Installation Guide

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Cisco Aironet 1560 Series Outdoor Access Point Hardware Installation Guide
Chapter 2 Installing the Access Point
Safety Warnings
Caution Before connecting or disconnecting a power cord, you must remove power from the power cord using a
suitable service disconnect.
For safety and to achieve a good installation, please read and follow these safety precautions:
• 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.
• Call your electric power company. Tell them your plans, and ask them to come look at your proposed
installation.
• 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.
• When installing the access point and antennas, remember:
– Do not use a metal ladder.
– Do not work on a wet or windy day.
– Do dress properly—shoes with rubber soles and heels, rubber gloves, long sleeved shirt or
jacket.
• Use a rope to lift the access point. If the assembly starts to drop, get away from it and let it fall.
• If any part of the antenna system should come in contact with a power line, do not 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 maximum
receive input level for the receiver. At levels above the normal 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 are less if
conditions are not non-line-of-sight.
•
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.
For a radiated test bed, the following equation describes the relationships among transmit power, antenna
gain, attenuation, and receiver sensitivity:
txpwr + tx gain + rx gain - [attenuation due to antenna spacing] < max rx input level