The dream of an intelligent home that automatically controls the living environment and responds to individual preferences has been around since the advent of the microcontroller first suggested the possibility. High cost, reliability issues, limited capability, and a lack of standards have imposed major constraints on the market, however, keeping home automation more in the realm of imagination than practice. The advent of wireless technologies, the emergence of home-networking standards, and pull from both the entertainment and the energy markets are now revitalizing efforts to realize that dream, although industry participants are still hotly contesting the implementation methods.
The first attempts at home automation provided only simple remote control of basic functions, such as turning lights, fans, and appliances off and on. The X10 power-line-signaling technology, which Scotland's Pico Electronics first developed in 1975, is typical of these early attempts. The X10 control system sends data at 1 bit/8.33 msec, is limited to 16 commands, and can control a maximum of 256 devices in a single network. Despite these limitations, however, X10 products have enjoyed limited but continuous success in the market and are still available for consumer purchase and installation.
