Exploring Performance Metrics and Scalability Challenges in a Three-Tiered Multi-Granular 10 Pb/s SDM/UWB Optical Node

We investigate the scaling potential and compute critical performance metrics of a three-tiered hierarchical optical node architecture. The optical node incorporates novel Photonic Integrated Circuit (PIC)-based WaveBand Selective Switches (WBSSs) to implement flexibly-defined band switching, across spatial lanes and degrees of connectivity, ranging from entire optical fibers, flexible-defined bands to individual wavelengths. We also develop a network simulator considering node's multiple switching layers, multiple/portion of bands and all key optical transmission parameters. Simulations reveal high optical Signal to Noise Ratio (OSNR) and low Bit Error Rate (BER) values, particularly for the Full Fiber Switching (FFS) scenario. Moreover, we analyze trade-offs among scalability, component number and complexity, and throughput across various configurations and traffic scenarios. Our results confirm high levels architecture adaptability and efficiency in addressing the evolving demands of future optical networks.