Voice and data exchange over a packet based network

• US 7,161,931 B1
• Filed: 03/09/2000
• Issued: 01/09/2007
• Est. Priority Date: 09/20/1999
• Status: Expired due to Term

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: LeBlanc, Wilf, Li, Henry, Tackin, Onur, Payton, John, Mitchell, Ross, Kwan, Kenny C., Stevenson, Shawn, Boora, Bill, Enns, David M., Nicol, Jordan J., Unger, Ken
• Primary Examiner(s): VINCENT, DAVID ROBERT
• Application Number:
  US09/522,184
• Time in Patent Office: 2,497 Days
• Field of Search: 370351- 4, 370/389, 370464- 6, 370473- 6, 370/498, 370276-296, 370/252, 370/310, 370400- 3, 370/419, 370/458, 370/431, 370/463, 370516-526, 370/395.1, 379/88.013, 379/88.01, 379/142.18, 379/225, 379/243, 379/399.01, 379/100.01, 379/399.02, 379/144.05, 379/142.07, 379/15.02, 379/88.13, 379/406.01
• US Class Current: 370/352
• CPC Class Codes: H04B 3/23 using a replica of transmitted signal in the time domain, e.g. echo cancellers
• CPC Class Codes: H04B 3/234 using double talk detection
• CPC Class Codes: H04J 3/0632 Synchronisation of packets and cells, e.g. transmission of voice via a packet network, circuit emulation service [CES] queuing arrangements in packet switching elements H04L49/90; synchronising systems for the synchronous transmission of a pulse code modulated video signal with one or more other pulse code modulated signals H04N7/56
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 65/1026 at the edge
• CPC Class Codes: H04L 65/103 in the network
• CPC Class Codes: H04L 65/1036 at the edge
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04M 7/125 Details of gateway equipment

Abstract

A signal processing system which discriminates between voice signals and data signals modulated by a voiceband carrier. The signal processing system includes a voice exchange, a data exchange and a call discriminator. The voice exchange is capable of exchanging voice signals between a switched circuit network and a packet based network. The signal processing system also includes a data exchange capable of exchanging data signals modulated by a voiceband carrier on the switched circuit network with unmodulated data signal packets on the packet based network. The data exchange is performed by demodulating data signals from the switched circuit network for transmission on the packet based network, and modulating data signal packets from the packet based network for transmission on the switched circuit network. The call discriminator is used to selectively enable the voice exchange and data exchange.

Claims

1. A signal processing system for processing modulated signals and voiceband signals for transmission over a packet based network, the signal processing system comprising:

means for receiving one of the modulated or voiceband signals at a respective input port;

means for detecting whether the received signal is a modulated signal or a voiceband signal by detecting presence of a predetermined tone;

a data pump for demodulating the received signal to generate a first data stream, if the received signal is a modulated signal;

a voice encoder for encoding the received signal to generate a second data stream, if the received signal is a voiceband signal;

a channel interface for outputting onto the packet based network the second data stream including the encoded voiceband signal or the first data stream including the demodulated signal, wherein the encoded information comprises voice signals;

a voice activity detector which suppresses the voice signals without speech; and

a comfort noise estimator which generates comfort noise parameters when the voice activity detector suppresses the voice signals, said comfort noise parameters being selectively outputted on the packet based network.

2. The signal processing system of claim 1 wherein the voiceband signal comprises information modulated by a voiceband carrier.

3. The signal processing system of claim 1 further comprising a jitter buffer for receiving packets of information of varying delay from the packet based network and compensating for the delay variation of the information packets.

4. The signal processing system of claim 3 wherein the jitter buffer outputs an isochronous stream of the received information.

5. The signal processing system of claim 3 wherein the jitter buffer comprises a queue which buffers the received information for a holding time, and a voice synchronizer which adaptively adjusts the holding time of the queue.

6. A signal processing system for processing modulated signals and voiceband signals for transmission over a packet based network, the signal processing system comprising:

means for receiving one of the modulated or voiceband signals at a respective input port;

means for detecting whether the received signal is a modulated signal or a voiceband signal by detecting presence of a predetermined tone;

a data pump for demodulating the received signal to generate a first data stream, if the received signal is a modulated signal;

a voice encoder for encoding the received signal to generate a second data stream, if the received signal is a voiceband signal;

a channel interface for outputting onto the packet based network the second data stream including the encoded voiceband signal or the first data stream including the demodulated signal, wherein the encoded information comprises voice signals;

a decoder for decoding packets of information from the packet based network, wherein the information packets include voice signals, the signal processing system further comprising a voice activity detector which detects the voice signals without speech, and a comfort noise generator which inserts comfort noise in place of the voice signals without speech; and

a comfort noise estimator which generates comfort noise parameters from at least a portion of the voice signals without speech, the comfort noise generator being responsive to the comfort noise parameters.

7. The signal processing system of claim 6 wherein the information packets include voice signals, the signal processing system further comprising a voice activity detector which detects lost voice signals, and a lost packet recovery engine which processes the voice signals to compensate for the lost voice signals.

8. A method of processing modulated signals and voiceband signals for transmission over a packet based network, the method comprising:

receiving one of the modulated or voiceband signals at a respective input port;

detecting whether the received signal is a modulated signal or a voiceband signal by detecting presence of a predetermined tone;

demodulating the received signal to generate a first data stream, if the received signal is a modulated signal;

encoding the received signal to generate a second data stream, if the received signal is a voiceband signal;

outputting onto the packet based network the second data stream including the encoded voiceband signal or the first data stream including the demodulated signal, wherein the encoded signal includes voice signals; and

suppressing the voice signals when the voice signals do not comprise speech,

wherein the suppression of the voice signals comprises generating comfort noise parameters in place thereof.

9. The method of claim 8 further comprising receiving information packets of varying delay from the packet based network, and compensating for the delay variation of the information packets.

10. The method of claim 9 wherein the information packet compensation comprises generating an isochronous stream of the information.

11. The method of claim 10 wherein the isochronous stream generation comprises adaptively buffering the information.

12. The method of claim 8 wherein the voiceband signal comprises information modulated by a voiceband carrier.

13. The method of claim 8 further comprising receiving packets of voice signals from the packet based network, detecting lost voice signals, decoding the received voice signals, and processing the decoded voice signals to compensate for the lost voice signals.

14. A method of processing modulated signals and voiceband signals for transmission over a packet based network, the method comprising:

receiving one of the modulated or voiceband signals at a respective input port;

detecting whether the received signal is a modulated signal or a voiceband signal by detecting presence of a predetermined tone;

demodulating the received signal to generate a first data stream, if the received signal is a modulated signal;

encoding the received signal to generate a second data stream, if the received signal is a voiceband signal;

outputting onto the packet based network the second data stream including the encoded voiceband signal or the first data stream including the demodulated signal; and

receiving packets of voice signals from the packet based network, identifying the received voice signals without speech, and inserting comfort noise in place of the identified voice signals without speech,

wherein the comfort noise insertion comprises estimating comfort noise in response to at least a portion of the received voice signals without speech.

15. A signal transmission system, comprising:

a first telephony device which outputs a voiceband signal;

a second telephony device which outputs a modulated modem data;

a packet based network; and

a signal processing system coupling the first and the second telephony devices to the packet based network, the signal processing system having means for detecting whether a received signal is the modulated signal or the voiceband signal by detecting presence of a predetermined tone, a voice encoder which encodes the voiceband signal to generate a first data stream, a data pump for demodulating the modulated modem data to generate a second data stream, a channel interface which outputs onto the packet based network the first data stream including the encoded voiceband signal or the second data stream including the demodulated modem data, and a voice activity detector which suppresses the voice signals without speech, and a comfort noise estimator which generates comfort noise parameters when the voice activity detector suppresses the voice signals, said comfort noise parameters being selectively output on the packet based network.

16. The signal processing system of claim 15 wherein the voiceband signal comprises information modulated by a voiceband carrier.

17. The signal transmission system of claim 15 further comprising a switched circuit network coupling the first and the second telephony devices to the signal processing system.

18. The signal transmission system of claim 17 wherein the switched circuit network comprises a public switching telephone network.

19. The signal transmission system of claim 15 wherein the packet based network comprises internet protocol.

20. The signal transmission system of claim 15 wherein the packet based network comprises frame relay.

21. The signal transmission system of claim 15 wherein the packet based network comprises asynchronous IP transfer mode.

22. The signal transmission system of claim 15 wherein the first telephony device comprises a telephone.

23. The signal transmission system of claim 15 wherein the second telephony device comprises a fax.

24. The signal transmission system of claim 15 wherein the second telephony device comprises a modem.

25. The signal transmission system of claim 15 wherein the signal processing system further comprises a jitter buffer for receiving packets of information of varying delay from the packet based network and compensating for the delay variation of the information packets.

26. The signal transmission system of claim 25 wherein the jitter buffer outputs an isochronous stream of the received information.

27. The signal transmission system of claim 25 wherein the jitter buffer comprises a queue which buffers the received information for a holding time, and a voice synchronizer which adaptively adjusts the holding time of the queue.

28. A signal transmission system, comprising:

a first telephony device which outputs a voiceband signal;

a second telephony device which outputs a modulated modem data;

a packet based network; and

a signal processing system coupling the first and the second telephony devices to the packet based network, the signal processing system having means for detecting whether a received signal is the modulated signal or the voiceband signal by detecting presence of a predetermined tone, a voice encoder which encodes the voiceband signal to generate a first data stream, a data pump for demodulating the modulated modem data to generate a second data stream, a channel interface which outputs onto the packet based network the first data stream including the encoded voiceband signal or the second data stream including the demodulated modem data, and a decoder for decoding packets of information from the packet based network,

wherein the information packets include voice signals, the signal processing system further comprising a voice activity detector which detects the voice signals without speech, and a comfort noise generator which inserts comfort noise in place of the voice signals without speech.

29. The signal transmission system of claim 28 wherein the signal processing system further comprises a comfort noise estimator which generates comfort noise parameters from at least a portion of the voice signals without speech, the comfort noise generator being responsive to the comfort noise parameters.

30. The signal transmission system of claim 28 wherein the information packets include voice signals, the signal processing system further comprising a voice activity detector which detects lost voice signals, and a lost packet recovery engine which processes the voice signals to compensate for the lost voice signals.