Digital PowerLine, developed by Northern Telecom and United Utilities, is capable of transmitting data at a rate of 1Mbps over existing electricity infrastructure.
Through "conditioning" of the existing electricity infrastructure, electrical utilities can transmit regular low frequency signals at 50 to 60Hz and much higher frequency signals above 1MHz without affecting either signal. The lower frequency signals carry power, while the higher frequency signals can transmit data.
Digital PowerLine use a network, known as a High Frequency Conditioned Power Network (HFCPN), to transmit data and electrical signals. A HFCPN uses a series of Conditioning Units (CU) to filter those separate signals.
The CU sends electricity to the outlets in the home and data signals to a communication module or "service unit". The service unit provides multiple channels for data, voice, etc.
Base station servers at local electricity substations connect to the Internet via fiber or broadband coaxial cable. The end result is similar to a neighborhood local area network.