Dynamic unicast/multicast traffic grooming using S/G light-tree in WDM networks

Internet traffic demands are constantly increasing and a considerable amount is expected to be of multicast type. Optical Transport Networks (OTN) must be prepared in terms of better resource utilization, for accommodating unicast and multicast traffic together. Dynamic traffic grooming in optical mesh networks is one of the most important and practical problems for designing Wavelength Division Multiplexing (WDM) based networks. Light-trees have been proposed for supporting multicast connections in OTN. Nevertheless when Traffic Grooming is applied in light-trees, resources can be underutilized as traffic can be routed to undesirable destinations in order to avoid Optical-Electrical-Optical (OEO) conversions. In this paper, a novel architecture named S/G Light-tree for supporting unicast/multicast connections is used. The architecture allows traffic dropping and aggregation in different wavelengths without performing OEO conversions. An on-line heuristic that routes traffic demands minimizing blocking probability by taking advantage of the architecture is proposed. Simulation results show that the architecture improves blocking probability and minimizes the number of used wavelengths when compared to light-trees.