In a radio system, the transmission power is controlled by a receiver (1; 2) evaluating the signal from a transmitter (2; 1) and a determining power adjustment information (TPC) as a function of this, and sending this information to the transmitter (2; 1) during successive timeslots (4), in order to control the transmission power. In what is referred to as the slotted mode, the same power adjustment information (TPC) is transmitted to the transmitter (2; 1) in a number of successive timeslots (4) following a section (9) which is not filled with information.