Okumura Model

This model is used for finding out Path Loss in the frequency range of 150MHz to 1920 MHz (typically extended up to 3 GHz) for distances of 1 to 100 Km & base station antenna heights ranging from 30m to 100 m. Approximations have taken from this model for transmitter antenna height of 3 m & distance below 1 Km.

    Okumura model is wholly based on measured data.

Path Loss = FPL + A(f,d) - G(hte) - G(hre) - G(Area)

Where :

FPL       = Free Space Path Loss = 20 log {4*PI*d*f/c}

                c       = Speed of Light

                  d      = distance

                  f       = Frequency

G(hte)     = 20log(hte /200)                          1000m > hte > 30 m

                   = 10 log (hte /200)                  hte   < 30 m   ( Approximation taken)

G(hre)     = 10log(hre / 3)                     hre   <  3 m

              = 20log(hre / 3)                     10 m >    hre  >  3 m

G(Area) @ 2.4 GHz from the Curves

              = 33 (Open Area)

              = 27 (Quasi Open Area)

              = 13 ( Suburban Area)

A(f,d)    = Median Attenuation : function of frequency & distance

              = 13 dB from curve @ 2.4 GHz & distance up to 1 Km.