The additional read operation permits interleaving to continue without waiting for {HEAD ~ a next frame} of {TAIL ~ data} to arrive at the interleaver 
The additional read operation permits interleaving to continue without waiting for { HEAD ~ a next frame } of { TAIL ~ data } to arrive at the interleaver
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH