Abstract

One of the main problems in the design of elastic optical networks is the Routing, Modulation-Level, and Spectrum Assignment problem (RMLSA). In this work, we propose new strategies to solve the spectrum assignment (SA) sub-problem for EONs architectures with static network operation. To this end, we developed two new approaches called Sliding-Fit (SF) and ParcelFit (PF), focused on minimizing the spectrum fragmentation obtained when attending network demands. These strategies change to standard paradigm use to search an amount of consecutive FSUs for a given user by choosing a subset of FSUs in the frequency spectrum and later finding users for the selected FSUs. Additionally, the method relies on a physical-later impairment (PLI) model to compute the maximum optical reach and bandwidth demands based on the modulation level - bitrate pair. Experimental results showed that the proposed algorithms obtain less spectrum fragmentation than the best found in the literature, allowing to assign a higher number of users, decreasing the network capacity or increasing the efficiency in the use of resources.