Power over Ethernet (PoE) is a networking feature defined by the IEEE 802.3af and 802.3at standards. PoE lets Ethernet cables supply power to network devices over the existing data connection.
PoE-capable devices can be power sourcing equipment (PSE), powered devices (PDs), or sometimes both. The device that transmits power is a PSE, while the device that is powered is a PD. Most PSEs are either network switches or PoE injectors intended for use with non-PoE switches. Common examples of PDs include VoIP phones, wireless access points, and IP cameras.
POE switches the port supports output power of 15.4W or 30W, which matches the IEEE802.3af/802.3at standard. Through power of Ethernet method to apply power to standard POE terminal equipment. Avoid the extra power wiring. POE switches .comply with IEEE802.3 standard, port output power can reach 30W, electrical equipment can be obtained by the power of 25.4 W. popular saying , POE switch is just switch which supports network cable power supply switch. It can not only realize the data transmission function of the general switch but also power the network terminal simultaneously.
POE switches refers under the existing Ethernet Cat. 5 cabling infrastructure do not make any changes in circumstances, for those terminals based on IP (e.g. IP telephone, wireless LAN access point AP, webcams etc.) to transmit data signals and meanwhile also provide dc power supply for such equipment technology . POE technology can ensure the existing network infrastructure security and guarantee the network normal operation, make the expense cost down in maximum.