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).

  • Publication number: 20240048941
    Abstract: 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: Application
    Filed: July 19, 2023
    Publication date: February 8, 2024
    Inventors: Daniel Rice, John Chrostowski, Benny Lewandowski, De Fu Li, Robert Gaydos
  • Patent number: 11758362
    Abstract: 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: Grant
    Filed: April 2, 2021
    Date of Patent: September 12, 2023
    Assignee: Comcast Cable Communications, LLC
    Inventors: Daniel Rice, John Chrostowski, Benny Lewandowski, De Fu Li, Robert Gaydos
  • Publication number: 20220322037
    Abstract: 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: Application
    Filed: April 2, 2021
    Publication date: October 6, 2022
    Inventors: Daniel Rice, John Chrostowski, Benny Lewandowski, De Fu Li, Robert Gaydos
  • Patent number: 9503180
    Abstract: 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: Grant
    Filed: September 4, 2014
    Date of Patent: November 22, 2016
    Assignee: Cisco Technology, Inc.
    Inventors: Hang Jin, Tong Liu, Pawel Sowinski, De Fu Li, John Skrobko
  • Publication number: 20160072578
    Abstract: 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: Application
    Filed: September 4, 2014
    Publication date: March 10, 2016
    Inventors: Hang Jin, Tong Liu, Pawel Sowinski, De Fu Li, John Skrobko
  • Patent number: 9237116
    Abstract: 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: Grant
    Filed: September 12, 2013
    Date of Patent: January 12, 2016
    Assignee: Cisco Technology, Inc.
    Inventors: Xuan Wang, Jingfeng Zhang, Jie Meng, Wenwen Dong, De Fu Li, Yong Lu
  • Publication number: 20150071305
    Abstract: 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: Application
    Filed: September 12, 2013
    Publication date: March 12, 2015
    Applicant: CISCO TECHNOLOGY, INC.
    Inventors: XUAN WANG, JINGFENG ZHANG, JIE MENG, WENWEN DONG, DE FU LI, YONG LU
  • Patent number: 8201207
    Abstract: 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: Grant
    Filed: December 15, 2008
    Date of Patent: June 12, 2012
    Assignee: Cisco Technology, Inc.
    Inventors: James S. An, Hui Sun, De Fu Li, Keil Brewer, John J. Downey, Chrisanto D. Leano
  • Patent number: 8134921
    Abstract: 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: Grant
    Filed: April 1, 2008
    Date of Patent: March 13, 2012
    Assignee: Cisco Technology, Inc.
    Inventors: Robert Goguen, De Fu Li, Pawel Sowinski, Nicos Achilleoudis
  • Patent number: 7839773
    Abstract: 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: Grant
    Filed: March 14, 2008
    Date of Patent: November 23, 2010
    Assignee: Cisco Technology, Inc.
    Inventors: De Fu Li, Pawel Sowinski, James An, Robert Goguen
  • Patent number: 7801040
    Abstract: 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: Grant
    Filed: October 1, 2007
    Date of Patent: September 21, 2010
    Assignee: Cisco Technology, Inc.
    Inventors: Hemant Singh, De Fu Li, Mark Millet
  • Publication number: 20100154016
    Abstract: 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: Application
    Filed: December 12, 2008
    Publication date: June 17, 2010
    Applicant: Cisco Technology, Inc.
    Inventors: De Fu Li, Pawel Sowinski, Robert Goguen, Tong Liu, Alon Bernstein
  • Publication number: 20100154017
    Abstract: 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: Application
    Filed: December 15, 2008
    Publication date: June 17, 2010
    Applicant: CISCO TECHNOLOGY, INC.
    Inventors: James S. An, Hui Sun, De Fu Li, Keil Brewer, John J. Downey, Chrisanto D. Leano
  • Publication number: 20090249417
    Abstract: 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: Application
    Filed: April 1, 2008
    Publication date: October 1, 2009
    Applicant: Cisco Technology, Inc.
    Inventors: Robert Goguen, Nicos Achilleoudis, De Fu Li, Pawel Sowinski
  • Publication number: 20090232111
    Abstract: 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: Application
    Filed: March 14, 2008
    Publication date: September 17, 2009
    Applicant: Cisco Technology, Inc.
    Inventors: De Fu Li, Pawel Sowinski, James An, Robert Goguen
  • Patent number: 7395309
    Abstract: 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: Grant
    Filed: June 28, 2001
    Date of Patent: July 1, 2008
    Assignee: Cisco Technology, Inc.
    Inventors: Gary M. Lewis, De Fu Li, Nathan R. Melhorn