In the examples provided herein, a system has a plurality of arrayed waveguide gratings (AWG) having a plurality of input ports and a plurality of output ports. A signal within a given wavelength channel transmitted to one of the input ports of a given AWG is routed to one of the output ports of the given AWG based on a signal wavelength. The system also has a plurality of nodes, with each node comprising a set of components for each AWG that the node is coupled to. Each set of components comprises a plurality of optical transmitters, where each optical transmitter is tunable over multiple wavelength channels within a different wavelength band; a band multiplexer to multiplex the multiple wavelength channels within each different wavelength band; and a first output fiber to couple an output of the band multiplexer to one of the input ports of a first AWG.