A survey on challenges of Spatial Division Multiplexing enabled elastic optical networks

Elastic Optical Networks (EON) emerge as a viable solution to support the current growing demand for bandwidth. With the application of multi-core fibers (MCF) in EON links, it is possible to increase the availability of spectral resources and explore the spatial dimension. An EON network with MCF enables Space-Division Multiplexing (SDM), allowing the use of more resources in fibers and increasing the capacity of attending circuit requests. However, the use of SDM brings some problems of interference between the circuits in fiber, with greater emphasis on inter-core crosstalk interference. In this survey, some important concepts around EON are presented, along with the characterization of SDM supporting equipment. The impact of crosstalk interference between fiber cores is discussed, with the elements responsible for its occurrence. The Routing, Modulation, Spectrum, and Core Allocation (RMSCA) problem is also characterized, and some solutions currently found in the literature are evaluated. The goal is to show the performance of different allocation techniques, in terms of the circuit blocking ratio. This survey is concluded with an evaluation of the state-of-art, and a presentation of the main challenges found from a systematic review of the related literature.