determining {HEAD ~ means} for determining whether a first portion of said feedback frame that is redundant to said data frame consists of {TAIL ~ a first predetermined bit stream} 
determining { HEAD ~ means } for determining whether a first portion of said feedback frame that is redundant to said data frame consists of { TAIL ~ a first predetermined bit stream }
OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL