HomePlug is the family name for various power line communications specifications under the HomePlug name, with each offering unique performance capabilities and coexistence or compatibility with other HomePlug specifications.
Some HomePlug specifications target broadband applications such as in-home distribution of low data rate IPTV, gaming, and Internet content, while others focus on low-power, low throughput, and extended operating temperatures for applications such as smart power meters and in-home communications between electric systems and satellite linux receivers. All of the HomePlug specifications were developed by the HomePlug Powerline Alliance, which also owns the HomePlug trademark.
The HomePlug Powerline Alliance was formed to develop standards and technology for enabling devices to communicate with each other, and the Internet, over existing home electrical wiring. One of the greatest technical challenges was finding a way to reduce sensitivity to the electrical noise that is inevitably present on power lines. Whenever an appliance is turned on or off, it creates electrical noise that can interfere with data transfer through the wiring. Noise sensitivity was problematic in early powerline technology, though later versions have solved this problem. Also, early powerline technology could not reliably communicate across different electrical phases. HomePlug solved this problem by increasing the communication carrier frequencies so that the signal is conveyed by the neutral conductor, which is common to all phases.