10-Gigabit-capablepassiveopticalnetworks(XG-PON):Physicalmediadependent(PMD)layerspecification-ThisRecommendationpertainstoflexibleaccessnetworksusingopticalfibretechnology.Thefocusisprimarilyonanetworksupportingserviceswithbandwidthrequirementsrangingfromthatofvoicetodataservicesrunningat