Expansion-Aware Design for Optical-Circuit-Switched Data Center Networks With Suppressed Fiber Link Rewiring
TL;DR
Numerical results show that the proposed model can reduce the number of fiber link rewirings at the expense of network size, which highlights the practical advantages of the proposed model for designing scalable and reliable OCS-based TF-Clos networks in real data center environments.
Abstract
While optical circuit switching (OCS)-based twisted and folded Clos (TF-Clos) networks offer high scalability, conventional design models address one-time construction and overlook incremental expansions. In actual deployments, such expansions require extensive optical fiber link rewiring, which increases operational complexity and risks service disruption. This paper proposes an expansion-aware OCS-based TF-Clos design model that incorporates multiple steps of network expansion while balancing two conflicting objectives: maximizing the switching network size and suppressing fiber link rewiring operations. We formulate the design problem as an optimization problem, and we introduce a pruning-based search algorithm to approximately solve it with reduced computational time. Numerical results show that the proposed model can reduce the number of fiber link rewirings at the expense of network size. Specifically, the number of rewires is reduced by up to 21.2%, while the decrease in network size is kept within 16.7%. These results highlight the practical advantages of the proposed model for designing scalable and reliable OCS-based TF-Clos networks in real data center environments.