PoE technology allows data and electric power to be simultaneously supplied to remote devices over an Ethernet network. The need to transmit power over Ethernet cables was first recognized by several companies, including 3Com, Intel, Mitel, National Semiconductor, Nortel, and PowerDsine, but each had its own method of implementing the technology. In 1999, the IEEE started to standardize the number of proprietary implementations that were available at the time. The IEEE 802.3af standard approved in 2003 established common specifications for implementing PoE networks. A typical PoE system requires both power sourcing equipment and powered devices.Download white paper