Phone-line networking is one of several ways to connect the computers in the home. If the computers are in different rooms, then phone-line networking is a good solution. Phone-line networking is easy to install, inexpensive and fast, and it doesn't require any additional wiring.
Phone-line networking, most commonly referred to as HomePNA, is based on the specifications developed by the Home Phone Networking Alliance (HPNA). The HPNA is a consortium of key networking technology companies that created a phone-line standard for the networking industry. HPNA 1.0, the original version of the standard, operated at a rather slow 1 megabit per second (Mbps). The current specification, HPNA 3.0, is based on technology developed by Broadcom and Copper Solutions. It operates at 128 Mbps.
HomePNA has several distinct advantages: It's easy to install, It's inexpensive,It's standardized,It's reliable; It operates at a constant 128 Mbps, even when the phone is in use. It requires no additional networking equipment (such as hubs or routers); It supports up to 50 devices; It is fast enough for bandwidth-intensive applications, such as video;It is compatible with other networking technologies; It works on Macs and older PCs (in addition to Windows and Linux systems).
HomePNA does have some drawbacks, though. A phone jack is needed close to each computer. Otherwise, phone extension cords are required or new wiring has to be installed. There is a physical limit of 1,000 feet (304.8 m) of wiring between devices, and the overall area of coverage should not exceed 10,000 square feet (929 m2).
See: http://computer.howstuffworks.com/phone-network.htm
