ZyXEL Communications ZyAIR B-5000, Руководство пользователя

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ZyAIR B-5000 User’s Guide
Site Planning
A-2
Availability of grounding, good grounding is important in all areas of the world, but in areas prone
to lightning, it is especially critical.
Whether or not strong RF interference exists in the neighborhood, within or adjacent to the
operating frequency.
Specific Considerations
The following information will help you determine site characteristics that are most applicable to your
outdoor wireless bridge and the actions that should be taken.
Weather
It is important to research any unusual weather conditions that are common to the site location. These
conditions include extreme
Rainfall
Fog
Wind
Temperature Ranges.
If extreme conditions exist that may affect the integrity of the radio link, the effects of these conditions
should be considered early in the planning process.
Rainfall
The system discussed in this guide operates at frequencies below 6 GHz, so rain is not a concern.
Except in extreme conditions, attenuation (weakening of the signal) due to rain does not present a serious
problem for frequencies up to the range of 6 to 8 GHz. When microwave frequencies are at 11 GHz and
above, attenuation due to rain becomes more of a concern, especially in areas where rainfall is of high
density and long duration. If this is the case, shorter paths may be required.
Fog
In most cases, the effects of fog are considered to be much the same as rain.
However, fog can adversely affect the radio link when it is accompanied by atmospheric conditions such as
temperature inversion, or very still air accompanied by stratification.
Temperature inversion can negate clearances. Temperature inversions and stratification can cause
ducting, which may increase the potential for interference between systems that do not normally
interfere with each other.
Stratification along with still air can cause severe refractive or reflective conditions with
unpredictable results.