Wavelength division multiplexing passive optical network having multiple branches of optical distribution

A wavelength division multiplexing passive optical network (WDM-PON) for performing bi-directional communication, the WDM-PON comprising:

• at least two remote distribution nodes including a first remote distribution node and a second remote distribution node between a central office and a plurality of optical network units, each of the first remote distribution node and the second remote distribution node is located in a physically separate location, wherein the first remote distribution node and the second remote distribution node are connected to each other sequentially, wherein the first remote distribution node has a plurality of band splitting filters, and a first multiplexer/demultiplexer and a second multiplexer/demultiplexer coupled to the plurality of band splitting filters, wherein the first remote distribution node is configured to couple a first composite optical signal and a second composite optical signal to a first optical cable connected to the central office, wherein the first composite signal travels on the first optical cable in a first direction, and the second composite optical signal travels on the first optical cable in a second direction opposite the first direction, and wherein the first remote distribution node is configured to connect to the second remote distribution node coupled to at least two optical network units, wherein each of the first remote distribution node and the second remote distribution node are configured to separate at least one wavelength channel from the first composite optical signal distributed through that remote distribution node, wherein the first remote distribution node has the first multiplexer/demultiplexer coupled to at least two band splitting filters configured to split the first composite optical signal that includes all of the wavelength channels in a first wavelength band into a first subset of wavelength channels and a second subset of wavelength channels.

An apparatus, comprising:

• a first optical network unit including an optical receiver and an optical transmitter;
• and
• means for separating a first composite optical signal that includes all of the wavelength channels in a first wavelength band into at least three smaller groups consisting of subsets of the wavelength channels in a transmission path between a central office and a plurality of optical network units, wherein the first composite optical signal is sequentially separated along the transmission path at least three times, wherein the means for separating includes a first remote distribution node connected sequentially to a second remote distribution node which is connected sequentially to a third distribution node via at least one filter to generate the at least three smaller groups consisting of subsets of the wavelength channels, wherein the at least one filter is configured to couple the first composite optical signal and a second composite optical signal to a first optical cable connected to the central office, wherein the first composite signal is transmitted on the first optical cable in a first direction, and the second composite optical signal is transmitted on the first optical cable in a second direction opposite the first direction, wherein the second remote distribution node comprises at least two filters coupled to at least two optical network units, and the third remote distribution node comprises a multiplexer/demultiplexer.