Effect of Link Margin on Capacity Benefits in Multi-Core Optical Fiber Networks

Multicore fibers (MCF) promise high capacity benefits to sustain future broadband traffic growth while deploying additional optical equipment like spatial multiplexers and hierarchical optical cross-connects. Therefore network operators will need to exercise usage of additional link margins (LM) as a precaution against equipment degradation that may prevent lightpaths operating at high capacity. However, LM can be reduced by deploying in-line optical performance monitoring (OPM) equipment while incurring additional costs. This paper accounts for the capacity benefits of operating with lower LM while accounting for the cost-per-bit-sec (cpbps) incurred in each LM operation region. Our results indicate that MCF fibers can provide 4.5 times the capacity compared to the traditional single-mode fiber (SMF) network at LM 0 dB while incurring an additional cost of 375 OPMs with a channel launch power of 0 dBm. However, similar capacity benefits can be achieved while reducing channel launch power to -1.5 dBm at LM 2 dB with a lower cost of 309 OPMs. Hence in this paper, we comprehensively correlate the effect of operating with a lower LM, and channel launch power while elaborating upon its trade-offs with cpbps metrics.