A spectrum allocation algorithm in multi-band EONs with farsighted band selection and ISRS impact reduction

Multi-band elastic optical networks (MB-EONs) have emerged as a promising solution to expand the capacity of optical transmission systems by exploiting previously underutilized spectral bands in single-core fibers, thereby addressing the exponential growth of global internet traffic. In this study, we propose a routing, modulation, band, and spectrum allocation (RMBSA) algorithm that intelligently integrates farsighted band selection and inter band stimulated raman scattering (ISRS) impact reduction spectrum allocation to optimize network performance. The farsighted band selection rule adopts a proactive approach by prioritizing bands with the smallest discrepancy between their maximum supported transmission distance and the current path’s required distance. This strategy ensures that the selected band not only meets immediate transmission demands but also maintains long-term spectral efficiency by minimizing unnecessary modulation downgrades. Meanwhile, the ISRS impact reduction spectrum allocation mechanism groups connection requests with similar frequency slices requirements and assigns them to contiguous spectral regions within each band, effectively reducing spectral fragmentation and improving resource utilization. Simulation results demonstrate that the proposed RMBSA algorithm significantly reduces blocking probability, enhances spectral efficiency, and improves the average optical signal-to-noise ratio of accommodated requests. By combining forward-looking band selection with intelligent spectrum allocation, this approach provides a robust framework for scalable and efficient MB-EONs deployment.