Power Line Communications

What Does Power Line Communications Mean?

Power line communications (PLC) provides broadband data communications on conductors already used for electric power transmission using a modular signal. This is commonly done through home or premises wiring, but may also be done through the electric power distribution system.


Uses of the PLC technology include transmitting radio programs, utility company control switching mechanisms, transmission line protection, and automatic meter reading. There are also some automotive uses where data, voice, and music are sent over a direct current (DC) battery power line with special filters to filter out the line noise.

This term is also known as power line carrier, power line digital subscriber line (PDSL), mains communication, power line telecom (PLT), power line networking (PLN), and broadband over power lines (BPL).

Techopedia Explains Power Line Communications

One of the technologies must be used to keep the electric power distribution system transformers from preventing the modular signal from going beyond them. Additionally, power lines have limited ability to carry high frequencies. One technology is called E-Line. It allows the conductor to function as a waveguide, allowing radio frequency signals and full duplex communications at transmission rates of many Gbps. However, without this technology or a similar one, transmission rates are limited to only a few hundred bps.

The circuits can be many miles long. However, for a LAN, shorter transmission lines allow operation at Mbps. This is sufficient for a single floor of an office building or a home and eliminates the need for dedicated cabling for data transmission.

Consumers may purchase powerline adapter sets to establish a wired connection using existing home wiring to set up their own LAN. Using an Ethernet port on their computer, many home entertainment devices may be connected using existing home wiring. These devices may include TVs, game consoles, Blu-ray players, and Internet video boxes. One adapter accesses an electrical outlet near the computer, while a second (and a third, fourth, etc.) accesses an electrical outlet near the TV, game console, or other device. A standard has been established for home adapter products by the HomePlug Powerline Alliance.

BPL, also known as power-line Internet, allows PLC technology for Internet access through ordinary electric transmission lines. This is often used in remote locations with little or no Internet access by cable or PDSL connections. Problems include lack of standards and dealing with the noisy environment of powerlines, which can result in pops or clicks in the line when devices are turned on or off.

As of early 2010, two different sets of standards apply to powerline networking. HomePlug AV and IEEE 1901 have been set up for homes. Another standard for smart grids and the use of BPL for data and telemetry is being used by power providers for internal and external communications. In North America, the IEEE standard group is supervising these standardization activities.


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Margaret Rouse

Margaret Rouse is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical, business audience. Over the past twenty years her explanations have appeared on TechTarget websites and she's been cited as an authority in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine and Discovery Magazine.Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages. If you have a suggestion for a new definition or how to improve a technical explanation, please email Margaret or contact her…