Throughput Maximization Leveraging Just-Enough SNR Margin and Channel Spacing Optimization

Flexible optical network is a promising technology to accommodate high-capacity demands in next-generation networks. To ensure uninterrupted communication, existing lightpath provisioning schemes are mainly done with the assumption of worst-case resource under-provisioning and fixed channel spacing, which preserves an excessive signal-to-noise ratio (SNR) margin. However, under over-provisioning scenario, SNR margin restricts transmission bit-rate or reach, leading physical layer waste stranded capacity. tackle this challenging problem, we leverage iterative feedback tuning algorithm provide just-enough margin, so as maximize throughput. Specifically, proposed implemented three steps. First, starting from high setup, establish integer linear programming model well heuristic throughput by solving problem routing, modulation format, forward error correction, baud-rate selection, spectrum assignment. Second, optimize spacing lightpaths obtained previous step, thereby increasing available resources. Finally, iteratively reduce each until cannot be increased. Through numerical simulations, confirm improvement different networks baud-rates. In particular, find that our enables over 20\% relative gain when over-provisioned, compared traditional method preserving