Proxim TSUNAMI CPN 65756B User Manual

Page of 54
Tsunami MP.11a Antenna Installation Guide
 
To minimize the influence of obstacles, signal interference, or reflections, note the following guidelines: 
▪ 
Mount the antenna as high as possible above the “ground” to allow maximum clearance: 
º  In open areas, “ground” is the actual surface of the earth. 
º  In dense urban areas, “ground” is to be interpreted as the height of the highest obstacle in the 
signal path between the two antenna sites. 
▪ 
Avoid trees in the signal path to avoid signal absorption due to seasonal changes (leaves or ice). 
▪ 
Install the antenna at least 2 m (6 ft) away from all other antennas. 
Other situations, in which reflections of the radio signal may cause interference, are environments where 
large reflecting surfaces exist in parallel or partly perpendicular to the antenna beam. 
Environments with large reflective surfaces include: 
▪ 
Mirror-glass buildings  
▪ 
Crowded parking lots  
▪ 
Water or moist earth and moist vegetation 
▪ 
Above ground power and telephone lines 
Note:  The use of reflective surfaces can be used to improve a link, especially if the direct line-of-sight is 
impaired or absent. 
Weather conditions such as rain or snow usually do not have much impact on the performance of your 
Tsunami MP.11a product, provided you have sealed all cable connectors with weatherproofing tape. 
Seasonal influence on signal propagation can occur in the following situations: 
▪ 
A marginal communications quality in late fall (with no leaves on the trees in the signal path) might fail in 
the summer. 
▪ 
In winter, a wireless link may fail when the antenna is exposed to ice buildup, or when the antenna 
elements are covered with snow. 
Radio paths over water or extremely flat ground may require optimization of antenna height at one end. This 
is due to in-phase or out-of-phase reflections.  Adjustment of antenna height by 1 to 3 meters may move the 
signal from a null to a peak. 
Long distance links may be obstructed b earth curvature, so the antenna height requirements must not only 
take the height of obstructions and Fresnel Zone into account, but also earth bulge.  The earth bulge is 
approximately 5 m (16.4 ft) at a link distance of 16 Km (10 mi). 
In these cases consult your supplier to take appropriate steps to maintain or optimize wireless link 
performance. 
Chapter 1.  Preparing for Installation 
14
 
CPN 65756B 
Issue Date:  August 2003