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An attenuation zone is an area where the
signal strength drops over distance. This makes it different from
walls and other obstructions, where the drop occurs only one time,
when the signal passes through a specific object, and where the
object thickness is negligible. To draw an attenuation zone on the
floor plan, press the attenuation zone drawing tool button and
select one of the pre-defined attenuation zone types; for
example “Elevator shaft.” You should select the type that best
matches the actual attenuation zone you are going to draw. Then
left-click on the floor plan to start a new zone, drag the mouse to
form a rectangle, and release the left mouse button to
finish.
After the zone has been drawn,
you can change its properties in the Attenuation Zone
Properties dialog. To
display this dialog, select a zone and double-click on it, or
select the Properties
context menu item. In the
dialog window, you can change the zone type by selecting one of the
existing presets or modify zone characteristics such as attenuation
or color. Attenuation
is a drop in strength measured
in dB per meter (or foot, depending on the measurement units of
your project) that the RF signal experiences when it moves across
the zone. Because materials might attenuate differently at
different frequencies, there are two separate attenuation values
for 2.4 and 5 GHz. You can enter a custom attenuation value. A
custom value can be obtained by measuring signal strength on each
side of the zone, calculating the difference, and dividing it by
the distance. Measurements can be performed using TamoGraph or any
WLAN analyzer; e.g., CommView for WiFi. Color
is an arbitrary color used to
show the zone on the floor plan. If you prefer zones to appear
colorless (i.e., grayscale), you can configure the application to
grayscale them in the Visualization
Settings panel. When
you have edited zone properties, you can save the current
configuration for future use by clicking the Save as Preset
button at the bottom of the
dialog window.
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