A17.3.1 Outdoor-outdoor propagation

The Extended Hata model implemented in SEAMCAT calculates propagation loss between transmitter and receiver as:

       

 (Eq. 190)

where:

f      : frequency (MHz)

h₁    : transmitter antenna height (m, above ground)

h₂    : receiver antenna height (m, above ground)

d      : distance between transmitter and receiver (km)

env  : general environment attenuation (dB)

L      : median path loss (dB)

     : Variation in path loss (dB)

The validity ranges identified by COST 231 based on the original work of Okumura and Hata should be applied when using the Extended Hata model in SEAMCAT, i.e. H_m: 1 to 10m and H_b: 30 to 200m (Note that the H_b is assumed to be above roof top) where:

H_m = min (h₁, h₂)

H_b = max (h_1, h₂)

If H_m is below 1m, a value of 1m should be used instead. If H_b is above 200m, this might also lead to significant errors. This gives the possibility to use this model reciprocally (DL and UL) as described in Report ITU-R SM.2028-1.

Median path loss

 

Table 80: Description of the median path loss L depending on the distance

where:

   (Eq. 199)

                                                            

   (Eq. 200)

         (Eq. 201)

when L is below the free space attenuation for the same distance, the free space attenuation is used instead.

Variation in path loss

The variation in path loss is achieved by applying the log-normal distribution (slow-fading), i.e. a normal (Gaussian) distribution of logarithmic values. The relative standard deviation is given by the following equations:

Table 81: Variation in path loss