Final report on link level and system level channel models - Winner

WINNER D5.4 v. 1.4
5.6.9 Frequency dependence of the propagation parameters
5.6.9.1 Path-loss and shadowing properties
In the Figure 5.90, the path losses at 5.25 GHz and 2.45 GHz are compared in a rural LOS environment in
the same route. It is obvious that the path-loss functions can be modeled so that the only the difference
between them is the difference between the free-space path-losses, i.e. 6.62 dB.
Figure 5.90: Propagation at 2.45 GHz and 5.25 GHz in rural LOS conditions.
In the figure Figure 5.91, the path losses at 2.45 GHz (a) and 5.25 GHz (b) are compared in a rural
LOS/NLOS environment in the same route. The over-all behaviour of the path loss is almost identical.
a
Figure 5.91: Path-loss at 2.45 GHz (a) and 5.25 GHz (b) measured in the same route.
b
It can be seen that the path losses are almost identical except for the difference due to the free-space
losses. However, we have calculated that there is a difference of 1.7 dB in the overall standard deviation
and a difference of 1 dB in the NLOS standard deviation of the path losses between the centre-frequencies
5.25 GHz and 2.45 GHz. From this we conclude that that the propagation is attenuated more in 5 GHz
than in 2 GHz due to shadowing. We assume that the higher standard deviation is caused by the fact that
the obstacles attenuate more at 5.25 Hz than in 2.45 GHz so that the fades caused by the shadowing are
deeper for the 5.25 GHz. From the measurements we can calculate that the extra loss is about 2 - 3 dB.
For the model we decided to select the value 2.5 dB. For LOS/OLOS conditions we could find a similar
result, but the difference was negligible.
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