It has been often used for the location service based the IEEE 802.15.4 to modeling propagation in the 2.4 GHz ISM band. The Received Signal Strength Indicator (RSSI) value of it is used to estimate distance, which is proportional to path loss of the RSSI in general. However it is not good to use to this method in general because it include multi path fading, and interference etc. In this paper, the statistical estimation method is suggested to better accuracy than the previous estimation method and exponential coefficients of a suggested propagation model shows better performance than the value suggested in previous studies.