1. LWM2M Interworking Group Name: Architecture
Source: ALU (TIA) / Gemalto N.V(ETSI)
Meeting Date: TP18
Agenda Item: LWM2M Interworking

2. LWM2M Interworking Reference Model
LWM2M Interworking aims at considering the association of a LWM2M Client and an Interworking Proxy Entity (IPE) as a oneM2M Application Entity (AE) .
LWM2M Application
CSE
LWM2M Protocol
LWM2M
IPE
Mca AE
ASN/MN/IN
Mcc/Mcc’
MN/IN
LWM2M Applications communicate with oneM2M Applications across the Mca&Mcc reference points. 2

3. LWM2M Interworking Transport Types
Transparent Transport
Semantic Transport
The information exchanged between the LWM2M Application and the oneM2M AE are transported in oneM2M <container> resources by either encapsulating or translating the LWM2M objects. 3

4. LWM2M Interworking Functions
For providing the interworking functions several LWM2M aspects have to be considered :
LWM2M Device and Endpoint Lifecycle (Client Registration)
LWM2M Object Discovery (Client Registration, Device Management and Service Enablement)
LWM2M Object Transport and Interworking (Device Management and Service Enablement)
LWM2M Object Subscription and Notification (Information Reporting)
LWM2M Object Security (Device Management and Service Enablement)
LWM2M Client Pre-provisioning (Bootstrap)
LWM2M Interworking Proxy Entity Administration 4

5. LWM2M Interworking Key Points (1)
oneM2M <node> & LWM2M Endpoint
LWM2M Endpoints are instantiated as <AE> resources with the LWM2M Client Endpoint Name used as the AE-ID.
A oneM2M <node> resource is created/associated with the LWM2M Endpoint and should use the LWM2M Client Endpoint Name as the M2M-Node-ID.
oneM2M AEs discover LWM2M Endpoints as <AE> and <node> resources using the labels associated with the resources. 5

6. LWM2M Interworking Key Points (2)
LWM2M Objects and Object Instances are discovered using the Registration Interface of the LWM2M Client. Discovered LWM2M Objects and Object Instances are interworked as <container> resources.
oneM2M AEs discover LWM2M Objects and Object Instances as <container> resources using the labels associated with the resources. 6

7. LWM2M Interworking Modes (1)
3 Interworking Modes are defined (Active, Lazy, Mixed ) for LWM2M, depending on the way oneM2M and LWM2M data information are synchronized.
Interworking Active Mode
The IPE creates the <contentInstance> resource when a LWM2M Object Instance is discovered or created
A LWM2M observation is placed on the Object Instances for any changes to keep the <container> and < contentInstance> resources updated.
Modifications made to the <contentInstance> is reflected back into the LWM2M Client as a write-back operation with a retry mechanism until the <contentInstance> is expired. 7

8. LWM2M Interworking Modes (2)
Lazy Interworking Mode
The IPE doesn’t instantiate the <contentInstance> resource until it is first needed by any CRUD operation
On a RETRIEVE Operation, the IPE goes to the LWM2M client for updating the <contentInstance> resource.
On a WRITE Operation, modifications made to the <contentInstance> is reflected back by the IPE into the LWM2M Client as a write-through atomic operation 8

9. LWM2M Interworking Modes (3)
Mixed Interworking Mode
As in the Lazy Interworking Mode, the IPE doesn’t instantiate the <contentInstance> resource until it is first needed by any CRUD operation
When the <contentInstance> resource is first instantiated, the IPE treats the container as in the Active instantiation method:
a LWM2M observation is placed on the Object Instance for any changes to keep the <container> and <contentInstance> resources updated
Modifications made to the <contentInstance> are reflected back into the LWM2M Client as a write-back operation with a retry mechanism until the <contentInstance> is expired. 9