LightPointe AireLink 60, Installation And User Manual, Page: 32 / 133

AireLink
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60 Installation and User Manual Rev. D Surveying the Installation Site
Page 32
2.4 ANTENNA LOCATION
For proper operation and easy maintenance the optimum location for the antennas must be
determined. The ideal location should provide for ease of erecting and mounting the antenna, as well
as providing unimpeded LOS to the remote location. The following factors should be taken into account:
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Type of mounting—fixed installation or non-penetrating roof pole mounting
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Access location of fiber/RJ-45 cables and power wiring of the building
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Length of cable runs
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Earth Grounding connection points
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Potential obstructions (also temporary), including allowances for tree growth
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Accessibility of the radio mounting location
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Accessibility of the site during and after working hours
2.5 ATMOSPHERIC AND RAIN ATTENUATION OF MILLIMETER WAVE BEAMS
Millimeter wave systems operating in the 60 GHz frequency ranges are able to transmit and receive
high data rates such as 1250 Mbps (Gigabit Ethernet) over short to medium distances. The actual
distance/availability performance of a specific system depends on parameters such as transmission
power, antenna size, and receiver sensitivity. In general terms millimeter wave frequencies are
attenuated by rain and additionally by oxygen absorption in the case of systems operating in the 60
GHz frequency range. Oxygen absorption plays a minor role in the higher 70/80/90 GHz millimeter
wave frequency ranges and therefore these systems are typically better suited in establishing a
connection over longer distances. Millimeter wave transmission does not suffer from attenuation in fog
or during sand storms. Figure 2-2 shows the typical atmospheric attenuation of signals in different
frequency bands.
Figure 2-2: Atmospheric attenuation of signals at different frequencies.