Spectrum-Efficiency Analysis for Trench-Assisted and Heterogeneous-Index Multicore Fiber Networks

Advanced multicore fiber (MCF) structures such as trench-assisted (TA)-MCF and heterogeneous index (HI)-MCF have been designed to reduce inter-core crosstalk (XT) in MCFs. However, optical networking studies have been primarily focused on the most common MCF structure, namely, homogeneous (HOM)MCF, where the high XT-levels limit the transmission reach (TR) of lightpaths. In this work, we investigate XT, XT-margin, and modulation selection for the TA-MCF and HI-MCF networks. Calculations for estimation of XT for different MCF structures, core-types, and modulation schemes are presented. We perform routing, spectrum, modulation, and core assignment (RSMCA) under incremental traffic using proactive XT-management schemes, and analyze the spectrum-efficiency of TA-MCF and HI-MCF networks. Simulations indicate that TA-MCF and HI-MCF structures can significantly improve the spectrum-efficiency in backbone optical networks, thus achieving higher lightpath establishment. We also highlight some of the open aspects of TA-MCF and HI-MCF networks.