User's Guide

Sensor Placement using ADSP
After you map out anticipated sensor locations, you can assess the eectiveness of coverage by
correlating site survey data and assumptions discussed previously. You can also use the test procedure
described here to validate sensor location.
Because sensors are passive devices that do not have the capability to transmit data, the process of
determining sensor coverage depends on a reverse site survey process in which a device introduces a
signal in your Wireless LAN, and then the signal is tracked through the facility using the deployed
sensors.
Prerequisites for Sensor Placement
You will need the following documents to help determine sensor placement:
• Floor Plans
• Existing Site Surveys
• Wiring layouts
• Regulatory rules and codes for wiring, construction, materials, etc., where applicable.
You will need the following tools:
• A laptop running AirDefense Mobile 4.0, or later, or Site Scanner.
• An 802.11a/g/n wireless device (wireless client or access point). The ideal output power for this
device (around 40 mW) would be that of a retail quality wireless client card or access point as these
are likely rogue candidates.
Note
A soft access point on a laptop is often an ideal target because it can be Locked On a
channel and is battery powered through being hosted on a laptop.
• Wiring layouts.
• Regulatory rules and codes for wiring, construction, materials, etc., where applicable.
• Access to all areas to be monitored is required during the survey.
Procedure
Follow these steps to plan your sensor placement:
1. Obtain Maps/Layouts of the facility and determine the traversal plan.
2. Start AirDefense Mobile.
3. Turn on the target device ( could be a laptop/PDA with wireless client card). AirDefense Mobile
should detect the target device.
4. Identify the target device in the AirDefense Mobile device tree.and use your mouse to right-click on
it to display a list of options.
5. Use AirDefense Mobile Options to Lock On the channel on which the target device is discovered.
6. Right-click select the device in the Dashboard tree; select LiveView.
7. Focus on Signal Strength in the Decode tab in LiveView. Verify that the target device is being
tracked by AirDefense Mobile.
8. When a wireless client (station) card is being used as a target, significant peaks and valleys are
observable in signal strength as the card rotates through channels probing for any intrusion. The
peaks are indicative of the eective signal strength relative to AirDefense Mobile.
Planning Your Sensor Placement
Legacy Content
1382 Extreme AirDefense User Guide for version 10.5.