Detachable Antenna Selection; Detachable Outdoor Antenna Types; Detachable Antenna Selection Tips - Aruba AP-85 Installation Manual

It is evident from
simplification of the real 3-D situation. Often, 2-D plots are reduced even further to a set of simple
specifications based on the antenna gain and 3 dB beamwidth.

Detachable Antenna Selection

Select the correct antenna type to support the required frequency band (2.4 GHz or 5 GHz) and desired
coverage pattern.
To select the correct antenna type for the deployment, download and read Aruba's outdoor antenna
specifications:
N O T E

Detachable Outdoor Antenna Types

These are some of the terms used to describe Aruba's detachable antenna offerings. Terminology and
degree of sector in Aruba's antenna specifications are determined by the horizontal 3 dB beamwidth.
Down-Tilt: An omni-directional antenna that focuses its energy downwards.

Sector/Patch: A directional antenna that provides a focused sector of coverage from a central point

(Example: +/- 45 degrees from a 90 degree center point).
Panel: A flat formed antenna that directs energy to a sector of coverage. This type of antenna is often

ideal for point-to-point WDS bridging or wireless mesh backhaul applications.

Detachable Antenna Selection Tips

If omni-directional coverage is desired with the greatest possible horizontal range from the AP,

select one of Aruba's detachable antennas with high-gain, omni-directional coverage. Due to the
tight vertical beamwidth of high-gain, omni-directional antennas, this typically requires mounting
the antenna not more than 5 meters (16.5 feet) above the expected client locations in elevation.
If omni-directional coverage is desired, but only high mounting locations are available 

(approx. 5 m (16.5 feet) to 10 m (33 feet), consider the use of lower gain (3 dBi to 5 dBi) omni-
directional antennas and a denser AP deployment. The lower gain antenna will reduce the maximum
horizontal range of the AP, but will provide better vertical coverage.
For very high mounting locations (>10 m/33 feet) such as light poles or monopoles, consider the use

of an omni-directional antenna with electrical downtilt. A downtilt omni-directional antenna is an
antennas that has a direction of maximum gain at approximately 45° down from horizontal.
Aruba AP-85 Outdoor Access Point Series
Figure 27 that 2-D pattern plots typically provided in antenna specifications are a
http://www.arubanetworks.com/products/access-points/antennas.php
All figures are shown with a 100 meter (328 feet) mounting height above the ground and for a 
18 Mbps coverage area.
| Installation Guide
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Understanding Antennas | 37