Power Over Ethernet (POE) Introduction

Power over Ethernet, also known to many as POE, describes one of many standardized or ad-hoc systems which transmit electrical power alongside data over Ethernet cabling.

POE allows a single cable to provide both a data connection as well as electrical power to devices such as network hubs, closed-circuit TV cameras, or peripheral equipment. Unlike standards such as Universal Serial Bus which also power devices over the data cables, POE allows for much longer cable lengths. Power may be carried on the same conductors as the data, or it may be carried on spare, usually unused pairs on the cable.