Patents Assigned to Unwire AB
  • Patent number: 6366216
    Abstract: A method and a system for monitoring a plurality of movable objects, wherein each of the objects is equipped with a transponder with which a stationary node is arranged to communicate. Each transponder is caused to reply to a unique signal from the node and each transponder that sends a response signal gives to the response signal a transponder identification addition. A node is caused to detect the speed and direction at which each transponder moves towards and away from the node. Movement of the transponder relative to the node is evaluated by node associated means on the basis of the speed and direction of the transponder. A register over those transponders with which the node shall communicate is set-up for each node. A plurality of separate nodes are provided and each node is provided with such a register. The nodes are arranged to communicate with one another, so as to enable a node to record in its monitoring register a transponder from another node.
    Type: Grant
    Filed: January 20, 1999
    Date of Patent: April 2, 2002
    Assignee: Unwire AB
    Inventor: Lykke Olesen