in a telecommunications network. In one example, a cable modem termination system (CMTS) is configured to receive upstream traffic from a plurality of cable modems. The CMTS detects collision characteristics resulting from substantially simultaneous transmissions from different combinations of the cable modems. Based on the detected collision characteristics, the CMTS designates/identifies collision groups for each of a plurality of the cable modems. After designation of the collision groups, the CMTS schedules upstream transmissions by the plurality of cable modems such that cable modems within the same collision group do not transmit within a same time frame and such that two or more cable modems that are not within the same collision group may transmit within a same time frame.Type: GrantFiled: September 4, 2014Date of Patent: November 22, 2016Assignee: Cisco Technology, Inc.Inventors: Hang Jin, Tong Liu, Pawel Sowinski, De Fu Li, John Skrobko
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Publication number: 20160072578Abstract: Presented herein are techniques for detection and avoidance of interference in a telecommunications network. In one example, a cable modem termination system (CMTS) is configured to receive upstream traffic from a plurality of cable modems. The CMTS detects collision characteristics resulting from substantially simultaneous transmissions from different combinations of the cable modems. Based on the detected collision characteristics, the CMTS designates/identifies collision groups for each of a plurality of the cable modems. After designation of the collision groups, the CMTS schedules upstream transmissions by the plurality of cable modems such that cable modems within the same collision group do not transmit within a same time frame and such that two or more cable modems that are not within the same collision group may transmit within a same time frame.Type: ApplicationFiled: September 4, 2014Publication date: March 10, 2016Inventors: Hang Jin, Tong Liu, Pawel Sowinski, De Fu Li, John Skrobko
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Patent number: 9237116Abstract: One embodiment of the invention includes a coax media converter (CMC) system communicatively coupled to at least one modem in a network system. The system includes a frequency reference configured to generate a clock signal in a local time domain. The system also includes a scheduling processor configured to extract a bandwidth allocation message from a data stream and to re-stamp each of at least one timestamp in the bandwidth allocation message in the local time domain based on the clock signal to generate a corresponding updated bandwidth allocation message comprising a respective at least one re-stamped timestamp. The system further includes a downstream physical interface configured to transmit the updated bandwidth allocation message to the at least one modem to schedule upstream burst transmissions from the respective at least modem based on the at least one re-stamped timestamp.Type: GrantFiled: September 12, 2013Date of Patent: January 12, 2016Assignee: Cisco Technology, Inc.Inventors: Xuan Wang, Jingfeng Zhang, Jie Meng, Wenwen Dong, De Fu Li, Yong Lu
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Publication number: 20150071305Abstract: One embodiment of the invention includes a coax media converter (CMC) system communicatively coupled to at least one modem in a network system. The system includes a frequency reference configured to generate a clock signal in a local time domain. The system also includes a scheduling processor configured to extract a bandwidth allocation message from a data stream and to re-stamp each of at least one timestamp in the bandwidth allocation message in the local time domain based on the clock signal to generate a corresponding updated bandwidth allocation message comprising a respective at least one re-stamped timestamp. The system further includes a downstream physical interface configured to transmit the updated bandwidth allocation message to the at least one modem to schedule upstream burst transmissions from the respective at least modem based on the at least one re-stamped timestamp.Type: ApplicationFiled: September 12, 2013Publication date: March 12, 2015Applicant: CISCO TECHNOLOGY, INC.Inventors: XUAN WANG, JINGFENG ZHANG, JIE MENG, WENWEN DONG, DE FU LI, YONG LU
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Patent number: 8201207Abstract: Disclosed are apparatus and methods for managing upstream channels on a per cable modem basis. In certain embodiments, one or more thresholds are defined for each of a plurality of upstream logical channels of a headend system for receiving data from a plurality of cable modems (or other types of access nodes). Each defined threshold corresponds to a measurable parameter of the corresponding upstream logical channel. One or more metrics are collected for each cable modem of each upstream logical channel. It is determined whether to downgrade a selected cable modem to a selected one of the logical channels that has a lower performance level than the selected cable modem's current logical channel.Type: GrantFiled: December 15, 2008Date of Patent: June 12, 2012Assignee: Cisco Technology, Inc.Inventors: James S. An, Hui Sun, De Fu Li, Keil Brewer, John J. Downey, Chrisanto D. Leano
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Patent number: 8134921Abstract: In one embodiment, a Cable Modem Termination System (CMTS) generates a bandwidth grant message corresponding to a time segment. The CMTS identifies a portion of the time segment to be assigned according to received bandwidth request messages originating from downstream cable modems. The CMTS determines whether a remaining portion of the time segment can accommodate more than N broadcast contention slots, and if so, selects at least one of the cable modems for receiving an upstream bandwidth boost.Type: GrantFiled: April 1, 2008Date of Patent: March 13, 2012Assignee: Cisco Technology, Inc.Inventors: Robert Goguen, De Fu Li, Pawel Sowinski, Nicos Achilleoudis
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Patent number: 7839773Abstract: In one embodiment, a first ranging timing description describing at least a duration of time during which a subject cable modem (CM) may burst and a duration of time during which the subject CM and other CMs in a multiple access network are not permitted to burst is translated into a second ranging timing description describing a duration during which a burst from the subject CM is expected to be received by a cable modem termination system (CMTS). The CMTS is conditioned to receive a burst from the subject CM during the duration of time described by the second ranging timing description. A timing offset is determined from at least an actual time a burst from the subject CM is received by the CMTS and the duration of time during which the subject CM and other CMs in the multiple access network are not permitted to burst to produce a determined timing offset. The determined timing offset is reported to compensate for delay in the multiple access network and the subject CM.Type: GrantFiled: March 14, 2008Date of Patent: November 23, 2010Assignee: Cisco Technology, Inc.Inventors: De Fu Li, Pawel Sowinski, James An, Robert Goguen
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Patent number: 7801040Abstract: In one embodiment a technique is disclosed for facilitating communication between nodes and a head end of an access network including a head end, at least one shared access upstream channel and at least one downstream channel. A first insertion rate estimate is determined. In at least one embodiment, the first insertion rate estimate may relate to an estimated number of nodes attempting to sign-on to the access network during one or more time interval(s). In at least one embodiment, a frequency of occurrence of initial maintenance opportunities available to a first plurality of network nodes may be dynamically adjusted, for example, using data relating to the first insertion rate estimate. According to one embodiment where the access network corresponds to a cable network, the head end of the cable network may be operable to sign on at least 40,000 cable modems within a time interval of not more than 300 seconds.Type: GrantFiled: October 1, 2007Date of Patent: September 21, 2010Assignee: Cisco Technology, Inc.Inventors: Hemant Singh, De Fu Li, Mark Millet
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Publication number: 20100154016Abstract: In one example, a Cable Modem Termination System (CMTS) sends first bandwidth allocation messages to a first upstream transmit interface on a cable modem and send second bandwidth allocation messages to a second upstream transmit interface on the cable modem. The bandwidth allocation messages indicate transmit windows for the cable modem to range over the interfaces. The transmit windows included in the first bandwidth allocation messages are spaced based on receipt of ranging requests from the second upstream transmit interface, and the transmit windows included in the second bandwidth allocation messages are spaced based on receipt of ranging requests from the first upstream transmit interface.Type: ApplicationFiled: December 12, 2008Publication date: June 17, 2010Applicant: Cisco Technology, Inc.Inventors: De Fu Li, Pawel Sowinski, Robert Goguen, Tong Liu, Alon Bernstein
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Publication number: 20100154017Abstract: Disclosed are apparatus and methods for managing upstream channels on a per cable modem basis. In certain embodiments, one or more thresholds are defined for each of a plurality of upstream logical channels of a headend system for receiving data from a plurality of cable modems (or other types of access nodes). Each defined threshold corresponds to a measurable parameter of the corresponding upstream logical channel. One or more metrics are collected for each cable modem of each upstream logical channel. It is determined whether to downgrade a selected cable modem to a selected one of the logical channels that has a lower performance level than the selected cable modem's current logical channel.Type: ApplicationFiled: December 15, 2008Publication date: June 17, 2010Applicant: CISCO TECHNOLOGY, INC.Inventors: James S. An, Hui Sun, De Fu Li, Keil Brewer, John J. Downey, Chrisanto D. Leano
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Publication number: 20090249417Abstract: In one embodiment, a Cable Modem Termination System (CMTS) generates a bandwidth grant message corresponding to a time segment. The CMTS identifies a portion of the time segment to be assigned according to received bandwidth request messages originating from downstream cable modems. The CMTS determines whether a remaining portion of the time segment can accommodate more than N broadcast contention slots, and if so, selects at least one of the cable modems for receiving an upstream bandwidth boost.Type: ApplicationFiled: April 1, 2008Publication date: October 1, 2009Applicant: Cisco Technology, Inc.Inventors: Robert Goguen, Nicos Achilleoudis, De Fu Li, Pawel Sowinski
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Publication number: 20090232111Abstract: In one embodiment, a first ranging timing description describing at least a duration of time during which a subject cable modem (CM) may burst and a duration of time during which the subject CM and other CMs in a multiple access network are not permitted to burst is translated into a second ranging timing description describing a duration during which a burst from the subject CM is expected to be received by a cable modem termination system (CMTS). The CMTS is conditioned to receive a burst from the subject CM during the duration of time described by the second ranging timing description. A timing offset is determined from at least an actual time a burst from the subject CM is received by the CMTS and the duration of time during which the subject CM and other CMs in the multiple access network are not permitted to burst to produce a determined timing offset. The determined timing offset is reported to compensate for delay in the multiple access network and the subject CM.Type: ApplicationFiled: March 14, 2008Publication date: September 17, 2009Applicant: Cisco Technology, Inc.Inventors: De Fu Li, Pawel Sowinski, James An, Robert Goguen
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Patent number: 7395309Abstract: A method for reducing Internet bandwidth used for data transfer between an originating modem and an answering modem over a VoIP connection is provided. Idle data received from the originating modem is detected by an Internet node. The Internet node does not forward the detected received idle data over the VoIP connection. To keep the modem connection between the originating modem and the answering modem alive, the Internet node regenerates idle data and transmits the regenerated idle data to the answering modem upon detecting no data received for forwarding to the answering modem.Type: GrantFiled: June 28, 2001Date of Patent: July 1, 2008Assignee: Cisco Technology, Inc.Inventors: Gary M. Lewis, De Fu Li, Nathan R. Melhorn