A control system for controlling at least one environmental parameter in an operating area in response to sensor signals. The system includes a central control unit, actuators and mobile sensor units, and also at least one, preferably a plurality, of communication nodes which are placed in the operating area. Each one of the communication nodes is configured to mediate signals between the sensor units and the central control unit in a monitoring area by wirelessly receiving sensor signals from sensor units located within its monitoring area and forwarding the sensor signals to the central control unit. A monitoring area of a communication node is defined by the signal coverage of the communication node.