As the handset realizes it is reaching {HEAD ~ the limits} of {TAIL ~ its operating range}, it will identify the cell area he is about to enter 
As the handset realizes it is reaching { HEAD ~ the limits } of { TAIL ~ its operating range } , it will identify the cell area he is about to enter
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH