Regenerator-Aware Inter-Core and Inter-Mode Crosstalk-Avoided Resource Allocation for Spectrally-Spatially Elastic Optical Networks

Optical regenerators are beneficial in resource utilization as they provide additional functionalities, such as modulation format (MF) and spectrum conversion, besides signal regeneration. In spectrally-spatially elastic optical networks (SS-EONs), regenerators can perform core and mode switching, which further improves the spectrum utilization. For the first time, this paper proposes a regenerator-aware routing, spectrum, core, and mode allocation model while avoiding inter-mode and inter-core crosstalks during resource allocation to enhance the spectrum utilization in SS-EONs. The proposed model performs core/mode switching operations at the regeneration sites along with spectrum and MF conversions. Apart from the regeneration sites, the proposed model maintains the spectrum continuity, spectrum contiguity, core continuity, and mode continuity constraints in the remaining intermediate nodes. We model the regenerator-aware resource allocation as an integer linear programming to minimize the highest utilized spectrum slot index under the condition that a limited number of regenerators with their placement are given in the network. We introduce a heuristic when the optimization problem is not tractable. Numerical results indicate that the proposed model improves resource utilization compared to a benchmark model that does not consider core and mode switching.