New Ethernet systems distribute DC power with data

摘要

Power-over-Ethernet (PoE) is a power-distribution technique recently approved as IEEE standard 802.3af. It allows that ubiquitous and universal network called the Ethernet to carry DC power along with your data packets. The recent ratification of this IEEE standard appears to be the first instance in which a universal power jack or plug has been defined for worldwide use. It means that local AC power is no longer needed for all network-attached devices that need continuous power—such as IP phones, wireless access nodes, and web-surveillance cameras. It also means that the devices do not have to be placed near wall outlets, and means that power cables can be eliminated.