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).
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Publication number: 20050286523Abstract: 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: ApplicationFiled: August 15, 2005Publication date: December 29, 2005Applicant: Microsoft CorporationInventors: HongBin Liao, Qian Zhang, Wenwu Zhu, Ya-Qin Zhang
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Publication number: 20050254553Abstract: Orthogonal pulse polarity modulation involves wireless communication in which the polarity of modulating pulses are set responsive to positive and negative character values of a corresponding code sequence. In a described implementation, data is converted to chip waveforms, spectrum lines are removed, and pulses are appropriately shaped. For example, a data bit stream may be converted into chip waveforms using a bit stream-to-symbol segmenter, a symbol-to-code sequence mapper, and a code sequence-to-chip waveform transformer. The polarities of respective individual chips in a given chip waveform match the signs of respective individual characters in a corresponding code sequence.Type: ApplicationFiled: May 17, 2004Publication date: November 17, 2005Applicant: Microsoft CorporationInventors: Richard Yao, Zihua Guo, Weiyu Xu, Wenwu Zhu
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Publication number: 20050251577Abstract: An end host in a peer-to-peer system stores identifiers for both its peers and the neighbors of its peers. When the IP address of the end host and one of the peers changes, the end host's new IP address can be sent to each neighbor of the peer so that communication between the end host and the peer will not be lost. The order in which the neighbors of the peer are stored can be prioritized for faster delivery of the end host's changed IP address to the peer. The prioritizing can be by available bandwidth of the neighbors, proximity of the neighbors, trust between the peer and its neighbors, the probability that the IP address of the neighbors will change, etc. Proximity of the peers from each other and the end host can be a function of the identifier, which can be generated from a public key.Type: ApplicationFiled: April 20, 2004Publication date: November 10, 2005Inventors: Chuanxiong Guo, Haitao Wu, Kun Tan, Qian Zhang, Wenwu Zhu
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Publication number: 20050250508Abstract: 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: ApplicationFiled: June 27, 2005Publication date: November 10, 2005Applicant: Microsoft CorporationInventors: Zihua Guo, Qian Zhang, Richard Yao, Wenwu Zhu
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Publication number: 20050240403Abstract: A scalable audio codec processes, quantizes and encodes audio signals into an embedded audio bitstream of bit-planes each having a data unit. The data unit has a beginning refinement bits partition, a second significance bits partition, a third sign boundary mark bits partition, and a fourth sign bits partition. The second and fourth partitions form a boundary for the third partition. The quantizing uses a variable length coding algorithm. The third partition is an invalid codeword for a predetermined encoding method being used to encode. The codec uses a decoder to decode the embedded audio bitstream of bit-planes using Reversible exponential Golomb (Exp-Golomb) codes in a Reversible Variable Length Code (RVLC) algorithm to produce quantized data of weighted subbands. An inverse quantizer dequantizes the quantized data into audio signals.Type: ApplicationFiled: June 30, 2005Publication date: October 27, 2005Applicant: Microsoft CorporationInventors: Jianping Zhou, Wenwu Zhu
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Publication number: 20050213542Abstract: 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: ApplicationFiled: June 7, 2005Publication date: September 29, 2005Applicant: Microsoft CorporationInventors: Zihua Guo, Qian Zhang, Richard Yao, Wenwu Zhu
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Publication number: 20050213503Abstract: In accordance with certain described implementation(s), a coordinating device performs bandwidth allocation procedures based on information from previously-unfulfilled bandwidth allocation requests and responsive to current bandwidth allocation requests. The current bandwidth allocation requests stipulate current requested bandwidth amounts for multiple streams, and the current bandwidth allocation requests may be received from multiple entities having the multiple streams. The information from previously-unfulfilled bandwidth allocation requests is taken into account when allocating available bandwidth between/among the multiple streams of the multiple entities for the current requested bandwidth amounts.Type: ApplicationFiled: March 23, 2004Publication date: September 29, 2005Inventors: Zihua Guo, Jun Zhao, Richard Yao, Wenwu Zhu
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Publication number: 20050201279Abstract: A spurious timeout (STO) response allows a sending device to conservatively adjust congestion state parameters and maintain the packet flow, after detection of the STO. Since occurrence of an STO may be accompanied by data loss, the STO response couples the spurious timeout and the loss event by maintaining a value of previously available bandwidth and increasing a limit that a sending host can send based on a pattern of returned acknowledgements. In particular, the limit is increased by the maximum size of a data segment that the sending host can send each time an acknowledgement is received from the receiving host indicating a successful transmission of a data packet. Thus, a positive data flow may be maintained conservatively while avoiding further packet losses and an unnecessary re-transmission of data packets that may have been successfully received by the receiving host.Type: ApplicationFiled: March 15, 2004Publication date: September 15, 2005Inventors: Kun Tan, Qian Zhang, Wenwu Zhu
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Publication number: 20050204247Abstract: Adaptive acknowledgement delay entails adaptively adjusting an acknowledgement delay period responsive to channel quality. A destination device is enabled to set the acknowledgment delay period between two successive acknowledgments that acknowledge blocks received from a source device over a wireless channel. In a described implementation, the acknowledgment delay period is decreased if the wireless channel quality is poor. Otherwise, the acknowledgment delay period is increased as bounded by a maximum acknowledgment delay period setting and a remaining number of unreceived blocks of a current suprablock. The quality of the wireless channel may be reflected by, for example, blocks that are received erroneously. The duration of the acknowledgment delay may be set in terms of number of blocks received at the destination device.Type: ApplicationFiled: March 5, 2004Publication date: September 15, 2005Inventors: Zihua Guo, Richard Yao, Wenwu Zhu, Xin Liu
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Patent number: 6944144Abstract: 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: GrantFiled: February 28, 2003Date of Patent: September 13, 2005Assignee: Microsoft CorporationInventors: Zihua Guo, Qian Zhang, Richard Yao, Wenwu Zhu
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Publication number: 20050198350Abstract: A method for detecting a spurious timeout in a TCP network which can be used to avoid unnecessarily triggering the TCP rate adaptation is disclosed. Upon detection of a timeout on a given packet, a shortened packet version of the possibly lost packet is retransmitted. The retransmitted packet is at least one byte shorter than the original packet. The node receiving this retransmitted packet will acknowledge the receipt of the packet as specified in the TCP protocol. The acknowledgment will contain the sequence number of the lowest byte the receiving node has not yet received. Because the retransmitted packet is shorter than the original packet, the sequence number of this as yet not received byte will be less than or equal to the last byte of the original packet if the original packet was not received indicating a valid timeout.Type: ApplicationFiled: January 15, 2004Publication date: September 8, 2005Applicant: Microsoft CorporationInventors: Kun Tan, Hongbin Liao, Chuanxiong Guo, Qian Zhang, Wenwu Zhu
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Patent number: 6937591Abstract: A method provides differentiated quality of service (QoS) by providing adaptive updates to media access control (MAC) layer parameters on a distributed basis. The method includes calculating a failure probability for a transmission over the network, determining a target value for determining a contention window according to a mapped function of the failure probability, and altering the contention window according to a scaling function of the target value. The mapped function and the scaling can provide QoS differentiation. A wireless device ensures fairness in a wireless time slotted network and includes a network interface card (NIC), a network driver interface, a network monitor, a statistics engine, and an adaptive parameter engine for determining a target value for determining a contention window according to a mapped function of the one or more probabilities to enable an alteration of the contention window and provide new parameters for the MAC layer.Type: GrantFiled: February 27, 2003Date of Patent: August 30, 2005Assignee: Microsoft CorporationInventors: Zihua Guo, Wenwu Zhu, Qian Zhang, Jun Zhao
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Patent number: 6934679Abstract: A scalable audio codec processes, quantizes and encodes audio signals into an embedded audio bitstream of bit-planes each having a data unit. The data unit has a beginning refinement bits partition, a second significance bits partition, a third sign boundary mark bits partition, and a fourth sign bits partition. The second and fourth partitions form a boundary for the third partition. The quantizing uses a variable length coding algorithm. The third partition is an invalid codeword for a predetermined encoding method being used to encode. The codec uses a decoder to decode the embedded audio bitstream of bit-planes using Reversible exponential Golomb (Exp-Golomb) codes in a Reversible Variable Length Code (RVLC) algorithm to produce quantized data of weighted subbands. An inverse quantizer dequantizes the quantized data into audio signals.Type: GrantFiled: March 7, 2002Date of Patent: August 23, 2005Assignee: Microsoft CorporationInventors: Jianping Zhou, Wenwu Zhu
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Publication number: 20050182975Abstract: 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: ApplicationFiled: January 20, 2004Publication date: August 18, 2005Inventors: Zihua Guo, Richard Yao, Wenwu Zhu, Xin Wang
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Publication number: 20050163098Abstract: 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: ApplicationFiled: March 17, 2005Publication date: July 28, 2005Applicant: Microsoft CorporationInventors: HongBin Liao, Qian Zhang, Wenwu Zhu, Ya-Qin Zhang
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Publication number: 20050155080Abstract: 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: ApplicationFiled: January 27, 2005Publication date: July 14, 2005Applicant: Microsoft CorporationInventors: Qian Zhang, Ya-Qin Zhang, Wenwu Zhu
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Publication number: 20050128944Abstract: 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: ApplicationFiled: January 27, 2005Publication date: June 16, 2005Applicant: Microsoft CorporationInventors: Qian Zhang, Wenwu Zhu, Jiangchuan Liu
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Publication number: 20050122902Abstract: A method provides differentiated quality of service (QoS) by providing adaptive updates to media access control (MAC) layer parameters on a distributed basis. The method includes calculating a failure probability for a transmission over the network, determining a target value for determining a contention window according to a mapped function of the failure probability, and altering the contention window according to a scaling function of the target value. The mapped function and the scaling can provide QoS differentiation. A wireless device ensures fairness in a wireless time slotted network and includes a network interface card (NIC), a network driver interface, a network monitor, a statistics engine, and an adaptive parameter engine for determining a target value for determining a contention window according to a mapped function of the one or more probabilities to enable an alteration of the contention window and provide new parameters for the MAC layer.Type: ApplicationFiled: January 12, 2005Publication date: June 9, 2005Applicant: Microsoft CorporationInventors: Zihua Guo, Wenwu Zhu, Qian Zhang, Jun Zhao
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Publication number: 20050100040Abstract: A method provides differentiated quality of service (QoS) by providing adaptive updates to media access control (MAC) layer parameters on a distributed basis. The method includes calculating a failure probability for a transmission over the network, determining a target value for determining a contention window according to a mapped function of the failure probability, and altering the contention window according to a scaling function of the target value. The mapped function and the scaling can provide QoS differentiation. A wireless device ensures fairness in a wireless time slotted network and includes a network interface card (NIC), a network driver interface, a network monitor, a statistics engine, and an adaptive parameter engine for determining a target value for determining a contention window according to a mapped function of the one or more probabilities to enable an alteration of the contention window and provide new parameters for the MAC layer.Type: ApplicationFiled: October 21, 2004Publication date: May 12, 2005Applicant: Microsoft CorporationInventors: Zihua Guo, Wenwu Zhu, Qian Zhang, Jun Zhao
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Publication number: 20050083874Abstract: 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: ApplicationFiled: October 18, 2004Publication date: April 21, 2005Applicant: Microsoft CorporationInventors: Zihua Guo, Qian Zhang, Richard Yao, Wenwu Zhu