The model based on the field measurements made by Okumura in Tokyo in 1968. Okumura’s measurements were later fitted in a mathematical formula by Hata. The Okumura-Hata model is valid for frequency range of 150–1500 MHz, the BS height is 30-200m, the MS height is 1-10m and the distance is 1-20km. Because of the frequency band limitation of the Okumura-Hata model, the original model was later extended by the European CO-operation in the field of Scientific and Technical research (COST 231) to the frequency band of 1500–2000 MHz, which covers the bands allocated to the 3G networks (E. Damasso 1999), is given in equation (4)