Cisco Cisco Aironet 1522 Lightweight Outdoor Mesh Access Point Guía De Diseño
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Cisco Mesh Access Points, Design and Deployment Guide, Release 7.0
OL-21848-01
Site Preparation and Planning
illustrates an obstructed Fresnel zone.
Figure 22
Point-to-Point Link Fresnel Zone
Figure 23
Typical Obstructions in a Fresnel Zone
It is possible to calculate the radius of the Fresnel zone (in feet) at any particular distance along the path
using this equation:
using this equation:
F1 = 72.6 X square root (d/4 x f)
where
F1 = the first Fresnel zone radius in feet
D = total path length in miles
F = frequency (GHz)
Normally, 60 percent of the first Fresnel zone clearance is recommended, so the above formula for
60 percent Fresnel zone clearance can be expressed as:
60 percent Fresnel zone clearance can be expressed as:
0.60 F1= 43.3 x square root (d/4 x f)
These calculations are based on a flat terrain.
shows the removal of an obstruction in the Fresnel zone of the wireless signal.
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