Free Space Path Loss Model

3. PATH LOSS MODELS
Path loss models play a vital role in planning of wireless communication systems. They represent a set of mathematical equations and algorithms that are used for radio signal propagation prediction in certain areas. Propagation path loss models are used for calculation of electromagnetic field strength for the purpose of wireless network planning during preliminary deployment. Path loss model describes the signal attenuation from transmitter to receiver antenna as a function of distance, carrier frequency, antenna heights and other significant parameters like terrain profile (urban, suburban and rural). In this section various path loss models are discussed.
3.1 Free Space Path Loss Model (FSPL)
Free-space path loss (FSPL) is the loss in signal strength of an electromagnetic wave that would result from a line-of-sight path through free space, with no obstacles nearby to cause reflection or diffraction. Path loss in free space PLFSPL defines how much strength of the signal is lost during propagation from transmitter to receiver. FSPL is diverse on frequency and distance. The calculation is done by using the following equation:
PLFSPL= 20log10(d)+20log10(f) + 32.45 Where, d: Distance between transmitter and receiver in mts. f: Frequency in MHz
3.2 COST 231 Hata Model
This model is a well-established model for the Ultra High Frequency (UHF) band. The International Telecommunication Union (ITU) encouraged this model for further extension up to 3.5 GHz . The original Okumura model does not provide any data greater than 3 GHz. Based on prior knowledge of Okumura model, an extrapolated method is applied to predict the model for higher frequency greater than 3 GHz. The tentatively proposed propagation model of Hata-Okumura model is referred to as ECC-33 (Electronic Communication Committee) model. In this model path loss is given