Design of Multicast Routing and Wavelength Assignment in Multifiber WDM Mesh Networks for Asymmetric Traffics

This paper proposes new mathematical formulations for solving the multicast routing and wavelength assignment (MC-RWA) in multifiber WDM mesh networks for asymmetric traffics. We investigated MC-RWA problems in three different MC-RWA network design approaches namely light-tree (LT), partial virtual light-tree (PVLT), and virtual light-tree (VLT) meshed network. Given a static multicast asymmetric traffic set, the number of wavelengths a fiber can support, and the network design approach (LT, PVLT, or VLT), we seek to realize the minimal number of fiber requirements. Numerical results on a small test network are given for highlighting the key characteristics of each MC-RWA strategies. Based on the test network, the numerical results demonstrate that in most cases PVLT and VLT networks require fewer fibers than LT network, signifying that wavelength conversions can be useful for reducing fiber requirements in asymmetrical multicast environments using mesh design approaches. Nonetheless, conversion is not always needed, as partial wavelength converter allocation appears to be as effective as full allocation with respect to capacity requirement under certain network environments.