The communication system includes a robust physical layer header (RPLH) which can be understood by all participating stations. This robust header (50) at least comprises a preamble (52) consisting of frames forming a periodic sequence of pulses, the number of slots per frame and the frame content being known to all participating stations. The preamble serves for relative synchronization and carrier detection of the receiving stations. The robust header further comprises a unique synchronization word (53) which is used for absolute synchronization of the receiving stations. This synchronization word is followed by a control field (59) of fixed length and known structure. The control field informs the receiving stations of which modulation method will be used for the transmission of data. Pref. the control field also includes data for communication link and network control.