Patents by Inventor Kar-Fat Poon

Kar-Fat Poon 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: 7058806
    Abstract: Method and apparatus for providing secure, controlled access to one or more functions in an electronic system which may have a plurality of functions having different access requirements. A desired function is enabled according to the result of a first authentication process which uses a public key which corresponds to the desired function, and access to the function is authorized by a second authentication process which uses a second, private session key computed as a result of a random challenge made by the system to an external entity during the first authentication process. Additional protection is also provided against passive and active wiretapper attacks, such that only an entity that has received authorization can access the system at the correct access level.
    Type: Grant
    Filed: March 29, 2001
    Date of Patent: June 6, 2006
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Bernhard Jan Marie Smeets, Kar-Fat Poon, Marcus Bodensjo
  • Patent number: 6857068
    Abstract: Device for processing data includes a processor for executing program routines, and a memory for storing program routines to be executed by the processor. Part of the memory includes a protected part from which data can be read but which is protected against being written into. The processor is arranged to necessarily execute a program routine stored in the protected part of the memory upon start-up.
    Type: Grant
    Filed: June 21, 2000
    Date of Patent: February 15, 2005
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Bernd Möller, Harro Osthoff, Ben Smeets, Kar-Fat Poon
  • Patent number: 6717985
    Abstract: A technique for efficiently equalizing a transmission channel in a data transmission system is disclosed. The technique is realized by creating a first model of a first transmission channel based upon at least a portion of a first message that has been transmitted over the first transmission channel, and then receiving a second message that has been transmitted over a second transmission channel. The first model is then evaluated so as to determine if the first model adequately represents the second transmission channel.
    Type: Grant
    Filed: March 8, 2000
    Date of Patent: April 6, 2004
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventor: Kar-Fat Poon
  • Patent number: 6466767
    Abstract: A test transmitter for verifying the positioning of antennas in a mobile telecommunications system and a method for manufacturing such a test transmitter that is particularly suited for indoor use are presented. A mobile terminal is modified so that it can transmit in the downlink frequency band, and preferably so that it can transmit one or more of the signal types used for downlink signalling in the mobile telecommunications system.
    Type: Grant
    Filed: September 8, 1998
    Date of Patent: October 15, 2002
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Stefan Lidbrink, Kenneth Schönfeldt, Björn Lindquist, Kar-Fat Poon, Kenneth Ekman, Niclas Ögren
  • Publication number: 20020059518
    Abstract: Method and apparatus for providing secure, controlled access to one or more functions in an electronic system which may have a plurality of functions having different access requirements. A desired function is enabled according to the result of a first authentication process which uses a public key which corresponds to the desired function, and access to the function is authorized by a second authentication process which uses a second, private session key computed as a result of a random challenge made by the system to an external entity during the first authentication process. Additional protection is also provided against passive and active wiretapper attacks, such that only an entity that has received authorization can access the system at the correct access level.
    Type: Application
    Filed: March 29, 2001
    Publication date: May 16, 2002
    Inventors: Bernard Jan Marie Smeets, Kar-Fat Poon, Marcus Bodensjo
  • Patent number: 6101383
    Abstract: The present invention relates to a method and a mobile station for use in a communications network of GSM type, or a type derived from GSM. According to the invention the identification (307) of an unidentified BCCH carrier is initiated in the mobile station when said BCCH carrier on the basis of measured signal strengths is foreseen (321) soon to be one of the strongest BCCH carriers with regard to the signal strength average value over a measuring period. The delay from the point in time when the BCCH carriers becomes one of the strongest BCCH carriers, taking into account the signal strength average values over a measuring period, to the point when the BCCH carrier has been identified can in many cases be reduced or in some cases eliminated. Thus the mobile station can report measurement data for the BCCH carrier to the network at an earlier stage so that handover to the corresponding cell may be made faster.
    Type: Grant
    Filed: December 18, 1997
    Date of Patent: August 8, 2000
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventor: Kar-Fat Poon
  • Patent number: 5940380
    Abstract: The invention provides a communication unit (MS1), communicating with a first radio base station (BTS1) on a dedicated communication channel (CH1) in a radio communication network (NET1) using a combination of TDMA and FDMA, with an increased flexibility in terms of when the communication unit (MS1) can receive signals from a second base station (BTS4). The increased flexibility is achieved by the communication unit (MS1) selecting some of the time slots comprising the dedicated communication channel (CH1) and ignoring to communicate with the first radio base station in these selected time slots and instead using them to receive signals (BCCH4) from the second radio base station (BTS4). In a GSM mobile station (MS1) according to the invention, the "stolen" time slots are used for identification of a neighboring base tranceiver station (BTS4), i.e.
    Type: Grant
    Filed: June 19, 1997
    Date of Patent: August 17, 1999
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventors: Kar-Fat Poon, Lars Wilhelmsson