Hi-LION: Hierarchical large-scale interconnection optical network with AWGRs [invited]

This paper proposes Hi-LION, a hierarchical large-scale interconnect optical network, exploiting high-radix arrayed waveguide grating routers (AWGRs) in hierarchy to achieve very large scale and low latency interconnection of many computing nodes. By using the unique wavelength routing property of AWGRs together with electrical switching inside the processors, Hi-LION can scale beyond 100,000 nodes. A comparison with a legacy fat-tree network with a 3:1 oversubscription ratio shows that Hi-LION can achieve 2.5-fold throughput increases while using less than 20% of the global switches and cables.