Power Line Communications (PLC) is a broadband access technology that uses the low and medium voltage electricity grid to transmit voice, data and video.
Even if the names are different in different countries, the technology is the same: broadband data is sent into people's homes as a high-frequency signal piggybacked on the 50 or 60-hertz mains electricity supply. In fact, the electricity grid may be used to supply broadband communications, as in addition to electricity.
PLC constitutes a competitive way of providing a wide array of services such as Internet access, telephony, multimedia and audiovisual services, in-home services as well as electrical energy-related applications. Just like cable systems, PLC is a medium that is shared by end-users in a local area with aggregate speeds up to about 10 MB/sec.
The US government gave the go-ahead to broadband over power line (BPL) technology in October 2004. The European Commission has now approved its own version, a recommendation to the EU Member States on so-called power-line communications (PLC).
What does PLC require in technological terms?
Installing PLC is simple, fast and cheap. The broadband communications signal is normally brought, via fibre optic cable, wireless technology, or leased lines, to a local transformer station, from where it is carried by the power line to the end user. It takes an engineer about one hour to install PLC equipment in a transformer station to offer the PLC signal to the area served by the transformer. Typically, a transformer connects 150-250 households.
The PLC technology is used to bridge the “last mile” between the broadband core (fibre optic) network and the home or office and also within the home (similar to the function of a local area network). A “Head-End” (HE) device, installed at the transformer, distributes the signal to a number of users. If necessary, repeaters are installed in street cabinets or in the meters room of buildings to reach the customer premises and to prevent interference from the power grid.
PLC is a direct competitor to digital subscriber line (DSL) technology and uses similar modulation techniques. Both technologies exploit existing copper wire networks (DSL is a telephone copper network based technology). The use of existing cabling greatly reduces installation costs as it avoids the need for putting in extra cabling.
What advantages does PLC offer to the consumer?
PLC is an alternative to cable networks and DSL services for supplying broadband to the end user. Typically, the commercial offerings are competitive and cheaper than DSL. PLC operators’ experience suggests that customer satisfaction with PLC is high
How expensive is PLC?
PLC is not more expensive than other broadband offerings over DSL or cable. In Germany, for instance, PLC is generally offered at a price below that of the DSL service from the incumbent operator
What equipment do I need to use it?
There is a variety of end-user modems (customer premise equipment or CPEs) on the market: data-only modems, modems with an integrated IP telephone, modems with a socket into which a normal telephone handset can be plugged etc. The characteristics of modern PLC modems are very similar to those of DSL modems.