A multicast contention resolution scheme based on shared spectrum converter for elastic optical switching node

The replication and forwarding of multicast traffic make spectrum contention probability significantly increase in elastic optical switching node. Spectrum conversion is considered as a very appealing solution to resolve spectrum contention without additional delay and traffic reordering at the receiver. In this paper, we propose a multicast switching node architecture configured with limited range spectrum converter (LRSC) and full range spectrum converter (FRSC) for elastic optical switching node. The proposed optical node architecture adopts a group of feedback shared LRSCs and a small number of output shared FRSCs to resolve optical multicast contention in frequency domain. To reduce the bandwidth blocking probability and node cost, a double weights maximal clique scheduling algorithm is designed. The number of frequency slots required by the traffic and the number of used LRSCs are considered as two weights, and graph coloring algorithm is introduced to select the scheduling scheme which uses the minimum number of LRSCs for achieving the maximum total number of frequency slots of output traffics. Simulation results show that the proposed node architecture and scheduling algorithm greatly improve the bandwidth blocking probability performance with relatively lower node cost.