US Patent 10341038 Multiplex conversion for a passive optical network

A passive optical network system having a node that is optically coupled to optical line terminals (OLTs), and that is optically coupled to optical network units (ONUs). The node includes at least one fiber link module (FLM), each FLM including an upstream multiplex conversion device (MCD), and a downstream MCD. The upstream MCD receives an upstream optical signal from the ONUs, converts the upstream optical signal to an upstream electrical signal, and transmits a regenerated upstream optical signal to the OLTs. The downstream MCD receives a downstream optical signal from the OLTs, converts the downstream optical signal to a downstream electrical signal, and transmits a regenerated downstream optical signal to the ONUs.