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Automatic mobile radio telephone system

  • US 3,894,194 A
  • Filed: 02/16/1973
  • Issued: 07/08/1975
  • Est. Priority Date: 02/16/1973
  • Status: Expired due to Term
First Claim
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1. A multi-channel mobile radio telephone system of the type wherein mobile stations are capable of initiating and receiving calls to and from other mobile stations and stations in a public telephone system, wherein a base station serves as a relay-link for all calls and is capable of transmitting and receiving signals via each of said channels, wherein a plurality of mobile stations are each individually tunable to respective channels for purposes of transmitting and receiving signals during calls, said system being characterized in that different channels are assigned as home channels to respective groups of mobile stations such that each mobile station can receive a call only on its assigned home channel but can initiate calls on any idle channel, said system comprising:

  • channel marker means at said base station for transmitting an idle marker signal on each channel on which no call is in progress;

    automatic tuning means at each mobile station for automatically tuning that mobile station to its home channel when that mobile station is not party to a call in progress; and

    selectively actuable call-initiating means at each mobile station for automatically seizing an idle channel upon actuation, said call-initiating means comprising;

    means for automatically scanning said channels to detect the presence of said idle marker signal;

    channel seizing means responsive to actuation of said call-initiating means for automatically tuning the mobile station to one of the channels on which said idle marker signal is detected;

    means at said base station for automatically removing said idle marker sIgnal from a channel which is seized;

    wherein each mobile station is assigned a unique identification number, and wherein each mobile station includes means responsive to seizure of a channel by that mobile station in initiating a call for automatically transmitting the identification of that channel in coded form to said base station in the seized channel;

    wherein said mobile stations constitute subscribers for the system assigned to said base station, and wherein said base station includes ticketing means for each subscriber for monitoring the time duration of calls initiated by that subscriber; and

    wherein said base station further includes;

    means responsive to reception of a coded mobile station identification on a channel seized by a calling mobile station for determining whether or not ticketing means is present at said base station for said calling mobile station; and

    means responsive to a determination that ticketing means is present at said base station for said calling mobile station for returning a dial tone signal to said calling mobile station via said seized channel.

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