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

Summary of Recommendations 12-13
12.8 Earth-Satellite Propagation Effects Inside Buildings (Chapter 8)
This chapter deals with propagation effects inside buildings for scenarios in which the
transmitter is located on a satellite or a platform simulating a satellite. Relative signal
losses are characterized in terms of spatial, temporal and frequency effects for different
structure types over a frequency interval of 500 to 3000 MHz.
12.8.1 Required Fade Margins Inside Buildings
Figure 12-5 gives the median, 95% and 5% fading inside six buildings at L and S-Bands.
It is clear that a fade margin of 30 dB is required to achieve reliable communications.
Signal Level Relative to
Copolarized Clear Path (dB)
20
10
0
-10
-20
-30
-40
-50
-60
Co-Polarized Reception
L
S
L
S L
S
L S
Frequency Band and Location
L
Non-Outlier Max...Min
95%...5%
Median
S L
Commons EERL Farmhouse House Motel Store
Figure 12-5: Median, 95%, and 5% fade levels of the relative power losses inside six
buildings at L- and S-Bands.
12.8.2 Fading Dependence on Frequency
Fade differences over 100 MHz frequency intervals may exhibit variations with
frequency as large as 25 dB. When these fade differences are averaged and examined
over a multi-GHz frequency interval, a fading trend of ≤ +3 dB/GHz ensues with
increasing frequency (to 3 GHz).
12.8.3 Distortion Due to Bandwidth
In Figure 12-6 is plotted the standard deviation of signal fading (inside building
structures) versus the bandwidth for frequencies ranging from 700 MHz to 1800 MHz
and bandwidths between 2 MHz and 90 MHz. These results imply that relatively small
distortions should be expected for bandwidths between 1 to 10 MHz (standard deviations
smaller than 1.7 dB in signal fading).
S