Abstract: An anomaly detection system comprises an echo canceler and anomaly detection logic. The echo canceler has a plurality of taps respectively associated with a plurality of tap coefficients. The anomaly detection logic is configured to determine a difference between a new tap coefficient associated with one of the taps and a previous tap coefficient associated with the one tap. The anomaly detection logic is configured to perform a comparison between the difference and a threshold and to detect an anomaly along a telecommunication line based on the comparison.

Abstract: An anomaly detection system comprises an echo canceler and anomaly detection logic. The echo canceler has a plurality of taps respectively associated with a plurality of tap coefficients. The anomaly detection logic is configured to determine a difference between a new tap coefficient associated with one of the taps and a previous tap coefficient associated with the one tap. The anomaly detection logic is configured to perform a comparison between the difference and a threshold and to detect an anomaly along a telecommunication line based on the comparison.

Abstract: An anomaly detection system comprises an echo canceler and anomaly detection logic. The echo canceler has a plurality of taps respectively associated with a plurality of tap coefficients. The anomaly detection logic is configured to determine a difference between a new tap coefficient associated with one of the taps and a previous tap coefficient associated with the one tap. The anomaly detection logic is configured to perform a comparison between the difference and a threshold and to detect an anomaly along a telecommunication line based on the comparison.

Abstract: An anomaly detection system comprises an echo canceler and anomaly detection logic. The echo canceler has a plurality of taps respectively associated with a plurality of tap coefficients. The anomaly detection logic is configured to determine a difference between a new tap coefficient associated with one of the taps and a previous tap coefficient associated with the one tap. The anomaly detection logic is configured to perform a comparison between the difference and a threshold and to detect an anomaly along a telecommunication line based on the comparison.

Abstract: An anomaly detection system comprises an echo canceler and anomaly detection logic. The echo canceler has a plurality of taps respectively associated with a plurality of tap coefficients. The anomaly detection logic is configured to determine a difference between a new tap coefficient associated with one of the taps and a previous tap coefficient associated with the one tap. The anomaly detection logic is configured to perform a comparison between the difference and a threshold and to detect an anomaly along a telecommunication line based on the comparison.

Abstract: An apparatus and method are provided for a data communications device, such as a modem (100, 101) or facsimile machine, to detect and discriminate various amplitude modulated signals, such as an ANS signal of the ITU V.25 protocol and an ANSam signal of the ITU V.8 protocol, which may be subject to impulse distortions (FIG. 5B). The apparatus and method embodiments band pass filter (204) an incoming signal at a first frequency, and dynamically limit (208) any impulse distortions of the incoming signal to a limit threshold (211). The limit thresholds may be dynamically determined by rectifying (209) and low pass filtering (210) the band pass filtered signal to determine a low frequency average magnitude level of the incoming signal, with the limit thresholds set as a predetermined variance from this low frequency average magnitude level.

Abstract: An apparatus and method for a data communications device, such as a modem (100, 101), to determine a symbol rate and carrier frequency combination, from a received probe signal, for optimizing a bit rate for data transmission and reception. The various embodiments utilizing a processor (108) or a digital signal processor (106) receive a probe signal, which also typically contains noise and other distortions. The various method and apparatus embodiments then determine signal to distortion ratios for a plurality of symbol rate and carrier frequency combinations (820), and other optimization parameters, such as channel characteristics and attenuation distortion parameters (830). These optimization parameters are then utilized to determine an optimal symbol rate and carrier frequency (840).

Abstract: An apparatus and method are provided for a data communications device (100), such as a modem, to detect the loss of a telecommunications channel connection, in the absence of other notification signals. The apparatus and method embodiments of the invention utilize a near end echo in full duplex transmission, and compare (630) periodically sampled transmit data (610), preferably composed of an n-bit sequence, with sampled values of received data (620), to determine the occurrence of a match between the data received and the data transmitted (640). If a predetermined number of consecutive matches have occurred (670), then a loss of a telecommunications channel connection has occurred and is detected (680). Preferrably, the apparatus is embodied in a processor (108) or a processor (107) coupled with a digital signal processor (106), which are within the data communications device (100).

Abstract: An apparatus and method for a data communications device such as a modem (100) to generate initial coefficient values for an equalizer (440) from a transmitted training signal received via a channel, in which the transmitted training signal has predetermined characteristics. The apparatus and method embodiments of the invention determine a finite impulse response characteristic of the inverse frequency response of the channel based on a received training signal and the transmitted training signal (610). In the various embodiments, an energy index, a magnitude index, and an offset index are generated and combined with an equalizer length index to select a sequence of initial coefficient values for the equalizer (630, 640, 650).