A method for defining a parameter value for controlling the transmission power of a set of user equipment served by a cell defined by a base station of a cellular telecommunication network, includes, for the base station, receiving, from the set of user equipment located in the cell, a set of attenuation values including, respectively by piece of equipment, an attenuation value of a signal transmitted by the base station and received by the piece of user equipment and, if the piece of user equipment is also located in a non-serving cell, an attenuation value of a signal transmitted by the base station of the non-serving cell and received by the piece of user equipment; determining, from the set of received attenuation values, a value of a parameter for controlling the transmission power; and sending, to the set of user equipment served by the cell, the value of the control parameter.