Spread spectrum involves starting a modulation at one frequency, and altering the frequency during it's cycle. The CEBus power line standard begins each burst at 100 kHz, and increases linearly to 400 kHz during a 100 microsecond duration. A digit 1 is created by an inferior or superior state that lasts 100 microseconds, and a digit 0 is created by an inferior or superior state that lasts 200 microseconds. Consequently, the transmission rate is variable, depending upon how many of the characters are 1's and how many are 0's, and 7,500 bits per second is the average rate. The CEBus transmissions are based upon strings or packets of data that also vary in length, depending upon how much data is included.
Some packets can be hundreds of bits in length.
The CEBus standard involves device addresses that are set in hardware at the factory, and include 4 billion possibilities. The standard also offers a defined language of many object oriented controls which include commands such as volume up, fast forward, rewind, pause, skip, and temperature up or down 1 degree. Presently, all of the communications hardware, language, and protocol is available on a chip produced by Intellon Corporation in Ocala, Florida. Intellon sells the chip to other manufacturers for use in their products, and Intellon also offers to manufacturer private label and OEM products using the CEBus standard. Although there is no restriction from anyone using the CEBus standard, the CIC is developing a non-profit testing laboratory which will be funded by certification charges.