Voice and data exchange over a packet based network

• US 7,423,983 B1
• Filed: 03/09/2000
• Issued: 09/09/2008
• Est. Priority Date: 09/20/1999
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Mitchell, Ross, Kwan, Kenny C., Stevenson, Shawn, Boora, Bill, LeBlanc, Wilf, Li, Henry, Enns, David M., Nicol, Jordan J., Tackin, Onur, Unger, Ken, Payton, John
• Primary Examiner(s): Moore; Ian N
• Application Number:
  US09/522,185
• Time in Patent Office: 3,106 Days
• Field of Search: 370276-296, 370/252, 370/310, 370351-353, 370370-381, 370/388, 370/395.1, 370400-403, 370/419, 370/458, 370/431, 370/463, 370/516, 370/493, 370/494, 370/356, 379/15.02, 379 8801- 8813, 379/88.14, 379/88.17, 379224-242, 379/250, 37940601-40616, 379/399.02, 704/707, 704/223
• US Class Current: 370/280
• CPC Class Codes: G10L 25/90 Pitch determination of speech signals
• 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: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 12/6418 Hybrid transport
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 2012/5671 Support of voice
• CPC Class Codes: H04L 2012/6481 Speech, voice
• CPC Class Codes: H04L 2027/0028 at passband only
• CPC Class Codes: H04L 2027/0034 using hypothesis testing
• CPC Class Codes: H04L 2027/0053 Closed loops
• CPC Class Codes: H04L 25/03044 using fractionally spaced delay lines or combinations of fractionally integrally spaced taps
• CPC Class Codes: H04L 27/0012 arrangements for identifying the type of modulation
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/11 Identifying congestion
• CPC Class Codes: H04L 47/263 Rate modification at the source after receiving feedback
• CPC Class Codes: H04L 47/28 in relation to timing considerations
• CPC Class Codes: H04L 5/1438 Negotiation of transmission parameters prior to communication modified according to link quality H04L1/0001
• 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 65/1043 : Gateway controllers, e.g. media gateway control protocol [MGCP] controllers
• CPC Class Codes: H04L 65/1069 : Session establishment or de-establishment
• CPC Class Codes: H04L 65/1101 : Session protocols
• CPC Class Codes: H04L 65/70 : Media network packetisation
• CPC Class Codes: H04L 65/80 : Responding to QoS
• CPC Class Codes: H04L 67/61 : taking into account QoS or priority requirements
• CPC Class Codes: H04L 69/329 : in the application layer [OSI layer 7]
• CPC Class Codes: H04L 7/027 : extracting the synchronising or clock signal from the received signal spectrum, e.g. by using a resonant or bandpass circuit
• CPC Class Codes: H04L 7/0278 : Band edge detection
• CPC Class Codes: H04L 9/40 : Network security protocols
• CPC Class Codes: H04M 11/062 : using different frequency bands for speech and other data
• CPC Class Codes: H04M 2201/40 : using speech recognition speech recognition per se G10L15/00
• CPC Class Codes: H04M 2201/52 : Telephonic communication in combination with fax communication
• CPC Class Codes: H04M 2203/2027 : Live party detection
• CPC Class Codes: H04M 2203/2066 : Call type detection of indication, e.g. voice or fax, mobile of fixed, PSTN or IP
• CPC Class Codes: H04M 3/002 : Applications of echo suppressors or cancellers in telephonic connections in two-way loud-speaking telephone systems H04M9/08, echo suppressors or cancellers per se H04B3/20
• CPC Class Codes: H04M 3/2209 : for lines also used for data transmission
• CPC Class Codes: H04M 3/2272 : Subscriber line supervision circuits, e.g. call detection circuits
• CPC Class Codes: H04M 7/006 : Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04M 7/0069 : comprising a residential gateway, e.g. those which provide an adapter for POTS or ISDN terminals
• CPC Class Codes: H04M 7/125 : Details of gateway equipment
• CPC Class Codes: H04Q 1/45 : using multi-frequency signalling H04Q1/46 takes precedence
• CPC Class Codes: Y02D 30/50 : in wire-line communication networks, e.g. low power modes or reduced link rate

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, comprising:

a voice exchange for exchanging voice signals between a first telephony device and a packet based network;

a full duplex data exchange for exchanging data signals from a second telephony device with demodulated data signals from the packet based network, wherein the full duplex data exchange demodulates data signals from the second telephony device, outputs the demodulated data signals to the packet based network, remodulates demodulated data signals from the packet based network, and outputs the remodulated data signals to the second telephony device;

a pitch period estimator for estimating a pitch period of a voice band signal from one or both of the first and second telephony devices, using an autocorrelation function;

signal power measurement circuitry for producing at least one measurement of power of the voiceband signal from one or both of the first and second telephony devices; and

a call discriminator for selectively enabling at least one of the voice exchange and the data exchange based at least upon a comparison of the pitch period estimate and a plurality of thresholds, and the at least one measurement of power of the voiceband signal.

2. The signal processing system of claim 1 wherein the voice exchange comprises a voice decoder for decoding packets of the voice signals from the packet based network for transmission to the first telephony device, 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.

3. The signal processing system of claim 2 wherein the voice exchange 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.

4. The signal processing system of claim 1 wherein the voice exchange comprises a voice decoder for decoding packets of the voice signals from the packet based network for transmission to the first telephony device, 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.

5. The signal processing system of claim 1 wherein the voice exchange comprises a voice encoder for encoding the voice signals from the first telephony device for transmission on the packet based network, and a voice activity detector which suppresses the voice signals without speech.

6. The signal processing system of claim 5 wherein the voice exchange further comprises a comfort noise estimator which generates comfort noise parameters when the voice activity detector suppresses the voice signals without speech.

7. The signal processing system of claim 1 wherein the voice exchange further comprises a decoder for decoding packets of the voice signals from the packet based network, and an echo canceller for canceling decoded voice signal echoes on incoming voice signals from the first telephony device.

8. The signal processing system of claim 7 wherein the voice exchange further comprises a non-linear processor which mutes the incoming voice signals when the incoming voice signals do not comprise speech and the echo canceller detects the decoded voice signals with speech.

9. The signal processing system of claim 1 wherein the voice exchange comprises a voice encoder for encoding the voice signals from the first telephony device into voice signal packets for the packet based network.

10. The signal processing system of claim 9 further comprising a tone exchange comprising a dual tone multi-frequency (DTMF) detector for detecting a DTMF signal from the first telephony device and generating a DTMF packet for the packet based network in response to the DTMF signal, the DTMF detector muting the voice signal packets when the DTMF signal is detected.

11. The signal processing system of claim 1 further comprising a fax exchange for exchanging fax signals from a third telephony device with demodulated fax signals from the packet based network, wherein the call discriminator selectively enables the fax exchange.

12. The signal processing system of claim 11 wherein the fax signals from the third telephony device are modulated by a voiceband carrier, and the fax exchange comprises a data pump for demodulating the fax signals from the third telephony device for transmission on the packet based network, and remodulating the demodulated fax signals from the packet based network with the voiceband carrier for transmission to the third telephony.

13. The signal processing system of claim 1, wherein the estimate of pitch period of the voice band signal is calculated by applying an autocorrelation function and a plurality of power measurements to the voice band signal.

14. A method of processing signals, comprising:

exchanging voice signals between a first telephony device and a packet based network;

demodulating data signals from the first telephony device for inputting to the packet based network;

remodulating demodulated data signals from the packet based network;

simultaneously exchanging demodulated data signals from a second telephony device with remodulated data signals from the packet based network;

estimating a pitch period of a voice band signal from one or both of the first and second telephony devices, using an autocorrelation function;

discriminating between voice signals and data signals based on a comparison of the estimated pitch period and a plurality of thresholds, and at least one power measurement of the voice band signal; and

invoking at least one of the voice exchange and the data exchange based on said discrimination.

15. The method of claim 14 further comprising:

exchanging fax signals from a third telephony device with demodulated fax signals from the packet based network, wherein the discriminating comprises selectively invoking the fax exchange, and wherein the fax signals from the third telephony device are modulated by a voiceband carrier, and the fax exchange comprises a data pump for demodulating the fax signals from the third telephony device for transmission on the packet based network, and remodulating the fax signals from the packet based network with the voiceband carrier for transmission to the third telephony device.

16. The method of claim 14, wherein the estimate of pitch period of the voice band signal is calculated by applying an autocorrelation function and a plurality of power measurements to the voice band signal.

17. A signal processing system, for interfacing telephony devices with packet-based networks, the system comprising:

a voice exchange for exchanging voice signals between a network line and a packet based network;

a full duplex data exchange for exchanging data signals from the network line with data signals from the packet based network, wherein the full duplex data exchange demodulates the data signals from the network line, outputs the demodulated data signals to the packet based network, remodulates demodulated data signals from the packet based network, and outputs the remodulated data signals to the network line;

wherein the data signals from the network line are modulated by a voiceband carrier, and the data exchange comprises a data pump for demodulating the data signals from the network line for transmission on the packet based network and remodulating the data signals from the packet based network with the voiceband carrier for transmission on the network line at a transmit rate; and

wherein the data exchange comprises a jitter buffer for receiving packets of the data signals of varying delay from the packet based network and compensating for the delay variation of the data signal packets by holding a number of the received data signals, and a clock synchronizer which adaptively adjusts the transmit rate of the data pump in response the number of the received data signals in the jitter buffer.

18. A signal processing system, for interfacing telephony devices with packet-based networks, the system comprising:

a voice exchange for exchanging voice signals between a network line and a packet based network;

a full duplex data exchange for exchanging data signals from the network line with data signals from the packet based network, wherein the full duplex data exchange demodulates the data signals from the network line, outputs the demodulated data signals to the packet based network, remodulates demodulated data signals from the packet based network, and outputs the remodulated data signals to the network line;

wherein the data signals from the network line are modulated by a voiceband carrier, and the data exchange comprises a data pump for demodulating the data signals from the network line for transmission on the packet based network and remodulating the data signals from the packet based network with the voiceband carrier for transmission on the network line at a transmit rate;

wherein the data exchange comprises a jitter buffer for receiving packets of the data signals of varying delay from the packet based network and compensating for the delay variation of the data signal packets by holding a number of the received data signals, and spoof logic which provides spoof data to the data pump when the number of the received data signals held in the jitter buffer is below a threshold.

19. A signal processing system, for interfacing telephony devices with packet-based networks, the system comprising:

a voice exchange for exchanging voice signals between a network line and a packet based network, wherein the voice exchange comprises a jitter buffer for receiving packets of the voice signals of varying delay from the packet based network and compensating for the delay variation of the voice signal packets, and wherein the jitter buffer comprises a voice queue which buffers the received voice signals for a holding time, and a voice synchronizer which adaptively adjusts the holding time of the voice queue;

a full duplex data exchange for exchanging data signals from the network line with data signals from the packet based network, wherein the full duplex data exchange demodulates the data signals from the network line, outputs the demodulated data signals to the packet based network, remodulates demodulated data signals from the packet based network, and outputs the remodulated data signals to the network line; and

a tone exchange for exchanging dual tone multi-frequency (DTMF) signals between the network line and the packet based network, the DTMF exchange comprising a DTMF queue for buffering packets of the DTMF signals from the packet based network, and a tone generator which generates a DTMF tone responsive to the buffered DTMF signals, the DTMF queue outputting a signal to the voice synchronizer to suppress the buffered voice signals when the DTMF signals are in the DTMF queue.

20. A signal processing system, comprising:

a voice exchange for exchanging voice signals between a first telephony device and a packet based network, wherein the voice exchange comprises a decoder for decoding packets of the voice signals from the packet based network, an echo canceller for canceling decoded voice signal echoes on incoming voice signals from the first telephony device, and a non-linear processor which mutes the incoming voice signals when the incoming voice signals do not comprise speech and the echo canceller detects the decoded voice signals with speech; and

a full duplex data exchange for exchanging data signals from a second telephony device with demodulated data signals from the packet based network, wherein the full duplex data exchange demodulates data signals from the first telephony device, outputs the demodulated data signals to the packet based network, remodulates demodulated data signals from the packet based network, and outputs the remodulated data signals to the first telephony device; and

a call discriminator for selectively enabling at least one of the voice exchange and the data exchange.

21. A signal processing system, for interfacing telephony devices with packet-based networks, the system comprising:

a voice exchange for exchanging voice signals between a network line and a packet based network;

a full duplex data exchange for exchanging data signals modulated by a voiceband carrier from the network line with data signals from the packet based network, the full duplex data exchange comprising;

a data pump for demodulating the data signals from the network line, outputting the demodulated data signals to the packet based network, remodulating the demodulated data signals from the packet based network with the voiceband carrier, and outputting the remodulated data signals to the network line at a transmit rate,

a jitter buffer for receiving packets of the data signals of varying delay from the packet based network and compensating for the delay variation of the data signal packets by holding a number of the received data signals, and

a clock synchronizer which adaptively adjusts the transmit rate of the data pump in response the number of the received data signals in the jitter buffer; and

a resource monitor that monitors processor resources during a call used by one or both of the voice exchange and the data exchange, and that dynamically enables and disables signal processing functionality used by the one or both of the voice exchange and the data exchange in the exchange of one or both of the voice and data signals of the call, to control processor computational load.

22. A signal processing system, for interfacing telephony devices with packet-based networks, the system comprising:

a voice exchange for exchanging voice signals between a network line and a packet based network;

a full duplex data exchange for exchanging data signals modulated by a voiceband carrier from the network line with data signals from the packet based network, the full duplex data exchange comprising;

a data pump for demodulating the data signals from the network line, outputting the demodulated data signals to the packet based network, remodulating the demodulated data signals from the packet based network with the voiceband carrier, and outputting the remodulated data signals to the network line at a transmit rate,

a jitter buffer for receiving packets of the data signals of varying delay from the packet based network and compensating for the delay variation of the data signal packets by holding a number of the received data signals, and

spoof logic which provides spoof data to the data pump when the number of the received data signals held in the jitter buffer is below a threshold; and

a resource monitor that monitors processor resources during a call used by one or both of the voice exchange and the data exchange, and that dynamically enables and disables signal processing functionality used by the one or both of the voice exchange and the data exchange in the exchange of one or both of the voice and data signals of the call, to control processor computational load.

23. A signal processing system, for interfacing telephony devices with packet-based networks, the system comprising:

a voice exchange for exchanging voice signals between a network line and a packet based network, wherein the voice exchange comprises a jitter buffer for receiving packets of the voice signals of varying delay from the packet based network and compensating for the delay variation of the voice signal packets, the jitter buffer comprising;

a voice queue which buffers the received voice signals for a holding time, and

a voice synchronizer which adaptively adjusts the holding time of the voice queue;

a full duplex data exchange for exchanging data signals from the network line with data signals from the packet based network, wherein the full duplex data exchange demodulates the data signals from the network line, outputs the demodulated data signals to the packet based network, remodulates demodulated data signals from the packet based network, and outputs the remodulated data signals to the network line;

a resource monitor that monitors processor resources during a call used by one or both of the voice exchange and the data exchange, and that dynamically enables and disables signal processing functionality used by the one or both of the voice exchange and the data exchange in the exchange of one or both of the voice and data signals of the call, to control processor computational load; and

a tone exchange for exchanging dual tone multi-frequency (DTMF) signals between the network line and the packet based network, the DTMF exchange comprising a DTMF queue for buffering packets of the DTMF signals from the packet based network, and a tone generator which generates a DTMF tone responsive to the buffered DTMF signals, the DTMF queue outputting a signal to the voice synchronizer to suppress the buffered voice signals when the DTMF signals are in the DTMF queue.