An Energy-Efficient and Obstruction-Free Design Scheme for FSO-based Data Center Network

With the rapid growth of Internet applications, the massive demand for cloud services has brought challenges to data center networks (DCNs). Traditional wired DCNs adopt multi-layer structure, which makes high-layers switches easily congested. Furthermore, complex cabling in wired DCNs affects the flow of cold air, reduces the cooling efficiency and increases energy consumption. To reduce flow congestion and power consumption problems and eliminate complex wiring, in this paper we introduce an architecture for intra-DCN based on free space optic (FSO) wireless communication. The proposed scheme exploits spatial position of FSO transceivers at different heights to realize obstruction-free transmission for inter-rack requests. We formulate the transceiver arrangement problem into a mathematical model while satisfying the requirement for direct line-of-sight communication between any pair of transceiver nodes. Moreover, we evaluate the performance of the proposed scheme via simulation in terms of flow completion time, server throughput, and power consumption. Compared with traditional ones, our scheme can considerably decrease power consumption while obtaining better network performance.