On routing, spectrum and network coding assignment problem for transparent flex-grid optical networks with dedicated protection

Abstract

Network coding (NC) is a revolutionary technique that fundamentally changes the traditional operations of networks to achieve better performance thanks to the excellent feature of in-network data manipulation. In optical networks, the failure recovery problem presents a ripe environment for applying NC and indeed, NC-based protection has marked a major departure from traditional protection schemes as it could potentially challenge the well-established trade-off between recovery time and resource efficiency. As elastic optical networks (EONs) have been widely accepted as the paradigm for next-generation optical core networks and the all-optical network coding technologies have been progressing quickly and maturing, this confluence features great opportunities for leveraging the network efficiency. In taking advantage of such opportunities, this paper conceives a perspective of integrating the all-optical XOR network coding to the dedicated path protection in EONs to boost the spectrum utilization efficiency while retaining the merit of near-instantaneous recovery capability. The proposal on NC-backed dedicated protection scheme empowers the conventional 1+1 routing and spectrum allocation with a new dimension on network coding assignment for improving network performance. We thus introduce a new research problem, called 1+1 routing, spectrum and network coding assignment and formulate it as an integer linear programming model aiming at maximizing the network throughput under capacity-constrained conditions. Numerical evaluations on realistic topologies highlight the efficacy of our proposal with a remarkable performance improvement as more than 20% traffic, in average, could be further accommodated in comparison with the traditional 1+1 counterpart.