Semantic and Cross-Platform Interoperability

In the Internet of Things (IoT) the smart devices can discover their context and build collaborations with other smart devices and services to create value. For example, smart devices in the home can discover each other (directly or through a gateway) and to work together to enhance the comfort and security of the home owner and to improve the power efficiency of the home. When driving into the city, a smart car can interact with smart city services to identify and reserve a parking place and should be able to collaborate with a personal smart phone to facilitate payment. Discovery, understanding and collaboration at this level requires more than just an ability to interact and exchange sensor data. Whereas interoperability is “the ability of two or more systems or components to exchange data and use information" [1] semantic interoperability “means enabling different agents, services, and applications to exchange information, data and knowledge in a meaningful way, on and off the Web” [2].

Semantic interoperability is achieved when interacting systems attribute the same meaning to an exchanged piece of data, ensuring consistency of the data across systems regardless of individual data format. This consistency of meaning can be derived from pre-existing standards or agreements on the format and meaning of data or it can be derived in a dynamic way using shared vocabularies in an ontology-driven approach. In this paper we will use the term "data-model based semantic interoperability" to refer to the former, and "ontology based semantic interoperability" to refer to the latter.

The IoT Platforms have become a central element in every domains like smart home, connected car, fitness, Industry 4.0 etc. But the fragmentation arising due to lack of interoperability among the platforms hinder a quick adoption of the IoT. The EU H2020 project BIG IoT [3] aims to bridge the interoperability gap among current and emerging IoT platforms [4]. Naturally the project exploits semantic web technologies to provide interoperability at IoT applications, services and among platforms. The first step towards that involves syntactic interoperability. It can be achieved through common vocabularies, agree data formats, interface definitions and encodings. The second step builds upon the first step and considers agreed-upon information model for the exposed interfaces and exchanged data. Together the two steps achieve semantic interoperability. The authors have closely examined the interaction of functional elements in the IoT platforms. Five interoperability patterns have emerged from the analysis - (i) cross platform access, (ii) cross application domain access, (iii) platform independence, (iv) platform scale independence and (v) higher level service facades.

To solve these issues, EURECOM participated in an Industrial extension of EU H2020 F-Interop project to jointly develop a semantic interoperability testing tool called SemTest. It supports conformance test and interoperability test.

References

[1] Van der Veer, H., Wiles, A. Achieving Technical Interoperability - the ETSI Approach. 3rd Ed. 2008. ETSI. http://www.etsi.org/images/files/ETSIWhitePapers/IOP%20whitepaper%20Edition%203%20final.pdf  

[2] W3C Semantic Integration & Interoperability Using RDF and OWL - https://www.w3.org/2001/sw/BestPractices/OEP/SemInt

[3] BIG IoT Website - http://big-iot.eu/

[4] A. Brring, S. Schmid, C. K. Schindhelm, A. Khelil, S. Kbisch, D. Kramer, D. L. Phuoc, J. Mitic, D. Anicic, and E. Teniente, “Enabling iot ecosystems through platform interoperability,” IEEE Software, vol. 34, pp. 54–61, Jan 2017.