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8.3 Guidelines for Mapping to the Base Ontology

8.3.1 Introduction

Clause 8.2 describes the structure and relationships of the LWM2M Objects and Object Instances along with their associated Resources and Resource Instances. Using that structure this clause provides guidance on mapping the Base Ontology described by [i.5] onto that resource structure. As ontologies are created for specific applications of LWM2M Objects (e.g. Device Management, Home Automation), this clause can only be used for a basis of creating the application specific ontology because certain elements of base ontology (e.g. Aspects, Functionality, Services) cannot be inferred by the LWM2M definitions of LWM2M Objects, Object Instances, Resources or Resource Instances.

8.3.2 Mapping of the LWM2M Client

LWM2M Clients are represented as <AE> resources and are mapped to an InterworkedDevice. <AE> resources exposed by the LWM2M Server associated with the IPE are mapped to the same Area Network.

8.3.4 Mapping of the LWM2M Object, Object Instance. Resource and Resource Instance

8.3.4.1 Introduction

Editor's note: Is a single sub-clause allowed?

Mapping the LWM2M Object, Object Instance. Resource and Resource Instance to the Base Ontology is based on the following guidelines:

  • LWM2M Clients are mapped to InterworkedDevices
  • LWM2M Objects are mapped to Services and Functionality
  • LWM2M Resources that represent static (configured) properties of LWM2M Objects are mapped to ThingProperties.
  • LWM2M operation of Execute map to Operation and Command
  • LWM2M Create, Update, Retrieve and Delete operations permitted for the LWM2M Object or Object Instances map to Operation and Command
  • LWM2M Resources (including those of type Object Link) are mapped to Input- / OutputDataPoints.
    • Sub-structures of LWM2M Resources are mapped to Variables that are sub-structures of Input- / OutputDataPoints (via the hasSubStructure relation).
      • Read-only LWM2M Resources map to Output DataPoint.
      • Write-only LWM2M Resources map to Input DataPoint.
      • Read-write LWM2M Resources map to Input Datapoint and Output Datapoint with the same instance of a Variable
    • If the LWM2M Object doesn't have a command state, the IPE will instantiate and maintain a <container> resource for command's state. In both instances the LWM2M Resource that represents the command state maps to Output DataPoint.