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