US 6,687,371 B1 · Maintaining an off-hook condition during a call bridge

Abstract

A line powered codec which adaptively allows operation with power supplied from a telephone line in many countries as conditions warrant. A startup procedure uses country-specific register settings, which are powered and maintained from a low voltage side other than the telephone line. Thus, during low line power conditions a programmed state of the line powered codec can be maintained even after a power loss in the telephone line. In another aspect, a current and voltage detection module in the line powered codec is always powered from the telephone line. If sufficient power is not present, the line powered codec does not power up. In yet another aspect, a plurality of power rails may be provided.

Claims23

Dependent claims

A method of maintaining a line powered codec in an off-hook condition through a low power condition during a call bridge, comprising:

powering high current components of said line powered codec from a telephone line used for an established call;
and
powering low current components of said line powered codec from a voltage source other than said telephone line, said low current components including a register storing an on-hook/off-hook status of said line powered codec;
wherein said register retains said on-hook/off-hook status during a low power condition of said telephone line in an off-hook status insufficient to power said line powered components.

1 more element

Dependencies are inferred from the claim text.

Maintaining an off-hook condition during a call bridge

Life of this patent

Maintaining an off-hook condition during a call bridge

Life of this patent

Abstract

Claims23