Patents by Inventor Long L. Duan

Long L. Duan 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: 7808952
    Abstract: A wireless communication network manages variable data rate communication channels using both short-term data rate adaptation and longer-term resource allocation adjustment. For example, an exemplary base station system may track the actual transmit power being used to transmit a given communication channel on a per frame basis, or faster, and use that tracked value to infer changing channel conditions, e.g., for a given current data rate, higher power indicates poorer channel conditions and lower power indicates better channel conditions. Additionally, or alternatively, channel quality information reported by a receiving mobile station can be used. Regardless, relatively fast data rate changes can be made responsive to monitoring the channel conditions, while retaining the communication resource allocation for the channel. Over the longer term, however, the allocation itself can be changed, e.g., increased or decreased, depending on whether the channel is being efficiently utilized.
    Type: Grant
    Filed: June 10, 2004
    Date of Patent: October 5, 2010
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Long L. Duan, Rath Vannithamby, Wanshi Chen, Reza Shahidi, Alpaslan Gence Savas, Joakim Hulten
  • Patent number: 7773502
    Abstract: In a wireless communication network providing voice and data services, one or more entities in the network, such as a base station controller and/or radio base station, can be configured to reduce data services overhead responsive to detecting a congestion condition, thereby increasing the availability of one or more network resources for voice services. In one or more exemplary embodiments, one or more current data services users are targeted for modification of their ongoing data services to effect the reduction in data services overhead. Modifications can include, but are not limited to, any one or more of the following: forward or reverse link data rate reductions, and shifting of forward or reverse link traffic from dedicated user channels to shared user channels. Targeting of users for service modification can be based on reported channel quality information. For example, users reporting poor radio conditions can be targeted first for service modifications.
    Type: Grant
    Filed: May 28, 2004
    Date of Patent: August 10, 2010
    Assignee: Telefonaktiebolaget lm Ericsson (publ)
    Inventors: Rath Vannithamby, Long L. Duan, Reza Shahidi, Wanshi Chen, Seema Madan
  • Patent number: 7519019
    Abstract: A radio base station performs reverse link rate control in a wireless communication network by “stealing” bits on a forward common power control channel. The forward common power control channel is divided into a plurality of frames, with each frame including a plurality of power control groups and each power control group including a plurality of power control slots. The radio base station may dynamically select power control slots depending on user demand to be used for reverse link rate control.
    Type: Grant
    Filed: March 15, 2004
    Date of Patent: April 14, 2009
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Young C. Yoon, Srinivasan Balasubramanian, David Reeves Comstock, Long L. Duan, Ralph Gholmieh, Thawatt Gopal, Patrick A. Hosein, Anthony C. K. Soong, Shiau-He Shawn Tsai, Rath Vannithamby, Jonas Wiorek
  • Patent number: 7406077
    Abstract: An apparatus and method provide MAC logic enabling the use of two or more reverse link rate controls at the same time in one or more sectors of a radio base station. That enables the base station to control reverse link loading via reverse link rate control, while assigning mobile stations to the type of reverse link rate control best suited to their needs. For example, the base station MAC logic may implement both a common rate controller that generates per-sector rate control commands, and a dedicated rate controller that generates per-user rate control commands and assign mobile stations having relatively lax reverse link service needs to the common rate controller, while assigning mobile stations having more demanding reverse link service requirements to the dedicated rate control. More than two rate controls can be implemented, and exemplary choices include per-user, per-sector, per-group, and scheduled rate control in any combination.
    Type: Grant
    Filed: January 9, 2004
    Date of Patent: July 29, 2008
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Srinivasan Balasubramanian, David Reeves Comstock, Long L. Duan, Ralph Gholmieh, Thawatt Gopal, Patrick Ahamad Hosein, Seong-Jun Oh, Anthony C. K. Soong, Shiau-He Shawn Tsai, Rath Vannithamby, Jonas Wiorek, Hsein Woo, Tao Wu, Young C. Yoon
  • Patent number: 6826161
    Abstract: A method for introducing hysteresis into a hard handoff decision in code division multiple access (CDMA) communications following an initial hard handoff is provided. The method introduces hysteresis when it is determined that the communicating mobile station system clock is slewing. The slewing determination follows from a calculation of the rate of change in the round trip delay (RTD) in communications with the mobile station. A calculated RTD rate of change is compared with a RTD slewing threshold, where the RTD threshold is the assumed slew rate of the mobile station. Hard handoffs are suspended as long as the calculated RTD rate of change exceeds the RTD slewing threshold. A system and apparatus to implement the above-described method are also provided.
    Type: Grant
    Filed: July 20, 2000
    Date of Patent: November 30, 2004
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Reza Shahidi, Octavio Jose De Franca Lima, Jen M. Chen, Long L. Duan, Tom T. Sesnic
  • Publication number: 20040179525
    Abstract: An apparatus and method provide MAC logic enabling the use of two or more reverse link rate controls at the same time in one or more sectors of a radio base station. That enables the base station to control reverse link loading via reverse link rate control, while assigning mobile stations to the type of reverse link rate control best suited to their needs. For example, the base station MAC logic may implement both a common rate controller that generates per-sector rate control commands, and a dedicated rate controller that generates per-user rate control commands and assign mobile stations having relatively lax reverse link service needs to the common rate controller, while assigning mobile stations having more demanding reverse link service requirements to the dedicated rate control. More than two rate controls can be implemented, and exemplary choices include per-user, per-sector, per-group, and scheduled rate control in any combination.
    Type: Application
    Filed: January 9, 2004
    Publication date: September 16, 2004
    Inventors: Srinivasan Balasubramanian, David Reeves Comstock, Long L. Duan, Ralph Gholmieh, Thawatt Gopal, Patrick Ahamad Hosein, Seong-Jun Oh, Anthony C.K. Soong, Shiau-He Shawn Tsai, Rath Vannithamby, Jonas L. Wiorek, Hsien Woo, Tao Wu, Young C. Yoon