The embodiments of the invention relate to a system for improving {HEAD ~ energy} and cost efficiency in {TAIL ~ a passive optical network} 
in
The embodiments of the invention relate to a system for improving { HEAD ~ energy } and cost efficiency in { TAIL ~ a passive optical network }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL