Patents by Inventor Lidong Zhou

Lidong Zhou 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: 20060282481
    Abstract: Tree data storage structures are implemented on respective computers in a distributed environment, such as on a network, so that information associated with nodes of one computer's tree data storage structure may be read or written to by another computer in the network. To promote efficiency, a cache may be employed on the computers in the network such that each computer caches information associated with nodes of tree data storage structures located on the computers in the network. A lock service may implement a caching protocol to provide efficient concurrency of caching operations while ensuring that current information associated with the nodes is available to all computers in the network.
    Type: Application
    Filed: June 10, 2005
    Publication date: December 14, 2006
    Applicant: Microsoft Corporation
    Inventors: Lidong Zhou, Chandramohan Thekkath
  • Publication number: 20060282438
    Abstract: The addition of a layer between a tree data storage structure and a persistent storage is disclosed. The additional layer, called a storage module, generates an identifier and allocates it to a node in the tree data storage structure. The storage module additionally performs a mapping function, allocating the identifier to a location in persistent storage. If the node is later deleted from the tree data storage structure, then the mapping of the identifier to the location in persistent storage is likewise deleted. In this way, if the node is deleted and, concurrently, a lookup or write operation is attempted on the deleted node, the storage module will read the identifier associated with the deleted node but will not be able to map the identifier to a location in persistent storage. Instead, an exception is generated and sent to the tree data storage module.
    Type: Application
    Filed: June 10, 2005
    Publication date: December 14, 2006
    Applicant: Microsoft Corporation
    Inventors: Lidong Zhou, Chandramohan Thekkath
  • Publication number: 20060155781
    Abstract: High-performance, scalable, and fault-tolerant distributed systems include decoupling data replication functions from reconfiguration and read functions to optimize system performance and provide a clean separation between scalability and fault tolerance. Each data object is replicated on multiple servers and a data replication protocol can be used to ensure data consistency. Read requests can be streamlined because any server can satisfy a read request, thus improving read performance, throughput, and overall system performance.
    Type: Application
    Filed: January 10, 2005
    Publication date: July 13, 2006
    Applicant: Microsoft Corporation
    Inventors: John MacCormick, Chandramohan Thekkath, Lidong Zhou
  • Publication number: 20060142033
    Abstract: An invention is disclosed whereby a wireless network node, equipped with two or more radio transceivers statically tuned to non-interfering frequency channels, can make decisions regarding which channel to use when communicating with a neighboring wireless node. A multi-radio unification protocol implemented in a wireless node coordinates the use of multiple wireless network interface cards and provides a virtual layer that hides the multiple physical network interfaces from higher layers of a node's network protocol stack. The invention is applicable to wireless networks generally, including those in which some nodes do not have multiple radios or do not recognize the multi-radio unification protocol. The invention makes possible simultaneous transmissions using available channels, thereby reducing interference and delay while increasing the overall capacity of the network.
    Type: Application
    Filed: February 24, 2006
    Publication date: June 29, 2006
    Applicant: Microsoft Corporation
    Inventors: Alastair Wolman, Atul Adya, Paramvir Bahl, Jitendra Padhye, Lidong Zhou
  • Patent number: 7065376
    Abstract: An invention is disclosed whereby a wireless network node, equipped with two or more radio transceivers statically tuned to non-interfering frequency channels, can make decisions regarding which channel to use when communicating with a neighboring wireless node. A multi-radio unification protocol implemented in a wireless node coordinates the use of multiple wireless network interface cards and provides a virtual layer that hides the multiple physical network interfaces from higher layers of a node's network protocol stack. The invention is applicable to wireless networks generally, including those in which some nodes do not have multiple radios or do not recognize the multi-radio unification protocol. The invention makes possible simultaneous transmissions using available channels, thereby reducing interference and delay while increasing the overall capacity of the network.
    Type: Grant
    Filed: November 26, 2003
    Date of Patent: June 20, 2006
    Assignee: Microsoft Corporation
    Inventors: Alastair Wolman, Atul Adya, Paramvir Bahl, Jitendra D. Padhye, Lidong Zhou
  • Publication number: 20060129612
    Abstract: Methods and apparatuses are provided for recovering one or more replicated datasets. In accordance to some embodiments of the invention, this is accomplished by determining whether a log contains one or more entries indicating a corruption in a replicated data item; and recovering the replicated data item if the log contains any such entries. The log, however, is maintained at a higher layer in a software hierarchy than the layer at which the replicated data item is recovered. As a result, there is no need to maintain a separate replication log at the layer where the replicated data item is recovered.
    Type: Application
    Filed: December 14, 2004
    Publication date: June 15, 2006
    Applicant: Microsoft Corporation
    Inventors: John MacCormick, Chandramohan Thekkath, Lidong Zhou
  • Publication number: 20050204028
    Abstract: 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: Application
    Filed: June 30, 2004
    Publication date: September 15, 2005
    Applicant: Microsoft Corporation
    Inventors: Paramvir Bahl, Lidong Zhou, Lili Qiu, Ananth Rao
  • Publication number: 20050169186
    Abstract: 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: Application
    Filed: June 30, 2004
    Publication date: August 4, 2005
    Applicant: Microsoft Corporation
    Inventors: Lili Qiu, Paramvir Bahl, Lidong Zhou, Ananth Rao
  • Publication number: 20050169185
    Abstract: 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: Application
    Filed: June 30, 2004
    Publication date: August 4, 2005
    Applicant: Microsoft Corporation
    Inventors: Lili Qiu, Paramvir Bahl, Lidong Zhou, Ananth Rao
  • Publication number: 20050071336
    Abstract: Systems and methods for logging and recovering updates to data structures in the event of failure of an information management system are provided. In exemplary implementations, methods for implementing an efficient redo log for a data structure that is concurrently accessed by multiple clients is provided. The data structure is implemented in two layers: the data structure algorithm layer which sits atop an allocator that provides distributed, persistent, and replicated storage allocation. Both the B-link tree algorithm layer and the allocator use the service of the logging mechanism to implement fault-tolerance and atomicity guarantees. The present invention uses a single log and allows periodic truncation of that log for space efficiency.
    Type: Application
    Filed: September 30, 2003
    Publication date: March 31, 2005
    Inventors: Marc Najork, Chandramohan Thekkath, Lidong Zhou
  • Publication number: 20040185887
    Abstract: An invention is disclosed whereby a wireless network node, equipped with two or more radio transceivers statically tuned to non-interfering frequency channels, can make decisions regarding which channel to use when communicating with a neighboring wireless node. A multi-radio unification protocol implemented in a wireless node coordinates the use of multiple wireless network interface cards and provides a virtual layer that hides the multiple physical network interfaces from higher layers of a node's network protocol stack. The invention is applicable to wireless networks generally, including those in which some nodes do not have multiple radios or do not recognize the multi-radio unification protocol. The invention makes possible simultaneous transmissions using available channels, thereby reducing interference and delay while increasing the overall capacity of the network.
    Type: Application
    Filed: November 26, 2003
    Publication date: September 23, 2004
    Applicant: Microsoft Corporation
    Inventors: Alastair Wolman, Atul Adya, Paramvir Bahl, Jitendra D. Padhye, Lidong Zhou
  • Publication number: 20020116611
    Abstract: A fault-tolerant and secure on-line certification authority uses replication to achieve availability. A client request is forwarded to a delegate server. The delegate forwards the request to all certification servers. After receiving responses from a quorum of certification servers, the delegate sends a client response including a threshold signature protocol to sign the client response. The delegate then forwards the client response to the client.
    Type: Application
    Filed: October 31, 2001
    Publication date: August 22, 2002
    Applicant: Cornell Research Foundation, Inc.
    Inventors: Lidong Zhou, Fred B. Schneider, Robbert VanRenesse, Zygmunt Haas