Static impairment-aware multicast session provisioning in metro optical networks

Abstract

This work investigates the static impairment-aware multicast routing and wavelength assignment (IA-MC-RWA) problem for transparent Wavelength Division Multiplexing (WDM) metro networks. The IA-MC-RWA problem, known to be NP-complete, is first formulated mathematically as an integer linear program (ILP) taking into account a number of impairments encountered by the multicast connections at the physical layer. Efficient heuristics are also developed to solve the multicast routing problem with practical network size parameters. To evaluate the heuristics, their optimality is first examined by comparing their performance results to the results of the ILP for a small-sized network. Their performance is subsequently evaluated over a practical-sized problem. The proposed Q-based Steiner Tree (QBST) heuristic that takes the physical layer impairments (PLIs) into consideration during the provisioning phase of the multicast tree, outperforms the rest of the multicast routing heuristic algorithms developed for comparison purposes and provides results closer to the optimal compared to the ILP.