Connect Sensor Networks to the Internet of Things

The Internet of Things (IoT) provides unparalleled means to connect the physical world with the digital world, enabling important applications such as Smart Infrastructures, Smart Parking, and Smart Toys. But existing systems are typically proprietary and tailored to one specific application and sacrifice interoperability for low power consumption. This hinders widespread adoption. This PhD thesis presents the scientific outcomes of a three-year research activity on low power IP-based wireless sensor networks. Within the scope of the FP7 CALIPSO (“Connect All IP-based Smart Objects!”) project, this thesis studies limitations and enhancements of the standard IETF/IPv6 framework, which includes the recent RPL (“Routing Protocol for Low Power and Lossy Networks”), 6LowPAN (“IPv6 over Low power Wireless Personal Area Networks”), and CoAP (“Constrained Application Protocol”) protocols, with a deep focus on radio duty cycling. In particular, the thesis contributes to three layers of the low power IP stack: MAC, network, and application. It also investigates cross-layer research challenges related to security in IoT. Each contribution has been implemented as open source software for Contiki OS, Europe's leading smart object operating system, and evaluated through simulations as well as experiments on target IoT-based applications and testbeds.