Avaya WLAN Series, Руководство по установке, Страница: 39 / 110

Determine Range & Clearance
Examples
Avaya Outdoor Antenna Installation Guide 3-13
Examples
Point-to-Point Links
Suppose you are installing a wireless point-to-point link between two Remote
Outdoor Routers as pictured in Figure 3-3 below, where:
■
Both sites have been equipped with a 24 dBi Directional Parabolic Grid
Antenna, connected via 6m.(20 ft.)/10 mm antenna cables.
■
The distance between site
a
and
b
is 25 km. (15.3 mi.).
■
The site is located in the US, which allows the use of FCC approved
equipment.
Figure 3-3 Calculating the Point-to-Point Range
Looking at Table 3-1 on page 3-5, we learn that a High Speed link between two
24 dBi Directional Grid Antennas may cover a maximum distance of 85 Km.(52
mi.), provided that the signal path clearance is 180 m. (590 ft.) or better.
Now let’s calculate the probable range for this example using the introduced
formula:
Range = Maximum Range x Cable Factor x Clearance Factor
Calculate the Clearance effect on Range
In the example pictured in Figure 3-3 on page 3-13, we see a set of trees in the
signal path. Let’s suppose the clearance (
c ) between these trees and the signal
path is only be 45 m (148 ft.).