Description
The IEEE 802. 3af is the first standard based on the Power over Ethernet. On the basis of the IEEE 802.3, it is an extension of the existing Ethernet attached with relevant standards of power supplement directly through network lines. It establishes itself as the first international standard on power distribution.The company also provide core switch and distribution switch, eoc converter, home ethernet switch and fiber converter switch. Sketched from 1999 by the IEEE, the initial standard was adopted by its first vendors of 3Com, Intel, PowerDsine, Nortel, Mitel and National Semiconductor. However, it curbed the expansion of the market. Until June 2003, the IEEE approved 802. 3af, which specified the power detection and control issues in remote systems. It, as well, prescribed the way in which routers, 802af POE and hubs provided power to devices like IP phones, security systems, and wireless LAN access points via Ethernet cables. The development of IEEE 802. 3af involved the efforts of numerous experts, which made it available for an overall practical testing. The 802af POE provides 15.4 W of power (with minimum 44V DC and 350mA) ,among which the stable one (the actual power received by the terminal device) is only 12.95 W due to the power loss in the twin cable. That 44 ~ 57V voltage and about 350mA DC current are provided by PSE for each port shall result at least 15.4 w power, which is delivered by 100 meters CAT-3 cable. Finally, at least 12.95 W left will be received by the PD terminal. https://www.huasnet.com/etherent-over-coax.html
The International Standard -- the IEEE 802.3af
