Radio frequency wireless technology is surely one of the most used technologies in indoor localization. RF-signals have been utilized in several ways to estimate the distances among the anchor nodes and the mobile nodes and, probably the methods based on the measure of the Received Signal Strength (RSS) are the most explored ones. RSS depends on the transmission medium and environment and this affects also the distance measurement performances. To mitigate the external influences, transmission parameters, as for example the transmission channel and transmission power, can be tuned. To this purpose, in this work the influence of the power transmission on the localization algorithm performance is investigated. In particular a method to select the power transmission that allows the best localization performance is presented. The results show that the localization performance depend on the transmission power. Moreover, a method to establish the best power transmission for the specific environment is presented and tested.