6.1 OGC/STA-to-oneM2M Data Model Mapping

According to oneM2M TS-0033 [2] a representation of a non-oneM2M Proximal IoT function/device in a oneM2M-specified resource instance is to be synchronized with the entity that it represents. Thus the OGC/STA data model has to be represented in the hosting CSE. The SensorThings data model is comprehensive and should be regarded as a n:m relational database structure, holding both: - sensor (IoT-data); and - administrative data (like historic locations or historic products IDs).

The IPE shall map the 'result' attribute of an OGC/STA 'Observation' to the 'content' attribute of a oneM2M <contentInstance>, and vice versa as shown in Figure 6.1-1. The data type of the 'result' field of an "Observation" is according to SensorThings API [i.1] 'any' and depends on the 'observationType' defined in the associated "Datastream". The 'content' attribute of an oneM2M instance may be stringified data [3] understandable with the help of the 'contentInfo' attribute. The 'contentInfo' attribute on the oneM2M side may be added by the IPE. The original timestamps, present in the "Observation" as 'phenomenonTime' and in the <contentInstance> as "creationTime," shall be discarded. These timestamps are to be reset by the OGC /STA server and the CSE. They may be transmitted for informational purposes as part of the 'result' or the 'content' fields.

Figure 6.1-1: OGC / STA-to-oneM2M data model mapping