Method for transmitting through a bidirectional communication channel at least one conventional frame (CVFR) split into time slots SLj (for j=1 to L) separated from each other by guard intervals G, each time slot SLj being allocated either to a first or to a second direction of communication uplink (UL) or downlink (DL) offered by the bidirectional communication channel. The method according to the invention includes: detecting at least two successive time slots SLj, SLm+1, SLj+2 allocated to a same direction of communication DL, and inserting data in the guard interval separating such successive time slots SLj, SLj+1, SLj+2.