In the evolution from EPON to 10G-EPON, a smooth transition is achieved at the central...

IEEE 802.3av (10G-EPON) explicitly enables coexistence of 1G-EPON and 10G-EPON on the same outside plant (ODN) by separating downstream wavelengths (1G ~1480–1500 nm vs 10G ~1575–1580 nm) and using dual-rate TDMA in the upstream (10G uses 1260–1280 nm within the broader 1G band). This wavelength plan and OLT capabilities allow operators to reuse existing ODN and achieve a smooth upgrade via WDM overlays at the OLT. Industry and standards materials emphasize this approach for incremental migration.