Power-line communication

Power-line communication (PLC) is the carrying of data on a conductor that is also used simultaneously for AC electric power transmission or electric power distribution to consumers. The line that does so is known as a power-line carrier.

In the past, power lines were solely used for transmitting electricity. However, with the introduction of advanced networking technologies, there has been a push for utility and service providers to find cost-effective and high-performance solutions. The possibility of using powerlines as a universal medium to transmit not just electricity or control signals, but also high-speed data and multimedia, is now under investigation.^{[by whom?][1]}

A wide range of power-line communication technologies are needed for different applications, ranging from home automation to Internet access, which is often called broadband over power lines (BPL). Most PLC technologies limit themselves to one type of wires (such as premises wiring within a single building), but some can cross between two levels (for example, both the distribution network and premises wiring). Typically transformers prevent propagating the signal, which requires multiple technologies to form very large networks. Various data rates and frequencies are used in different situations.

A number of difficult technical problems are common between wireless and power-line communication, notably those of spread spectrum radio signals operating in a crowded environment. Radio interference, for example, has long been a concern of amateur radio groups.^[2]