5.3 Types of Interworking

LWM2M IPEs provide the following types of interworking:

1. Interworking using the Content Sharing Resource for transparent transport of encoded LWM2M Objects that are available to AEs as depicted in Figure 5.3-1.
2. Interworking with full mapping of the semantics of LWM2M Objects to semantically enabled resources that are available to AEs as depicted in Figure 5.3-2.
3. Interworking with one-to-one mapping of LWM2M Objects to oneM2M <mgmtObj> resources as depicted in Figure 5.3-3.

While depicted outside the hosting CSE, the Content Sharing Resources are hosted in a CSE (e.g. CSE1).

Figure 5.3-1: LWM2M Transparent Interworking Function

In Figure 5.3-1, the LWM2M Objects are provided by the LWM2M Application to the LWM2M IPE using the LWM2M Protocol. The LWM2M IPE then encapsulates the LWM2M Objects in Content Sharing Resources and then hosts the Content Sharing Resources in a CSE using the Mca reference points for use by AEs. The AE accesses the Content Sharing Resource from the CSE that hosts the resource using the Mca reference point. Once the AE receives the Content Sharing Resource, the AE extracts the LWM2M Object from the Content Sharing Resource for the AE's purpose. Clause 7 describes this type of interworking in greater detail.

Figure 5.3-2: LWM2M Semantically Enabled Interworking Function

In Figure 5.3-2, the LWM2M Objects are provided by the LWM2M Application to the LWM2M IPE using the LWM2M Protocol. The LWM2M IPE then interworks the LWM2M Objects into Content Sharing Resources. The Content Sharing Resources are based on the oneM2M defined Semantic Ontology. The LWM2M IPE hosts the Content Sharing Resource in a CSE across the Mca reference for use by other AEs. The AE accesses the Content Sharing Resource from the CSE that hosts the resource using the Mca reference point. Once the AE receives the Content Sharing Resource, the AE encodes the information using the Semantic Ontology for the AE's purpose. Clause 8 describes this type of interworking in greater detail.

Figure 5.3-3: LWM2M Translation Interworking Function

In Figure 5.3-3, the IPE is provisioned with knowledge of the resource definition for a LWM2M Object and the corresponding oneM2M <mgmtObj> XSD, which shall be generated as described in TS-0005 [5]. The XSD shall map each LWM2M resource of a particular LWM2M Object ID to an [objectAttribute] in the corresponding oneM2M <mgmtObj>. The ordering of the [objectAttribute] in the XSD shall match the same order of resources defined in the corresponding LWM2M Object. For a given LWM2M Object, the IPE shall create a corresponding <mgmtObj> resource on the CSE and configure the mgmtSchema attribute with a URI of the XSD file for that <mgmtObj>. All AEs can then access the <mgmtObj> the same way they access other oneM2M resources. Clause 9 describes this type of interworking in more details.

An instance of a LWM2M IPE shall provide the capability for transparent transport of encapsulated LWM2M Objects as Content Sharing Resources and/or translation of LWM2M Objects as oneM2M semantically enabled Content Sharing Resources or as mapped oneM2M <mgmtObj> resources.