An output then outputs the synthesized audio tones to {HEAD ~ a voice channel} of {TAIL ~ a digital wireless telecommunications network} 
An output then outputs the synthesized audio tones to { HEAD ~ a voice channel } of { TAIL ~ a digital wireless telecommunications network }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL