Patents by Inventor Wenwu Zhu

Wenwu Zhu 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: 7260826
    Abstract: A resource allocation of multiple compressed AV streams delivered over the Internet is disclosed that achieves end-to-end optimal quality through a multimedia streaming TCP-friendly transport (MSTFP) protocol that adaptively estimates the network bandwidth while smoothing the sending rate. Resources allocated dynamically according to a media encoding distortion and network degradation algorithm. A scheme is also disclosed for dynamically estimating the available network bandwidth for streaming of objects, such as MPEG-4 multiple video objects, in conjunction with the MSTFP protocol. The scheme can account for packet-loss rates to minimize end-to-end distortion for media delivery.
    Type: Grant
    Filed: May 25, 2001
    Date of Patent: August 21, 2007
    Assignee: Microsoft Corporation
    Inventors: Qian Zhang, Ya-Qin Zhang, Wenwu Zhu
  • Publication number: 20070168683
    Abstract: A power management technique for a network including a plurality of computing devices. The power management technique includes identifying an order in which one or more devices of the plurality of computing devices can transmit data within the prescribed time period. In one aspect, the number of wakeups are reduced for the computing devices within the network by increasing a number of adjacent channel time allocation periods within a prescribed time period that share a common computing device.
    Type: Application
    Filed: March 30, 2007
    Publication date: July 19, 2007
    Applicant: Microsoft Corporation
    Inventors: Zihua Guo, Richard Yao, Wenwu Zhu, Xin Wang
  • Patent number: 7203850
    Abstract: A power management technique for a network including a plurality of computing devices. The power management technique includes identifying an order in which one or more devices of the plurality of computing devices can transmit data within the prescribed time period. In one aspect, the number of wakeups are reduced for the computing devices within the network by increasing a number of adjacent channel time allocation periods within a prescribed time period that share a common computing device. In one aspect, the network can be based on Time Division Multiple Access (TDMA).
    Type: Grant
    Filed: January 20, 2004
    Date of Patent: April 10, 2007
    Assignee: Microsoft Corporation
    Inventors: Zihua Guo, Richard Yuqi Yao, Wenwu Zhu, Xin Wang
  • Patent number: 7194002
    Abstract: A network performance (e.g., latency and bandwidth) measurement infrastructure for large scale networks based on self-organized probing groups of devices. Each group of devices has a lead device that measures network characteristics, and then shares the measurement information with other devices. This grouping method reduces the amount of network bandwidth needed for adequate measurements, while still providing necessary information to individual devices. The system utilizes a novel multicast-based algorithm that is adopted for both intra-group and inter-group performance measurement. The measurement groups (MeGroups) are dynamic and self-forming, and use a set of heuristic algorithms to optimize the dynamic groupings.
    Type: Grant
    Filed: February 1, 2002
    Date of Patent: March 20, 2007
    Assignee: Microsoft Corporation
    Inventors: Qian Zhang, Wenwu Zhu, Jiangchuan Liu, XinYan Zhang
  • Patent number: 7177271
    Abstract: A method and system for managing admission to a network considers the packet delay of the network in making an admission decision. The packet delay of the network is periodically probed. To avoid disturbing or impairing the traffic of the network, a sequence of probing packets is sent to the network at an irregular interval. Responses to the probing packets are analyzed to obtain delay information of the network. If the delay information is insufficient to make an admission decision, then the packet loss rate of the network is measured and considered.
    Type: Grant
    Filed: September 21, 2001
    Date of Patent: February 13, 2007
    Assignee: Microsoft Corporation
    Inventors: Huai-Rong Shao, Wenwu Zhu, Ya-Qin Zhang, Jian-Ming Qiu
  • Patent number: 7158539
    Abstract: A unique sync mark is applied by an encoder to the beginning of each frame in a data packet of a Windows Media™ Audio bitstream by a Microsoft® Windows Media™ Audio (WMA) codec. The WMA decoder handles errors at the frame level for each data packet. When a frame in a data packet of a WMA file is corrupted, the decoder can continue to decode the next frame by searching for the next sync mark at the beginning of the next frame. Accordingly, error propagation is confined to a single frame and the decoder can simultaneously handle bit errors and packet erasures when decompressing a received audio bitstream.
    Type: Grant
    Filed: April 16, 2002
    Date of Patent: January 2, 2007
    Assignee: Microsoft Corporation
    Inventors: Qian Zhang, Jianping Zhou, Wenwu Zhu
  • Patent number: 7154869
    Abstract: A system and method for improved vertical handoff between different types of wireless network. Network allocation vector occupation and packet collision probability are used as quality of service measures, enabling vertical handoffs to be delayed until actually beneficial to quality of service. Improved wireless network cell boundary detection in vertical handoff scenarios is achieved with a Fourier-based technique in conjunction with an adaptively determined minimum operating signal strength threshold. Improved wireless network cell boundary detection enables vertical handoffs from high quality of service networks to be delayed as long as possible. Together, practical wireless network quality of service measures and improved detection of wireless network cell boundaries in vertical handoff scenarios reduce the rate of unnecessary vertical handoff resulting in higher overall quality of service experienced by a mobile computing device roaming between wireless network types.
    Type: Grant
    Filed: June 27, 2005
    Date of Patent: December 26, 2006
    Assignee: Microsoft Corporation
    Inventors: Zihua Guo, Qian Zhang, Richard Yao, Wenwu Zhu
  • Patent number: 7133368
    Abstract: A peer-to-peer (P2P) probing/network quality of service (QoS) analysis system utilizes a UDP-based probing tool for determining latency, bandwidth, and packet loss ratio between peers in a network. The probing tool enables network QoS probing between peers that connect through a network address translator. The list of peers to probe is provided by a connection server based on prior probe results and an estimate of the network condition. The list includes those peers which are predicted to have the best QoS with the requesting peer. Once the list is obtained, the requesting peer probes the actual QoS to each peer on the list, and returns these results to the connection server. P2P probing in parallel using a modified packet-pair scheme is utilized. If anomalous results are obtained, a hop-by-hop probing scheme is utilized to determine the QoS of each link. In such a scheme, differential destination measurement is utilized.
    Type: Grant
    Filed: February 1, 2002
    Date of Patent: November 7, 2006
    Assignee: Microsoft Corporation
    Inventors: Qian Zhang, Wenwu Zhu, XinYan Zhang, YongQiang Xiong
  • Patent number: 7113796
    Abstract: A framework and method for quality of service (QoS) aware resource discovery in mobile ad hoc networks are presented. Self-organized discovery agents manage the directory information that describes the network resources available for use by clients. In one embodiment, hash indexing of available resources is utilized. The discovery agents also partition the network into domains and collect intra- and inter-domain QoS information. This information is used to allow clients to select appropriate resource providers. This framework and method has low discovery latency and cost in terms of the number of packets for each resource discovery query.
    Type: Grant
    Filed: January 18, 2002
    Date of Patent: September 26, 2006
    Assignee: Microsoft Corporation
    Inventors: Qian Zhang, Wenwu Zhu, Jiangchuan Liu
  • Publication number: 20060209701
    Abstract: A peer-to-peer (P2P) probing/network quality of service (QoS) analysis system utilizes a UDP-based probing tool for determining latency, bandwidth, and packet loss ratio between peers in a network. The probing tool enables network QoS probing between peers that connect through a network address translator. The list of peers to probe is provided by a connection server based on prior probe results and an estimate of the network condition. The list includes those peers which are predicted to have the best QoS with the requesting peer. Once the list is obtained, the requesting peer probes the actual QoS to each peer on the list, and returns these results to the connection server. P2P probing in parallel using a modified packet-pair scheme is utilized. If anomalous results are obtained, a hop-by-hop probing scheme is utilized to determine the QoS of each link. In such a scheme, differential destination measurement is utilized.
    Type: Application
    Filed: June 2, 2006
    Publication date: September 21, 2006
    Applicant: Microsoft Corporation
    Inventors: Qian Zhang, Wenwu Zhu, XinYan Zhang, YongQiang Xiong
  • Patent number: 7096034
    Abstract: A power control scheme for a wireless network communication system that includes a base station and multiple wireless mobile device dynamically adjusts transmission power of a mobile device in conjunction with adjusting its bit allocation in source coding and channel coding to minimize its total power consumption while maximizing the system capacity in terms of the total effective transmission rates received by the base station. The base station sets a target signal quality value for each mobile station, and the target values are determined by the base station such that the total effective data rate from all the mobile devices is maximized under constraints of the total received power and the error protection level requirements for the mobile devices.
    Type: Grant
    Filed: October 1, 2001
    Date of Patent: August 22, 2006
    Assignee: Microsoft Corporation
    Inventors: Qian Zhang, Wenwu Zhu, Ya-Qin Zhang, Ji Zhu
  • Patent number: 7092405
    Abstract: A system and method for vertical handoff between different types of wireless networks. A network allocation vector of a first wireless network is sampled for a period of time. The network allocation vector may include a transmission time advertised by a sender in the first wireless network. A network allocation vector occupation is calculated. The calculation of the network allocation vector may include calculating a ratio of an amount of time that the network allocation vector is busy during the time period to a total amount of time during the time period. A wireless network quality of service measure is calculated as a function of the network allocation vector occupation. A vertical handoff may be initiated from a second wireless network to the first wireless network based at least in part on the calculated wireless network quality of service measure.
    Type: Grant
    Filed: October 18, 2004
    Date of Patent: August 15, 2006
    Assignee: Microsoft Corporation
    Inventors: Zihua Guo, Qian Zhang, Richard Yao, Wenwu Zhu
  • Publication number: 20060156201
    Abstract: A resource allocation of multiple compressed AV streams delivered over the Internet is disclosed that achieves end-to-end optimal quality through a multimedia streaming TCP-friendly transport (MSTFP) protocol that adaptively estimates the network bandwidth while smoothing the sending rate. Resources allocated dynamically according to a media encoding distortion and network degradation algorithm. A scheme is also disclosed for dynamically estimating the available network bandwidth for streaming of objects, such as MPEG4 multiple video objects, in conjunction with the MSTFP protocol. The scheme can account for packet-loss rates to minimize end-to-end distortion for media delivery.
    Type: Application
    Filed: March 23, 2006
    Publication date: July 13, 2006
    Applicant: Microsoft Corporation
    Inventors: Qian Zhang, Ya-Qin Zhang, Wenwu Zhu
  • Publication number: 20060156200
    Abstract: A resource allocation of multiple compressed AV streams delivered over the Internet is disclosed that achieves end-to-end optimal quality through a multimedia streaming TCP-friendly transport (MSTFP) protocol that adaptively estimates the network bandwidth while smoothing the sending rate. Resources allocated dynamically according to a media encoding distortion and network degradation algorithm. A scheme is also disclosed for dynamically estimating the available network bandwidth for streaming of objects, such as MPEG4 multiple video objects, in conjunction with the MSTFP protocol. The scheme can account for packet-loss rates to minimize end-to-end distortion for media delivery.
    Type: Application
    Filed: March 23, 2006
    Publication date: July 13, 2006
    Applicant: Microsoft Corporation
    Inventors: Qian Zhang, Ya-Qin Zhang, Wenwu Zhu
  • Patent number: 7046672
    Abstract: An implementation of a technology, described herein, for transmitting compressed network transport-layer-protocol headers in a speedy, efficient, inferentially synchronized, and robust manner. An implementation, described herein, models the transmission of compressed headers to the congestion procedure of the network transport-layer protocol (e.g., TCP's). Doing so, the sender of the compressed headers can infer whether the receiver correctly received them. Unlike the slow direct synchronization employed by conventional schemes, this implementation of the present claimed invention inferentially synchronizes by modeling after the congestion procedure of the network transport-layer protocol. This is inherently faster than direct synchronization. Since the implementation performs well over both noiseless and noisy links, it is particularly suited to use over wireless communications channels. This abstract itself is not intended to limit the scope of this patent.
    Type: Grant
    Filed: May 3, 2001
    Date of Patent: May 16, 2006
    Assignee: Microsoft Corporation
    Inventors: HongBin Liao, Qian Zhang, Wenwu Zhu, Ya-Qin Zhang
  • Publication number: 20060072628
    Abstract: Emulating a packet reorder condition in a network includes maintaining a counter variable to count packets sent out since the most recent reordered packet. When a new packet arrives, if the counter variable is less than or equal to zero, a current packet lag value is determined. If the current packet lag value is not equal to zero, the new packet is delayed before being sent out in accordance with the lag value, and the counter is updated with the lag value. Otherwise, the new packet is sent out without delay and the counter is decreased by one. The current packet lag value is computed based on supplied configuration parameters. Delaying the new packet includes applying a latency to the packet, the latency comprising a time cost to transmit the packet multiplied by the current packet lag value.
    Type: Application
    Filed: September 30, 2004
    Publication date: April 6, 2006
    Applicant: Microsoft Corporation
    Inventors: Yunxin Liu, Zheng Ni, Jian Wang, Qian Zhang, Wenwu Zhu
  • Publication number: 20060069544
    Abstract: A network emulator provides both per-connection and non-connection-based emulation. The emulator includes a host computer, and a kernel-mode emulator driver and user-mode application component running on the host computer. The application component supplies configuration parameters to the driver. The driver includes a packet filter list that filters a captured packet, a virtual network link that receives the packet from the packet filter list, a link group list that applies an emulation procedure to the packet, a timer management component that manages a timer associated with the emulation procedure, and a packet dispatcher component that sends out the packet. A connection pool component facilitates per-connection emulation.
    Type: Application
    Filed: September 30, 2004
    Publication date: March 30, 2006
    Applicant: Microsoft Corporation
    Inventors: Yunxin Liu, Zheng Ni, Jian Wang, Qian Zhang, Wenwu Zhu
  • Publication number: 20060067351
    Abstract: A method and system for emulating a network bandwidth condition includes maintaining a queue for holding packets that are received, maintaining a virtual time that is updated whenever a packet timer is scheduled, and, for a selected packet waiting in the queue, calculating a timer expiration time based on the virtual time. A bandwidth emulation module is controlled by an emulator link that comprises a virtual network link to which a first computer is connected. One or more computers may be linked to the first computer.
    Type: Application
    Filed: September 30, 2004
    Publication date: March 30, 2006
    Applicant: Microsoft Corporation
    Inventors: Yunxin Liu, Zheng Ni, Jian Wang, Qian Zhang, Wenwu Zhu
  • Patent number: 6999432
    Abstract: A cross-layer architecture is provided for delivering multiple media streams over 3G W-CDMA channels in adaptive multimedia wireless networks. A resource management mechanism dynamically allocates resources among different media streams adapted to channel status and Quality of Service (QoS) requirements. By taking the time-varying wireless transmission characteristics into account, an allocation of resources is performed based on a minimum-distortion or minimum-power criterion. Estimates of the time-varying wireless transmission conditions are made through measurements of throughput and error rate. Power and distortion minimized bit allocation schemes are used with the estimated wireless transmission conditions to for dynamically adaptations in transmissions.
    Type: Grant
    Filed: June 28, 2001
    Date of Patent: February 14, 2006
    Assignee: Microsoft Corporation
    Inventors: Qian Zhang, Wenwu Zhu, Ya-Qin Zhang, Guijin Wang
  • Patent number: 6982949
    Abstract: A system and method for improved vertical handoff between different types of wireless network. Network allocation vector occupation and packet collision probability are used as quality of service measures, enabling vertical handoffs to be delayed until actually beneficial to quality of service. Improved wireless network cell boundary detection in vertical handoff scenarios is achieved with a Fourier-based technique in conjunction with an adaptively determined minimum operating signal strength threshold. Improved wireless network cell boundary detection enables vertical handoffs from high quality of service networks to be delayed as long as possible. Together, practical wireless network quality of service measures and improved detection of wireless network cell boundaries in vertical handoff scenarios reduce the rate of unnecessary vertical handoff resulting in higher overall quality of service experienced by a mobile computing device roaming between wireless network types.
    Type: Grant
    Filed: February 28, 2003
    Date of Patent: January 3, 2006
    Assignee: Microsoft Corporation
    Inventors: Zihua Guo, Qian Zhang, Richard Yao, Wenwu Zhu