SYNCHRONOUS SUPERVISORY UNIT FOR MOBILE TELEPHONE SYSTEM

• US 3,571,519 A
• Filed: 10/31/1968
• Issued: 03/16/1971
• Est. Priority Date: 10/31/1968
• Status: Expired due to Term

• Current Assignee: John J. Tsimbidis
• Original Assignee: John J. Tsimbidis
• Inventors: Tsimbidis, John J.
• Application Number:
  US04/772,098
• Time in Patent Office: 866 Days
• US Class Current: 455/554.2
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A synchronous supervisory unit for mobile telephone operation is capable of assuming any one of a plurality of states depending upon the operations to be carried out by the supervisory system. A shift from one state to another occurs when certain predetermined conditions exist. A single oscillator provides a plurality of timing pulses to synchronize the operation of the system. A separate oscillator develops a plurality of tone signals for use in the telephone system.

Claims

1. Mobile radiotelephone apparatus for communication to a particular land telephone through radio equipment at a base station including in combination, a mobile transmitter, a mobile receiver adapted to receive signals from the base station and to develop a plurality of first control signals therefrom, control means coupled to said mobile receiver and adapted to develop a second plurality of control signals, supervisory means coupled to said receiver and to said control means for controlling the operation of the mobile radio telephone apparatus, said supervisory means having a plurality of discrete operating states for establishing a communication path between the mobile radio telephone apparatus and the particular telephone, said supervisory means including first, second and third bistable circuits each having set and reset positions for providing said operating states and timing means for providing a plurality of timing signals at predetermined time intervals, said first bistable circuit being set in response to one of said first control signals so that said supervisory means switches from a first state to a second state for holding the mobile radiotelephone apparatus in condition for receiving signals from the base station, said second bistable circuit being set and said first bistable circuit being reset in response to particular ones of said first control signals and to a timing signal so that said sUpervisory means conditions the mobile radiotelephone apparatus for ringing action, said third bistable circuit being set in response to one of said second control signals so that said supervisory means applies a connect tone signal to the transmitter for transmission to the base station, and said first bistable circuit being set in response to a timing signal after transmission of said connect signal to place the supervisory unit in a state causing the mobile radio telephone apparatus to be operative for voice communication.

2. Mobile radiotelephone apparatus in accordance with claim 1 wherein said supervisory means includes decoder means operative during the second state and responsive to first control signals representing a particular address to cause the supervisory means to provide an acknowledge tone signal and applying the same to said mobile transmitter for transmission to the base station.

3. Mobile radio telephone apparatus in accordance with claim 1 wherein said control means includes a handset and hook switch means for providing said one second control signal for operating said third bistable circuit in response to removal of the handset.

4. Mobile radio telephone apparatus in accordance with claim 3 wherein said control means removes said one second control signal in response to hangup of the handset and said first and third bistable circuits are reset thereby to cause said supervisory means to apply a disconnect tone signal to said mobile transmitter.

5. Mobile telephone apparatus in accordance with claim 4 wherein said second bistable circuit is reset by a timing signal after transmission of the disconnect tone signal so that said supervisory means conditions the mobile radio telephone apparatus for a subsequent operation.

6. Mobile radio telephone apparatus in accordance with claim 1 wherein said control means includes a handset and hook switch means for providing one second control signal in response to removal of said handset, and said third bistable circuit is set by said one second control signal and operates with said first and second bistable circuits reset to apply a call tone signal to said mobile transmitter for transmission to said base station to initiate a call, and said timing means provides a timing signal to terminate the transmission of said call signal

7. The mobile radiotelephone apparatus in accordance with claim 6 wherein said supervisory means includes means operating in response to said timing signals to apply a connect tone signal to said mobile transmitter for transmission to the base station for a predetermined time following transmission of said call tone signal, and wherein said second bistable circuit is responsive to said timing signals to cause said supervisory unit to apply said call tone signal to said mobile transmitter for a further time period.

8. Mobile radio telephone apparatus in accordance with claim 7 wherein said supervisory unit includes means for applying tone signals to said mobile transmitter for transmission to the base station for identifying the particular mobile radiotelephone apparatus, and said first bistable circuit responds to a further first control signal produced by a signal received from the base station by said mobile receiver to cause operation of such means.

9. The mobile radiotelephone apparatus of claim 1 wherein said timing means includes first oscillator means for generating a series of first time signal pulses of a particular duration, and counting means coupled to said first oscillatory means for counting said first time signal pulses, said counting means having a plurality of outputs for developing a plurality of output timing pulses of different durations which are integral multiples of said particular duration, said first time signal pulses and said plurality of output timing pulses forming said plurality of timing signals.

10. The mobile radio telephone apparatus of claim 9 wherein said supervisory means includes second oscillator means for developing tone signals of a fIxed frequency, and a plurality of divider circuit means coupled to said second oscillator means, each of said divider circuit means being operative to divide said tone signals in frequency to develop a plurality of tone signals for transmission by said mobile transmitter.