AnalyticalBP: Analytical Model for Blocking Probabilities Considering Crosstalk-Avoided Approach in Spectrally-Spatially Elastic Optical Networks

Abstract

A well-known drawback of spectrally-spatially elastic optical networks (SS-EONs) is crosstalk, which increases blocking probability; evaluating blocking probability analytically is challenging due to additional constraints. Not surprisingly, all the existing studies at this time mainly use simulation-based techniques to quantify blocking probabilities in multi-core and multi-mode fibers-based SS-EONs. This paper proposes AnalyticalBP, an exact analytical continuous-time Markov chain model for blocking probabilities considering the crosstalk-avoided approach in SS-EONs. AnalyticalBP generates all the feasible states and their transitions while avoiding inter-core and inter-mode crosstalks for both single and multi-class requests. Single-class requests use the same number of slots, whereas multi-class requests adopt different numbers of slots to satisfy clients' requirements. When AnalyticalBP is not tractable due to scalability, we introduce an iterative approximate model for a single-hop link. We further extend the single-hop model for a multi-hop network. We compare AnalyticalBP, the iterative approximate model, and Monte Carlo simulation studies for a single-hop link. Numerical results indicate that the performances obtained by AnalyticalBP and the simulation studies, in terms of blocking probabilities and resource utilization, are comparable, and the accuracy of the iterative approximate model is also acceptable.