Integration of Data Center into the Distributed Satellite Cluster Networks: Challenges, Techniques, and Trends

Benefiting from the distributed concept and ultra-dense constellation deployment, the distributed satellite cluster (DSC) networks have emerged as a promising architecture to enhance single-satellite capability and network capacity. Integrating data center (DC) into the DSC networks can promote the rapid development of satellite internet. This article innovatively proposes the satellite data center networks (SDCNs) framework to accommodate future extensive applications. Networking of the SDCNs suffers network heterogeneity, dynamic change, constrained resources, and multigranular services. To tackle these issues, many key techniques are detailed, including topology control, wavelength assignment and routing, traffic grooming, SDCNs virtualization, and OpenFlow controller deployment. Based on the framework, we conduct traffic grooming to enhance wavelength efficiency and evaluate the proposed grooming schemes through simulations. To heighten the overall resource efficiency, the cross-layer resource scheduling approach is developed enabling physical-layer sources to fulfill the requirements of upper-layer applications. Finally, three promising directions of the SDCNs are discussed.