The radio network controller estimates respective attenuation ratios of radio signals received by a terminal from transmitters of an active set. It commands at least some of the transmitters of the active set to transmit to the terminal with respective powers such that the difference p.sub.i-p.sub.j between the respective transmission powers p.sub.i and p.sub.j of two transmitters i and j is substantially proportional to ##EQU00001## where L.sub.i and L.sub.j designate the attenuation ratios estimated for the transmitters i and j, respectively.