Extending the Internet of Things

This article proposes a theoretical and practical extension of the IoT, taking in all "things" that can be sensed by sensors, without requiring them to be fitted with a tag or a digital network interface. These physical entities, whatever they may be (legacy appliances, passive items, subsets of physical space), become nodes of a broader network, extending the internet of sensor/actuator devices. We explain how such an evolution for environment-to-information interfaces draws upon a similar, long-standing evolution of human-to-information interfaces. Multisensor acquisition of physical context supports this extended IoT, bypassing the need for network-ready identification of target entities. We describe a three-layer reference architecture for an infrastructure supporting the integration of applications into the extended IoT. We show on a few examples how this can expand IoT applications and endow them with features of robustness, scalability and self-configurability.