This Recommendation contains the set of G-PON physical media-dependent requirements and transmission convergence layer requirements that allow extending the maximum differential fibre distance of a G-PON system to 40 km versus the conventional 20 km differential fibre distance, as required by Recommendation ITU-T G.984.1. This Recommendation introduces additional capabilities to the ITU-T G.984-series Recommendations and does not replace other Recommendations in the series. The appropriate ITU-T G.984-series Recommendations should be selected for the intended application and distance requirements.