Power over Ethernet (PoE) provides power through the Ethernet. It is also called Power over LAN (PoL) or active Ethernet.
As IP phones, network video monitoring, and wireless Ethernet networks are widely applied, the power supply requirements on the Ethernet become urgent. In most situations, access point devices need DC power supply, but access point devices are often installed outdoors or on the ceiling that has a long distance from the ground. The nearby proper power socket is difficult to find. Even if the proper power socket is available, the network administrator finds it hard to install the AC/DC converter required by access point devices. On many large-scale LANs, administrators need to manage multiple access point devices that require uniform power supply and management. In this case, power supply management is difficult. The PoE function addresses this problem.
The PoE technology is used on the wired Ethernet and is most widely used on local LANs. The PoE function transmits power together with data to terminals over cables or transmits power without data over idle lines. This technology provides power on the 2.5GE Base-T, 1000Base-T, 100Base-TX, or 10Base-T Ethernet at a distance of up to 100 m. PoE can be used to effectively provide centralized power for terminals such as IP phones, Access Points (APs), chargers of portable devices, POS machines, cameras, and data collection devices. Terminals are provided with power when they access the network. Therefore, indoor cabling of power supply is not required.
The PoE has the following advantages: