Method and apparatus for quick modem reconnect

• US 7,027,573 B2
• Filed: 07/02/2003
• Issued: 04/11/2006
• Est. Priority Date: 04/12/1999
• Status: Expired due to Fees

• Current Assignee: Silicon Laboratories Incorporated
• Original Assignee: Silicon Laboratories Incorporated
• Inventors: Olafsson, Sverrir, Beadle, Burk
• Primary Examiner(s): CHAN, WING F
• Application Number:
  US10/614,410
• Publication Number:
  US 20040096044A1
• Time in Patent Office: 1,014 Days
• Field of Search: 379/93.01, 379/93.05, 379/93.08, 379/93.09, 379/93.31, 379/93.32, 379/93.33, 379/93.34, 379/93.35, 379/100.15, 379/215.01, 348/14.1, 370/252, 375/220, 375/222, 375/231, 375/235
• US Class Current: 379/93.32
• CPC Class Codes: H04L 25/4902 Pulse width modulation; Pulse position modulation
• CPC Class Codes: H04L 27/02 Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation H04L27/32 takes precedence
• CPC Class Codes: H04L 5/1438 Negotiation of transmission parameters prior to communication modified according to link quality H04L1/0001
• CPC Class Codes: H04L 69/24 Negotiation of communication capabilities
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04M 11/00 Telephonic communication systems specially adapted for combination with other electrical systems
• CPC Class Codes: H04M 11/06 Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
• CPC Class Codes: H04M 11/066 Telephone sets adapted for data transmision

Abstract

A quick 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 quick 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 quick initialization routine that eliminates, abbreviates, or modifies a number of procedures or protocols that are carried out in conventional modem startup processes. The general quick startup techniques may also be applied in the context of a quick reconnect procedure that can be performed in response to a temporary pausing or disconnecting of the data modem mode.

Claims

1. A method of reducing time for use by a first modem to reconnect to a second modem via a communication channel, said method comprising the steps of:

receiving a first digital impairment learning sequence from said second modem over said communication channel;

determining first one or more digital impairment attributes of said communication channel based on analyzing said first digital impairment learning sequence;

interrupting said communication channel;

terminating said interrupting;

receiving an signal point sequence from said second modem;

determining second one or more digital impairment attributes of said communication channel based on analyzing said signal point sequence; and

initializing said first modem with said one or more parameters to reconnect to said second modem if said first one or more digital impairment attributes are similar to corresponding said second one or more digital impairment attributes.

2. The method according to claim 1, wherein said signal point sequence is a modified answer tone.

3. The method according to claim 1, wherein said modified answer tone is an ANSpcm signal.

4. The method according to claim 1, further comprising:

obtaining one or more parameters for initializing said first modem for connection over said communication channel;

storing said one or more parameters at said first modem;

wherein said terminating said interrupting comprises transmitting a reconnect indication after said interrupting and wherein said signal point sequence is received from said second modem in response to said reconnect indication.

5. The method according to claim 1, further comprising storing said first one or more digital impairment attributes of said communication channel at said first modem.

6. The method according to claim 1, wherein said interrupting disconnects said first modem from said second modem.

7. The method according to claim 6, wherein said terminating includes dialing a phone number associated with said second modem.

8. The method according to claim 1, wherein said interrupting places communication between said first modem and second modem on hold.

9. The method according to claim 8, wherein said terminating is performed without dialing a phone number associated with said second modem.

10. The method according to claim 1, wherein said first one or more digital impairment attributes include first points/levels, and second one or more digital impairment attributes include second points/levels, wherein similarity is determined by comparing said first points/levels with said second points/levels.

11. The method according to claim 1, wherein said one or more of parameters comprise data associated with a signal point constellation for said first modem.

12. The method according to claim 1, wherein said one or more of parameters comprise data associated with echo canceler settings for said first modem.

13. The method according to claim 1, wherein said one or more of parameters comprise data associated with power level settings for said first modem.

14. The method according to claim 1, wherein said one or more of parameters comprise data associated with equalizer settings for said first modem.

15. The method according to claim 1, further comprising a step of receiving a reply signal prior to said receiving said ANSpcm signal, wherein said reply signal comprising a transition sequence configured to enable said first modem to determined robbed bit signaling characteristics of said communication channel.

16. A computer readable medium including computer software program executable by a processor in a first modem for implementing a method of reducing time for use by the first modem to reconnect with a second modem over a communication channel, said computer software program comprising:

code for receiving a first digital impairment learning sequence from said second modem over said communication channel;

code for determining first one or more digital impairment attributes of said communication channel based on analyzing said first digital impairment learning sequence;

code for interrupting said communication channel;

code for terminating said interrupting;

code for receiving an signal point sequence from said second modem;

code for determining second one or more digital impairment attributes of said communication channel based on analyzing said signal point sequence; and

code for initializing said first modem with said one or more parameters to reconnect to said second modem if said first one or more digital impairment attributes are similar to corresponding said second one or more digital impairment attributes.

17. The computer software program of claim 16, wherein said signal point sequence is a modified answer tone.

18. The computer software program of claim 16, wherein said modified answer tone is an ANSpcm signal.

19. The computer software program of claim 16, further comprising:

code for obtaining one or more parameters for initializing said first modem for connection over said communication channel;

code for storing said one or more parameters at said first modem;

wherein said code for terminating said interrupting comprises code for transmitting a reconnect indication after said interrupting and wherein said signal point sequence is received from said second modem in response to said reconnect indication.

20. The computer software program of claim 16, further comprising code for storing said first one or more digital impairment attributes of said communication channel at said first modem.

21. The computer software program of claim 16, wherein said code for interrupting disconnects said first modem from said second modem.

22. The computer software program of claim 21, wherein said code for terminating includes dialing a phone number associated with said second modem.

23. The computer software program of claim 16, wherein said code for interrupting places communication between said first modem and said second modem on hold.

24. The computer software program of claim 23, wherein said code for terminating is performed without dialing a phone number associated with said second modem.

25. The computer software program of claim 16, wherein said one or more parameters include a receiver parameter.

26. The computer software program of claim 16, wherein said one or more stored parameters include a parameter associated with said communication channel.