On-demand routing, modulation level and spectrum allocation (OD-RMSA) for multicast service aggregation in elastic optical networks.

The light-tree based multicast service aggregation (LT-MSA) scheme provides a cost-efficient method to accommodate a large number of finer-grained multicast services in optical networks. However, when multiple multicast services that do not have exactly the same requesters are aggregated together, some fiber links will be allocated with redundant spectrum. This shortcoming causes high spectrum consumption and narrow application range. In elastic optical networks (EONs), leveraging node architecture that supports both optical multicasting and bandwidth-variable spectrum selection, we consider on-demand routing, modulation level and spectrum allocation (OD-RMSA) for the LT-MSA scheme. It improves resource utilization by allocating spectrum on each link according to the desired multicast services of downstream destination users of this link. We also define the maximum aggregating group (MAG) to eliminate node adjacent redundancy on each link. An Integer Linear Programing (ILP) model and a heuristic approach are developed to realize the OD-RMSA strategy. Simulations show that the OD-RMSA strategy can eliminate spectrum redundancy and greatly reduces transceiver consumption than the light-tree scheme. Moreover, it can also greatly reduce spectrum consumption than the conventional consistent routing, modulation level and spectrum allocation (C-RMSA) strategy.