An inband signaling modem communicates digital data over {HEAD ~ a voice channel} in {TAIL ~ a digital wireless telecommunications network} 
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An inband signaling modem communicates digital data over { HEAD ~ a voice channel } in { TAIL ~ a digital wireless telecommunications network }
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