1. A lighting device comprising:a light engine comprising at least one solid state lighting element;
a controller for controlling a dimming level of the light engine;
a wireless communication module communicatively coupled to the controller for receiving a wireless dimming instruction from a wireless controller;
a further communication module communicatively coupled to the controller for connecting to a wired communication channel and for receiving a further dimming instruction from a further controller wired to the further communication module through the wired communication channel;
a memory device, and
a timer for timing a duration of a disruption, wherein the controller is adapted to store a specified dimming level in the memory device when said timed duration does not exceed the disruption threshold and retain a previously stored specified dimming level when said timed duration exceeds the disruption threshold;
wherein the controller is adapted to independently control the dimming level of the light engine in response to the wireless dimming instruction and the further dimming instruction;
wherein the controller is adapted to enter a sleep mode in response to a sleep mode instruction, in said sleep mode, at least the wireless communication module disabled.