  Lighting systems based on light-emitting diodes (LEDs) possess many benefits
over their incandescent counterparts including longer lifespans, lower energy
costs, better quality of light and no toxic elements, all without sacrificing
consumer satisfaction. Their lifespan is not affected by switching frequency
allowing for better illumination control and system efficiency. In this paper,
we present a fully distributed energy-saving illumination dimming control
strategy for the system of a lighting network which consists of a group of LEDs
and user-associated devices. In order to solve the optimization problem, we are
using a distributed approach that utilizes factor graphs and the belief
propagation algorithm. Using probabilistic graphical models to represent and
solve the system model provides for a natural description of the problem
structure, where user devices and LED controllers exchange data via
line-of-sight communication.
