Performance Evaluation of Conventional Spectrum-Allocation Policies for C+L Band Elastic Optical Networks

Multiband elastic optical network (MB-EON) technology is a promising solution to support the exponential traffic growth in optical backbone networks. For C-band-only systems, optimal routing and spectrum allocation (RSA) policies have been investigated in the context of EON to enhance its spectrum utilization. However, for a multiband system, the same allocation strategies may not provide the best performance due to the presence of heterogeneous, complex, non-linear, physical-layer impairments (PLI), such as inter-channel stimulated Raman scattering (ISRS). This paper investigates the performance of the state-of-the-art spectrum-allocation policies in different geographies with different channel launch power for C+l band systems. Simulation results show that the Last-Fit policy performs best in terms of traffic admissibility, blocking probability, resource utilization, contiguous aligned available slot ratio (CAASR), and quality of established lightpaths.