Method and apparatus for battery switching during ringing

Abstract

A method for providing a ringing signal includes providing a plurality of batteries coupled to a subscriber line interface circuit operable to generate the ringing signal during a ringing cycle and switching selected batteries during the ringing cycle based on values of the ringing signal during the ringing cycle. A line card includes a subscriber line audio-processing circuit operable to generate values for a ringing signal during a ringing cycle, a subscriber line interface circuit coupled to the subscriber line audio-processing circuit and operable to drive the ringing signal on a subscriber line based on the generated values, a plurality of batteries coupled to a subscriber line interface circuit and a control unit operable to switch selected batteries during the ringing cycle based on the generated values of the ringing signal.

Dependencies are inferred from the claim text.