Spread spectrum data leap through AC power wiring

There have been two serious impediments to the growth of the power-line carrier (PLC) communications industry in particular, and the home and building automation market in general: line noise, which plays havoc with communications' reliability, and the lack of a standard communication network protocol. Both stumbling blocks have been removed-the first, by the development of spread-spectrum PLC technology, which all but eliminates the noise impediment, and the second, by the industry-wide adoption of the Electronic Industries Association's Consumer Electronics Bus (CEBus) standard. The author discusses the use of spread spectrum for distributed control systems. The techniques of spread spectrum and carrier-detect narrowband communication are compared. Impulse noise is also discussed as are frequency hopping and the CEBus approach.