Patents by Inventor Zhifeng Tao

Zhifeng Tao 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: 20090059815
    Abstract: A system for self-organizing and auto-configuring mesh networks is disclosed. Special nodes (deemed special for their topological significance) are used as a starting point for forming clusters of fully connected nodes. Here, all nodes can communicate directly with one another and links are scheduled to meet the traffic requirements as indicated by their individual configuration and topological positions. Links that do not interfere with each other are scheduled to operate concurrently, thereby increasing the bandwidth offered by the whole system. When there is change to the system, such as leaving or introduction of a node, the system will adjust with minimum impact on its operation. Once all of the clusters are formed in a system, the clusters are now capable of inter-cluster communications with an increase in bandwidth for such communications.
    Type: Application
    Filed: October 20, 2008
    Publication date: March 5, 2009
    Inventors: Alexander L. Cheng, Zhifeng Tao
  • Publication number: 20090016372
    Abstract: A method selects antennas in an OFDMA wireless network including a base station and a mobile station. The mobile station measures a channel state of a downlink in a downlink subframe using different subsets of available antennas, and selects a subset of receive antennas for downlink reception based on the channel states between the base station and the different subsets of antennas at the mobile station. The base station measures the channel state in an uplink using an uplink subframe received in the base station from the mobile station, and selects a subset of transmit antennas for mobile station's uplink transmission based on the channel states between the base station and different subset of antennas at the mobile station.
    Type: Application
    Filed: May 8, 2008
    Publication date: January 15, 2009
    Inventors: Zhifeng Tao, Andreas F. Molisch, Philip V. Orlik, Jinyun Zhang, Shigeru Uchida, Kentarou Sawa
  • Publication number: 20090016312
    Abstract: A method selects antennas in an OFDMA network. A channel state of a downlink is measured using a downlink subframe received in a mobile station from a base station. A channel state of an uplink is measured using an uplink subframe received in the base station from the mobile station. Next, the method compares the channel states to determine whether the downlink and the uplink are reciprocal or not. The mobile station can perform receive antenna selection based on the quality of the downlink channel state. The mobile station can also perform transmit antenna selection when instructed by the base station.
    Type: Application
    Filed: July 13, 2007
    Publication date: January 15, 2009
    Inventors: Zhifeng Tao, Chun Nie, Neelesh B. Mehta, Andreas F. Molisch, Jinyun Zhang
  • Patent number: 7474676
    Abstract: A method aggregates frames to be transmitted over a channel in a wireless network into a single frame. Multiple MSDU frames having identical destination addresses and identical traffic classes, received in the media access control layer from the logical link layer in a transmitting station are aggregated into a single aggregate MPDU frame, which can be transmitted on the channel to a receiving station. In addition, aggregate MSDU frames with different destination addresses and different traffic classes received from the media access control layer can be further aggregated into a single aggregate PPDU frame before transmission.
    Type: Grant
    Filed: September 10, 2004
    Date of Patent: January 6, 2009
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Zhifeng Tao, Daqing Gu, Yukimasa Nagai
  • Publication number: 20080285480
    Abstract: When it is advantageous to do so, a wireless LAN station sends data packets to a destination station via an intermediate station, instead of to the destination station directly. That is, the intermediate station, which serves as a helper to the source, forwards packets received from the source station to the intended destination station. This cooperative data transmission approach can result in system performance improvement, as long as the total time consumed by two-hop transmission (i.e., transmission via the helper station) is less than direct transmission. Such a determination may be made using rate information stored at each station. Specifically, using the rate information, signaling needed to set up a transmission, the amount of data to be transmitted, etc., transmitting the data directly and via a help station may be compared.
    Type: Application
    Filed: November 9, 2007
    Publication date: November 20, 2008
    Applicant: POLYTECHNIC UNIVERSITY
    Inventors: Shivendra S. Panwar, Pei Liu, Zhifeng Tao
  • Patent number: 7440436
    Abstract: A system for self-organizing and auto-configuring mesh networks is disclosed. Special nodes (deemed special for their topological significance) are used as a starting point for forming clusters of fully connected nodes. Here, all nodes can communicate directly with one another and links are scheduled to meet the traffic requirements as indicated by their individual configuration and topological positions. Links that do not interfere with each other are scheduled to operate concurrently, thereby increasing the bandwidth offered by the whole system. When there is change to the system, such as leaving or introduction of a node, the system will adjust with minimum impact on its operation. Once all of the clusters are formed in a system, the clusters are now capable of inter-cluster communications with an increase in bandwidth for such communications.
    Type: Grant
    Filed: May 13, 2005
    Date of Patent: October 21, 2008
    Inventors: Alexander L. Cheng, Zhifeng Tao
  • Publication number: 20080212513
    Abstract: The invention provides a data structure embodied in a computer readable media. The data structure is a protocol data packet (PDU) communicated in a mobile multihop network between stations. The data structure includes a relay media access header, a payload and an optional cyclical redundancy checksum for the protocol data unit; and an indication whether the PDU is a relay media access protocol data unit or not.
    Type: Application
    Filed: June 28, 2007
    Publication date: September 4, 2008
    Inventors: Zhifeng Tao, Jinyun Zhang
  • Publication number: 20080165736
    Abstract: Handover procedures and a collection of new handover MAC management messages are provided for a wireless mobile multi-bop relay (MMR) network. The types of handovers supported include macro diversity handover (MDHO) and fast access station switching (FASS). The handover procedures for these two types of handover and the MAC messages are described for nine main classes of network topologies. The nine classes of topology are further classified into to main categories, namely, intra multi-hop base station (MR-BS), when and where the handover is in the MMR cell, and inter MR-BS handover, when and where the handover is between two different MMR cells.
    Type: Application
    Filed: January 5, 2007
    Publication date: July 10, 2008
    Inventors: Shengjie Zhao, Koon Hoo Teo, Zhifeng Tao, Jinyun Zhang
  • Publication number: 20080165776
    Abstract: A method communicates packets in a relay network. The packets are communicated from a set of mobile stations to a relay station using a set of connections, there being one connection between each mobile station and the relay station. The packets are communicated between the relay station and a base station using a relay tunnel connection, between the relay station and its adjacent relay station the packets are communicated using the relay tunnel connection.
    Type: Application
    Filed: January 8, 2007
    Publication date: July 10, 2008
    Inventors: Zhifeng Tao, Toshiyuki Kuze, Jinyun Zhang
  • Publication number: 20080165881
    Abstract: A method accesses channels in an OFDMA mobile multihop relay wireless network. The method partitions a downlink sub-frame into at least one downlink access zone and a set of downlink relay zones. The uplink subframe is partitioned into at least one uplink access zone and a set of uplink relay zones. During the downlink access zone, the base station and the relay stations transmit only to the set of mobile stations. During the downlink relay station, the base station and the set of relay stations communicate with each other, while the mobile stations are idle. During the uplink access zone, the set of mobile stations transmit only to the set of relay stations and the base station. During the uplink relay station, the base station and the set of relay stations communicate with each other, while the mobile stations are idle.
    Type: Application
    Filed: September 5, 2007
    Publication date: July 10, 2008
    Inventors: Zhifeng Tao, Koon Hoo Teo, Jinyun Zhang
  • Publication number: 20080165670
    Abstract: A method and system enables and improves performance of hybrid automatic repeat request (HARQ) operations on channels between stations of an orthogonal frequency division multiple access (OFDMA) wireless communication network. There, the number of parallel HARQ channels is increased adaptively, and one connection identifier is used to unambiguously identify a set of MAC protocol data units (MPDUs) communicated over parallel HARQ channels. A sequence number is used to avoid out-of-order MPDU delivery when MPDUs are transmitted over parallel HARQ channels. The MPDUs can be concatenated or encapsulated. The maximum number of the parallel HARQ channels can be increased to 256, and can be negotiated when a station enters or re-enters the network.
    Type: Application
    Filed: January 5, 2007
    Publication date: July 10, 2008
    Inventors: Zhifeng Tao, Toshiyuki Kuze, Shigeru Uchida, Kentarou Sawa, Koon Hoo Teo, Jinyun Zhang
  • Publication number: 20080144512
    Abstract: A method selects a route in a wireless cooperative relay network of nodes, the nodes including a source, a set of relays, and a destination. A codeword is encoded as a data stream. The data stream is transmitted from a source to a destination via a set of relays. Mutual information is accumulated at a particular node to decode the data stream and recover the codeword. Then, a route from the source to the destination is selected based on channel state information between the nodes while transmitting and accumulating.
    Type: Application
    Filed: December 5, 2006
    Publication date: June 19, 2008
    Inventors: Andreas F. Molisch, Neelesh B. Mehta, Jonathan S. Yedidia, Zhifeng Tao, Zafer Sahinoglu, Philip V. Orlik, Jin Zhang
  • Patent number: 7385976
    Abstract: A method selectively acknowledges data packets in a network including a multiple stations connected by a common wireless channel. A transmitting station requests a block acknowledgement from a receiving station. The transmitting station transmits a block of data packets to the receiving station. The receiving station determines a number of successfully received data packets and a number of incorrectly received packets. Then, the receiving station selectively acknowledges only the successfully received data packets if the number of usefully received data packets is less than the number of incorrectly received data packets, and otherwise acknowledging only the incorrectly received packets.
    Type: Grant
    Filed: August 12, 2004
    Date of Patent: June 10, 2008
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Daqing Gu, Zhifeng Tao, Jinyun Zhang
  • Publication number: 20080107061
    Abstract: A method communicates packets in a relay network. Multiple packets are communicated between a set of mobile stations and a relay station using a set of connections. There is one connection between each mobile station and the relay station. The multiple packets are aggregated on single connection between the relay station and a base station.
    Type: Application
    Filed: November 6, 2006
    Publication date: May 8, 2008
    Inventors: Zhifeng Tao, Koon Hoo Teo, Toshiyuki Kuze, Jinyun Zhang
  • Patent number: 7330457
    Abstract: When it is advantageous to do so, a wireless LAN station sends data packets to a destination station via an intermediate station, instead of to the destination station directly. That is, the intermediate station, which serves as a helper to the source, forwards packets received from the source station to the intended destination station. This cooperative data transmission approach can result in system performance improvement, as long as the total time consumed by two-hop transmission (i.e., transmission via the helper station) is less than direct transmission. Such a determination may be made using rate information stored at each station. Specifically, using the rate information, signaling needed to set up a transmission, the amount of data to be transmitted, etc., transmitting the data directly and via a help station may be compared.
    Type: Grant
    Filed: October 7, 2005
    Date of Patent: February 12, 2008
    Assignee: Polytechnic University
    Inventors: Shivendra S. Panwar, Pei Liu, Zhifeng Tao
  • Patent number: 7328026
    Abstract: A method signals data in a channel of a network including multiple stations and an access point connected by a wireless channel. A station first requests access to the channel using a sequential coordinated channel access method of an access point. After the station receives permission to access the channel during a contention free period at a time corresponding to a sequence index value received by the station from the access point, the station transmits a resource request message to the access point to obtain a bandwidth allocation. In response, the station receives the bandwidth allocation, and the station can then transmit data during the contention free period according to the bandwidth allocation.
    Type: Grant
    Filed: August 11, 2004
    Date of Patent: February 5, 2008
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Daqing Gu, Zhifeng Tao, Jinyun Zhang
  • Publication number: 20060268791
    Abstract: A system for self-organizing and auto-configuring mesh networks is disclosed. Special nodes (deemed special for their topological significance) are used as a starting point for forming clusters of fully connected nodes. Here, all nodes can communicate directly with one another and links are scheduled to meet the traffic requirements as indicated by their individual configuration and topological positions. Links that do not interfere with each other are scheduled to operate concurrently, thereby increasing the bandwidth offered by the whole system. When there is change to the system, such as leaving or introduction of a node, the system will adjust with minimum impact on its operation. Once all of the clusters are formed in a system, the clusters are now capable of inter-cluster communications with an increase in bandwidth for such communications.
    Type: Application
    Filed: May 13, 2005
    Publication date: November 30, 2006
    Inventors: Alexander Cheng, Zhifeng Tao
  • Publication number: 20060077942
    Abstract: When it is advantageous to do so, a wireless LAN station sends data packets to a destination station via an intermediate station, instead of to the destination station directly. That is, the intermediate station, which serves as a helper to the source, forwards packets received from the source station to the intended destination station. This cooperative data transmission approach can result in system performance improvement, as long as the total time consumed by two-hop transmission (i.e., transmission via the helper station) is less than direct transmission. Such a determination may be made using rate information stored at each station. Specifically, using the rate information, signaling needed to set up a transmission, the amount of data to be transmitted, etc., transmitting the data directly and via a help station may be compared.
    Type: Application
    Filed: October 7, 2005
    Publication date: April 13, 2006
    Inventors: Shivendra Panwar, Pei Liu, Zhifeng Tao
  • Publication number: 20060056443
    Abstract: A method aggregates frames to be transmitted over a channel in a wireless network into a single frame. Multiple MSDU frames having identical destination addresses and identical traffic classes, received in the media access control layer from the logical link layer in a transmitting station are aggregated into a single aggregate MPDU frame, which can be transmitted on the channel to a receiving station. In addition, aggregate MSDU frames with different destination addresses and different traffic classes received from the media access control layer can be further aggregated into a single aggregate PPDU frame before transmission.
    Type: Application
    Filed: September 10, 2004
    Publication date: March 16, 2006
    Inventors: Zhifeng Tao, Daqing Gu, Yukimasa Nagai
  • Publication number: 20060034247
    Abstract: A method selectively acknowledges data packets in a network including a multiple stations connected by a common wireless channel. A transmitting station requests a block acknowledgement from a receiving station. The transmitting station transmits a block of data packets to the receiving station. The receiving station determines a number of successfully received data packets and a number of incorrectly received packets. Then, the receiving station selectively acknowledges only the successfully received data packets if the number of usefully received data packets is less than the number of incorrectly received data packets, and otherwise acknowledging only the incorrectly received packets.
    Type: Application
    Filed: August 12, 2004
    Publication date: February 16, 2006
    Inventors: Daqing Gu, Zhifeng Tao, Jinyun Zhang