substituting {HEAD ~ means} for substituting a second portion of {TAIL ~ said feedback frame} with said second predetermined bit stream upon determining that said first portion of said feedback frame consists of said first predetermined bit stream; and 
substituting { HEAD ~ means } for substituting a second portion of { TAIL ~ said feedback frame } with said second predetermined bit stream upon determining that said first portion of said feedback frame consists of said first predetermined bit stream ; and
OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL 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