Transparent inband signaling

• US 5,267,305 A
• Filed: 07/29/1991
• Issued: 11/30/1993
• Est. Priority Date: 10/05/1987
• Status: Expired due to Fees

• Current Assignee: John Richard Prohs
• Original Assignee: Ambassador College
• Inventors: Little, Michael J., Prohs, John R., Efthyvoulos, Nick, Scheid, Michael R.
• Primary Examiner(s): Dwyer, James L.
• Assistant Examiner(s): MATAR, AHMAD
• Application Number:
  US07/737,494
• Time in Patent Office: 855 Days
• Field of Search: 379/210, 379/211, 379/212, 379/213, 379/214, 379/265, 379/266, 379/201, 379/202, 379/205, 379/283, 379/224, 379/233, 379/234
• US Class Current: 379/233
• CPC Class Codes: H04M 2201/14 Delay circuits; Timers
• CPC Class Codes: H04M 3/42 Systems providing special services or facilities to subscribers specially adapted for wireless communication networks H04W4/00
• CPC Class Codes: H04M 3/4283 Call holding circuits
• CPC Class Codes: H04M 3/5125 with remote located operators
• CPC Class Codes: H04M 3/5175 Call or contact centers supervision arrangements
• CPC Class Codes: H04M 3/523 with call distribution or queueing
• CPC Class Codes: H04M 7/00 Arrangements for interconnection between switching centres
• CPC Class Codes: H04M 7/0096 Trunk circuits
• CPC Class Codes: H04Q 1/45 using multi-frequency signalling H04Q1/46 takes precedence
• CPC Class Codes: H04Q 1/46 comprising means for distinguishing between a signalling current of predetermined frequency and a complex current containing that frequency, e.g. speech current

Abstract

A method and apparatus for transparent inband signaling during a telephone conversation provides an advantageous way of enabling a party to a telephone conversation to signal a telecommunications system to perform desired functions. A person signaling a system with a general inband signal, such as DTMF, can do so transparently, that is without the other party hearing the inband signals used. This innovation is based on detecting the inband signal, muting the inband signal to prevent the other party from hearing it, and determining which party generated it while allowing the conversation to continue substantially uninterrupted. The inband signal is delayed prior to muting for a short period of time in an alternate embodiment in order to compensate for the time delay in reliably detecting DTMF signals thus mute the inband signal more completely.

Claims

1. An apparatus for transparent inband signaling coincident with an active telephone conversation conducted by parties with at least one party having a user station capable of generating inband signals, the apparatus comprising:

means for detecting the inband signals in a signal path between the user stations,

means for determining the source direction of the inband signal responsive to detection of the inband signal;

means for selectively blocking propagation through the signal path of the inband signal; and

means for processing the inband signal responsive to the determined source direction.

2. An apparatus as defined in claim 1 wherein the means for blocking the propagation of inband signals comprises means for selectively opening the signal path carrying the inband signal, said opening means intermediate the user stations.

3. An apparatus as defined in claim 1 wherein the means for determining the source direction of the inband signals comprises means for selectively opening the signal path carrying the inband signal, said opening means intermediate one of the user stations and the detection means.

4. An apparatus as defined in claim 1 further comprising delaying means intermediate the detecting means and blocking means for delaying propagation in the signal path of the inband signal for a predetermined period.

5. An apparatus as defined in claim 1 wherein the means for processing the inband signal includes means for generating logic signals in response to the detection of inband signals.

6. An apparatus as defined in claim 5 wherein the generating means comprises a decoder receiving the inband signals, and a logic circuit receiving the decoded signal and producing signals compatible with a telecommunications system for initiating functions within the system.

7. An apparatus as defined in claim 1 wherein the inband signals are dual tone multi-frequency signals.

8. An apparatus as defined in claim 1 wherein the detecting means comprises a digital signal processors.

9. An apparatus as defined in claim 1 wherein the user stations are connected to the apparatus through a public switched network.

10. A telecommunications system interface providing for the initiation of functions in an associated telecommunications system coincident with an active telephone conversation conducted through the interface, the interface comprising:

first means for connection to a telecommunications link, the telecommunication link receiving signals from a multi-purpose telecommunications station having inband signal generation capability;

second means for connection to a telecommunications system;

a signal path interconnecting the first and second connection means;

means for detecting inband signals, said detecting means in the signal path intermediate the first and second connection means;

means for determining the source direction of the inband signals responsive to the detection means;

means for selectively blocking the propagation of the inband signals in the signal path; and

means for initiating functions in the telecommunications system responsive to the source direction of the inband signals.

11. An interface as defined in claim 10 wherein the means for blocking the propagation of inband signals comprises means for selectively opening the signal path carrying the inband signal, said opening means intermediate the first and second connection means.

12. An interface as defined in claim 10 wherein the means for determining the source direction of the inband signals comprises means for selectively opening the signal path carrying the inband signal, said opening means intermediate the first and second connection means.

13. An interface as defined in claim 10 further comprising delaying means intermediate the detecting means and blocking means for delaying propagation in the signal path of the inband signal for a predetermined period.

14. An interface as defined in claim 10 wherein the means for initiating system functions includes means for generating logic signals in response to the detection of inband signals.

15. An interface as defined in claim 14 wherein the generating means comprises a decoder receiving the inband signals, and a logic circuit receiving the decoded signal and producing signals compatible with the telecommunications system for initiating functions within the system.

16. An interface as defined in claim 10 wherein the inband signals are dual tone multi-frequency signals.

17. An interface as defined in claim 10 wherein the detecting means comprises a digital signal processor.

18. An interface as defined in claim 10 wherein the multi-purpose station is connected to the telecommunications link through a public switched network.

19. A telecommunications system providing for the initiation of system functions coincident with an active telephone conversation conducted from multi-purpose stations having inband signal generation capability, the system comprising:

a plurality of telecommunications interfaces;

means for interconnecting a first and second interface of the plurality of interfaces to establish a communications path through the system;

means for detecting inband signals during a telephone conversation in process on the communications path;

means for determining the source direction of the inband signals responsive to the detecting means;

means for blocking the propagation of the inband signals on the communications path; and

means for initiating system functions responsive to the source direction of the inband signals.

20. A system defined in claim 19 wherein the means for blocking the propagation of inband signals comprises means for selectively opening the communication path carrying the inband signal.

21. A system defined in claim 19 wherein the means for determining the source direction of the inband signals comprises means for selectively opening the communication path carrying the inband signal.

22. A system as defined in claim 19 further comprising delaying means intermediate the detecting means and the blocking means for delaying propagation in the communication path of the inband signal for a predetermined period.

23. A system as defined in claim 19 wherein the means for initiating system functions includes means for generating logic signals in response to the detection of inband signals.

24. A system as defined in claim 23 wherein the generating means comprises a decoder receiving the inband signals, and a logic circuit receiving a decoded signal from the decoder and producing signals for initiating functions within the system.

25. A system as defined in claim 19 wherein the inband signals are dual tone multi frequency signals.

26. A system as defined in claim 19 wherein the detecting means comprises a digital signal processor.

27. A system as defined in claim 19 wherein the plurality of telecommunications interfaces are connected to a public switched network.

28. A method for transparent inband signaling coincident with an active telephone conversation conducted by parties with at least one party having a user station capable of generating inband signals, the method comprising the steps of:

detecting the inband signals in a signal path between the user stations,

determining the source direction of the inband signal responsive to detection of the inband signal;

selectively blocking propagation through the signal path of the inband signal; and

processing the inband signal responsive to the determined source direction.

29. A method as defined in claim 28 wherein blocking the propagation of inband signals comprises the step of selectively opening the signal path carrying the inband signal.

30. A method as defined in claim 28 wherein the step of determining the source direction of the inband signals comprises selectively opening the signal path carrying the inband signal and determining if the inband signal is still detected.

31. A method as defined in claim 28 wherein detecting the inband signal includes the step of delaying propagation in the signal path of the inband signal for a predetermined period.

32. A method as defined in claim 28 wherein the step of processing the inband signal includes generating logic signals in response to the detection of inband signals.

33. A method as defined in claim 32 wherein the step of generating logic signals comprises the steps of decoding the inband signals and producing signals compatible with a telecommunications system for initiating functions within the system.

34. An apparatus for transparent inband signaling coincident with an active telephone conversation conducted by parties with at least one party having a user station capable of generating inband signals, the apparatus comprising:

means for detecting the inband signals in a signal path between the user stations,

means for selectively blocking propagation through the signal path of the inband signal; and

means for processing the inband signal responsive to the detected inband signals.

35. A telecommunications system interface providing for the initiation of functions in an associated telecommunications system coincident with an active telephone conversation conducted through the interface, the interface comprising:

first means for connection to a telecommunications link, the telecommunication link receiving signals from a multi-purpose telecommunications station having inband signal generation capability;

second means for connection to a telecommunications system;

a signal path interconnecting the first and second connection means;

means for detecting inband signals, said detecting means in the signal path intermediate the first and second connection means;

means for selectively blocking the propagation of the inband signals in the signal path; and

means for initiating functions in the telecommunications system responsive to the detected inband signals.

36. A telecommunications system providing for the initiation of system functions coincident with an active telephone conversation conducted from multi-purpose stations having inband signal generation capability, the system comprising:

a plurality of telecommunications interfaces;

means for interconnecting a first and second interface of the plurality of interfaces to establish a communications path through the system;

means for detecting inband signals during a telephone conversation in process on the communications path;

means for blocking the propagation of the inband signals on the communications path; and

means for initiating system functions responsive to the detected inband signals.