Patent ID: 8300666

Claim:
A method for communicating a message from a powered device (PD) to power sourcing equipment (PSE) in a wired data telecommunications network, the method comprising: performing a PD detection and classification to verify that the PD is configured to be supplied with inline power from the PSE; responsive to said performing, establishing an initial inline power relationship between the PD and the PSE so that the PD is receiving an initial minimum level of power from the PSE; and current modulating the inline power at the PD with a predetermined communications protocol to communicate the message from the PD to the PSE; wherein establishing the initial inline power relationship comprises biasing a first pair of conductors with one direct current (DC) voltage level and a second pair of conductors with a second DC voltage level, the difference between the first and second voltage level being a difference voltage, the PD and PSE being powered by the difference voltage, and the difference voltage exceeding 20 Volts, wherein the message includes a request for a different minimum level of power from the PSE to the PD, and further comprising, responsive to said current modulating, providing the different minimum level of power from the PSE to the PD, wherein the first pair of conductors are used for performing at least the function of transmitting data from the PD to the PSE, and the current modulating will remain operable to communicate the message from the PD to the PSE even if at least one of the following occurs: (a) one conductor of said first pair of conductors is open, and (b) both conductors of said first pair of conductors are shorted together.