PON
OLT -> Splitter -> ONU L——- ODN —————J
CWDM 2003 1270nm ~ 1610nm 20nm lamda1 ~ lamda18 DWDM 1990 1530nm ~ 1565nm (50GHz 0.4nm, 100GHz 0.8nm, 200GHz 1.6nm) lamda1 ~ lamda40