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.

Description

FIELD OF THE INVENTIONThe present invention relates generally to modem systems. More particularly, the present invention relates to the initialization of a V.90 modem system.BACKGROUND OF THE INVENTION56 kbps modems are now standardized in accordance with the ITU V.90 Recommendation. However, many 56 kbps modems, particularly end user modems, may only be compatible with legacy modes such as K56flex, V.34, V.FC, and V.32. Such legacy modems, and downwardly compatible V.90 modems, may have an undesirably long connect or initialization time between dial-up and full rate data mode. The startup time can be up to 30 seconds, which can be rather annoying and unattractive from the perspective of the end user, especially in light of other data communication protocols that appear to operate in an “always connected” manner.V.90 modems that support legacy modem protocols typically perform the functions shown in Table 1 during initialization. The time periods associated with the operations set f...

AI Technical Summary

Benefits of technology

The present invention provides techniques to shorten the startup time associated with a data communication system that employs a modem. The fast startup technique leverages the known channel characteristics of a previous connection to reduce the initialization period associated with subsequent attempts to establish the same connection. In accordance with one illustrative embodiment, the techniques of the present invention are utilized to reduce the connection time for a communication session that follows an upper layer protocol, e.g., PPP. Although not limited to any specific modem application, the fast startup procedure may be used to eliminate portions of the initialization protocols or processes normally employed by a V.90 modem, e.g., V.8bis, V.8, digital impairment learning, initial training, probing and ranging, or the like. In addition, the fast startup technique may perform certain operations at a different time or in a different order in comparison to a conventional modem startup technique.

The above and other aspects of the present invention may be carried out in one form by a method for reducing startup latency associated with a data transmission system having a first device configured to communicate with a second device over a communication channel. The illustrative method involves the establishment of a call between the first device and the second device, followed by a determination of whether a characteristic of the present communication channel is similar to a corresponding characteristic associated with a previously established communication channel. If the characteristic of the present channel is similar to the characteristic of the previous channel, then the first device and / or the second device is initialized in response to a number of stored parameters associated with the previous channel.

Problems solved by technology

Such legacy modems, and downwardly compatible V.90 modems, may have an undesirably long connect or initialization time between dial-up and full rate data mode.

The startup time can be up to 30 seconds, which can be rather annoying and unattractive from the perspective of the end user, especially in light of other data communication protocols that appear to operate in an “always connected” manner.

However, many channels can only support legacy modes such as V.34.

The long initialization period associated with V.90 modems that fall back into legacy modes may be annoying and undesirable in many applications and can be a serious hindrance where a user would like to establish an immediate connection after an unanticipated disconnect.

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