This document explains how to use the
Bridge Range Calculation Utility to determine the range for the
There are no specific requirements for this document.
The information in this document is based on these Cisco Aironet 2.4
GHz and Cisco Aironet 5G Hz Outdoor Link models:
BR340, BR350, BR500
The information in this document was created from the devices in a
specific lab environment. All of the devices used in this document started with
a cleared (default) configuration. If your network is live, make sure that you
understand the potential impact of any command.
Technical Tips Conventions for more information on document
The Cisco Outdoor Bridge Range Calculation Utility is the best tool to
calculate the Fresnel zone, the distance between bridges, cable loss, required
antenna height and the recommended fade margin. Cisco strongly advises you to
use this utility as a part of the site survey to calculate the range
parameters, before you deploy the bridges. This ensures higher throughput and
consistent bridge performance.
The Outdoor Bridge Range Calculation Utility uses parameters that
include regulatory domain, device type, data rate, antenna gain, and a few
others as inputs.
You can avoid connectivity problems with the Outdoor Bridge Calculation
Utility, as this tool helps you to predict the distance between devices. In a
wireless environment without a tool like this, you cannot predict the distance
between the bridges, the height at which you must place the antennas for
maximum throughput, and other variables. This utility also helps you decide on
the type of antenna that you must use in order to cover the distance between
Note: The values that the tool provides are only theoretical. Use these
values only as guidelines to deploy wireless bridges.
Complete these steps to use the Outdoor Bridge Range Calculation
Note: This calculation utility has been edited to stay within limitations
for TX power and Effective Isotropic Radiated Power (EIRP) under the listed
regulatory domains. There might be cases where it exceeds the limitations, and
it is the responsibility of the installing parties to verify that the
installation is within the laws of the location in which it is installed. The
older 2.4 Ghz calculation utility has been retained and can be found at the
last page of this
Go to the
Bridge Range Calculation Utility
. Select the proper Regulatory Domain based upon your approvals for
installation locations. (see 2.4 GHz Regulatory Information or the 5 GHz
Regulatory Information Worksheet).
Select the Product you use for both sides of the link.
Select the Datarate that is used.
Select the Power level for both sides of the link.
Select the Antenna you use on each site. If you use an antenna
other than the Cisco Aironet antenna, specify the gain factor in dBi.
Select the Cables you use on each side. If you use a cable other
than the Cisco Aironet cable, select Other, and type the loss
per 100 feet and length of cable.
Note: These calculations are theoretical.
Note: Line of sight is required.
Select typical environmental conditions in order to match your
The worksheet displays the appropriate isotropic maximum distance in
miles and kilometers, Earth Bulge at above distance, Fresnel Zone clearance for
above distance, Required antenna height above obstructions, and Recommended
Fade Margin (factor of distance)