Clustering Large Optical Networks for Distributed and Dynamic Multicast

For a large-scale mesh network with dynamic traffic, maintaining the global state information in a centralized fashion is impractical. Hence, distributed schemes are needed to organize nodes and to manage state information in a more localized manner. One such effective scheme for organizing nodes is to cluster the nodes into a hierarchical structure. In this paper, we address the problem of determining the appropriate clustering of nodes for providing scalability in wavelength division multiplexed (WDM) optical networks with dynamic traffic. We present an on-line load-based (or bandwidth availability based) clustering technique that determines clusters adaptively in response to current network conditions. We also consider the problem of dynamic multicast on clustered networks with wavelength conversion capability. We introduce a heuristic using an auxiliary graph model to address routing, wavelength assignment, and traffic grooming jointly. Simulation results demonstrate the feasibility of our approach.