Performance Modeling of Partitioning and Slicing Spectrum Assignment Schemes in EONs

Routing and Spectrum Assignment (RSA) is a well-known problem in Elastic Optical Networks (EONs), and the literature abounds with numerous heuristic algorithms that attempt to efficiently utilize spectrum and mitigate spectrum fragmentation. However, blocking performance modeling of EONs is a relatively under-explored topic, mainly because of the complexity of handling variable request sizes. In this paper, we analyze three spectrum assignment policies and compare their blocking performance. In the full slicing policy, every request is sliced into multiple one-slot calls. In the partitioning policy, each request size is allocated a dedicated spectrum partition, and each request can be only assigned spectrum from its corresponding partition. The partition with slicing policy is a hybrid of the two - there are dedicated partitions for small request sizes, but large requests are sliced into multiple sub-requests of the smaller sizes and assigned spectrum from those partitions. We obtain expressions for the bandwidth blocking probability for these three policies, and validate the analysis with extensive simulation results. Our results show that partitioning with slicing has the best performance.