Adaptive linefeed control for varying load on a subscriber loop

A method comprising:

• a. providing a subscriber loop with an initial current selected from a plurality of pre-determined currents;
• and
• b. providing the subscriber loop with another current selected from the plurality of pre-determined currents if a metallic voltage of the subscriber loop reaches a lower voltage threshold, wherein the another current is greater than the initial current, wherein the lower voltage threshold is the same for each of the plurality of pre-determined currents.

A method comprising:

• a. providing a subscriber loop with an initial current selected from a plurality of pre-determined currents;
• and
• b. providing the subscriber loop with another current selected from the plurality of pre-determined currents if a metallic voltage of the subscriber loop reaches an upper voltage threshold, wherein the another current is less than the initial current, wherein the upper voltage threshold is the same for each of the plurality of pre-determined currents.

A subscriber loop linefeed apparatus, comprising:

• a linefeed driver providing a subscriber loop with a current;
• and
• adaptive linefeed control circuitry controlling the linefeed driver to provide an initial current selected from a plurality of pre-determined currents while a subscriber loop metallic voltage is between an associated upper voltage threshold and an associated lower voltage threshold, wherein the linefeed driver is controlled to provide another current selected from the plurality of currents if the metallic voltage reaches the associated upper or lower voltage thresholds, wherein each of the plurality of currents has the same associated upper and lower voltage thresholds.