POE
close PoE is also called PoL (Power over LAN) or Active Ethernet (sometimes referred to as Ethernet power supply), which is the latest standard specification for simultaneous transmission of data and power using existing standard Ethernet transmission cables, and maintains compatibility with existing Ethernet systems and users. IEEE 802.3af standard is a new standard based on POE of Ethernet power supply system. It adds related standards of direct power supply through network cables on the basis of IEEE 802.3. It is an extension of existing Ethernet standards and the first international standard on power distribution. IEEE began to develop this standard in 1999. The earliest manufacturers involved are 3Com, Intel, PowerDsine, Nortel, Mitel and National Semiconductor. However, the shortcomings of the standard have been restricting the expansion of the market. Until June 2003, IEEE approved the 802. 3af standard, which clearly stipulated the power detection and control matters in the remote system, and specified the way in which routers, switches and hubs supply power to IP phones, security systems, wireless LAN access points and other equipment through Ethernet cables. The development of IEEE 802.3af includes the efforts of many company experts, which also enables the standard to be tested in all aspects. A typical Ethernet power supply system. Keep Ethernet switch equipment in the distribution cabinet, and use a power supply hub (Midspan HUB) to supply power to the twisted pair of the LAN. At the end of the twisted pair, the power supply is used to drive telephones, wireless access points, cameras and other devices. To avoid power failure, a UPS can be selected.