Design and Evaluation of a Flexible-Bandwidth OFDM-Based Intra-Data Center Interconnect

Data center networks are facing growing challenges to deliver higher bandwidth efficiency, lower latency, better flexibility, and lower cost. Various optical interconnect schemes have been proposed to take advantage of the high bandwidth capacity and low power consumption offered by optical switching. However, these schemes cannot offer flexible bandwidth sharing due to the large granularity in optical circuit switching, and they require costly optical components. In this paper, we introduce a novel data center network architecture based on cyclic arrayed waveguide grating device and multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing technology with parallel signal detection (PSD). This architecture offers flexible bandwidth resource sharing at fine granularity. Other features include high-speed switching, low and uniform latency, and the ability to change the data rates dynamically. By eliminating costly optical components and keeping the core optical router passive and static, the power consumption, hardware cost, and operation cost are reduced. The fine granularity bandwidth sharing and MIMO switching through PSD are verified experimentally. We also propose and evaluate efficient subcarrier allocation schemes to achieve high bandwidth utilization. Finally, we present the implementation of an efficient scheduler for the bandwidth allocation of the proposed scheme.