Power line communication (PLC) is a technology that can allow data to be transmitted by an existing electricity infrastructure. Also known as broadband over power lines (BPL), power line communication can be used to create home networks or to provide high speed Internet services to end users. Each time the voltage in a power grid is stepped down between high tension lines, local distribution lines, and home or business users, different power line communication technologies may be required. As a delivery method for Internet service providers (ISPs), it may offer a cost effective way to provide high speed broadband to remote or sparsely populated areas. Home or business users may find PLC useful, as it can negate the need for a wireless router or a costly wired local network.
Electricity can be transmitted at a variety of different voltages, depending on the area being serviced and the distance that the lines cross. Long distance lines will typically have a very high voltage, while local distribution lines use a medium voltage, and the voltage is further reduced for home and business use. There are different forms of PLC technology for each of these situations, and a power grid may make use of one or all of them. The transformers used to step down the voltage between different levels of power distribution can interfere with the data signals, though this may be overcome with specialized converters.
In certain circumstances, it may be too expensive for a cable or telephone company to install the infrastructure necessary to serve their rural customers with broadband Internet access. The cost of installing expensive data infrastructure often must be offset by a particular number of users, and sparsely populated areas may not provide enough potential customers to justify the cost. One potential solution for this problem is power line communication, since it can use existing infrastructure to deliver broadband Internet access.
Home networks can also utilize certain forms of power line communication to replace existing network structures. A typical wired network can be costly to install, and wireless routers have drawbacks such as signal interference from walls, floors, and other objects. Power line networking can use the existing wiring in a home or business to transmit data. These systems typically involve an adapter that allows a modem to be connected to a power outlet via an Ethernet cable. Additional adapters can then be plugged into outlets around the home or business, allowing computers or other devices access to the network.