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