A hybrid approach for efficient multicasting in WDM networks

Multicasting has emerged as an important service of communication networks. Many approaches have been proposed for multicast tree design for wavelength division multiplexing (WDM) networks. All the existing works however, consider only use of physical resources for tree design using light-trees without taking into consideration existing unicast lightpaths. In this thesis we identify and explore the optimal design problem of multicast tree for WDM networks. Using wavelength sharing among traffic demands of unicast and multicast, we build a hybrid virtual topology which exploits both light-trees and lightpaths. By optimizing WDM resources in addition to resource sharing with unicast, we truly maximize the WDM layer capability and efficiently support multicast traffic demands. Through simulation we demonstrate that our proposed solution indeed can support more multicast traffic demands than light-tree only approach. We also show that as the cost of using lightpaths for tree design increases, more physical resources are used.