ComDeX: A Context-aware Federated Platform for IoT-enhanced Communities.

This paper presents ComDeX, a context-aware federated architecture and IoT platform for enabling data exchange between IoT-enhanced communities. Today, such smart communities are highly heterogeneous and siloed as they can offer IoT applications and services only to their local community inhabitants. ComDeX uses property graphs to represent smart community entities and automatically maps them to context-aware publish/subscribe messages. Such messages can be discovered and exchanged between communities via a hierarchical federated topology and an advertisement-based mechanism. The ComDeX prototype is implemented using well-known IoT technologies such as MQTT and NGSI-LD. ComDeX is evaluated using a realistic smart port scenario and compared against different federation topologies. The experimental results demonstrate that our approach outperforms existing NGSI-LD solutions in realistic IoT scenarios with synthetically generated workloads, with low impact in larger deployments where the number of hops between brokers of the federation increases.