Method and system for dynamic call type detection for circuit and packet switched networks

• US 7,684,383 B1
• Filed: 01/30/2003
• Issued: 03/23/2010
• Est. Priority Date: 01/30/2002
• Status: Active Grant

• Current Assignee: Valtrus Innovations Limited (f/k/a Dolya Holdco 9 Limited) (Key Patent Innovations Limited), Vendavo, Inc.
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Patel, Tejal S., Nicholas, Michael G., Thompson, Leland Otis
• Primary Examiner(s): Gauthier, Gerald
• Application Number:
  US10/356,704
• Time in Patent Office: 2,609 Days
• Field of Search: 370352-357, 370/401, 370/402, 379/93.26, 379/93.09, 379/74, 379/84, 379/242, 375/319, 455/401, 709/227
• US Class Current: 370/352
• CPC Class Codes: H04M 2201/52 Telephonic communication in combination with fax communication
• CPC Class Codes: H04M 7/1295 Details of dual tone multiple frequency signalling

Abstract

A method and system for dynamic call type detection for circuit and packet-switched networks. A network endpoint, such as a gateway, will receive an incoming signal and make an examination of the signal to detect characteristics of the signal. Upon detection of a characteristic of the signal, the gateway will generate a data packet, identifying the characteristic, and send the packet to a receiving network endpoint. The initial gateway will continue to examine the incoming signal and continue to send packets identifying characteristics of the signal as more characteristics are detected. The receiving gateway may then begin reproducing the signal in part by generating a signal that has the characteristics as indicated by the data packets. Once the initial gateway no longer receives the incoming signal, and determines that an event has occurred, the gateway will send a packet to the receiving gateway to inform it of the event.

Claims

1. A method of communicating signals between a first and a second communication network endpoint through a communication network, the method comprising:

receiving an incoming signal at the first communication network endpoint;

examining the incoming signal to detect at least one partial characteristic of the incoming signal, the at least one partial characteristic being insufficient to fully define the incoming signal according to predefined signal types;

upon detection of the at least one partial characteristic of the incoming signal, generating and transmitting to the second communication network endpoint a message that identifies the at least one partial characteristic of the incoming signal; and

further examining the incoming signal to detect additional partial characteristics.

2. The method of claim 1, wherein receiving the incoming signal comprises receiving a signal selected from the group consisting of a fax signal and a modem signal.

3. The method of claim 2, wherein receiving the fax signal comprises receiving a given signal selected from the group consisting of a calling tone (CNG) signal, an answer tone (CED) signal, and a high level data link (HDLC) flag signal.

4. The method of claim 2, wherein receiving the modem signal comprises receiving a given signal selected from the group consisting of an answer signal (ANS), an answer signal with a phase reversal ( ANS), an answer signal with amplitude modulation (ANSam), and an answer signal with amplitude modulation and a phase reversal ( ANSam).

5. The method of claim 4, wherein examining the incoming signal comprises detecting characteristics selected from the group consisting of a 2100 Hz tone, a 180 degree phase reversal, and a 15 Hz amplitude modulation.

6. The method of claim 1, wherein examining the incoming signal comprises examining the incoming signal over a given time frame interval that is less than a minimum time duration required to unambiguously define the incoming signal.

7. The method of claim 1, wherein examining the incoming signal comprises detecting characteristics selected from the group consisting of a frequency of the incoming signal, a phase change of the incoming signal, and a modulation frequency of the incoming signal.

8. The method of claim 1, wherein upon detection of an additional partial characteristic of the signal, the method further comprises generating a second message identifying the at least one partial characteristic and the additional partial characteristic of the incoming signal.

9. The method of claim 1, wherein the first communication network endpoint is a gateway and the message is formatted according to the Internet protocol.

10. The method of claim 1, wherein transmitting to the second communication network endpoint the message comprises sending incremental information indicative of the incoming signal from the first communication network endpoint through the communication network to the second communication network endpoint.

11. The method of claim 1, wherein further examining the incoming signal to detect the additional partial characteristics comprises examining the incoming signal until a predetermined set of characteristics has been detected, such that the predetermined set of characteristics are sufficient to fully define the incoming signal according to the predefined signal types.

12. The method of claim 1, wherein the message comprises fields selected from the group consisting of a modulation field, a frequency field, an event field, a volume field, a duration field, a timestamp field, and an end packet indicator.

13. A method of communicating an event between a first and a second communication network endpoint through a communication network, the event comprising a set of predetermined characteristics, the method comprising:

receiving a signal at the first communication network endpoint;

detecting a subset of the set of predetermined characteristics within the signal;

generating a message that identifies the subset of the set of predetermined characteristics;

sending the message from the first communication network endpoint to the second communication network endpoint by way of the communication network;

determining that the signal includes the set of predetermined characteristics;

generating an event message that includes information indicative of the event, the information comprising an event identifier; and

sending the event message from the first communication network to the second communication network endpoint by way of the communication network.

14. The method of claim 13, wherein generating the event message that includes information indicative of the event further comprises generating the event message to include information identifying each characteristic of the set of predetermined characteristics.

15. The method of claim 13, wherein generating the event message comprises assigning a decimal number to correspond to the event, the decimal number being the event identifier.

16. A method of communicating a first signal between a first and a second communication network endpoint through a communication network, the first signal comprising a set of predetermined characteristics, the method comprising:

at the second communication network endpoint receiving a message from the first communication network endpoint, the message identifying a subset of the set of predetermined characteristics;

at the second communication network endpoint producing a second signal that has the subset of the set of predetermined characteristics, the second signal being different from the first signal;

at the second communication network endpoint receiving an event message from the first communication network endpoint, the event message identifying the set of predetermined characteristics and containing a signal identifier; and

at the second communication network endpoint producing a third signal that has the set of predetermined characteristics, the third signal being equivalent to the first signal.

17. The method of claim 16, wherein the subset of the set of predetermined characteristics is insufficient to fully define the first signal.

18. The method of claim 16, wherein the subset of the set of predetermined characteristics identifies at least one partial characteristic of the first signal.

19. A gateway coupled to a communication network, the gateway comprising:

a signal detector operable to receive a signal and to detect at least one partial characteristic of the signal, the at least one partial characteristic being insufficient to fully define the signal according to predefined signal types, the signal detector further operable to determine if the signal includes a set of predetermined characteristics that is indicative of an event;

a tone encoder coupled to the signal detector and operable to receive the at least one partial characteristic, to generate a first message that identifies the at least one partial characteristic of the signal, to transmit the first message on the communication network, to generate subsequent messages in response to the signal detector detecting additional partial characteristics of the signal, and to transmit the subsequent messages on the communication network, wherein the subsequent messages at least identify the at least one partial characteristic and the additional partial characteristics of the signal; and

an event encoder coupled to the signal detector and operable to generate an event message in response to the signal detector determining that the signal is indicative of the event, and to transmit the event message on the communication network.

20. The gateway of claim 19, further comprising:

a tone decoder operable to receive a given message that includes partial characteristics of a given signal and to identify the partial characteristics;

a tone generator coupled to the tone decoder and operable to receive the partial characteristics from the tone decoder and to generate a given signal that has the partial characteristics; and

an event decoder operable to receive a given event message and to determine what event has occurred.

21. The gateway of claim 19, wherein the signal detector determines that the signal is indicative of the event if the at least one partial characteristic and the additional partial characteristics of the signal comprise the set of predetermined characteristics.

22. The gateway of claim 19, wherein the signal detector continuously examines the signal to detect partial characteristics of the signal until the signal detector determines that the signal is indicative of the event.

23. A system comprising:

a communication network;

a first gateway coupled to the communication network, the first gateway operable to receive a first signal, to detect partial characteristics of the first signal, and to generate and send on the communication network a message that identifies at least one partial characteristic of the first signal, the first gateway further operable to determine if the first signal is indicative of an event and if so, to send an event message indicative of the event; and

a second gateway coupled to the communication network, the second gateway operable to receive the message from the first gateway through the communication network and to produce a second signal having the at least one partial characteristic of the first signal, the second gateway further operable to receive the event message and to determine a state of the first gateway based on the event message.

24. The system of claim 23, wherein the first gateway generates a new message in response to detecting another partial characteristic of the first signal.

25. The system of claim 24, wherein the first gateway sends the new message through the communication network to the second gateway.

26. The system of claim 23, wherein the message comprises fields selected from the group consisting of a modulation field, a frequency field, an event field, a volume field, a duration field, a timestamp field, and an end packet indicator.

27. The system of claim 23, wherein the state of the first gateway indicates a type of a call established between the first gateway and the second gateway.