Patents by Inventor Nan Tu

Nan Tu 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: 7483411
    Abstract: Public wireless communications will increasingly extend into wireless LAN (WLAN) environments in order to meet the ubiquitous access, high data rate, and local services demands of future Internet appliances. By relying on IP-level services mechanisms, the Public Access Mobility LAN (PAMLAN) can simultaneously support different air interfaces, franchises for multiple services providers, and a multi-segment LAN environment including handoffs. The PAMLAN supports virtual operator LANs representing different network services providers, authorization and accounting mechanism, support of multiple air interfaces, and local IP mobility. A router associated with each base station realizes this highly distributed IP networking environment, and a QoS-enabled switched Ethernet core supports virtual networks and QoS services.
    Type: Grant
    Filed: January 30, 2002
    Date of Patent: January 27, 2009
    Assignee: NEC Corporation
    Inventors: Stephen B. Weinstein, Jun Li, Junbiao Zhang, Nan Tu
  • Publication number: 20050015511
    Abstract: A Method and apparatus for dynamically discovering and utilizing unused resources for practical and efficient creation of optimized network mechanisms for data distribution. Proposed techniques for data distribution, assembly, routing and scheduling in broadband networks can be implemented as content-level server platform architecture enabled by application-level control plane. Such a platform accelerates content transfer, mirroring and replication. It applies coordinated data partitioning and resource discovery and sharing of information replication by multiple network systems. Furthermore, it harvests the unutilized bandwidth in the network by disassembling the large content to be distributed into different components. These components are then routed in spatially and temporally diverse routes through multiple paths and trees and assembled at the destination nodes. The result is accelerated content distribution, added security, scalability and robustness.
    Type: Application
    Filed: December 31, 2003
    Publication date: January 20, 2005
    Applicant: NEC Laboratories America, Inc.
    Inventors: Rauf Izmailov, Samrat Ganguly, Nan Tu, Aikaterini Varsou
  • Patent number: 6757522
    Abstract: A technique is disclosed for determining a carrier-to-noise ratio (CNR) value for a selected channel of an access network. A background noise level on the selected channel is measured during a first time interval during which none of the network nodes are transmitting signals on the selected channel. A first signal strength on the selected channel is also measured during a second time interval during which a first network node is transmitting at least one signal on the selected channel. A CNR value for the selected channel may then be calculated using the measured background noise level information and the measured first signal strength information. According to a specific implementation, the calculation of the CNR value for the selected channel is not based upon an Error Vector Magnitude value associated with the signal transmitted from the first network node.
    Type: Grant
    Filed: December 11, 2000
    Date of Patent: June 29, 2004
    Assignee: Cisco Technology, Inc.
    Inventors: Charles Naegeli, Hungsan Chen, Nan Tu, Harihara Mahesh, Chrisanto de Jesus Leano, Nozar Azarakhsh
  • Publication number: 20020191572
    Abstract: Public wireless communications will increasingly extend into wireless LAN (WLAN) environments in order to meet the ubiquitous access, high data rate, and local services demands of future Internet appliances. By relying on IP-level services mechanisms, the Public Access Mobility LAN (PAMLAN) can simultaneously support different air interfaces, franchises for multiple services providers, and a multi-segment LAN environment including handoffs. The PAMLAN supports virtual operator LANs representing different network services providers, authorization and accounting mechanism, support of multiple air interfaces, and local IP mobility. A router associated with each base station realizes this highly distributed IP networking environment, and a QoS-enabled switched Ethernet core supports virtual networks and QoS services.
    Type: Application
    Filed: January 30, 2002
    Publication date: December 19, 2002
    Applicant: NEC USA, INC.
    Inventors: Stephen B. Weinstein, Jun Li, Junbiao Zhang, Nan Tu
  • Publication number: 20020174335
    Abstract: Mobile users access the Internet and local network services at hot spots such as airports, hotels, coffee shops and vacation resorts. The mobile users' Internet Service Providers (ISPs) are used as the single point of contact for all authentication, accounting, and authorization (AAA) transactions. AAA transactions for such ISPs acting as “virtual operators” are handled according to a system entirely based on IP. Converging both the AAA process and data transmission at the IP layer works across multiple air interfaces and is interoperable with wireless LAN cards from different vendors.
    Type: Application
    Filed: November 21, 2001
    Publication date: November 21, 2002
    Inventors: Junbiao Zhang, Jun Li, Stephen Weinstein, Nan Tu
  • Patent number: 6285960
    Abstract: A system and method are disclosed for calibrating a line card having a gain control circuit and memory device. The gain control circuit is configured to receive an input signal and an adjustment signal and to output an adjusted output signal that is based on the input signal and the adjustment signal. The gain control circuit also is configured to alter the adjustment signal to a nominal adjustment value so that an adjusted amplitude value of the adjusted signal converges with a nominal amplitude value. A first input signal, a first adjustment signal, and a nominal amplitude value are provided to the gain control circuit. A first nominal adjustment value is determined. The first nominal adjustment value is substantially permanently stored within a first address of the memory device with the first address being associated with the first input signal.
    Type: Grant
    Filed: October 7, 1998
    Date of Patent: September 4, 2001
    Assignee: Cisco Technology, Inc.
    Inventors: Joseph C. H. Fung, Mark E. Millet, Charles J. Naegeli, Nan Tu, Guenter Roeck, Yuzon Hao