POE is also known as the power supply system based on local area network (POL, Power over LAN) or Active Ethernet (Active Ethernet), sometimes referred to as Power over Ethernet, which is using the existing transmission standard Ethernet cable At the same time, the transmission of data and electrical power of the latest standards, and maintained with the existing Ethernet system and user compatibility. IEEE 802.3af Power over Ethernet standard is based on the new standard for POE system, which based on the IEEE 802.3 an increase of direct power supply cable through the relevant standards, is an extension of the existing Ethernet standards, is the first of a international standards for power distribution.