The plurality of {HEAD ~ commercial aircraft} in {TAIL ~ flight} at any given time provides extensive geographic coverage including areas currently unserved or underserved by terrestrial cellular systems 
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The plurality of { HEAD ~ commercial aircraft } in { TAIL ~ flight } at any given time provides extensive geographic coverage including areas currently unserved or underserved by terrestrial cellular systems
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH