An Evolution Method From a TDM-PON With a Video Overlay to a WDM-PON

We propose an evolution method from a time-division-multiplexing passive optical network (TDM-PON) with a video overlay to a wavelength-division-multiplexing (WDM)-PON as a next-generation access network. In order to establish a smooth evolution path, a single type of three-port wavelength band combiner/splitter (WC) was used at the remote node and optical network terminations. At the central office, a four-port WC was used to combine the TDM-PON, the video overlay, and the WDM-PON. Crosstalk among those signals is negligibly small.