Comparing Gigabit PON Technologies: ITU-T G.984 GPON vs. IEEE 802.3ah EPON
GPON systems enable the service provider to provide 2.5Gbps converged data and voice services for the last mile, in a cost-effective and bandwidth-efficient manner. There is a growing concern that weaknesses in the efficiencies of the Ethernet protocol will create major obstacles to use Ethernet as a transport mechanism for access in the last mile. Specifically, many Ethernet access implementations provide as little as 50% of usable bandwidth to the service provider and may be inadequate to support legacy TDM and Voice. Moreover, EPON supports only ODN (Optical Distribution Network) Classes A and B, while GPON also supports ODN Class C required by service providers all over the world.