Interfaces between the segments include {HEAD ~ cellular type links} 127, 129 between {TAIL ~ users} and aircraft and feeder links 137, 139 between aircraft and ground stations 
between
Interfaces between the segments include { HEAD ~ cellular type links } 127 , 129 between { TAIL ~ users } and aircraft and feeder links 137 , 139 between aircraft and ground stations
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH