Fundamental Challenges Toward Making the IoT a Reachable Reality: A Model-Centric Investigation.

Constantly advancing integration capability is paving the way for the construction of the extremely large scale continuum of the Internet where entities or things from vastly varied domains are uniquely addressable and interacting seamlessly to form a giant networked system of systems known as the Internet-of-Things (IoT). In contrast to this visionary networked system paradigm, prior research efforts on the IoT are still very fragmented and confined to disjoint explorations of different applications, architecture, security, services, protocol, and economical domains, thus preventing design exploration and optimization from a unified and global perspective. In this context, this survey article first proposes a mathematical modeling framework that is rich in expressivity to capture IoT characteristics from a global perspective. It also sets forward a set of fundamental challenges in sensing, decentralized computation, robustness, energy efficiency, and hardware security based on the proposed modeling framework. Possible solutions are discussed to shed light on future development of the IoT system paradigm.