If the IBS modem 28 is external to the receiving circuitry 91, then {HEAD ~ a A/D converter} 96 converts {TAIL ~ the analog signals} back into digital signals 
If the IBS modem 28 is external to the receiving circuitry 91 , then { HEAD ~ a A / D converter } 96 converts { TAIL ~ the analog signals } back into digital signals
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH