Handbook of Propagation Effects for Vehicular and ... - Courses

Earth-Satellite Propagation Effects Inside Buildings 8-27
Table 8-15: Median decorrelation distances at each building location.
Building Median Decorrelation Distance (m)
Commons 1.1
EERL 0.5
Farmhouse 0.85
House 0.55
MER 0.7
Motel 0.55
Overall Average 0.71
8.4.5 Relative Signal Loss Versus Frequency
An example of the trend of the relative signal loss versus frequency over the interval
500 MHz to 3000 MHz at a fixed location in the Farmhouse is given in Figure 8-18. The
trend slope of -0.006 dB/MHz is shown to exist over the frequency interval between
500 MHz and 3000 MHz. The trend slope should not be confused with the smaller scale
frequency slope FS given by (8-6) which characterizes the change of signal level per
MHz of bandwidth. The indicated trend slope in Figure 8-18 implies that over the
frequency interval of 2500 MHz (500 MHz to 3000 MHz) the attenuation trend is such
that the signal level is diminished by approximately 15 dB. An overall summary of the
trend slope statistics is given in Figure 8-19 where all positions within each building are
considered. We note that the Farmhouse represents an extreme case for the trend loss as
all the other sites have significantly smaller values.
Signal Level (dB)
-5
-10
-15
-20
-25
-30
-35
-40
y = -11.51 - 0.006*x
-45
500 750 1000 1250 1500 1750 2000 2250 2500 2750 3000
Frequency (MHz)
Figure 8-18: Dependence of relative signal level with frequency in the Farmhouse. The
trend slope is shown to be -0.006 dB per MHz.