The purpose of {HEAD ~ this feature} is twofold: first, to prevent {TAIL ~ duplication} of a packet transmission, and second, to protect the network from being captured by a single station 
The purpose of { HEAD ~ this feature } is twofold : first , to prevent { TAIL ~ duplication } of a packet transmission , and second , to protect the network from being captured by a single station
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH