# Overcoming Challenges in Large-Core SI-POF-Based System-Level Modeling and Simulation
## 7 Conclusions  
In this paper, we have stressed the need for an accurate comprehensive system-level modeling and simulation framework that allows system designers to explore various design options before building and deploying their particular network. We have presented a review of the fundamental challenges associated with the modeling and simulation of large-core POF-based systems and how we have addressed them at the component and system levels for SI-POF. Specifically, we have described the time domain and the alternative frequency domain approaches to model SI-POF based on the power-flow equation. We then reviewed our approach to modeling various other components, followed by a description of the important system-level modeling considerations. Our approach is rooted in first developing efficient experimentally verified models of the individual components and observed behaviors. Subsequently, the models are used to construct various link or network configurations whose performances are estimated at the system level via typical metrics such as BER and eye diagrams.  
We then described our historical approaches to address our need to model POF-based systems since there was a lack of commercial offerings. Thankfully, commercial software packages are now emerging and we have described an approach based on a custom Simulink library and ModeSYS, which is primarily a glass multimode fiber simulation environment which has more recently been adapted to handle large-core POF-based systems.  
Figure 11: (**a**) Equalized eye at the receiver demonstrating compensation of eye closure. (**b**) Analytical BER estimate in comparison to an ideal reference curve.  
Figure 10: Simulated POF input (**a**) and output (**b**) eyes, showing the effects of intermodal dispersion and mode coupling.  
Our future work will investigate other types of POFs, including various MC SI-POF and GI-POF. The ultimate goal is to again develop reliable models of the components and study them at the system level with an emphasis on high-speed data transmission over these media as we push the limits of POF-based networks. Among other things, the study will naturally involve modulation formats and DSP algorithms for pre- and post-processing at the transmitter and receiver, respectively. Also, the variability of model parameters for the fiber and all the other components will be quantified and more extensively studied at the system level to ensure that the predicted system-level performances are realistic.  
Conceptualization, D.R., A.L., M.A.L., N.A., J.M., X.J. and P.V.M.; methodology, A.L., D.R., M.A.L., J.M., P.V.M., and E.G.; software, D.R., A.L., P.V.M., E.G., J.M., and M.A.L.; validation, M.A.L., J.M., X.J. and P.V.M.; resources, M.A.L., A.L., D.R., N.A., P.V.M., E.G., J.M. and X.J.; writing--original draft preparation, D.R., M.A.L. and A.L.; writing--review and editing, A.L., M.A.L., D.R. and P.V.M.; visualization, M.A.L., A.L., D.R., P.V.M., E.G. and J.M.  
This work was funded by Gobiermo de Aragon (DGA) under grant T20-17R, MICINN/FEDER under grant RTI2018-094669-B-C33, and by the National Science Foundation (NSF) under GOALI grant 1809242. The APC was funded by the NSF.  
The authors would like to acknowledge the many useful discussions and technology gained from interactions with [PERSON] formerly of The Boeing Company, as well as with [PERSON] formerly at Toyota Central R&D Labs.  
The authors declare no conflict of interest.