Method and apparatus for fast V.90 modem startup

Abstract

A fast startup procedure for a modem system utilizes known characteristics of a previously established communication channel to reduce the initialization period associated with subsequent connections over the same channel. In response to the establishment of a call, the modem devices determine whether the fast connect protocol is supported. If so, then the called modem transmits a modified answer tone to the calling modem. The calling modem analyzes the signal received in response to the modified answer tone to determine whether characteristics of the current channel are similar to stored characteristics associated with a previous connection over the same channel. If a channel “match” is found, then the modem devices carry out a fast initialization routine that eliminates, abbreviates, or modifies a number of procedures or protocols that are carried out in conventional modem startup processes.

1. A training method for use by a first modem to reduce a training time for training said first modem with a second modem, said training time including a capabilities exchange phase time, a probing phase time, an impairment learning phase time and a constellation phase time, where said first modem is capable of training with said second modem over a communication channel in accordance with the V.90 modem protocol including the V.8bis capabilities exchange phase, said training method comprising the steps of:
 receiving a call from said second modem to establish said communication channel; 
 initiating, in response to said call, a modified V.8bis capabilities exchange phase of the V.90 modem protocol, wherein said modified V.8bis capabilities exchange phase of the V.90 modem protocol is indicative of a fast connect capability; 
 receiving a fast connect capability identifier from said second modem in response to said fast connect capability; and 
 skipping at least a portion of the V.8bis capabilities exchange phase of the V.90 modem protocol to reduce said capabilities exchange phase time, said skipping step being performed in response to said receiving said fast connect capability identifier. 
 
     
     
       2. The method of  claim 1  further comprising the step of transmitting an acknowledgment in response to said fast connect capability identifier. 
     
     
       3. The method of  claim 2  further comprising the step of obtaining points for a transition sequence after said step of transmitting said acknowledgment. 
     
     
       4. The method of  claim 3  further comprising the step of transmitting said transition sequence after said step of obtaining said points. 
     
     
       5. The method of  claim 4  further comprising the step of transmitting an ANSpcm after said step of transmitting said transition sequence. 
     
     
       6. A first modem capable of reducing a training time for training with a second modem, said training time including a capabilities exchange phase time, a probing phase time, an impairment learning phase time and a constellation phase time, where said first modem is capable of training with said second modem over a communication channel in accordance with the V.90 modem protocol including the V.8bis capabilities exchange phase, said first modem comprising:
 a receiver section configured to receive a call from said second modem to establish said communication channel; 
 a transmitter section configured to transmit, in response to said call, a modified V.8bis capabilities exchange phase of the V.90 modem protocol, wherein said modified V.8bis capabilities exchange phase of the V.90 modem protocol is indicative of a fast connect capability; 
 wherein said receiver section is further configured to receive a fast connect capability identifier from said second modem in response to said fast connect capability, and wherein said transmitter section is further configured to skip at least a portion of the V.8bis capabilities exchange phase of the V.90 modem protocol to reduce said capabilities exchange phase time in response to said receiver section receiving said fast connect capability identifier. 
 
     
     
       7. The first modem of  claim 6 , wherein said transmitter section is further configured to transmit an acknowledgment in response to said fast connect capability identifier. 
     
     
       8. The first modem of  claim 7 , wherein said first modem obtains points for a transition sequence after transmitting said acknowledgment. 
     
     
       9. The first modem of  claim 8 , wherein said transmitter section is further configured to transmit said transition sequence. 
     
     
       10. The first modem of  claim 9 , wherein said transmitter section is further configured to transmit an ANSpcm after transmitting said transition sequence. 
     
     
       11. A training method for use by a first modem to reduce a training time for training said first modem with a second modem, said training method comprising the steps of:
 receiving a call from said second modem to establish a communication channel;   initiating, in response to said call, a capabilities exchange phase of the V.90 modem protocol, wherein said capabilities exchange phase of the V.90 modem protocol is indicative of a fast connect capability;   receiving a fast connect capability identifier from said second modem in response to said fast connect capability indication; and   skipping at least a portion of the capabilities exchange phase of the V.90 modem protocol to reduce said capabilities exchange phase time, said skipping step being performed in response to receiving said fast connect capability identifier.   
     
     
       12. The method of claim 11, wherein the capabilities exchange phase of the V.90 modem protocol is based on ITU Recommendation V.8. 
     
     
       13. The method of claim 11, wherein the capabilities exchange phase of the V.90 modem protocol is based on ITU Recommendation V.8bis. 
     
     
       14. The method of claim 11 further comprising the step of transmitting an acknowledgment in response to said fast connect capability identifier. 
     
     
       15. The method of claim 14 further comprising the step of obtaining points for a transition sequence after said step of transmitting said acknowledgment. 
     
     
       16. The method of claim 15 further comprising the step of transmitting said transition sequence after said step of obtaining said points. 
     
     
       17. The method of claim 16 further comprising the step of transmitting an ANSpcm after said step of transmitting said transition sequence. 
     
     
       18. A first modem capable of reducing a training time for training with a second modem, said first modem comprising:
 a receiver section configured to receive a call from said second modem to establish a communication channel;   a transmitter section configured to transmit, in response to said call, a capabilities exchange phase of the V.90 modem protocol, wherein said capabilities exchange phase of the V.90 modem protocol is indicative of a fast connect capability; and   wherein said receiver section is further configured to receive a fast connect capability identifier from said second modem in response to said fast connect capability indication, and wherein said transmitter section is further configured to skip at least a portion of the capabilities exchange phase of the V.90 modem protocol to reduce said capabilities exchange phase time in response to said receiver section receiving said fast connect capability identifier.   
     
     
       19. The first modem of claim 18, wherein the capabilities exchange phase of the V.90 modem protocol is based on ITU Recommendation V.8. 
     
     
       20. The first modem of claim 18, wherein the capabilities exchange phase of the V.90 modem protocol is based on ITU Recommendation V.8bis. 
     
     
       21. The first modem of claim 18, wherein said transmitter section is further configured to transmit an acknowledgment in response to said fast connect capability identifier. 
     
     
       22. The first modem of claim 21, wherein said first modem obtains points for a transition sequence after transmitting said acknowledgment. 
     
     
       23. The first modem of claim 22, wherein said transmitter section is further configured to transmit said transition sequence. 
     
     
       24. The first modem of claim 23, wherein said transmitter section is further configured to transmit an ANSpcm after transmitting said transition sequence. 
     
     
       25. A training method for use by a first modem to reduce a training time for training said first modem with a second modem, said training method comprising the steps of:
 initiating a call from said first modem to establish a communication channel;   receiving from said second modem a portion of a capabilities exchange phase of the V.90 modem protocol, wherein said capabilities exchange phase of the V.90 modem protocol is indicative of a fast connect capability;   sending a fast connect capability identifier to said second modem in response to said fast connect capability indication;   receiving from said second modem a fast connect capability acknowledgement; and skipping at least a portion of the capabilities exchange phase of the V.90 modem protocol to reduce said capabilities exchange phase time, said skipping step being performed in response to receiving said fast connect capability acknowledgement.   
     
     
       26. The method of claim 25, wherein the capabilities exchange phase of the V.90 modem protocol is based on ITU Recommendation V.8. 
     
     
       27. The method of claim 25, wherein the capabilities exchange phase of the V.90 modem protocol is based on ITU Recommendation V.8bis. 
     
     
       28. The method of claim 25 further comprising the step of receiving a transition sequence. 
     
     
       29. The method of claim 28 further comprising the step of receiving an ANSpcm after said step of receiving said transition sequence. 
     
     
       30. A first modem capable of reducing a training time for training with a second modem, said first modem comprising:
 a transmitter section configured to initiate a call from said first modem to establish a communication channel;   a receiver section configured to receive, in response to said call, a capabilities exchange phase of the V.90 modem protocol, wherein said capabilities exchange phase of the V.90 modem protocol is indicative of a fast connect capability; and   wherein said transmitter section is further configured to transmit a fast connect capability identifier from said first modem in response to said fast connect capability indication, and wherein said receiver section is further configured to receive a fast connect capability acknowledgement and to skip at least a portion of the capabilities exchange phase of the V.90 modem protocol to reduce said capabilities exchange phase time in response to said receiver section receiving said fast connect capability acknowledgement.   
     
     
       31. The first modem of claim 30, wherein the capabilities exchange phase of the V.90 modem protocol is based on ITU Recommendation V.8. 
     
     
       32. The first modem of claim 30, wherein the capabilities exchange phase of the V.90 modem protocol is based on ITU Recommendation V.8bis. 
     
     
       33. The first modem of claim 30, wherein said receiver section is further configured to receive a transition sequence. 
     
     
       34. The first modem of claim 33, wherein said receiver section is further configured to receive an ANSpcm after receiving said transition sequence.