Semantic Interoperability in data spaces

Data sovereignty is a central aspect of the International Data Spaces. It can be defined as a natural person's or legal entity's “supreme authority with regard to the digital domain particular to themselves“. The International Data Spaces initiative proposes a Reference Architecture Model for this capability and related aspects, including requirements for secure and trusted data exchange in business ecosystems. 

This paper focuses on the semantic interoperability aspects of data spaces, as interoperability is a key concern in data spaces because, simply put, nothing works without
it. Further, interoperability can be addressed on multiple levels. The New European Interoperability Framework defines an interoperability model with four layers of
interoperability: technical, semantic, organizational and legal. In addition to the new European Interoperability Framework [3], which is applicable to all digital public services, ISO/IEC 21823-1:2019 introduces a five-facet model specifically for IoT systems interoperability: transport, syntactic, semantic, behavioral and policy interoperability. Although they use slightly different names, both frameworks address very similar concepts.

Semantic interoperability enables the exchange of data between entities using understood data information models (or semantic meanings) [8]. According to [3], [9], 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 either in a schema form and/or in an ontology driven approach.