POE & POE+
•POE is a standard protocol for transmitting DC power over copper Ethernet data wiring.
•The IEEE group managing the 802.3 Ethernet data standard added POE functionality in 20003.
•The original POE specification is 802.3af, which allows 48V DC power up to 13W, which was popular in the beginning, but due to the 13W upper limit, the number of possible applications was limited.
•In 2009, the IEEE increased its voltage and current requirements to supply 25.5W of power by announcing a new standard called 802.3at, or POE +.
...