Abstract: A method for digital semi-duplex transmission. To allow transmission of information to subscribers during the transmitting permission of one of the subscribers, a selected number (N-1) of blocks are transmitted during a time period shorter than the original total duration (t) of the blocks from a subscriber (MS A) having the permission to transmit to a base station (BS) having the permission to receive; the base station (BS) having the receiving permission utilizes the original total duration (t) of the blocks reduced by the actual transmission period of the blocks and by a first and a second guard period (301, 302) for transmitting reverse information (203) and time synchronization information (202) to the subscriber having the transmitting permission; and the base station (BS) having the receiving permission transmits information during at least one of said guard periods (301, 302) to at least one subscriber (MS B) having no transmitting permission. (FIG.