{TAIL ~ Blockage levels} are first translated into transmission link parameters, from which the methods of bit rate reduction, increasing modem density, or system bandwidth, or {HEAD ~ higher encoding rate} are derived 
{ TAIL ~ Blockage levels } are first translated into transmission link parameters , from which the methods of bit rate reduction , increasing modem density , or system bandwidth , or { HEAD ~ higher encoding rate } are derived
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH