estimating {TAIL ~ one or more network conditions} of a network using a comparison between the certain time and {HEAD ~ the acquired timestamp} 
estimating { TAIL ~ one or more network conditions } of a network using a comparison between the certain time and { HEAD ~ the acquired timestamp }
OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD