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Wireless personal paging, communications, and locating system

  • US 5,479,408 A
  • Filed: 02/22/1994
  • Issued: 12/26/1995
  • Est. Priority Date: 02/22/1994
  • Status: Expired due to Fees
First Claim
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1. A method for transmitting a message to an individual in a building, returning a response message to the originator of said message, and determining the current location of said, individual, comprising the steps of:

  • originating said message addressed to the individual;

    transmitting the message to a central station;

    receiving and storing the message at said central station;

    creating a data packet containing data from the message;

    transmitting said data packet from the central station to a communications unit carried by the individual by the steps of;

    (1) adding a code to said data packet identifying said communications unit;

    (2) adding a code to the data packet uniquely identifying the data packet;

    (3) computing an error checking code and adding said error checking code to the data packet;

    (4) transmitting the data packet by means of radio from the central station to the communications unit;

    (5) receiving the data packet at the communications unit;

    (6) determining whether the data packet has been correctly received at the communications unit by computing an error checking code using the received data and comparing said error checking code with the error checking code contained in the data packet;

    transmitting an acknowledgment packet from the communications unit to the central station, should the data packet be received correctly, by the steps of;

    (1) constructing an acknowledgment packet at the communications unit containing said code uniquely identifying the data packet just received, so as to serve as an acknowledgment of said received data packet;

    (2) transmitting said acknowledgment packet from the communications unit by means of a medium selected from the group consisting of infrared light and ultrasonic sound to one or more of a plurality of remote stations installed at fixed locations in said building;

    (3) receiving the acknowledgment packet from the communications unit at a remote station and storing it in memory;

    (4) transmitting the acknowledgment packet from said remote station, by means of radio, to said central station;

    repeating the steps of creating a data packet containing data from the message, transmitting said data packet from the central station to a communications unit, and transmitting an acknowledgment packet from the communications unit to the central station, until all data in the message has been transmitted from the central station to the communications unit;

    displaying the message to the individual;

    accepting a response message from the individual at the communications unit in response to the received message;

    creating a response packet containing data from said response message;

    transmitting said response packet from the communications unit by means of a medium selected from the group consisting of infrared light and ultrasonic sound to one or more of a plurality of remote stations installed at fixed locations in the building;

    receiving the response packet at a remote station and temporarily storing the response packet;

    adding a code to the response message uniquely identifying said remote station;

    transmitting the response packet from the remote station by means of radio to the central station;

    receiving the response packet at the central station and storing it;

    extracting the location of the remote station from the response packet and storing the location associated with the individual at the central station;

    transmitting the response message from the central station to the originator of the message.

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