Fragmentation-aware Routing, Space, and Spectrum Assignment using Ant Colony Optimization

Space division multiplexing (SDM) allows for capacity expansion in the Elastic Optical Network (EON) by providing different spatial paths in the same link for the lightpaths. Thus, in addition to the Routing and Spectrum Assignment (RSA) problem, the Space sub-problem must be tackled during the allocation of resources in an SDM-EON environment. In this work, we propose a fully distributed provisioning algorithm based on the Ant Colony optimization (ACO) metaheuristics with a crankback mechanism to solve the Routing, Space, and Spectrum Assignment (RSSA) problem. The proposed algorithm can mitigate the blocking by taking into consideration the fragmentation caused by the dynamic establishment and release of lightpaths. The obtained simulation results demonstrate the effectiveness of the proposed approach when compared to fragmentation-aware algorithms that rely on the OSPF-TE protocol to gather the network state information while maintaining much lower levels of control overhead.