Since the location of this smartcard wireless device can be tracked in the airport by normal wireless antenna location means, by GPS, or by {HEAD ~ direction fixing} between multiple antennas, or {TAIL ~ any other tracking means}, the approximate location of the person is known at all times while in any area of the airport or building 
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Since the location of this smartcard wireless device can be tracked in the airport by normal wireless antenna location means , by GPS , or by { HEAD ~ direction fixing } between multiple antennas , or { TAIL ~ any other tracking means } , the approximate location of the person is known at all times while in any area of the airport or building
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