Multipassive-star-coupler hub for metro WDM networks

We consider a metro wavelength-division-multiplexing network in which a hub connects the local networks to the backbone network. In many recent studies, the hub is made up of an arrayed waveguide grating (AWG). In this letter, we use multiple passive star couplers (PSCs) to construct the hub and allocate wavelength channels to its input-output pairs based on the traffic requirements. The resulting hub, called the multipassive-star-coupler hub or multi-PSC hub, can provide the same communication functions as AWG hubs and two additional functions: 1) it can efficiently transport nonuniform metro traffic via nonuniform channel allocation within the hub and 2) it can easily be scaled up by adding more PSCs for handling the ever-increasing traffic load.