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