The ONU improves cost and energy efficiency for the PON by entering a sleep mode that disables {TAIL ~ communication} with {HEAD ~ the OLT} to reduce energy consumption when the ONU is idle 
The ONU improves cost and energy efficiency for the PON by entering a sleep mode that disables { TAIL ~ communication } with { HEAD ~ the OLT } to reduce energy consumption when the ONU is idle
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH