A data network that uses a building's electrical system as the transmission medium and regular wall outlets as connecting points. It is commonly used to extend a wired Ethernet network into another room.
Powerline networks do not interfere with the delivery of electricity in the same circuit because data are transmitted at a much higher frequency than the 60Hz or 50Hz used for AC power. For example, the HomePlug powerline technology uses frequencies from 4.5 MHz to 21 MHz. See powerline adapter
and broadband over power lines
Wired, Wireless and Powerline
A powerline network can be used with existing wired and wireless networks to extend the network via the building's electrical system. See Wi-Fi bridge