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Malfunction detection system for a mobile radio telephone system

  • US 4,415,770 A
  • Filed: 04/13/1982
  • Issued: 11/15/1983
  • Est. Priority Date: 04/24/1981
  • Status: Expired due to Term
First Claim
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1. In a mobile radio telephone system of the type having mobile subscriber stations;

  • mobile base stations, each mobile base station having a plurality of speech channel transmitter/receivers to transmit and receive signals respectively through a plurality of speech channels and an access channel transmitter/receiver to control calls from said mobile subscriber stations through an access chanell; and

    a mobile control center capable of enabling communication between said mobile subscriber stations and of connecting a telephone exchange network to said mobile subscriber stations by way of said mobile base stations, the improvement comprising;

    detecting means connected to the output of said access channel receiver for detecting both a calling signal originated from said mobile subscriber stations and a test calling signal to provide a detection output;

    test transmitter means responsive to a first control signal for transmitting said test calling signal to said access channel receiver through said access channel;

    center controller means responsive to said test calling signal received by said access channel receiver for transmitting a first response signal to test receiver means through said access channel transmitter, said test receiver means receiving said first response signal transmitted from said access channel transmitter; and

    controller means connected to said detecting means, test transmitter and receiver means and center controller means for generating said first control signal when said detection output is not generated within a first predetermined interval of time and supplying a first alarm signal to said center controller when the first response signal is not received within a second predetermined interval of time after the transmission of said test calling signal.

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