以太网供电(power over Ethernet)技术是目前新兴的一项具有广阔实用前景的技术。这项技术允许供电设备(power sourcingequipment)通过同一根以太网电缆在传送数据的同时向具有电源接口(power interface)的网络设备直接供电。本文基于该项技术的工业 标准(IEEE Std 802. 3af - 2003)介绍了以太网供电的设备、接入方法、工作机理以及相关参数。 关键词POE(以太网供电) 802. 3af PSE(供电设备) PD(用电设备) Abstract The POE(power over Ethernet)technology is an uprising star with bright future of practicability. This technology makes it possible that the PSE(power Sourcing Equipment)can supply power to the network equipment having PI(Power Interface)directly through the same Ethernet cable while transferring data. This article gives a detailed explanation about the Industrial Standard(IEEE Std 802. 3af - 2003)for this technology. Keywords Power over Ethernet(POE) 802. 3af Power sourcing equipment(PSE) Powered device(PD)