Patent ID: 7773838

Claim:
A method for upgrading a legacy time division multiplexing-passive optical network (TDM-PON) to a wavelength division multiplexing-passive optical network (WDM-PON) based next-generation passive optical network (next-generation PON), wherein the legacy TDM-PON comprises: a central office (CO) having a first optical line termination (OLT); a remote node (RN) having a splitter; a single mode fiber (SMF) connecting the first OLT and the splitter; and a first group of one or more optical network terminations (ONTs) being connected to the splitter by a first group of one or more distribution fibers, and wherein the method for upgrading comprises: in case that the next-generation PON is a WDM-PON, positioning a first apparatus for combining and splitting wavelength bands between the SMF and the first OLT, in order to add a second OLT to be used for the WDM-PON within the CO or within another CO which is located in a position different from the CO, while sharing the SMF; positioning a second apparatus for combining and splitting wavelength bands at a front terminal of the splitter; and installing additionally an arrayed waveguide grating (AWG) within the RN or within another RN which is located in a position different from the RN, wherein the AWG is connected to the second apparatus for combining and splitting wavelength bands and is connected to a second group of one or more ONTs by a second group of one or more distribution fibers.