Hi everyone
I agree with alistu that NGPON1 systems has already been standardised well before NGPON2 even came up.NGPON1 is basically 10 giga bit capable XGPON system and NGPON2 systems are an improevemnt over the XGPON systems now.The main aim of NGPON2 is to design systems which are backward compatible with NGPON1 systems and support a higher data rate of at least 40 Gb/s in DS and 10 in US compared to the 10 Gb/s support by NGPON1 systems.
G.987 is the standard defined for NGPON1 systems.
Regards