The OLT restarts communication with the ONU over the optical line upon receipt of {HEAD ~ data traffic} for {TAIL ~ the ONU} 
for
The OLT restarts communication with the ONU over the optical line upon receipt of { HEAD ~ data traffic } for { TAIL ~ the ONU }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL