MOBILE RADIO EXTENSION INTERFACE FOR CONVERTING CONVENTIONAL TRANSMIT/RECEIVE TO A REPEATER

• US 3,745,462 A
• Filed: 01/20/1972
• Issued: 07/10/1973
• Est. Priority Date: 01/20/1972
• Status: Expired due to Term

• Current Assignee: Melvin Earl Trimble
• Original Assignee: Melvin Earl Trimble
• Inventors: Trimble, Melvin Earl
• Primary Examiner(s): Mayer, Albert J.
• Application Number:
  US05/219,247
• Time in Patent Office: 537 Days
• Field of Search: 325/2-8,16-18,21,22,53,55,57,64
• US Class Current: 455/11.1
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A unit connectable to a conventional transmitter and receiver to convert them for use as a repeater or transponder with provision for automatically inhibiting multiple transmissions by units within range of one another. The unit is particularly useful for using a mobile transceiver as a repeater to form communications links in both directions between a base station and a hand held portable unit in the proximity of the mobile transceiver.

Claims

1. Apparatus connectable to a first transmitter and a first receiver for converting said first transmitter and first receiver for use as a repeater in response to a signal from a station attempting to seize the repeater comprising second receiver means for receiving a signal on a frequency different from the receiving frequency of said first receiver, interfacing means responsive to a control signal for interfacing said first transmitter and said second receiver means and for energizing said first transmitter, first detector means connected to said first receiver for providing a first signal when a signal is received by said first receiver, first transmitter keying means connected to said second receiver means for providing a first transmitter keying signal in response to said signal from a station attempting to seize the repeater received by said second receiver, means for generating a signal occurring a random time after said first transmitter keying signal, and control signal generating means connected to said first detector means, said first transmitter keying means, said delay signal means and said interfacing means for continuously applying a control signal to said interfacing means during the presence of said first transmitter keying signal subsequent to the coincidence in said control signal generator means of said first transmitter keying signal and said delay signal in the absence of said first signal whereby signals received by said second receiver means are repeated by said first transmitter.

2. Apparatus according to claim 1 wherein said first transmitter requesting means comprises second detector means connected to said second receiver means for generating said first transmitter keying signal when said second receiver is receiving said signal.

3. Apparatus according to claim 2 wherein said second detector means generates a first transmitter keying signal only when the signal received by said second receiver has a predetermined characteristic.

4. Apparatus according to claim 1 wherein said delay signal comprises a repetitively occurring clock signal.

5. Apparatus according to Claim 2 wherein said delay signal comprises a repetitively occurring clock signal.

6. Apparatus according to claim 3 wherein said delay signal comprises a repetitively occurring clock signal.

7. Apparatus according to claim 1 further comprising second transmitter means for transmitting a signal on a frequency different from the frequency of said first transmitter, further interfacing means responsive to a control signal for interfacing said first receiver and said second transmitter means and for energizing said second transmitter, and wherein said control signal generating means is also connected to said further interfacing means for continuously applying a control signal to said further interfacing means during the presence of said first signal subsequent to the coincidence in said control signal generating means of said first signal and said delay signal in the absence of said first transmitter keying signal whereby signals received by said first receiver are repeated by said second transmitter means.

8. Apparatus according to claim 7 wherein said delay signal comprises a repetitively occurring clock signal.

9. Apparatus according to claim 7 wherein said first detector means provides a first signal only when the signal received by said first receiver has a predetermined characteristic.

10. In a communication system of the type having a plurality of stations, each station including a transmitter and a receiver normally tuned to substantially the same frequency, with the receivers normally energized and the transmitters normally de-energized, and wherein the transmitters of at least two stations can be simultaneously energized to transmit in response to one or more control signals resulting in interference by the simultaneous transmission over the same frequency, apparatus for each station whereby simultaneous transmission of signals by two or more transmitters within reception range of each is inhibited comprising keying signal generating means for generating a keying signal in response to a control signal, means for generating a signal occurring a random time after said keying signal, means connected to a receiver at said one of said stations to provide a frequency-in-use signal when a signal is received by said receiver, and means receiving said delay signal, said keying signal and said frequency-in-use signal for energizing said transmitter when said keying signal and said delay signal coincide in the absence of said frequency-in-use signal.

11. The combination of claim 10 wherein delay signal is a repetitively occurring clock signal.