In this paper, the authors present how computer simulation can be used to estimate the mean output power and the probability cumulative distribution function of one base station output power in GSM. The basis of the method is adding the simulation of random distance between the Mobile Station (MS) and Base Transceiver Station (BTS) to the known method of telephone traffic simulation. The simulation is a suitable method for the estimation of base station output power, especially in the case when it is not easy to calculate the output power’s dependence on these factors.