Optimizing Spatial Channel Networks (SCNs) in Hierarchical Optical Cross-Connect (HOXC) architectures: Impact of wavelength switching granularity on performance

The increasing demand for network bandwidth highlights the critical need to enhance optical transmission systems. Utilizing the entire C-band for a single optical channel(OCh) eliminates the requirement for wavelength switching, prompting the emergence of spatial channel networks (SCNs). SCNs transform the optical layer into hierarchical spatial division multiplexing (SDM) and wavelength division multiplexing (WDM) layers through the implementation of hierarchical optical cross-connects (HOXCs). A HOXC comprises a spatial channel cross-connect (SXC) for spatial bypass switching and multiple wavelength cross-connects (WXCs) for wavelength channel switching, ensuring efficient optical transmission. Therefore, the design of the HOXC plays a pivotal role in determining both the device cost and network performance in SCNs. This study investigates the impact of wavelength switching granularity on core-selective switch (CSS)-based HOXC architectures. We propose an adaptive dynamic Routing, Spatial Channel, and Spectrum Assignment (RSCSA) algorithm to solve routing and resource allocation problems in SCNs. By examining SCN designs with varying wavelength switching granularities, we assess the overall network deployment cost, considering both network throughput and spectrum resource utilization. Our findings indicate that adjusting the granularity of wavelength switching in SCNs can significantly affect device costs and performance, highlighting the importance of identifying an optimal SCN design that strikes a balance between these factors. These insights offer valuable guidance for the practical planning and management of future SCN deployments.