Page 231 - Integrated Wireless Propagation Models

M i c r o c e I P r e d i c t i o n M o d e I s 209
I

230 ft 3
1 8 4 ft
1 3 8 ft
82 ft
46 ft
0 ft 0 0.2 0.4 0.6 0.8 1 . 0 1 . 2
Miles from site
FIGURE 4.2.4.2.3 Building blockage loss.

Building height might be an important issue if the antennas are placed on the top of the
building, but this issue is not discussed in this section.
If L ws is the LOS loss of the direct wave reaching the mobile due to the transmitter
of power P and only the building blockage is considered, then the received signal at
erp
the mobile would be
P , = p erp - LOS ( t Mobile) - B (4.2.4.2.2)
L
L
n
Introducing the elevated terrain contour along the radial path from the transmitter
to the mobile and considering only the terrain effect, it is found in Fig. 4.2.4.2.4 that the
mobile is blocked. The knife-edge height h is calculated, and the corresponding diffrac­
P
tion loss L" due to the knife edge h can be obtained from Fig. 3.1.2.3.2.
P
Figure 4.2.4.2.5 is a caption of the tool that provides the gains and losses along the
radial due to the terrain contour and the effective antenna height gains/losses. Those
gains/losses will be added to the received signal P , shown in Eq. 4.2.4.2.3.

230 ft
1 8 4 ft
hp
1 3 8 ft
+
82 ft
...
46 ft
O f t 0 0.2 0.4 0.6 0.8 1 . 0 1 . 2
Miles from site
FIGURE 4.2.4.2.4 Diffraction loss.

!I
�
1 I � :-s; � <--G---- - - - --- - - -- - -1 � !I

-10 dB - - · -10 dB
-15 dB �· -- -- -- -- r- -- -- -- -- +- -- -- -- -- �-- -- -- � -15 d B
0.2 0.4 0.6
--- Gain •••••••••• ••• Loss
Distance (in mile)
FIGURE 4.2.4.2.5 Gain and loss curves.