Cross-layering consideration for network and quantum resources-aware quantum-secured networking

Quantum-secured networking constitutes a layering architecture comprising a user network and a quantum key distribution network (QKDN). In the wavelength division multiplexing-based quantum-secured optical networking, wavelength and quantum key are scarce resources in the user network and QKDN, respectively; hence, an effective resource dimensioning algorithm is required for practical quantum-secured services. Therefore, we investigated a resource dimensioning problem for the standardization-compatible quantum-secured networking model, where a data routing path in the user network and a quantum key relay path in the QKDN are interdependent. As benchmarking solutions, we first developed integer linear programming (ILP) formulations for wavelength resource and quantum key resource optimal quantum-secured networking. To obtain the tractable solution, an iterative heuristic algorithm was proposed, in which a path of a quantum-secured service was calculated by considering the statuses of both wavelength and quantum key resources. Simulation study on practical backbone topologies revealed that the proposed heuristic algorithm reduced manifold order-of-magnitude in the algorithm computation time at the costs of acceptable overheads in the wavelength and quantum key resources, from those of the ILP optimizations.