RSS: a relay-based schedule scheme for optical data center network

The ever-increasing communication requirements have led to the introduction of optical circuit switch (OCS) to data center, which is capable of providing more flexible bandwidth allocation compared to the electrical packet switching. However, the challenge still arises due to non-negligible reconfiguration delay of commercially available MEMS-based optical circuit switching technology, even though it provides high bandwidth with low per-bit cost and power. Additionally, existing scheduling schemes amortize long switch delay by means of reconfiguring OCS every a few 100 s of milliseconds, not only causing the degradation of the latency performance, but also incurring the low utilization of optical links. In this paper, we propose an OCS-based scheduling scheme called relay-based schedule scheme (RSS), which can leverage idle optical paths to forward traffic from remote nodes only with straightforward software modifications on controller. We evaluate the performance of the proposed scheme via OMNET++ simulator, and the results demonstrate that our proposal delivers significant benefits, including reducing the average mice flow FCTs (flow complete time) by up to 80% and reducing the end-to-end packet delay by 50% compared to non-RSS schemes.