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Cisco Confidential - Draft 1
2-5
Cisco Aironet 1500 Series Outdoor Mesh Access Point Hardware Installation Guide
OL-9977-05
Chapter 2 Mounting Instructions
Avoiding Damage to Radios in a Testing Environment
Each year hundreds of people are killed or injured when attempting to install an antenna. In many of
these cases, the victim was aware of the danger of electrocution, but did not take adequate steps to avoid
the hazard.
For safety, and to help you achieve a good installation, please read and follow these safety precautions.
They may save your installer’s life!
1. Select your installation site with safety, as well as performance in mind. Remember: electric power
lines and phone lines look alike. For safety, assume that any overhead line can kill.
2. Call your electric power company. Tell them your plans and ask them to come look at your proposed
installation. This is a small inconvenience considering your installer’s life is at stake.
3. Plan your installation carefully and completely before you begin. Successful raising of a mast or
tower is largely a matter of coordination. Each person should be assigned to a specific task, and
should know what to do and when to do it. One person should be in charge of the operation to issue
instructions and watch for signs of trouble.
4. When installing the access point and antennas, remember:
a. Do not use a metal ladder.
b. Do not work on a wet or windy day.
c. Do dress properly—shoes with rubber soles and heels, rubber gloves, long sleeved shirt or
jacket.
5. Use a rope to lift the access point. If the assembly starts to drop, get away from it and let it fall.
6. If any part of the antenna system should come in contact with a power line, don’t touch it or try to
remove it yourself. Call your local power company. They will remove it safely.
If an accident should occur call for qualified emergency help immediately.
Avoiding Damage to Radios in a Testing Environment
The radios on outdoor units (bridges) have higher transmit power levels than radios on indoor units
(access points). When you test high power radios in a link, you must avoid exceeding the receiver’s
maximum receive input level. At levels above normal the operating range, packet error rate (PER)
performance is degraded. At even higher levels, the receiver can be permanently damaged. To avoid
receiver damage and PER degradation, you can use one of the following techniques:
• Separate the omnidirectional antennas by at least 2 ft (0.6 m) to avoid receiver damage or by at least
25 ft (7.6 m) to avoid PER degradation.
Note These distances assume free space path loss and are conservative estimates. Required
separation distances for damage and performance degradation levels in actual deployments will be less
due to non line-of-sight propagation conditions.
•
Reduce the configured transmit power to the minimum level.
• Use directional antennas and keep them away from each other.
• Cable the radios together using a combination of attenuators, combiners, or splitters to achieve a total
attenuation of at least 60 dB.