Huawei RF, the nearest feature I can think of for GSM that you mean when you say “perfect power” is called APC (Adaptive Power Control) which is there to prevent such things as Near-Far Effect. APC command can be sent with TA to regulate MSs operating at full power with regard how they might effect the base station, minimum coupling loss (MCL) of the radiating elements (ie the antennas) and so on based upon on how far MSs are from Mast. The objective is to stop MSs near to the Mast operating at full power that may cause dropped calls or at minimum high handover rate for mobiles that maybe on or in fringe/boundary area of coverage from the same Mast.