Apparatus and an accompanying method for use in a long-haul echo control device for detecting changes in path length and compensating the performance of an echo canceller therein

Apparatus for an echo control device for use in canceling echo occurring over a communications facility that carries multiple communication channels over a communication path that connects near and far-end locations, the apparatus comprising, for each channel:

• a corresponding one of a plurality of far-end echo cancellers, said corresponding far-end echo canceller having an associated delay register, the associated delay register imparting a given amount of delay to an input signal applied to the corresponding echo canceller and destined for transmission over said channel and the path to the far-end location;
• and
• a corresponding one of a plurality of measurement circuits for measuring length of the path and adjusting, in response to the measured length, the given amount of delay provided by the associated delay register.

In apparatus for an echo control device for use in canceling echo occurring in a communication channel and over a communication path that connects near and far-end locations, the echo control device comprising a far-end echo canceller having a delay register, a method comprising the steps of:

• imparting, through the delay register, a given amount of delay to an input signal applied to the far-end echo canceller and destined for transmission over the path to the far-end location;
• and
• measuring length of the path and adjusting, in response to the measured length, the given amount of delay provided by the delay register.

In apparatus for an echo control device for use in canceling echo occurring over a communications facility that carries multiple communication channels over a communication path that connects near and far-end locations, the apparatus comprising, for each channel, a corresponding one of a plurality of far-end echo cancellers, said corresponding far-end echo canceller having an associated delay register, the method comprising the steps of:

• imparting, through the associated delay register, a given amount of delay to an input signal applied to the corresponding far-end echo canceller and destined for transmission over said channel and the path to the far-end location;
• and
• measuring length of the path and adjusting, in response to the measured length, the given amount of delay provided by the associated delay register.