Ontologies used for oneM2M
Ontologies and their OWL representations are used in oneM2M to provide syntactic and semantic interoperability of the oneM2M System with external systems. These external systems are expected to be described by ontologies.
The only ontology that is specified by oneM2M is the oneM2M Base Ontology, as described in TS-0012. The oneM2M Base Ontology is the minimal ontology (i.e. mandating the least number of conventions) that is required such that other ontologies can be mapped into oneM2M.
External organizations and companies are expected to contribute their own ontologies that can be mapped (e.g. by sub-classing, equivalence..) to the oneM2M Base Ontology. That way oneM2M data can be supplemented with information on the meaning/purpose of the data.
The oneM2M Gitlab page (see link below) contains an example with the SAREF ontology.
Syntactic interoperability allows for interworking with non-oneM2M devices. In this case an ontology - represented as an OWL file - that contains the specific types of communication parameters (names of operations, input/output parameters, their types and structures, etc.) of the non-oneM2M device types is used to configure an Interworking Proxy Entity to a oneM2M solution. This Interworking Proxy for ontology based interworking is described in TS-0030.
Semantic interoperability can be achieved by mapping ontologies from external organizations – possibly with the help of intermediate ontologies – ultimately onto the oneM2M Base Ontology.
The oneM2M Base Ontology can be found at the oneM2M Gitlab page: https://git.onem2m.org/MAS/BaseOntology.
At that page you will also find an example of an OWL file, containing the sub-classing and sub-Properties relationships between SAREF and the oneM2M Base Ontology.