POE technology analysis

The PoE switch is a switch that supports power supply to the network cable. Compared with the ordinary switch, the power receiving terminal (such as AP, digital camera, etc.) does not need to be wired for power supply, and the reliability of the entire network is higher.

Overview of Power Over Ethernet (POE) POE (Power Over Ethernet) refers to the use of IP-based terminals (such as IP telephones, wireless LAN access points (APs, network cameras, etc.) can provide DC power supply technology for such devices while transmitting data signals. The POE technology can ensure the normal operation of the existing network while ensuring the safety of the existing structured cabling, minimizing costs.

POE is also known as a power supply system based on local area network (POL, Power over LAN) or Active Ethernet (Active Ethernet), sometimes also referred to as Power over Ethernet for short. This is the use of existing standard Ethernet transmission cables to transmit data and electrical power at the same time The latest standards and specifications, and maintain compatibility with existing Ethernet systems and users. IEEE

The 802.3af standard is a new standard based on the POE of the Ethernet power supply system. It adds related standards for direct power supply through the network cable on the basis of IEEE802.3. It is an extension of the existing Ethernet standard and the first international power distribution standard. standard.

IEEE began to develop the standard in 1999, and the earliest participating vendors were 3Com, Intel, PowerDsine, Nortel, Mitel, and National Semiconductor. However, the shortcomings of this standard have been restricting the expansion of the market. Until June 2003, the IEEE approved the 802.3af standard, which clearly specifies the power detection and control issues in the remote system, and connects routers, switches, and hubs to IP phones, security systems, and wireless LAN access points through Ethernet cables. The power supply mode of the equipment is regulated. The development of IEEE802.3af includes the efforts of many company experts, which also allows the standard to be tested in all aspects.