6.1 Concept of Representation

In the oneM2M system, any kind of device, application or service or more generally speaking any kind of function that needs to be exposed to oneM2M-specified entities such as CSEs or AEs is represented by instances of specified resource types. Interaction with these termed functions is enabled by executing operations (e.g. create, delete, retrieve, update) on the resource instances. For example, by updating an attribute of a particular resource instance, an AE can change the state of a light actor from on to off. In addition, the concept of subscribing to resource instances and receiving notifications about content changes is also specified in oneM2M to allow for efficient monitoring of resource instances and thus the exposed function(s).

Following that fundamental concept of representing all functions by resource instances and their operations, real world devices or things in Proximal IoT networks that were not designed according to oneM2M specifications including the applications running on devices and/or services provided by devices can be represented by resource instances in the oneM2M system if interworking with those devices or things is needed. The resource instances are digital representations for the real world devices or things that are exposed to other entities in the oneM2M system via the oneM2M-specified interfaces for executing operations on those resource instances. How such resource instances, representing non-oneM2M Proximal IoT functions, are to be created and managed is described in the remainder of the present document. Furthermore, it is also described how to expose functions that are natively accessible in the oneM2M system, via the oneM2M-specified resource types and interfaces, to non-oneM2M Proximal IoT networks.

A representation of a non-oneM2M Proximal IoT function in a oneM2M-specified resource instance needs to be synchronized with the entity that it actually represents. For instance, if an attribute of a resource instance that represents the power state of an external Proximal IoT light is modified, the actual light state needs to be modified accordingly. The remainder of the present document describes how such synchronization is accomplished. Essentially any request targeting the representation of a non-oneM2M Proximal IoT function results in the corresponding interaction with the external device or thing in the Proximal IoT network. Similarly, any action in a non-oneM2M Proximal IoT function that is associated with a representation in the oneM2M system contained in a oneM2M resource instance shall result in an according operation on that resource instance.

Adhering to this concept of representation, oneM2M entities (AEs and CSEs) are enabled to request services or information provided by external non-oneM2M devices or things - termed "non-oneM2M Proximal IoT functions" - in the same way as interaction with native oneM2M devices or things - termed native oneM2M functions - is done.