Patent ID: 8185764

Claim:
A method, comprising: connecting power sourcing equipment (PSE) with a powered device (PD) through data communications cabling; negotiating an acceptable power level for the PD and a data rate for the PD; and enforcing delivery of power to the PD using only wire pairs of the data communications cabling which carry data between the PSE and the PD, wherein the data communications cabling includes a first pair of wires, a second pair of wires, a third pair of wires, and a fourth pair of wires; wherein enforcing delivery of power to the PD using only the wire pairs of the data communications cabling which carry data between the PSE and the PD includes: delivering power to the PD using the first, second, third, and fourth pairs of wires when each of the first, second, third, and fourth pairs of wires carry data between the PSE and the PD, and delivering power to the PD using the first and second pairs of wires and not delivering power to the PD using the third and fourth pairs of wires when each of the first and second pairs of wires carry data between the PSE and the PD and the third and fourth pairs of wires do not carry data between the PSE and the PD, wherein negotiating the acceptable power level for the PD and the data rate for the PD includes establishing the acceptable power level for the PD based on a minimum acceptable power requirement of the PD, and wherein negotiating the acceptable power level for the PD and the data rate for the PD further includes, after establishing the acceptable power level for the PD based on the minimum acceptable power requirement of the PD, establishing the data rate for the PD based on the acceptable power level for the PD.