Power Line Carrier (PLC) techniques (primarily X-10) have been explored over the past two decades as a means of sending control signals over existing power lines without the need to install additional wiring. Early attempts at PLC using the X-10 protocol met with only mixed success due to a number of factors, especially the difficulty of consistently receiving clear signals sent over long wire runs in imperfect electrical systems.

A few years ago, the patents concerning X-10 expired, which cleared the path for the new A-10 protocol which is much more robust than X-10 and is thought to be applicable to controlling commercial building lighting systems. For example, in the PIER contract, High Performance Commercial Buildings (contract #400-99-012), Lawrence Berkeley National Laboratory (LBNL) demonstrated the feasibility of using PLC control techniques to switch fixture-mounted relays, thus implementing bi-level lighting without the need to run additional wiring.

The success of that effort led to the current proposed project which targets dimming, rather than switching, applications. Based on current knowledge, no manufacturer currently produces a powerline-carrier controlled lighting controller suitable for use with "inline controlled" ballasts. As a result, there is no research literature on the specific approach that LBNL has adopted.