Described herein is an autonomous distributed lighting network which comprises a plurality of luminaires for providing lighting levels in accordance with idle dimming profiles, at least one sensor for sensing ambient conditions, and a communications network. Luminaire nodes, sensor nodes, a timer node and a controller node are connectable to the communications network. Each luminaire node is associated with a luminaire and is operable for receiving broadcast messages from the communications network, the luminaire overriding its normal idle dimming profile in response to an appropriate broadcast message. Each sensor node is associated with at least one sensor device and transmits broadcast messages onto the communications network in accordance with events sensed by each related sensor device. A timer node, if present, provides time synchonisation for the luminaires within the network. In addition, a controller node is used for set up and maintenance of the network.