User guide

March 2005 Designing Your Canopy Network
Through Software Release 6.1
Page 98 of 425 Issue 1
Canopy System User Guide
12.2 ANALYZING THE RF ENVIRONMENT
An essential element in RF network planning is the analysis of spectrum usage and the
strength of the signals that occupy the spectrum you are planning to use. Regardless of
how you measure and log or chart the results you find (through the Spectrum Analyzer in
SM and BHS feature or by using a spectrum analyzer), you should do so
◦ at various times of day.
◦ on various days of the week.
◦ periodically into the future.
As new RF neighbors move in or consumer devices in your spectrum proliferate, this will
keep you aware of the dynamic possibilities for interference with your network.
12.2.1 Mapping RF Neighbor Frequencies
In Release 4.1 and later releases, you can
◦ use an SM or BHS, or an AP in Release 6.1 or later, as a spectrum analyzer.
◦ view a table (or graphical display in Release 4.2 or a later release) that shows
power level in RSSI and dBm for each frequency throughout the entire 20-MHz
range, regardless of limited selections in the Custom RF Frequency Scan
Selection List field of the SM Configuration page.
◦ select an AP channel that minimizes interference from other RF equipment.
You can use this functionality during the alignment of an SM, but you may find it
especially helpful for frequency selection during site planning. The Spectrum Analyzer in
SM and BHS feature provides this functionality.
The SM measures only the spectrum of its manufacture. So if, for example, you wish to
analyze an area for both 2.4- and 5.7-GHz activity, take both a 2.4- and 5.7-GHz SM to
the area. To enable this functionality, perform the following steps:
CAUTION!
The following procedure causes the SM to drop any active RF link. If a
link is dropped when the spectrum analysis begins, the link can be re-
established when either a 15-minute interval has elapsed or the
spectrum analyzer feature is disabled.
Procedure 2: Analyzing the spectrum
1. Predetermine a power source and interface that will work for the SM or BHS in
the area you want to analyze.
2. Take the SM or BHS, power source, and interface device to the area.
3. Access the Expanded Stats page of the SM or BHS.
4. On the Expanded Stats page, click Spectrum Analyzer.
5. On the Spectrum Analyzer page, click Enable.
RESULT: The feature is enabled.