For wireless communication in the industrial environment, there is, inter alia, an iWLAN protocol, which meets the requirements but provides no time synchronization in the data transmission. According to the invention, an additional—ideally wireless—channel is used for the synchronization. In an advantageous embodiment of the invention, a simple radio system is used for this. Pulses or telegrams for time synchronization are initiated directly from a unit, which is designed as hardware and which is responsible for the time synchronization and which has a highly accurate clock, or supplied on the side to be synchronized of such a unit. The radio system can be designed very simply and unidirectionally. The transmission process is started without delay in order to prevent variable delays.