An IEEE standard for powering network devices via Ethernet cable. Also known as "Power-over-Ethernet" (PoE), the 802.3af specification provides 48 volts over 4-wire or 8-wire twisted pair. The 8-wire cable uses one twisted pair for the power, while the 4-wire transmits the power over the same pair as the data, but uses different frequencies. Designed for such devices as IP phones, cameras and Wi-Fi access points, 802.3af allows them to be placed in locations that have no electrical outlets. Only the Ethernet cable needs to be connected. See
inline power and
PoE.