Method and apparatus for quick modem reconnect

• US 20060159244A1
• Filed: 02/09/2006
• Published: 07/20/2006
• Est. Priority Date: 04/12/1999
• Status: Active Grant

• Current Assignee: Silicon Laboratories Incorporated
• Original Assignee: Silicon Laboratories Incorporated
• Inventors: Beadle, Burk, Olafsson, Sverrir
• Granted Patent: US 7,305,072 B2
• Time in Patent Office: Days
• US Class Current: 379/93.320
• 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

1-30. -30. (canceled)

31. 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 reconnect indication by the second modem in response to a reconnect indication;

transmitting a transition sequence to the first modem;

transmitting a signal point sequence to the first modem;

acknowledging the first modem received the signal point sequence; and

transmitting data at full data rate.

32. The method of claim 31, further comprising determining whether the signal point sequence has been received by the first modem prior to the acknowledgement by the first modem.

33. The method of claim 32, further comprising obtaining characteristics and parameters associated with channel connections prior to temporary hold of modem connection.

34. The method of claim 31, wherein a data access arrangement (DAA) associated with the first modem generates a reconnect signal in respond to a change in line current related to on-hook status of telephone set.

35. The method of claim 31, wherein the transition sequence is a QTS signal.

36. The method of claim 35, wherein the signal point sequence is a modified answer tone.

37. The method of claim 36, wherein the signal point sequence is an ANSpcm signal.

38. 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 request to terminate a temporary pause in a modem communication session;

receiving a reconnect indication by the second modem;

transmitting a transition sequence to the first modem;

transmitting a signal point sequence to the first modem;

determining whether the signal point sequence has been received by the first modem;

acknowledging the first modem received the signal point sequence;

obtaining characteristics and parameters associated with channel connections prior to temporary hold of modem connection; and

transmitting data at full data rate.

39. The method of claim 38, wherein a data access arrangement (DAA) associated with the first modem generates a reconnect signal in respond to a change in line current related to on-hook status of telephone set.

40. The method of claim 38, wherein the transition sequence is a QTS signal.

41. The method of claim 40, wherein the signal point sequence is a modified answer tone.

42. The method of claim 41, wherein the signal point sequence is an ANSpcm signal.

43. 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:

establishing a call between the first modem and the second modem;

placing the second modem in an off hook state;

initializing a capabilities exchange protocol;

transmitting by a first modem a quick connect identifier to the second modem;

transmitting a quick connect acknowledgement by the second modem;

obtaining by the second modem signal points for use in a transition sequence;

transmitting by the second modem a transition sequence;

transmitting by the second modem a specific signal point sequence;

obtaining by the first modem a received sequence that is related to the signal point sequence;

determining whether a characteristic of a current channel is similar to a corresponding characteristic of a previously established channel;

triggering by the second modem a quick startup routine;

issuing a connect message to host software;

transmitting authentication data over the communication channel by the first and second modems;

exchanging constellation parameters and modulation parameters; and

transmitting data at full data rate.

44. The method of claim 43, further comprising the step of comparing by the first modem a number of attributes of a previously received sequence associated with a previously received sequence associated with a previously established communication channel.

45. The method of claim 44, further comprising the step of obtaining by the first modem a number of attributes or characteristics of a previously established connection to a current channel.

46. The method of claim 45, further comprising the step of saving by the first modem the obtained number of attributes or characteristics of a previously established connection to a current channel.

47. The method of claim 46, further comprising the step of conducting an error correction protocol by the modem system.

48. The method of claim 47, further comprising the step of conducting a data compression protocol by the modem system.

49. The method of claim 43, wherein the capabilities exchange protocol comprises:

transmitting a capabilities request signal (CRe′

); and

informing by said CRe′

signal the first modem that the second modem supports a quick connect procedure.

50. The method of claim 49, wherein the transmission of the quick connect identifier is prompted in response to detection of the CRe′

signal by the first modem.

51. The method of claim 50, wherein the quick connect signal conveys a signal point identifier that identifies signal points for use by the second modem in a transition sequence, said signal points make apparent digital impairments present in the communication channel.

52. The method of claim 51, wherein the transition sequence includes positive and negative values of the signal points.

53. The method of claim 52, wherein the transition sequence is a QTS signal.

54. The method of claim 53, wherein the signal point sequence is an ANSpcm signal.

55. The method of claim 54, wherein a current digital impairment channel profile is validated with a stored digital impairment channel profile.

56. The method of claim 55, wherein the authentication data transmission is a CHAP/PAP data transmission.

57. 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:

dialing by the first modem a telephone number associated with the second modem;

placing the second modem in an off hook state;

initializing capabilities exchange protocol;

transmitting by a first modem a quick connect identifier to the second modem;

transmitting a quick connect acknowledgement by the second modem if the second modem supports a quick connect methodology;

obtaining by the second modem signal points for use in a transition sequence;

transmitting by the second modem a transition sequence;

transmitting by the second modem a specific signal point sequence;

obtaining by the first modem a received sequence that is related to the signal point sequence;

comparing by the first modem a number of attributes of a previously received sequence associated with a previously established communication channel;

determining whether a characteristic of a current channel is similar to a corresponding characteristic of a previously established channel;

obtaining and saving by the first modem a number of attributes or characteristics of a previously established connection to a current channel;

triggering by the second modem a quick startup routine;

conducting error correction and data compression protocols by the modem system;

issuing a connect message to host software;

transmitting authentication data over the communication channel by the first and second modems;

exchanging constellation parameters and modulation parameters; and

transmitting data at full data rate.

58. The method of claim 57, wherein the capabilities exchange protocol comprises:

transmitting a capabilities request signal (CRe′

); and

informing by said CRe′

signal the first modem that the second modem supports a quick connect procedure.

59. The method of claim 58, wherein the transmission of the quick connect identifier is prompted in response to detection of the CRe′

signal by the first modem.

60. The method of claim 59, wherein the quick connect signal conveys a signal point identifier that identifies signal points for use by the second modem in a transition sequence, said signal points make apparent digital impairments present in the communication channel.

61. The method of claim 60, wherein the transition sequence includes positive and negative values of the signal points.

62. The method of claim 61, wherein the transition sequence is a QTS signal.

63. The method of claim 62, wherein the signal point sequence is an ANSpcm signal.

64. The method of claim 63, wherein a current digital impairment channel profile is validated with a stored digital impairment channel profile.

65. The method of claim 64, wherein the authentication data transmission is a CHAP/PAP data transmission.