Determine Range & Clearance
Determine the Outdoor Range
3-10
Avaya Outdoor Antenna Installation Guide
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In open areas without obstacles in the signal path, clearance is measured
as height above the surface of the earth.
For example, if the antenna is mounted on the roof, this height includes the
height of the building plus the height of the mast above the rooftop.
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In areas with obstacles in the signal path between the two antenna(s),
clearance should be measured as height above the highest obstacle(s) in
the signal path.
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In dense urban areas, the clearance should be measured as height above
the highest rooftop or any other obstacle(s) in the signal path between the
two antenna(s).
Looking at the minimum clearance requirements as identified in Table 3-1 and
Table 3-2, you may realize that local authorities, the proprietor of the premises,
or other reasons may not allow you to set up an antenna mast that will enable
you to meet the listed clearance requirement.
In such situations, you may not be able to achieve a full line-of-sight clearance.
At the same time however, you may not even need full clearance, since the
distance that your wireless outdoor installation needs to cover is less than the
listed maximum range.
To determine the effect of insufficient signal path clearance, you will need to
determine the Clearance Factor as described below, and calculate its effect on
the range for your antenna installation using the formula described in “Determine
the Outdoor Range” on page 3-2.
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If the clearance for your antenna installation is equal to, or better than the
minimum clearance requirement identified in Table 3-1 and Table 3-2, the
Clearance Factor for your installation is 100%.
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If your actual clearance is less than the minimum clearance identified in
Table 3-1 or Table 3-2, you will need use the diagram pictured in Figure 3-2
to determine the actual range that will apply in your situation.