Patents by Inventor Dahai Xu

Dahai Xu 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).

  • Patent number: 8422379
    Abstract: A resilient load balancing method uses fixed paths and a fixed path-splitting strategy to enable ingress routers to efficiently reroute traffic after a failure. An off-line management system computes a set of fixed paths and a set of splitting ratios for routing demand from ingress routers to egress routers, with sufficient capacity to meet demands under each failure scenario. That data is then used by the ingress router to reroute demand after observing a failure.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: April 16, 2013
    Assignee: AT&T Intellectual Property I, LP
    Inventors: Dahai Xu, Robert Doverspike, David Johnson, Jennifer Rexford, Martin Suchara
  • Publication number: 20120213520
    Abstract: A method of providing routes through heterogeneous subsystems in an optical network is disclosed, which includes generating, using a processing device, a reachability matrix based on subnetwork information; and generating, using the processing device, a topology associated with the optical network using the reachability matrix. The method also includes determining, using the processing device, a shortest path through the optical network using the reachability matrix and a cost model graph; and displaying, using a graphical user interface, subsystems associated with the shortest path, regeneration locations associated with the shortest path, wavelengths associated with the shortest path, the topology, and the shortest path. Corresponding apparatus and computer-readable storage media are also disclosed.
    Type: Application
    Filed: February 18, 2011
    Publication date: August 23, 2012
    Applicant: AT&T INTELLECTUAL PROPERTY I LP
    Inventors: Robert Doverspike, Guangzhi Li, Angela Lan Chiu, Monica Gerhardstein, Yici Guo, Dongmei Wang, Dahai Xu
  • Publication number: 20120087665
    Abstract: A method and apparatus for providing a route recommendation are disclosed. For example, the method obtains network topology information, wherein the network topology information comprises a plurality of underlying subnetwork types for a network. The method creates a cost model for the network, and receives a request from a user for a connection to be supported by the network. The method provides the route recommendation for supporting the connection by applying the cost model.
    Type: Application
    Filed: October 11, 2010
    Publication date: April 12, 2012
    Inventors: GUANGZHI LI, Angela Lan Chiu, Chris Dailey, Robert Duncan Doverspike, Monica Naukam Gerhardstein, Dah-Min David Hwang, Dongmei Wang, Dahai Xu
  • Publication number: 20110141877
    Abstract: A resilient load balancing method uses fixed paths and a fixed path-splitting strategy to enable ingress routers to efficiently reroute traffic after a failure. An off-line management system computes a set of fixed paths and a set of splitting ratios for routing demand from ingress routers to egress routers, with sufficient capacity to meet demands under each failure scenario. That data is then used by the ingress router to reroute demand after observing a failure.
    Type: Application
    Filed: December 15, 2009
    Publication date: June 16, 2011
    Inventors: Dahai Xu, Robert Doverspike, David Johnson, Jennifer Rexford, Martin Suchara
  • Patent number: 7944856
    Abstract: A method and apparatus for providing redundancy for an access network are disclosed. For example, the method receives an access network structure, and removes one or more unnecessary 2D edges or 3D edges from a simplex cover for the access network structure. The method then performs a search on the simplex cover; and, generates a new access network structure that includes the redundancy.
    Type: Grant
    Filed: December 23, 2008
    Date of Patent: May 17, 2011
    Assignee: AT&T Intellectual Property I, L.P.
    Inventors: Dahai Xu, Elliot Anshelevich, Mung Chiang
  • Publication number: 20100157847
    Abstract: A method and apparatus for providing redundancy for an access network are disclosed. For example, the method receives an access network structure, and removes one or more unnecessary 2D edges or 3D edges from a simplex cover for the access network structure. The method then performs a search on the simplex cover; and, generates a new access network structure that includes the redundancy.
    Type: Application
    Filed: December 23, 2008
    Publication date: June 24, 2010
    Inventors: Dahai Xu, Elliot Anshelevich, Mung Chiang
  • Patent number: 7701848
    Abstract: An efficient trap avoidance and shared protection method in a survivable network with shared risk link groups. The invention includes a fast and efficient heuristic algorithm for avoiding traps, an algorithm, which may also be applied effectively to shared SRLG protection. Compared to other existing algorithms, the algorithm embodied in the present invention runs much faster, and yet falls into few traps, and achieves a much higher bandwidth efficiency. This technology can be applied to MPLS, ATM, SONET, WDM, and other high-speed survivable network designs.
    Type: Grant
    Filed: July 9, 2004
    Date of Patent: April 20, 2010
    Inventors: Chunming Qiao, Dahai Xu, Yizhi Xiong
  • Patent number: 7398321
    Abstract: This invention broadly comprises a novel segment protection scheme (survivability framework) for a network, which we refer to as PROMISE (Protection using MultIple SEgments). It combines the best of existing link and path protection schemes (e.g., bandwidth efficiency and fast recovery). The PROMISE approach divides an active path or AP (along which a survivable connection is established) into several, possibly overlapping active segments or ASs, and then protects each AS with a detour called backup segment or BS (instead of protecting the AP as a whole as in path protection schemes). This facilitates the bandwidth sharing not only among the BSs for different APs, but also among those for the same AP. In addition, recovery time can be shortened due to the limited length of each AS and BS. This technology can be applied to MPLS, ATM, SONET, WDM and other high-speed link layers under the evolving G-MPLS framework.
    Type: Grant
    Filed: May 13, 2003
    Date of Patent: July 8, 2008
    Assignee: The Research Foundation of SUNY
    Inventors: Chunming Qiao, Dahai Xu, Yizhi Xiong
  • Publication number: 20050031339
    Abstract: An efficient trap avoidance and shared protection method in a survivable network with shared risk link groups. The invention includes a fast and efficient heuristic algorithm for avoiding traps, an algorithm, which may also be applied effectively to shared SRLG protection. Compared to other existing algorithms, the algorithm embodied in the present invention runs much faster, and yet falls into few traps, and achieves a much higher bandwidth efficiency. This technology can be applied to MPLS, ATM, SONET, WDM, and other high-speed survivable network designs.
    Type: Application
    Filed: July 9, 2004
    Publication date: February 10, 2005
    Inventors: Chumning Qiao, Dahai Xu, Yizhi Xiong
  • Publication number: 20030229807
    Abstract: This invention broadly comprises a novel segment protection scheme (survivability framework) for a network, which we refer to as PROMISE (Protection using MultIple SEgments). It combines the best of existing link and path protection schemes (e.g., bandwidth efficiency and fast recovery). The PROMISE approach divides an active path or AP (along which a survivable connection is established) into several, possibly overlapping active segments or ASs, and then protects each AS with a detour called backup segment or BS (instead of protecting the AP as a whole as in path protection schemes). This facilitates the bandwidth sharing not only among the BSs for different APs, but also among those for the same AP. In addition, recovery time can be shortened due to the limited length of each AS and BS. This technology can be applied to MPLS, ATM, SONET, WDM and other high-speed link layers under the evolving G-MPLS framework.
    Type: Application
    Filed: May 13, 2003
    Publication date: December 11, 2003
    Applicant: The Research Foundation of State University of New York, University at Buffalo
    Inventors: Chunming Qiao, Dahai Xu, Yizhi Xiong
  • Publication number: 20030009582
    Abstract: The invention is a novel and efficient distributed control scheme for dynamic allocation and de-allocation of bandwidth.
    Type: Application
    Filed: June 26, 2002
    Publication date: January 9, 2003
    Inventors: Chunming Qiao, Dahai Xu