{HEAD ~ The pointer value changes} over {TAIL ~ a period} are labeled Extra Long Mega Frame which consists of n Mega Frames 
over
{ HEAD ~ The pointer value changes } over { TAIL ~ a period } are labeled Extra Long Mega Frame which consists of n Mega Frames
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH