The receipt time is used for estimating program clock reference adjustments, but final program clock reference adjustment is performed in {TAIL ~ hardware} in relation to the precise output timing of {HEAD ~ each transport packets} 
The receipt time is used for estimating program clock reference adjustments , but final program clock reference adjustment is performed in { TAIL ~ hardware } in relation to the precise output timing of { HEAD ~ each transport packets }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD