Patents by Inventor Joseph Siufai Chan

Joseph Siufai Chan 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).

  • Received signal strength distance determination of low frequency tags
    Patent number: 8111141
    Abstract: Systems and methods provide for determining a distance between a signpost and a tag and for locating a tag using multiple signposts. The system uses a signal received at a tag from a signpost, and from them measures the signal strength of the signal with respect to one or more antennas on the tag. The system calculates an RSSI using the measured signal strength, from which a distance can be determined between the signpost and the tag. The system also uses signals received from multiple signposts, to measure multiple signal strengths, resulting in multiple distance determinations corresponding to the various signposts, thereby establishing a location for the tag.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: February 7, 2012
    Assignee: Savi Technology, Inc.
    Inventors: Timothy K. Brand, Stephen Earl Hilliker, Joseph Siufai Chan, Albert Nardelli, Nikola Cargonja, Bruno Skracic, Don Ahn
  • Received signal strength location determination of low frequency tags
    Patent number: 7768392
    Abstract: Systems and methods provide for determining a distance between a signpost and a tag and for locating a tag using multiple signposts. The system uses a signal received at a tag from a signpost, and from them measures the signal strength of the signal with respect to one or more antennas on the tag. The system calculates an RSSI using the measured signal strength, from which a distance can be determined between the signpost and the tag. The system also uses signals received from multiple signposts, to measure multiple signal strengths, resulting in multiple distance determinations corresponding to the various signposts, thereby establishing a location for the tag.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: August 3, 2010
    Assignee: Savi Technology, Inc.
    Inventors: Timothy K. Brand, Stephen Earl Hilliker, Joseph Siufai Chan, Albert Nardelli, Nikola Cargonja, Bruno Skracic, Don Ahn
  • Two-phase commit synchronizing seal state
    Patent number: 7358856
    Abstract: A conveyance tracking system provides two-phase transaction commit processing for synchronizing seal state information between a seal device attached to a conveyance and a host for tracking conveyances. The system uses a reader device for synchronization and communication between the seal device and host system regarding various operations, such as a lock operation, an unlock operation, and a clear tamper operation. In the first phase of the two-phase commit, the seal device prepares for the operation and the host executes the operation. In the second phase, the seal device fulfills the irreversible operation, ensuring that the seal state of the seal device and host are in sync.
    Type: Grant
    Filed: March 17, 2005
    Date of Patent: April 15, 2008
    Assignee: Savi Technology, Inc.
    Inventors: Ravindra U. Rajapakse, Leo Shang-Hua Chang, Joseph Siufai Chan, Jeyappragash Jeyakeerthi, Andrew Edward Savige Alcock