To avoid interference, {TAIL ~ neither} of {HEAD ~ these inter segment interfaces} uses terrestrial cellular operating frequencies 
To avoid interference , { TAIL ~ neither } of { HEAD ~ these inter segment interfaces } uses terrestrial cellular operating frequencies
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH