Building Dynamic and Dependable Component-Based Internet-of-Things Applications with Dawn

The Internet of Things (IoT) embeds sensors, actuators and computation into everyday 'things' such as lights and thermostats. These things form low-power wireless networks connecting to the Internet via IPv6 for monitoring and control. Such IoT systems are increasingly subject to runtime reconfiguration, wherein new hardware and software may be installed dynamically to accommodate changing application objectives. Supporting runtime reconfiguration, while maintaining reliability and low-power operation requires cross-layer optimisation of network resources. This paper introduces Dawn, a network optimisation approach for component-based systems that automatically extracts and enforces bandwidth requirements from component compositions. Dawn allows application developers to build extremely flexible and yet dependable IoT networks. We implemented a prototype of Dawn for a 50-node testbed composed of state-of-the-art embedded IoT devices. Our evaluation shows that Dawn preserves 100% end-to-end reliability in the face of network reconfiguration, while extending battery lifetime three-fold compared to a one-size-fits-all network configuration with minimal memory and performance overhead.