PoE

Power over Ethernet (PoE) describes a systems which passes electrical power along with data on Ethernet cabling with long cable lengths. This allows a single cable to provide both data connection and electrical power to devices such as wireless access points or IP cameras.

Since only two of the four pairs of the Ethernet CATx twisted-pair cable are needed for 10BASE-T or 100BASE-T, PoE power is transmitted on the unused conductors of a cable. Because twisted-pair Ethernet uses differential signaling, this does not interfere with data transmission.

Using PoE eliminates the need for a dedicated power supply for the connected device, making remote deployments easy and independent of power source. The Ethernet router or switch to which the device is connected must, of course, support PoE.