{HEAD ~ Channel detection} is accomplished by means of counting the number of negative acknowledgements, which classifies {TAIL ~ the channel degradation level} and determines which alternatives to be adapted in order to combat specific blockage phenomenon 
classifies
{ HEAD ~ Channel detection } is accomplished by means of counting the number of negative acknowledgements , which classifies { TAIL ~ the channel degradation level } and determines which alternatives to be adapted in order to combat specific blockage phenomenon
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH