A lighting control system providing distributed lightning control and including a plurality of lighting control sub-systems , wherein the plurality of lighting control sub-systems each comprises: 1.1 a luminaire ; 1.2 a controller coupled to the luminaire ; 1.3 a sensor coupled to the controller , the sensor generating a sensed input; 1.4 a communication interface , the communication interface coupling the controller to an external device being a central controller or another lighting control sub-unit; 1.5 a power monitoring unit operative to measure power usage of the plurality of the lighting control sub-system , the power monitoring unit being part of the sensor; wherein the controller is operative to: 1.5 control a light output of the luminaire based at least in part on the sensed input; 1.6 communicate at least one of state or sensed information to the external device; 1.7 communicate with other sub-systems , and identify logical groups of two or more sub-systems of the plurality of sub-systems ; 1.8 communicate the measured power usage of the plurality of the lightning control sub-systems to the external device; 1.9 wherein identifying the at least one logical group comprises at least the controller and at least one of the other sub-systems auto-determining the logical group ; and 1.10 wherein the controller is operative to identify an emergency condition and initiate an emergency mode, characterised in that the controller is further operative to confirm the identification of the emergency mode, including the controller initiating a communication with a non-emergency device, and confirming the identified emergency condition, if the initiated communication is not successful. 1.1 a luminaire ; 1.2 a controller coupled to the luminaire ; 1.3 a sensor coupled to the controller , the sensor generating a sensed input; 1.4 a communication interface , the communication interface coupling the controller to an external device being a central controller or another lighting control sub-unit; 1.5 a power monitoring unit operative to measure power usage of the plurality of the lighting control sub-system , the power monitoring unit being part of the sensor; wherein the controller is operative to: 1.5 control a light output of the luminaire based at least in part on the sensed input; 1.6 communicate at least one of state or sensed information to the external device; 1.7 communicate with other sub-systems , and identify logical groups of two or more sub-systems of the plurality of sub-systems ; 1.8 communicate the measured power usage of the plurality of the lightning control sub-systems to the external device; 1.9 wherein identifying the at least one logical group comprises at least the controller and at least one of the other sub-systems auto-determining the logical group ; and 1.10 wherein the controller is operative to identify an emergency condition and initiate an emergency mode, 1.5 control a light output of the luminaire based at least in part on the sensed input; 1.6 communicate at least one of state or sensed information to the external device; 1.7 communicate with other sub-systems , and identify logical groups of two or more sub-systems of the plurality of sub-systems ; 1.8 communicate the measured power usage of the plurality of the lightning control sub-systems to the external device; 1.9 wherein identifying the at least one logical group comprises at least the controller and at least one of the other sub-systems auto-determining the logical group ; and 1.10 wherein the controller is operative to identify an emergency condition and initiate an emergency mode, characterised in that the controller is further operative to confirm the identification of the emergency mode, including the controller initiating a communication with a non-emergency device, and confirming the identified emergency condition, if the initiated communication is not successful. <EOS>