Patents by Inventor Kin K. Leung

Kin K. Leung 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: 7206586
    Abstract: A frequency planning method for use in an IEEE 802.11 wireless network is described. The frequency planning method obtains traffic load information associated with access points belonging to a multi-cell wireless network and assigns channels to the access points based on the traffic load information.
    Type: Grant
    Filed: September 28, 2005
    Date of Patent: April 17, 2007
    Assignee: AT&T Corp.
    Inventors: Byoung-Jo J. Kim, Kin K Leung
  • Patent number: 7180876
    Abstract: An access interface module includes a first network interface module for interfacing with a first access network and a second network interface module for interfacing with a second access network of a type that is different from the first network. The access module can further include a processor coupled to the first and second network interface modules and a device interface module coupled to the processor for interfacing with a host device.
    Type: Grant
    Filed: May 14, 2002
    Date of Patent: February 20, 2007
    Assignee: AT&T Corp.
    Inventors: Paul Shala Henry, Byoung-Jo J Kim, Kin K Leung, Bruce Edwin McNair
  • Patent number: 7124193
    Abstract: A method for improving the performance for a streaming service by link-adaptation and power-control in a wireless packet network such as an Enhanced General Packet Radio Services (EGPRS) cellular network is described. In particular, the effects of a combined link adaptation and power control scheme (referred to as an error-based scheme) for achieving a target error rate, which is non-zero but low enough so that limited retransmission and error concealment techniques are effective, is presented.
    Type: Grant
    Filed: August 23, 2001
    Date of Patent: October 17, 2006
    Assignee: AT&T Corp.
    Inventors: Kin K. Leung, Kapil K. Chawla, Peter F. Driessen, Xiaoxin Qiu
  • Patent number: 7068599
    Abstract: A wireless network includes a plurality of proxy servers located at various locations to selectively transform data based upon network conditions, such as link congestion. A queueing model for the network can be used to determine optimal operating parameters for the network.
    Type: Grant
    Filed: July 24, 2001
    Date of Patent: June 27, 2006
    Assignee: AT&T Corp.
    Inventors: Zhimei Jiang, Kin K. Leung
  • Patent number: 7058059
    Abstract: A method and apparatus to enable IP networking for mobile hosts without requiring changes to be made to the TCP/IP stack in the operating system installed on the mobile hosts. The apparatus is an “intelligent device” that can be installed on or connected to a mobile host, and may comprise a software-only logical module, physical hardware, or a combination of both. To a mobile host, the intelligent device emulates a network interface such as an Ethernet card or a telephone modem. The intelligent device appears to an access network just like any regular IP host connected to the access network through a physical network interface device. The intelligent device handles all mobile networking functions for the mobile host, and may control multiple different physical network interface devices to enable a connection to the “best” access network available to the mobile user at his location.
    Type: Grant
    Filed: August 30, 2001
    Date of Patent: June 6, 2006
    Assignee: AT&T Corp.
    Inventors: Paul Shala Henry, Zhimei Jiang, Byoung-Jo J Kim, Kin K Leung, Hui Luo
  • Patent number: 6996579
    Abstract: A conditional e-coupon distribution method distributes e-coupons predefined by sellers to mobile users only if the number of mobile users requesting such e-coupons equals or exceeds a threshold. The method receives a request to browse e-coupons from a mobile user. The method receives the location of the mobile user and determines a plurality of sellers local to the mobile electronic device and a plurality of corresponding e-coupons available from the local sellers. The method receives a request for a particular e-coupon from a seller and authorizes the provision of said e-coupon to the mobile user. At the end of a processing cycle, the mobile user receives the requested e-coupon if all conditions, such as a period of time and threshold, have been met. A computer-usable medium having computer-readable program code embodied therein allows for storage of the method.
    Type: Grant
    Filed: November 2, 2001
    Date of Patent: February 7, 2006
    Assignee: AT&T Corp.
    Inventors: Kin K. Leung, Hui Luo, Nemmara K. Shankaranarayanan
  • Patent number: 6963580
    Abstract: A method and an apparatus provide for controlled access to a shared communication medium. Time slots on a forward channel include information regarding status useful for remote units to determine whether a reverse channel is available for seizure. Additionally, information along the forward channel provides guidance to the remote units to control attempts to seize the reverse channel. In one embodiment a remote unit divides a data package into a plurality of portions and attempts to seize the reverse channel using a single portion of the data package which corresponds to one time slot on the reverse channel. It then waits until it receives notification along the forward channel that the first data portion was successfully received before it attempts to send any of the remainder of its data in consecutive time slots on the reverse channel.
    Type: Grant
    Filed: February 16, 2001
    Date of Patent: November 8, 2005
    Assignee: AT&T Corp.
    Inventors: Herman Chien, Jin-Meng Ho, Liang A. Hong, Elliott Hoole, Kin K. Leung
  • Publication number: 20040022207
    Abstract: A system and method for predicting future interference power in packet-switched networks is disclosed, allowing improved performance in such networks via optimized link adaptation and power control. In an embodiment for use in a cellular network, Kalman filtering can be used to provide the interference estimation through identification of the number of active co-channel interferers in the cellular networks and correlation of the interference power with the number of active interferers. A two-dimensional Kalman filter can be used to exploit that correlation to enhance prediction accuracy. In an alternative embodiment, a one-dimensional Kalman filter can be used where the number of active interferers is not considered.
    Type: Application
    Filed: August 2, 2002
    Publication date: February 5, 2004
    Inventors: Kin K. Leung, Jack Harriman Winters
  • Patent number: 6657982
    Abstract: A method and apparatus for scheduling transmissions between a plurality of communications sites within a communications system. The communications system provides service to a service area which is divided into sectors. Each sector is assigned a time subframe in a pattern where adjacent sectors use different subframes. Communications sites within each sector communicate packets of information in at least one time subframe according to a schedule to minimize interference from other communications sites.
    Type: Grant
    Filed: January 27, 2000
    Date of Patent: December 2, 2003
    Assignee: AT&T Corp.
    Inventors: Thomas K. Fong, Paul Shala Henry, Kin K. Leung, Xiaoxin Qiu, Nemmara K. Shankaranarayanan
  • Publication number: 20030152058
    Abstract: A method for setting and adjusting MAC fragmentation threshold for IEEE 802.11 networks operating at different data rates is presented. The fragmentation threshold is adjusted based on throughput performance, delay constraints and hidden node influence.
    Type: Application
    Filed: November 14, 2002
    Publication date: August 14, 2003
    Applicant: AT&T Corp.
    Inventors: Leonard Joseph Cimini, Zoran Kostic, Kin K. Leung, Hujun Yin
  • Publication number: 20030139197
    Abstract: A network having distribution of access point loading includes access points to which mobile stations can associate themselves based upon access point beacon signal levels and loading levels for the various access points. A mobile station receives beacon signals from various access points and determines a signal strength for the received beacon signals. The mobile station also receives access point loading information from the access points. The mobile station associates with an access point based upon the access point beacon signal strengths and the access point loading information.
    Type: Application
    Filed: November 12, 2002
    Publication date: July 24, 2003
    Applicant: AT&T Corp.
    Inventors: Zoran Kostic, Kin K. Leung, Hujun Yin
  • Publication number: 20030134642
    Abstract: A network includes access points that admit/terminate mobile station associations based upon the loading level of the access point and/or whether a mobile station can associate with a further access point. Mobile stations transmit information indicative of the access points to which they can associate. The access points determine whether to admit/terminate a mobile station association based upon access point loading.
    Type: Application
    Filed: November 12, 2002
    Publication date: July 17, 2003
    Applicant: AT&T Corp.
    Inventors: Zoran Kostic, Kin K. Leung, Hujun Yin
  • Publication number: 20030133427
    Abstract: A method of shaping data packet transmissions by nodes in a wireless network is presented. Each node sets a maximum limit for MAC service data unit size based on data rate so that maximum transmission times for data packet transmissions by all of the nodes are approximately the same.
    Type: Application
    Filed: November 14, 2002
    Publication date: July 17, 2003
    Applicant: AT&T Corp.
    Inventors: Leonard Joseph Cimini, Zoran Kostic, Kin K. Leung, Hujun Yin
  • Patent number: 6580912
    Abstract: A method and apparatus for a high-capacity cellular network by improved sectorization and interleaved channel assignment is presented. Data transmission over a cellular network is carried out by implementation of a sectorization scheme, called the Narrow-Beam Quad-sector Cell (NBQC) sectorization scheme, and the corresponding Interleaved Channel Assignments (ICA). The NBQC sectorization scheme calls for each cell of a cellular network to be divided into four sectors, with each sector covered by a 60 degree antenna. Use of the NBQC sectorization scheme allows for implementation of the corresponding ICA, in which assignment of transmission channels to each cell is based on a re-use factor of N=2. Accordingly, the interleaved channel assignments allow for the use of the transmission channels in cells which are adjacent in the cellular network.
    Type: Grant
    Filed: September 10, 2001
    Date of Patent: June 17, 2003
    Assignee: AT&T Corp.
    Inventors: Kin K. Leung, Li-Chun Wang
  • Publication number: 20030093314
    Abstract: A conditional e-coupon distribution method distributes e-coupons predefined by sellers to mobile users only if the number of mobile users requesting such e-coupons equals or exceeds a threshold. The method receives a request to browse e-coupons from a mobile user. The method receives the location of the mobile user and determines a plurality of sellers local to the mobile electronic device and a plurality of corresponding e-coupons available from the local sellers. The method receives a request for a particular e-coupon from a seller and authorizes the provision of said e-coupon to the mobile user. At the end of a processing cycle, the mobile user receives the requested e-coupon if all conditions, such as a period of time and threshold, have been met. A computer-usable medium having computer-readable program code embodied therein allows for storage of the method.
    Type: Application
    Filed: November 2, 2001
    Publication date: May 15, 2003
    Inventors: Kin K. Leung, Hui Luo, Nemmara K. Shankaranarayanan
  • Publication number: 20030087645
    Abstract: A frequency planning method for use in an IEEE 802.11 wireless network is described. The frequency planning method obtains traffic load information associated with access points belonging to a multi-cell wireless network and assigns channels to the access points based on the traffic load information.
    Type: Application
    Filed: November 5, 2002
    Publication date: May 8, 2003
    Inventors: Byoung-Jo J. Kim, Kin K. Leung
  • Patent number: 6519705
    Abstract: An enhanced power control method for use in a wireless packet-switched network having an interference prediction algorithm which includes an error margin. In particular, the method can measure an interference power and a path gain between an intended receiver and transmitter. Based upon the past performance of the network, a future interference value may be predicted by using a prediction algorithm. Furthermore, based upon the prior accuracy of the interference prediction, the method can also estimate an error margin for the interference prediction. Finally, a transmission power for the transmitter can be calculated using the predicted interference power, the estimated error margin for the predicted interference power, the path gain, and the target SINR.
    Type: Grant
    Filed: December 15, 1999
    Date of Patent: February 11, 2003
    Assignee: AT&T Corp.
    Inventor: Kin K. Leung
  • Publication number: 20020115459
    Abstract: A Kalman-filter power control method is applied to a packet voice service in a wireless network based on interference tracking and predictions. An Enhanced Data for GSM Evolution (EDGE) system is used as an illustrative platform for the invention. The power-control method significantly improves the spectral efficiency by enabling the 1/3 frequency reuse while maintaining a stringent requirement of 2% packet loss probability for voice service. For allocated spectrum of 1.8, 3.6 and 5.4 MHz, the 1/3 reuse with the Kalman power control can yield 102.5%, 49.5% and 32.5% improvement in spectral efficiency over the 3/9 reuse, respectively.
    Type: Application
    Filed: February 22, 2001
    Publication date: August 22, 2002
    Inventors: Justin Che-l Chuang, Kin K. Leung, Xiaoxin Qiu, Li-Chun Wang, Shailehnder Timiri
  • Patent number: 6404753
    Abstract: A method and an apparatus provide for controlled access to a shared communication medium. Time slots on a forward channel include information regarding status useful for remote units to determine whether a reverse channel is available for seizure. Additionally, information along the forward channel provides guidance to the remote units to control attempts to seize the reverse channel. In one embodiment a remote unit divides a data package into a plurality of portions and attempts to seize the reverse channel using a single portion of the data package which corresponds to one time slot on the reverse channel. It then waits until it receives notification along the forward channel that the first data portion was successfully received before it attempts to send any of the remainder of its data in consecutive time slots on the reverse channel.
    Type: Grant
    Filed: September 4, 1998
    Date of Patent: June 11, 2002
    Assignees: AT&T Corp., AT&T Wireless Services Inc.
    Inventors: Herman Chien, Kin K. Leung
  • Patent number: 6400697
    Abstract: A method and apparatus for sector based resource allocation in a broadband wireless communications system. A service region is divided into a plurality of cells, and each cell is divided into a plurality of labeled sectors. Each label is selected to avoid an unacceptable amount of interference from any other sector while ensuring that at least two sectors in a cell share the same label. Transmissions are scheduled for a cell by assigning each communications site a channel, such as a time slot associated with the sector's label. The transmissions are then communicated according to this schedule.
    Type: Grant
    Filed: January 15, 1998
    Date of Patent: June 4, 2002
    Assignee: AT&T Corp.
    Inventors: Kin K. Leung, Nemmara K. Shankaranarayanan, Arty Srivastava