Edge-centric Distributed Discovery and Access in the Internet of Things

Massive diffusion of constrained devices communicating through low-power wireless technologies in the future Internet of Things will require in many scenarios the deployment of IoT gateways to allow applications to discover and access IoT resources. In this context, Fog/Edge Computing will represent an opportunity to deploy IoT gateways in proximity of IoT domains, meeting the requirements of applications needing low-latency interactions with devices. In this work, we present an Edge-centric distributed architecture to provide resource discovery and access services to IoT applications. The proposed approach leverages the CoRE Resource Directory interface and the CoAP protocol to expose a standard interface for global discovery and access. Multiple IoT gateways are federated through a P2P overlay implemented by a Distributed Hash Table (DHT), which is exploited to share the information on IoT resources available across multiple domains. The proposed solution is validated by means of a small-scale prototype, and extensively evaluated through emulation in large scale deployment in comparison to a centralized Cloud-based approach. Experimental results demonstrated that the proposed approach guarantees lower latencies than a centralized solution and can ensure scalability for small to medium sized deployments.