A control apparatus (110-k, 140-m) for a node (120-k, 145-m) of a first network that is arranged to communicatively couple, to each other, a plurality of nodes (120, 145), wherein said plurality of nodes (120, 145) comprises a plurality of luminaires arranged for illuminating one or more spaces, the control apparatus (110-k, 140-m) comprising: a communication portion (112-k, 142-m) for communicating with other apparatuses via the first network and a second network; and a control portion (111-k, 141-k) arranged to: derive, based on one or more occupancy states that are associated with the node (120-k, 145-m), a node occupancy state that pertains to a location of the node (120-k, 145-m) within the one or more spaces and indicates one of occupancy or non-occupancy at the location of the node; receive, via the first network, one or more status indications originating from other ones of the plurality of nodes (120, 145) of the first network, wherein said status indications are indicative of respective occupancy states at respective locations of said other ones of the plurality of other nodes (120, 145); characterized in that the control portion (111-k, 141-k) is arranged to: derive, based on said one or more status indications, at least one regional occupancy state such that each regional occupancy state pertains to a respective plurality of other locations within the one or more spaces and indicates one of occupancy or non-occupancy at the respective plurality of other locations; and broadcast, via the second network to one or more external apparatuses that are external to the first network, a network occupancy status message that indicates the node occupancy state and the at least one regional occupancy state. a communication portion (112-k, 142-m) for communicating with other apparatuses via the first network and a second network; and a control portion (111-k, 141-k) arranged to: derive, based on one or more occupancy states that are associated with the node (120-k, 145-m), a node occupancy state that pertains to a location of the node (120-k, 145-m) within the one or more spaces and indicates one of occupancy or non-occupancy at the location of the node; receive, via the first network, one or more status indications originating from other ones of the plurality of nodes (120, 145) of the first network, wherein said status indications are indicative of respective occupancy states at respective locations of said other ones of the plurality of other nodes (120, 145); derive, based on one or more occupancy states that are associated with the node (120-k, 145-m), a node occupancy state that pertains to a location of the node (120-k, 145-m) within the one or more spaces and indicates one of occupancy or non-occupancy at the location of the node; receive, via the first network, one or more status indications originating from other ones of the plurality of nodes (120, 145) of the first network, wherein said status indications are indicative of respective occupancy states at respective locations of said other ones of the plurality of other nodes (120, 145); characterized in that the control portion (111-k, 141-k) is arranged to: derive, based on said one or more status indications, at least one regional occupancy state such that each regional occupancy state pertains to a respective plurality of other locations within the one or more spaces and indicates one of occupancy or non-occupancy at the respective plurality of other locations; and broadcast, via the second network to one or more external apparatuses that are external to the first network, a network occupancy status message that indicates the node occupancy state and the at least one regional occupancy state. derive, based on said one or more status indications, at least one regional occupancy state such that each regional occupancy state pertains to a respective plurality of other locations within the one or more spaces and indicates one of occupancy or non-occupancy at the respective plurality of other locations; and broadcast, via the second network to one or more external apparatuses that are external to the first network, a network occupancy status message that indicates the node occupancy state and the at least one regional occupancy state.