Rf Fingerprints Too Large; Two Rf Fingerprints Appear To Be The Same; Walk-Through - Nortel 2340 Configuration Manual

RF Fingerprints too large

While capturing RF Fingerprint data during calibration it involves the following two distinct motions:
• standing in the center of the RF Fingerprint for the first half of the calibration interval
• walking in a circle for the second half.
If the circle traversed during the second part of the calibration interval is larger than 15 ft in diameter, then the Evaluator
will flag the RF Fingerprint as being too large. If you really want to secure the entire area traversed during the original
calibration, then split the RF Fingerprint into an appropriate number of smaller RF fingerprints. Else, recalibrate making
sure that the diameter of the circle traversed for the offending RF Fingerprint is not greater than 15 ft.
Note.
likely means that there is some type of obstruction nearby, such as an elevator
shaft, not that the person traversed too large a circuit during the original
calibration. Obstructions will produce this type of error, because they cause a
dramatic drop in the signal strength coming from the calibration device, making the
Nortel WLAN Location Engine Tracking Engine think that the person has walked
too far from the center of the RF Fingerprint. To fix this problem, you may need to
add another Location AP to compensate for the interference being caused by the
obstruction.

Two RF Fingerprints appear to be the same

When the Nortel WLAN Location Engine Tracking Engine isn't able to distinguish between two RF fingerprints in
different locales, the Evaluator flags this as critical because you may experience tracking inaccuracies and performance
degradation.
For either of these RF Fingerprint overlap conditions, a number of factors can be evaluated before choosing the correct
fix, and so the Evaluator does not indicate a specific fix.

Walk-Through

To test the ability of the Nortel WLAN Location Engine Tracking Engine to transition you from one locale to another,
based on the RF Fingerprint data collected during the Calibration phase, you walk through all locales holding a wireless
device.
Simply connect to the Nortel WLAN Location Engine Console and the Monitoring section to see where the device is
tracked during the walk-through (see 'Fine-tuning the Tracking Engine' chapter on Monitoring for more details).
When you cross the boundary between two locales, the Server can shortly update the web page with the new locale and
RF Fingerprint. If it takes too long, or if the wrong location is displayed, make a note of the trouble spot and move on.
Once the entire walk-through is finished, follow the instructions in 'Calibrating the Tracking Engine' chapter to identify
the cause of these problems and choose the proper fix.
If an RF Fingerprint is still flagged as being too large after recalibration, it
Nortel WLAN - Location Engine 2340 Configuration - Using Interfaces
Nortel WLAN Location Engine 2340 Web GUI 39