Method and apparatus for communicating data over a radio transceiver with a modem

• US 5,483,576 A
• Filed: 06/01/1995
• Issued: 01/09/1996
• Est. Priority Date: 03/31/1993
• Status: Expired due to Fees

• Current Assignee: Data Race, Inc.
• Original Assignee: Data Race, Inc.
• Inventors: Staples, Leven E.
• Primary Examiner(s): Bost, Dwayne D.
• Assistant Examiner(s): Chernoff, Michael B.
• Application Number:
  US08/457,742
• Time in Patent Office: 222 Days
• Field of Search: 379/58, 379/59, 379/63, 379/98, 379/93, 379/97, 375/216, 375/222, 375/223
• US Class Current: 455/557
• CPC Class Codes: H04M 11/06 Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A modem normally adapted for use on the PSTN communicates with a radio transceiver, typically a cellular telephone via an interface. The interface is coupled to the modem to communicate audible frequency computer data, control signals and status signals. The interface converts the audio-frequency control signals from the modem into binary signals for the radio transceiver and converts status signals from the radio transceiver to audible-frequency control signals detectable by the modem.

Claims

1. An interface between a modem capable of sending and detecting audio frequency tone bursts and a radio transceiver for communication of computer data and control of said radio transceiver, comprising:

circuitry for transferring the computer data between said modem and said radio transceiver, said computer data being in the form of modulated audio signals produced by said modem and by a remote modem;

circuitry, coupled to said transferring circuitry, for converting audio-frequency tone bursts sent by said modem into corresponding sequences of binary high and low logic states for controlling the radio transceiver; and

circuitry, coupled to said transferring circuitry, for converting binary high and low logic states representing status information sent by the radio transceiver into corresponding audio frequency tone bursts which are detectable by the modem.

2. The interface of claim 1 wherein said circuitry for converting said high and low logic states comprises:

circuitry for integrating the audio-frequency tone bursts; and

circuitry, coupled to said integrating circuitry, for comparing the integrated audio-frequency tone bursts to a signal of predetermined value to determine high and low logic levels represented by integrated audio-frequency signal.

3. The interface of claim 1 wherein said circuitry for transferring computer data comprises circuitry for transferring computer data to and from said modem over a single pair of wires.

4. The interface of claim 1 wherein said circuitry for transferring computer data comprises circuitry for transferring computer data to and from said modem using separate lines for data transferred from the radio transceiver to the modem and for data transferred from the modem to the radio transceiver.

5. The interface of claim 1 and further comprising control circuitry for assembling said sequences of binary high and low logic states from the converting circuitry/into a binary control word.

6. The interface of claim 5 wherein said control circuitry detects the presence of predetermined values of said binary control word and sets state information responsive thereto.

7. The interface of claim 6 wherein said control circuitry further selectively transfers the binary control word to the radio transceiver responsive to said state information.

9. The interface of claim 1 wherein said circuitry for converting audio-frequency tone bursts comprises circuitry for converting continuous wave keying of audio-frequency alternating current signals to binary high and low logic states.

10. The interface of claim 1 wherein said circuitry for converting audio-frequency tone bursts comprises circuitry for converting frequency-shift-keying of audio-frequency alternating current signals to binary high and low logic states.

11. The interface of claim 1 wherein said circuitry for converting audio-frequency tone bursts comprises circuitry for converting discrete tone frequencies representing individual control words into binary high and low logic states.

12. The interface of claim 1 wherein said circuitry for converting audio-frequency tone bursts comprises circuitry for converting dual tone multi-frequency signals representing individual control words into binary high and low logic states.

13. The interface of claim 1 wherein said circuitry for converting binary high and low logic states comprises circuitry for converting binary high and low logic states to continuous wave keying of audio-frequency alternating current signals.

14. The interface of claim 1 wherein said circuitry for converting binary high and low logic states comprises circuitry for converting binary high and low logic states to frequency-shift-keying of audio-frequency alternating current signals.

15. The interface of claim 1 wherein said circuitry for converting binary high and low logic states comprises circuitry for converting binary high and low logic states to discrete tone frequencies representing individual status words.

16. The interface of claim 1 wherein said circuitry for converting binary high and low logic states comprises circuitry for converting binary high and low logic states to dual tone multi-frequency signals representing individual status words.

8. The interface of claim wherein said control circuitry selectively transfers the status information from the radio transceiver to the modem responsive to said state information.

17. A system for communication of data by a computer via a radio transceiver, comprising:

a microprocessor-based modem which is capable of sending and detecting discrete audio frequency tone bursts representing control and status information as well as modulating and demodulating computer data;

an interface coupled to said modem and said radio transceiver to communicate audio-frequency signals representing both computer data and control signals, said interface comprising;

circuitry for converting audio-frequency tone bursts sent by said modem into corresponding sequences of binary high and low logic states for controlling the radio transceiver; and

circuitry for converting sequences of binary high and low logic states representing status information sent by the radio transceiver into corresponding audio frequency tone bursts which are detectable by the modem.

18. The system of claim 17 wherein said interface further comprises:

circuitry for integrating the audio-frequency tone bursts; and

circuitry, coupled to said integrating circuitry, for separating computer data signals from control signals and outputting said control signals to said radio transceiver.

19. The system of claim 18 wherein said interface further comprises circuitry for combining said audio-frequency status signals with said computer data signals.

20. The system of claim 17 wherein said interface communicates with said modem using separate lines for signals sent to the modem and signals received from the modem.

21. The system of claim 17 wherein said modem has a port including a pair of wires for connection to the Public Switched Telephone Network.

22. The system of claim 21 wherein said interface is coupled to said port for connection to the Public Switched Telephone Network.

23. The system of claim 22 wherein said pair of wires for coupling the modem to the interface is coupled to said pair of wires for connection of the modem to the Public Switched Telephone System.

24. The system of claim 21 wherein said interface is coupled to a second port not used for connection to the Public Switched Telephone Network.

25. The system of claim 17 wherein said circuitry for converting audio frequency tone bursts comprises circuitry for converting continuous wave keying of audio frequency signals to binary high and low signal states.

26. The system of claim 17 wherein said circuitry for converting audio frequency tone bursts comprises circuitry for converting frequency-shift-keying of audio frequency signals to binary high and low signal states.

27. The system of claim 17 wherein said circuitry for converting audio frequency tone bursts comprises circuitry for converting discrete frequencies of audio frequency signals to binary high and low signal states.

28. The system of claim 17 wherein said circuitry for converting audio frequency tone bursts comprises circuitry for converting dual tone multi-frequency signals to binary high and low signal states.

29. A method of communicating data from a computer via a radio transceiver, comprising the steps of:

receiving audio-frequency computer data and control signals from a modem capable of sending and detecting a sequence of audio frequency tone bursts into an interface;

translating each audio-frequency tone bursts of a sequence representing a control signal into a corresponding binary high or low logic state and outputting the binary high or low logic states to the radio transceiver;

transmitting the audio-frequency computer data to the radio transceiver;

receiving high and low logic states representing status signals from the radio transceiver into the interface; and

translating the high and low logic states to respective audio-frequency tone bursts and outputting the audio frequency tone bursts to the modem.

30. The method of claim 29 wherein said step of translating the audio-frequency tone bursts comprises the step of integrating a signal transmitted by the modem and comparing the integrated signal to a predetermined signal.

31. The method of claim 29 and further comprising the step of separating signals output by the modem from signals being sent to the modem.

32. The method of claim 29 and further comprising the step of accumulating the corresponding high and low logic states to form control words.

33. The method of claim 32 and further comprising the step of detecting predetermined control words and setting state information responsive to a detection of said predetermined control words.

34. An interface between a modem capable of sending and detecting audio frequency tone bursts and a radio transceiver for communication of computer data, comprising:

circuitry for transferring the computer data to and from said modem over a single bus for communicating audio frequency signals;

circuitry, coupled to said transferring circuitry, for converting audio-frequency tone bursts representing control information received from the modem on said single bus, each tone burst corresponding to a logical high or low state, into binary into logical high or low logic signals;

circuitry, coupled to said transferring circuitry, for converting binary status signals from the radio transceiver into corresponding audio-frequency tone bursts detectable by the modem; and

circuitry for transferring said corresponding audio-frequency tone bursts to said modem over said single bus.