At present, the maximal transmission distance between the optical line terminal (OLT) and optical network unit (ONU) of an Ethernet passive optical network (EPON) system is 20 km. However, this distance should be extended to 50 km or even longer in some applications such as fiber to the village (FTTV). A method for extending the transmission distance of an EPON system is proposed in this paper, in which the optical power amplifier and the adjustment of dynamic bandwidth allocation (DBA) are the key technologies.
