Light-tree configuration for multicast traffic grooming in WDM mesh networks

Recent advances in wavelength-division multiplexing (WDM) technology will provide bandwidth intensive multicast applications with large transmit capacities. This article provides two new grooming schemes that lead to efficient resource utilization in WDM networks. They are called Light-Tree Division-Destination Branch Node-based Grooming scheme (LTD-DBNG) and Light-Tree Division-Adjacent Node Component-based Grooming scheme (LTD-ANCG). These schemes are based on the idea of dividing a light-tree into smaller sub-light-trees. They improve the efficiency of resource utilization and also lower the optical-electronic-optical conversion overhead. We use computer simulations to evaluate the performance of these schemes. Our simulations demonstrate that compared with existing algorithms, these schemes significantly reduce the request blocking probability (BP) but can be implemented with very reasonable electronic processing, with LTD-ANCG performing better than LTD-DBNG but with greater complexity. We also evaluate the BP of these schemes considering variations in the add/drop ratio and demonstrate that a proper choice of this ratio will provide target BP with low network costs.