Figure 12: Fresnel Zone - Geokon GeoNet 8900 Series Instruction Manual

FRESNEL ZONE
The Fresnel zone is the geographic area between the sending antenna and the
receiving antenna. Objects in the Fresnel zone can cause reflections of the
transmitted signal. When these reflections arrive at the receiving antenna, they
may be out of phase with the signal that took a straight-line path, and this can
weaken the straight-line signal.
For optimum performance, recommends creating as much vertical
GEOKON
space as possible between the straight-line path and obstacles, including the
ground.
The Fresnel zone must be at least 60% obstruction-free to ensure optimal
wireless communication. The figure below illustrates the Fresnel zone.
12:
Fresnel Zone
Building Building

FIGURE 12: Fresnel Zone

IMPORTANT: If communication cannot be established when GeoNet is
deployed to a site, it may be necessary to elevate the devices or their antennas,
or to move them to a location where a radio link can be established. This may
require extending the readout cable of the attached sensors, or adding an
antenna cable extension.
10 | NETWORK COMPONENTS | GEOKON