Device tracking concepts and features 15Nortel WLAN - Location Engine 2340 Configuration - Using InterfacesCalibrationCalibration refers to the process where the Nortel WLE2340 Tracking Engine collects the RF Fingerprint data thatuniquely identifies a Locale. Calibration is accomplished by directing the Nortel WLE2340 to collect traffic from aspecific 802.11 wireless device while physically located in the area corresponding to the RF fingerprint. Based on the RFfingerprints you collect and bound (associated) to each Locale, the Tracking Engine will be able to accurately andprecisely locate any wireless device.EvaluatorAfter calibration, run the Evaluator. It flags locations where the Nortel WLE2340 Tracking Engine has trouble in recog-nizing and indicates how to correct the problem. The Evaluator examines the calibration for problems such as missing,conflicting, or inconsistent data to determine if it is adequate for the Tracking Engine. Hence, it is not necessary to havelive wireless devices in the building when the Evaluator is run.For any problem, a simple fix is to include in the body of the report, recalibrate in order to capture new RF data,eliminate or split an RF fingerprint or replace on line a Location AP.Once all the fixes are done, you can rerun the Evaluator to verify their effectiveness. The process of running the Evalu-ator, fixing the flagged problems, and rerunning the evaluator can be repeated until the Evaluator does not detect anycritical problems.WalkthroughsTo catch any remaining accuracy and to detect all latency problems, it is necessary to perform a test run of the systemwith live wireless devices called a walkthrough. When you perform a walkthrough, you do not have to test every squareinch of the space. The Nortel WLE2340 Tracking Engine will report your location accurately and with acceptablelatency when you are in the center of a locale. The only two areas you need to concentrate while you do yourwalk-through are the transitions between locales and the borders between locales. Is your new position reported accu-rately soon after you enter the new locale or when you are standing just inside the border between locales? If you need tobe far into a locale before the Tracking Engine reports your device's new position, or the wrong locale is reported, youneed to refer to Fine Tuning information in 'Calibrating the Tracking Engine' chapter to diagnose and correct theNote. Unusual building RF dynamics, malfunctioning Location APs, or incorrect execution ofthe calibration procedure will effect the Nortel WLE2340 Tracking Engine's ability to accuratelyrecognize RF fingerprints and the Locales that contain them.Note. For overlapping RF fingerprints tracking problem - see ‘Deploying Location APs’ chapterof this manual, since there are more than one possible cause and the fix involves evaluating anumber of factors.