Redline Communications AN-50, User Manual

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AN-50 System User Manual
Redline Communications …..solving the first mile challenge .
A fade margin graph for this link budget is given in Figure 39 below for four conditions:
LOS (a - blue line), OLOS with the first Fresnel zone obstructed (b - red line), NLOS
scattered trees and buildings (c - green line) and heavily treed residential NLOS (d -
magenta line).
Figure 39: Fade Margin Graphs For LOS, OLOS and NLOS
The graph assumes a fade margin of 3 dB. The effects of rain at 5.8 GHz bands are
negligible, hence are not included in the link budget.
It is important to note the link calculation assumes that the Earth’s curvature is not
blocking the propagation path. The equation for determining the distance at which the
Earth will cause blockage is called the Radar Horizon, and is given as follows:
R
h
=
) ( 1 . 4
2 1
h h
+
(km)
where,
h
1
is the height of terminal 1 (m)
h
2
is the height of terminal 2 (m)
The table below specifies the horizon distance (km) that can be achieved for different
terminal heights ranging from 10 to 70 m above mean terrain level.
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