Disclosed herein is system level occupancy counting in a lighting system configured to obtain an indicator data of a RF spectrum signal (signal) generated by a number of receivers at a number of times in an area. At each respective one of the number of times, for each respective one of the receivers, apply one of a plurality of heurist algorithm heuristic algorithm coefficients to each indicator data of the signal, based on results of the application of the heuristic algorithm coefficients, generate an indicator data metric value for each of the indicator data for the respective time. The lighting system is also configured to process each of the indicator data metric value to compute a plurality of metric values for the respective time and combine the plurality of metric values to compute an output metric value for each of a plurality of probable number of occupants in the area for the respective time. The lighting system is further configured to determine an occupancy count in the area at the respective time based on the computed output metric value.