Patents by Inventor Lili Qiu
Lili Qiu 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: 20060240835Abstract: Disclosed is a general model and method for computing performance bounds in multi-hop wireless networks. Rather than focusing on computing asymptotic performance bounds under assumptions of homogeneity or randomness in the network topology and/or workload, the present invention accommodates any given network, technology, interference model, routing paradigm, and workload. Using a conflict graph to formally characterize the impact of wireless interference on the performance of multi-hop wireless networks, methods for computing upper and lower bounds on the capacity of a given wireless network are detailed. Besides computing network capacity, the model and method disclosed can also enable or benefit other applications including maximizing fairness and minimizing maximum link utilization.Type: ApplicationFiled: June 26, 2006Publication date: October 26, 2006Applicant: Microsoft CorporationInventors: Kamal Jain, Jitendra Padhye, Venkata Padmanabhan, Lili Qiu
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Patent number: 7096200Abstract: A system and method is provided for evaluating the effectiveness of data encryption for hiding the identity of the source of Web traffic. A signature is constructed from encrypted Web traffic for a Web page sent by a target Web site, and the signature is compared with archived traffic signatures obtained by accessing various Web pages of interest in advance. If the signature of the detected encrypted Web traffic matches a stored traffic signature beyond a pre-set statistical threshold, a positive match is found, and the source of the traffic is identified. Countermeasures for reducing the reliability of source identification based on traffic signature matching are provided.Type: GrantFiled: April 23, 2002Date of Patent: August 22, 2006Assignee: Microsoft CorporationInventors: Yi-Min Wang, Qixiang Sun, Daniel R. Simon, Wilfred Russell, Lili Qiu, Venkata N. Padmanabhan
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Publication number: 20060068811Abstract: Methods are described for using collaboration of neighboring wireless devices to enable location of disconnected wireless devices and rogue wireless access points. A central server computes the locations of the neighboring clients and uses those locations to estimate the location of a disconnected client. These techniques may take advantage of the beaconing and probing mechanisms of IEEE 802.11 to ensure that connected clients do not pay unnecessary overheads for detecting disconnected clients. Methods are also described for detecting and locating rogue devices by collaboratively collecting information from neighboring devices and comparing the information to a database.Type: ApplicationFiled: January 31, 2005Publication date: March 30, 2006Applicant: Microsoft CorporationInventors: Atul Adya, Paramvir Bahl, Ranveer Chandra, Lili Qiu
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Publication number: 20060068769Abstract: Systems and methods are described for detecting and diagnosing performance problems in wireless communications networks. Diagnostic programs execute on a wireless device, neighboring devices, and a wireless access point to collaborate in diagnosing network problems. The neighboring devices eavesdrop on a diagnostic session between the device and the access point to determine problems at the device, the access point, and in the wireless medium. Data from the eavesdropping devices can be summarized and sent to a network administrator for further action. The diagnostic programs are described to contain a passive component for detecting problems, and an active component for running the diagnostic techniques.Type: ApplicationFiled: January 31, 2005Publication date: March 30, 2006Applicant: Microsoft CorporationInventors: Atul Adya, Paramvir Bahl, Ranveer Chandra, Lili Qiu
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Publication number: 20060059091Abstract: A system and method is provided for evaluating the effectiveness of data encryption for hiding the identity of the source of Web traffic. A signature is constructed from encrypted Web traffic for a Web page sent by a target Web site, and the signature is compared with archived traffic signatures obtained by accessing various Web pages of interest in advance. If the signature of the detected encrypted Web traffic matches a stored traffic signature beyond a pre-set statistical threshold, a positive match is found, and the source of the traffic is identified. Countermeasures for reducing the reliability of source identification based on traffic signature matching are provided.Type: ApplicationFiled: October 31, 2005Publication date: March 16, 2006Applicant: Microsoft CorporationInventors: Yi-Min Wang, Qixiang Sun, Daniel Simon, Wilfred Russell, Lili Qiu, Venkata Padmanabhan
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Publication number: 20060020700Abstract: An improved method and system for optimizing the allocation of bandwidth within a network system is presented. When a client device is engaged in communication with a remote computing device, an access point measures the throughput of the connection between the client device and the network. If the throughput is less than the amount of bandwidth reserved for usage by the client device, the access point adjusts the amount of bandwidth allocated for the client device to an amount equivalent to the measured throughput multiplied by an error variance factor. This process is then repeated periodically for the duration of the communication between the client device and the remote computing device in order to continually adapt the bandwidth allocation of the client device.Type: ApplicationFiled: September 21, 2005Publication date: January 26, 2006Applicant: Microsoft CorporationInventors: Lili Qiu, Paramvir Bahl, Atul Adya
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Publication number: 20050204028Abstract: A network troubleshooting framework is described. In an implementation, a method includes forming a plurality of reports by a plurality of nodes in a network, wherein each of the reports is formed by a respective one of the nodes and includes trace data obtained from the respective node and another of the nodes. An inconsistency is detected in the trace data in one of the reports when compared with corresponding trace data in another of the reports. A set of the nodes is found that formed one or more of the reports having the inconsistency in the trace data.Type: ApplicationFiled: June 30, 2004Publication date: September 15, 2005Applicant: Microsoft CorporationInventors: Paramvir Bahl, Lidong Zhou, Lili Qiu, Ananth Rao
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Publication number: 20050180329Abstract: Disclosed is a method for determining the placement of ITAPs in wireless neighborhood networks. The method disclosed provides for efficient integration of multi-hop wireless networks with the Internet by placing ITAPs at strategic locations. Initially the method provides for the formulation of the ITAP placement problem under three wireless models. For each model, methods are developed to efficiently place ITAPs in the networks. The methods aim to minimize the number of required ITAPs while guaranteeing users' bandwidth requirements. Next, a fault tolerance version of the placement method is presented that provides bandwidth guarantees in the presence of failures. Finally the methods are extended to take into account variable traffic demands by developing an approximation algorithm to simultaneously optimize ITAP placement based on demands over multiple periods.Type: ApplicationFiled: February 17, 2004Publication date: August 18, 2005Applicant: Microsoft CorporationInventors: Lili Qiu, Kamal Jain, Ranveer Chandra, Mohammad Mahdian
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Publication number: 20050169186Abstract: A network troubleshooting framework is described. In an implementation, a method includes generating a first estimation of network performance by a simulator based on network settings obtained from a network, estimating the new performance under an alternative setting by providing the alternative setting to the network simulation and observing the simulation output, repeating the procedure for other alternative settings, and suggesting the alternative setting that improves network performance.Type: ApplicationFiled: June 30, 2004Publication date: August 4, 2005Applicant: Microsoft CorporationInventors: Lili Qiu, Paramvir Bahl, Lidong Zhou, Ananth Rao
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Publication number: 20050169185Abstract: A network troubleshooting framework is described. In an implementation, a method includes detecting discrepancy in operation of a network by supplying data that describes the network to a network simulation so that the network simulation provides an estimation of network performance. A determination is made as to whether the estimation of network performance differs from observed network performance of the network. A root cause of the discrepancy id diagnosed by injecting one or more of a plurality of faults into the network simulation until the estimation of network performance approximates the observed network performance.Type: ApplicationFiled: June 30, 2004Publication date: August 4, 2005Applicant: Microsoft CorporationInventors: Lili Qiu, Paramvir Bahl, Lidong Zhou, Ananth Rao
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Publication number: 20050157706Abstract: A system and method is provided for evaluating the effectiveness of data encryption for hiding the identity of the source of Web traffic. A signature is constructed from encrypted Web traffic for a Web page sent by a target Web site, and the signature is compared with archived traffic signatures obtained by accessing various Web pages of interest in advance. If the signature of the detected encrypted Web traffic matches a stored traffic signature beyond a pre-set statistical threshold, a positive match is found, and the source of the traffic is identified. Countermeasures for reducing the reliability of source identification based on traffic signature matching are provided.Type: ApplicationFiled: February 24, 2005Publication date: July 21, 2005Applicant: Microsoft CorporationInventors: Yi-Min Wang, Oixiang Sun, Daniel Simon, Wilfred Russell, Lili Qiu, Venkata Padmanabhan
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Publication number: 20050075104Abstract: Disclosed is a general model and method for computing performance bounds in multi-hop wireless networks. Rather than focusing on computing asymptotic performance bounds under assumptions of homogeneity or randomness in the network topology and/or workload, the present invention accommodates any given network, technology, interference model, routing paradigm, and workload. Using a conflict graph to formally characterize the impact of wireless interference on the performance of multi-hop wireless networks, methods for computing upper and lower bounds on the capacity of a given wireless network are detailed. Besides computing network capacity, the model and method disclosed can also enable or benefit other applications including maximizing fairness and minimizing maximum link utilization.Type: ApplicationFiled: October 7, 2003Publication date: April 7, 2005Applicant: Microsoft CorporationInventors: Kamal Jain, Jitendra Padhye, Venkata Padmanabhan, Lili Qiu
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Publication number: 20040181588Abstract: A system and method for enabling highly scalable multi-node event distribution networks through the use of summary-based routing, particularly event distribution networks using a content-based publish/subscribe model to distribute information. By allowing event routers to use imprecise summaries of the subscriptions hosted by matcher nodes, an event router can eliminate itself as a bottleneck thus improving overall event distribution network throughput even though the use of imprecise summaries results in some false positive event traffic. False positive event traffic is reduced by using a filter set partitioning that provides for good subscription set locality at each matcher node, while at the same time avoiding overloading any one matcher node. Good subscription set locality is maintained by routing new subscriptions to a matcher node with a subscription summary that best covers the new subscription.Type: ApplicationFiled: March 13, 2003Publication date: September 16, 2004Applicant: Microsoft CorporationInventors: Yi-Min Wang, Lili Qiu, Chad E. Verbowski, Demetrios Achlioptas, Gautam Das, Per-Ake Larson
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Publication number: 20040044759Abstract: A computer network has links for carrying data among computers, including one or more client computers. Packet loss rates are determined for the client computers and, a system of equations is set up expressing the relationship between the loss rates at the client computers and the loss rates at the links. The system of equations is then solved using one or more linear programming techniques, and optimized by making an effort to find the most parsimonious solution.Type: ApplicationFiled: February 7, 2003Publication date: March 4, 2004Applicant: Microsoft CorporationInventors: Venkata N. Padmanabhan, Lili Qiu
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Publication number: 20040044764Abstract: A computer network has links for carrying data among computers, including one or more client computers. Packet loss rates are determined for the client computers and, based on the loss rates, a number of possible sets of solutions for the loss rates at each of the links are generated. The sets of possible solutions are subjected to a statistical analysis. Based on the results of the analysis, a determination is made regarding which of the links are excessively lossy.Type: ApplicationFiled: January 31, 2003Publication date: March 4, 2004Applicant: Microsoft CorporationInventors: Venkata N. Padmanabhan, Lili Qiu
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Publication number: 20040044765Abstract: A computer network has links for carrying data among computers, including one or more client computers. Packet loss rates are determined for the client computers. Probability distributions for the loss rates of each of the client computers are then developed using various mathematical techniques. Based on an analysis of these probability distributions, a determination is made regarding which of the links are excessively lossy.Type: ApplicationFiled: March 3, 2003Publication date: March 4, 2004Applicant: Microsoft CorporationInventors: Christopher A. Meek, Venkata N. Padmanabhan, Lili Qiu, Jiahe Wang, David B. Wilson, Christian H. Borgs, Jennifer T. Chayes, David E. Heckerman
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Publication number: 20030212787Abstract: An improved method and system for optimizing the allocation of bandwidth within a network system is presented. When a client device is engaged in communication with a remote computing device, an access point measures the throughput of the connection between the client device and the network. If the throughput is less than the amount of bandwidth reserved for usage by the client device, the access point adjusts the amount of bandwidth allocated for the client device to an amount equivalent to the measured throughput multiplied by an error variance factor. This process is then repeated periodically for the duration of the communication between the client device and the remote computing device in order to continually adapt the bandwidth allocation of the client device.Type: ApplicationFiled: May 13, 2002Publication date: November 13, 2003Applicant: Microsoft CorporationInventors: Lili Qiu, Paramvir Bahl, Atul Adya
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Publication number: 20030200175Abstract: A system and method is provided for evaluating the effectiveness of data encryption for hiding the identity of the source of Web traffic. A signature is constructed from encrypted Web traffic for a Web page sent by a target Web site, and the signature is compared with archived traffic signatures obtained by accessing various Web pages of interest in advance. If the signature of the detected encrypted Web traffic matches a stored traffic signature beyond a pre-set statistical threshold, a positive match is found, and the source of the traffic is identified. Countermeasures for reducing the reliability of source identification based on traffic signature matching are provided.Type: ApplicationFiled: April 23, 2002Publication date: October 23, 2003Applicant: Microsoft CorporationInventors: Yi-Min Wang, Qixiang Sun, Daniel R. Simon, Wilfred Russell, Lili Qiu, Venkata N. Padmanabhan