Installation Manual

Tsunami Multipoint Version 1.3 Installation Guide
Specific Considerations
Weather
You should research any unusual weather conditions common to the site location. These conditions can
include excessive amounts of rain, wind velocity, or extreme temperature ranges. If extreme conditions
exist that may affect the integrity of the radio link, take these conditions into consideration early in the
planning process.
Rain
Except in extreme conditions, attenuation (weakening of the signal) due to rain does not require serious
consideration for frequencies up to the range of 6 GHz. When microwave frequencies are at the 10-12
GHz range or higher, attenuation due to rain becomes much more of a concern, especially in areas where
rainfall is of high density and long duration. The systems discussed in this manual operate at frequencies
below 6 GHz, so rain is not a concern.
Temperature
Temperature can adversely affect the radio link when phenomena such as temperature inversion or very
still air accompanied by stratification occur. Temperature inversion can negate clearances; still air, along
with stratification, can cause severe refractive or reflective conditions, with unpredictable results.
Temperature inversions and stratification can also cause ducting, which may increase the potential for
interference between systems that do not normally interfere with each other. Where these conditions
exist, you should use shorter paths and adequate clearance.
Wind
Any system components mounted outdoors are subject to the effect of wind. You should know the
direction and velocity of the wind common to the site. Antennas and their supporting structures must be
able to prevent these forces from affecting the antenna or causing damage to the building or tower on
which the components are mounted. Antenna designs react differently to wind forces. This is known as
wind loading.
BSU and SU Wind Loading
Maximum operational wind speed during operation of BSUs and SUs is 50 m/s (112mph).
Survivable wind speed (tested to equivalent speed) is 90m/s (200mph).
The wind loading effect of the BSU and SU on their respective mounting masts is provided in Figure 1
(BSU) and Figure 2 (SU). The units of force in pounds can be converted to metric units by multiplying by
Chapter 1. Site Planning 8
CPN 63179 Issue Date: 01/24/03