Syntactic and Semantic Edge Interoperability

The Internet of Things (IoT) has transformed various sectors, from home automation to healthcare, leveraging a multitude of sensors and actuators communicating through cloud, fog, and edge networks. However, the diversity in device manufacturing and communication protocols necessitates interoperable communication interfaces. Most existing IoT interoperability solutions often rely on cloud-based centralised architectures and suffer from latency and scalability issues. This work specifically focuses on scenarios where decisions need to be made with IoT edge devices in real-time, even in situations where there might be internet disruptions, low bandwidth, or no internet connection. While typical IoT interoperability solutions support edge devices, their reliance on cloud-based architectures makes them unsuitable for mission-critical applications, environmental monitoring, or water quality monitoring, where internet connectivity cannot be guaranteed. To tackle these challenges, the project InterEdge proposed a theoretical interoperability model supporting hierarchical decentralised communication between edge devices. The aforementioned framework has four levels to handle network, syntactic, semantic, and organisational aspects of interoperability. As part of the same project, this work focuses on the implementation of the syntactic and semantic levels of the aforementioned framework. This work involves tackling the implementation challenges, particularly considering key issues related to transmission latency and memory requirements. We have created profiles for edge devices and data formats to store their essential and extra information. Using the profiles, communications can be established and maintained seamlessly among edge devices. We have conducted a comparative analysis between InterEdge implementation and three other implementations of established open standards. The experimental results demonstrate that the syntactic and semantic levels of the implemented interoperability solution, InterEdge, significantly outperforms the existing open standards in terms of standard benchmarking metrics such as code size, memory usage, and response latency. The contribution of this paper lies in these implementation results, which provide concrete evidence of the superior performance of our proposed solution, InterEdge, thereby validating its efficacy in real-world IoT scenarios.