Utilizing Synchronous Flooding for Reliable and Scalable SDN in Low-Power Wireless Networks

The adoption of Software Defined Networking (SDN) within traditional networks has provided operators the ability to manage diverse resources and easily reconfigure or re-purpose networks as requirements change. Recent research has extended this concept to IEEE 802.15.4 low-power wireless networks, which form a key component of the Internet of Things (IoT). It is, however, difficult to apply the high-overhead approach of SDN, which requires both regularly scheduled and reactive asynchronous communication, to the low-bandwidth, unreliable environment present in IEEE 802.15.4. Although recent research has attempted to address this issue through optimization, interoperability with the low-power IPv6 stack inevitably results in trade-offs and contention with other protocols. This paper introduces Atomic-SDN: a low-latency, reliable, and energyefficient cross-layer architecture for SDN control in low-power wireless networks. Atomic-SDN utilizes synchronous flooding, which has recently been shown as a highly capable solution for fast and reliable communication in low-power mesh networks. Additionally, Atomic-SDN introduces cross-layer architecture to satisfy the different traffic patterns required by SDN, through configuration and scheduling of multiple synchronous flooding protocols. Using this approach, controller communication is facilitated at theoretical lower bounds of latency. We demonstrate the practicality of Atomic-SDN through emulation, with extremely high reliability and minimal latency as the mesh scales; presenting end-to-end delivery ratios of over 99.99% for SDN traffic, and controller association within milliseconds as opposed to seconds. We evaluate the Atomic-SDN in comparison to other SDN architectural configurations for IEEE 802.15.4, showing how Atomic-SDN improves SDN performance by orders-of-magnitude across latency, reliability, and energy-efficiency metrics.