Tridental Resource Assignment Algorithm for Spectrally-Spatially Flexible Optical Networks

Abstract

Recent advances in Spectrally-Spatially Flexible Optical Networks (SS-FONs) have enhanced service provisioning by leveraging elastic optical transmission with a fine-grained and flexible frequency grid, multiple spatial modes (fiber cores), and a variety of advanced modulation formats (MFs) to increase the capacity of optical fiber. An important lightpath resource assignment problem in SS-FONs is the routing, modulation, core, and spectrum assignment (RMCSA) problem. Crosstalk (XT) between connections on different cores degrades the quality of transmission, and the RMCSA algorithm must ensure that XT constraints are met while maximizing performance. In this paper, we propose an RMCSA algorithm called Tridental Resource Assignment algorithm (TRA), as it balances network capacity, spectrum utilization and spectrum fragmentation that affect network performance. Our resource assignment approach includes both an offline/static network planning component and an online/dynamic provisioning component. In the former, MFs and spectrum utilization are used to compute path priorities for a lightpath. The dynamic provisioning component then allocates the resources on a selected path using TRA. Extensive simulation experiments performed in realistic network scenarios indicate that TRA significantly reduces the bandwidth blocking probability (BBP) in a variety of scenarios by maintaining a good balance between spectrum utilization and XT.