Voice and data exchange over a packet based network

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.

1 . 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;    if the received signal is a modulated signal, demodulating the received signal and outputting onto the packet based network the demodulated signal;    if the received signal is a voiceband signal, encoding the received signal and outputting onto the packet based network the encoded signal; and    generating comfort noise parameters to be selectively outputted onto the packet based network.    
   
   
       2 . The method of  claim 1  wherein the voiceband signal comprises information modulated by a voiceband carrier.  
   
   
       3 . The method of  claim 1  further comprising receiving information packets of varying delay from the packet based network, and compensating for the delay variation of the information packets.  
   
   
       4 . The method of  claim 3  wherein the information packet compensation comprises generating an isochronous stream of the information.  
   
   
       5 . The method of  claim 4  wherein the isochronous stream generation comprises adaptively buffering the information.  
   
   
       6 . The method of  claim 1  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.  
   
   
       7 . A signal processing system comprising: 
 means for receiving one of a modulated signal or a voiceband signal at a respective input port;    a data pump for demodulating the modulated signal;    a voice encoder for encoding the voiceband signal;    a channel interface for outputting onto a packet based network the encoded voiceband signal or the demodulated signal; and    a comfort noise estimator for generating comfort noise parameters being selectively outputted on the packet based network.    
   
   
       8 . The signal processing system of  claim 7  wherein the voiceband signal comprises information modulated by a voiceband carrier.  
   
   
       9 . The signal processing system of  claim 7  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.  
   
   
       10 . The signal processing system of  claim 9  wherein the jitter buffer outputs an isochronous stream of the received information.  
   
   
       11 . The signal processing system of  claim 9  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.  
   
   
       12 . A signal transmission system comprising: 
 a first telephony device for outputting a voiceband signal;    a second telephony device for outputting 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 demodulating a modulated signal, means for encoding a voiceband signal, means for outputting onto the packet based network one of the encoded voiceband signal or the demodulated signal, and means for generating comfort noise parameters.    
   
   
       13 . The signal processing system of  claim 12  wherein the voiceband signal comprises information modulated by a voiceband carrier.  
   
   
       14 . The signal transmission system of  claim 12  further comprising a switched circuit network coupling the first and the second telephony devices to the signal processing system.  
   
   
       15 . The signal transmission system of  claim 14  wherein the switched circuit network comprises a public switching telephone network.  
   
   
       16 . The signal transmission system of  claim 12  wherein the packet based network comprises internet protocol.  
   
   
       17 . The signal transmission system of  claim 12  wherein the packet based network comprises frame relay.  
   
   
       18 . The signal transmission system of  claim 12  wherein the first telephony device comprises a telephone.  
   
   
       19 . The signal transmission system of  claim 12  wherein the second telephony device comprises a fax.  
   
   
       20 . The signal transmission system of  claim 12  wherein the second telephony device comprises a modem.