A network of nodes interconnected by links, such as a wavelength division multiplexing (WDM) ring network, is modeled by a delayed graph in which propagation delay between nodes is accounted for. Given the delayed graph, a traffic matrix for an admissible traffic pattern is scheduled over a frame period. Scheduling of the traffic matrix formulates a set of scheduling constraints based on the delays and decomposes the traffic matrix into a set of transmission matrices. Each of the set of transmission matrices is scheduled over the frame period.