×

SYSTEM FOR LOCATING AND COMMUNICATING WITH MOBILE UNITS

  • US 3,662,267 A
  • Filed: 05/20/1970
  • Issued: 05/09/1972
  • Est. Priority Date: 05/20/1970
  • Status: Expired due to Term
First Claim
Patent Images

1. A locating system for determining the location of mobile units within a geographic area comprising:

  • a central office;

    an array of pickup terminals arranged throughout the geographic area, each pickup terminal being located within a different sector of the geographic area;

    each pickup terminal including signal producing means for producing an interrogating signal which is different from the interrogating signal produced by the pickup terminals in contiguous sectors, and transmitter means for radiating the interrogating signal throughout the associated sector;

    a plurality of mobile units adapted to move from sector to sector throughout the geographic area;

    each mobile unit including receiver means for receiving interrogating signals from the pickup terminals in the array, detection means for selecting the interrogating signal of the pickup terminal associated with the sector in which the mobile unit is located from the interrogating signals of pickup terminals in contiguous sectors, signal producing means for producing an identifying signal containing encoded data identifying the mobile unit, and transmitter means for transmitting the identifying signal in a particular mode determined by the interrogating signal selected by said detection means when the mobile unit moves into the sector from another sector causing the detection means to select the interrogating signal from the pickup terminal associated with said sector, the particular mode of transmitting being different from the particular modes of transmitting determined by selecting of the interrogating signals radiated by pickup terminals In sectors contiguous said sector;

    each of said pickup terminals also including receiver means for receiving identifying signals transmitted in the particular mode corresponding to the interrogating signal selected by a mobile unit within the sector, and connection means for transferring identifying signals to the central office over a particular path which identifies the pickup terminal; and

    said central office including a memory, and control means coupled to said connection means for storing in the memory data on the mobile unit identified by a received identifying signal in association with the pickup terminal identified by the particular path over which the identifying signal is received.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×