{TAIL ~ A transmitting unit} is coupled to the receiving unit and transmits {HEAD ~ the data} to an antenna 
{ TAIL ~ A transmitting unit } is coupled to the receiving unit and transmits { HEAD ~ the data } to an antenna
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH