Patent ID: 8520835

Claim:
An apparatus comprising: a network interface device (NID) located outside a residence; and a power supply unit located inside the residence, the power supply unit having an electrical isolation component and one or more ports that couple via one wire of a first phone line and one wire of a second phone line to the NID to provide isolated direct current (DC) power to the NID, each of the first phone line and the second phone line provide a voice service to the residence while simultaneously providing a power circuit for supplying power to the NID; wherein the power supply unit comprises: a first converter to receive AC voltage and to convert that voltage to a ground referenced DC voltage, where the first converter couples to a controller and a battery charger; the battery charger couples to a battery that couples to the controller; and a second converter couples to the controller, wherein the second converter receives the ground referenced DC voltage and converts that voltage to the supplied isolated DC voltage.