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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Patent number: 7640215Abstract: 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: February 24, 2005Date of Patent: December 29, 2009Assignee: Microsoft CorporationInventors: Yi-Min Wang, Qixiang Sun, Daniel R. Simon, Wilfred Russell, Lili Qiu, Venkata N. Padmanabhan
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Patent number: 7613105Abstract: 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: GrantFiled: June 30, 2004Date of Patent: November 3, 2009Assignee: Microsoft CorporationInventors: Paramvir Bahl, Lidong Zhou, Lili Qiu, Ananth Rajagopala Rao
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Patent number: 7606165Abstract: 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: GrantFiled: June 30, 2004Date of Patent: October 20, 2009Assignee: Microsoft CorporationInventors: Lili Qiu, Paramvir Bahl, Lidong Zhou, Ananth Rajagopala Rao
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Patent number: 7603460Abstract: 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: GrantFiled: January 31, 2005Date of Patent: October 13, 2009Assignee: Microsoft CorporationInventors: Atul Adya, Paramvir Bahl, Ranveer Chandra, Lili Qiu
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Patent number: 7583587Abstract: 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 is 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: GrantFiled: June 30, 2004Date of Patent: September 1, 2009Assignee: Microsoft CorporationInventors: Lili Qiu, Paramvir Bahl, Lidong Zhou, Ananth Rajagopala Rao
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Publication number: 20090086652Abstract: 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: November 18, 2008Publication date: April 2, 2009Applicant: Microsoft CorporationInventors: Kamal Jain, Jitendra D. Padhye, Venkata N. Padmanabhan, Lili Qiu
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Patent number: 7469143Abstract: 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: GrantFiled: October 7, 2003Date of Patent: December 23, 2008Assignee: Microsoft CorporationInventors: Kamal Jain, Jitendra D. Padhye, Venkata N. Padmanabhan, Lili Qiu
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Patent number: 7421510Abstract: 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: GrantFiled: February 7, 2003Date of Patent: September 2, 2008Assignee: Microsoft CorporationInventors: Venkata N. Padmanabhan, Lili Qiu
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Patent number: 7409217Abstract: 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: GrantFiled: June 26, 2006Date of Patent: August 5, 2008Assignee: Microsoft CorporationInventors: Kamal Jain, Jitendra D. Padhye, Venkata N. Padmanabhan, Lili Qiu
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Patent number: 7363375Abstract: A method for refinishing a countertop in order to achieve a granite, a marble, or other desired look uses an oil-based paint having a glaze therein applied as a base coat to a countertop that has been prepared smooth and taped as needed. Once the base coat dries, one or more additional coats each coat may be the same color as the other additional coats or different from the other coats, and each additional coat being a different color from the base coat. One of three applicators is used for the additional coats including a feather, a rag, and a sponge, the selection of the applicator or applicators, and the color or colors to apply with each, being dependant on the particular look desired. Once all paint is applied and a dried, a polyurethane coat is applied to give additional luster, in order for the finish to be either more granite-like or more marble-like in appearance and in order to protect the finish.Type: GrantFiled: May 13, 2002Date of Patent: April 22, 2008Assignee: Microsoft CorporationInventors: Lili Qiu, Paramvir Bahl, Atul Adya
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Publication number: 20080070563Abstract: 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: November 15, 2007Publication date: March 20, 2008Applicant: Microsoft CorporationInventors: Atul Adya, Paramvir Bahl, Ranveer Chandra, Lili Qiu
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Patent number: 7346679Abstract: 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: GrantFiled: January 31, 2003Date of Patent: March 18, 2008Assignee: Microsoft CorporationInventors: Venkata N. Padmanabhan, Lili Qiu
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Patent number: 7330893Abstract: 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. Optionally, the method and system can be also deployed in client devices instead of the access point.Type: GrantFiled: September 21, 2005Date of Patent: February 12, 2008Assignee: Microsoft CorporationInventors: Lili Qiu, Paramvir Bahl, Atul Adya
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Patent number: 7317914Abstract: 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: GrantFiled: January 31, 2005Date of Patent: January 8, 2008Assignee: Microsoft CorporationInventors: Atul Adya, Paramvir Bahl, Ranveer Chandra, Lili Qiu
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Publication number: 20070248059Abstract: Utilization of wireless access points (APs) is optimized by dynamically managing transmitted AP power levels of beacon packets to control wireless AP coverage. This permits traffic congestion at one wireless AP to be reduced and shifted to other wireless APs. AP coverage management is provided by a centralized mechanism that employs various interpretations and/or measurements of client received power to handle dynamic changes in client workloads. The control does not require protocol changes to clients that utilize a wireless AP and can also incorporate hand-off costs and/or manufacturer specified power level constraints. Thus, these techniques can be employed in existing wireless LANs without impacting clients. Various instances are employable with continuous power and/or discrete power based wireless APs, providing a non-client impacted means to increase throughput and/or load balance.Type: ApplicationFiled: April 21, 2006Publication date: October 25, 2007Applicant: Microsoft CorporationInventors: Kamal Jain, Paramvir Bahl, Lili Qiu, Vahab Mirrokni, Mohammadtaghi Hajiaghayi, Amin Saberi
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Publication number: 20070168550Abstract: A system arid 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: February 6, 2007Publication date: July 19, 2007Inventors: Yi-Min Wang, Lili Qiu, Chad Verbowski, Demetrios Achlioptas, Gautam Das, Per-Ake Larson
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Publication number: 20070081488Abstract: 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: December 12, 2006Publication date: April 12, 2007Applicant: Microsoft CorporationInventors: Atul Adya, Paramvir Bahl, Ranveer Chandra, Lili Qiu
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Patent number: 7200675Abstract: 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: GrantFiled: March 14, 2003Date of Patent: April 3, 2007Assignee: Microsoft CorporationInventors: Yi-Min Wang, Lili Qiu, Chad E. Verbowski, Demetrios Achlioptas, Gautam Das, Per-Ake Larson
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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