1. LWM2M Interworking Proxy Procedures ARC Considerations
Group Name: WG2
Source: Gemalto N.V (ETSI) R01
Meeting Date:
Agenda Item: ARC / LWM2M Interworking

2. IW Proxy mechanisms improvements
Rational
There is a need for oneM2M Application to target IOT sensor/actuator in technology-independent way when <container> resource is used (Interworking use case)
The latest <contentInstance> resource and its parent <container> resource are the oneM2M representation for sensor/actuator inside the Hosting CSE
Illustration : the following command could be used to retrieve the value given by a Temperature sensor whatever the interworking technology underneath (LWM2M, OIC .. or “native” oneM2M one)
RETRIEVE Hosting-CSE-Address/the-Hosting-CSE-ID/myTemperatureSensor/la
In similar way, we need to define procedures for Deleting or « Updating » information related to sensors/actuators represented by <container> resources whatever is the sensor/actuator technology behind.
For achieving that goal, oneM2M architecture specification related to <latest> resource has to support minor improvments which any Interworked technology OMA-LWM2M / OIC / AllJoyne should take benefit.

3. IW Proxy mechanisms improvements
Proposal :
oneM2M requests will target <latest> Resource (latest <contentInstance> Resource) for a basic access to retrieve / update and delete (LWM2M) Interworked resources sit behind the Hosting CSE / IPE
In addition, oneM2M request can also target the parent <container> resource to provide extra access capability
In the following slides :
Proposed ARC modifications are exposed
Main mechanisms are explained
This simple proposal should be affordable to any Interworked technologies (LWM2M / OIC / AllJoyne ..)
oneM2M Request
CREATE
RETRIEVE
DELETE
<container> resource
(LWM2M Object Instantiation) 
FFS
Retrieval of partial or complete <container> resource according to parameters of the request
(useful to collect Metadata ..)
LWM2M Object Instance Deletion ( to provoke de- registration)
<latest> resource
LWM2M Object Instance Update
LWM2M Object Instance Retrieval
Delete <latest> resource to make resource obsolete

4. IW Proxy mechanisms improvements
RETRIEVE Data Information from a LWM2M Interworked sensor
oneM2M request :
e.g. : RETRIEVE Hosting-CSE-Address/the-Hosting-CSE-ID/myTemperatureReading/la
IW Mechanisms (RETRIEVE)
0. Prerequisite : the <container> resource myTemperatureReading
has a subscription with the eventType ‘E’ : Subscription Clause
« Retrieval attempt of obsolete or non existing direct child resource for the subscribed-to resource  »
Originator Application sends a RETRIEVE request over Mcc Ref Point
e.g. GET /myTemperatureReading/la
* If the <latest> resource is present and not obsolete
=> Jump to step 6
* else event is triggered according to eventType ‘E’
& NOTIFICATION is sent to IPE
LWM2M GET DATA request
LWM2M DATA retrieved / status
IPE/AE (through Mca) updates of the <latest> resource
<latest> resource with up-to-date information is returned
to Originator Application

5. IW Proxy mechanisms improvements
UPDATE Data Information into a LWM2M Interworked actuator
oneM2M request :
e.g. : CREATE Hosting-CSE-Address/the-Hosting-CSE-ID/myMotorActuator/la <payload>
Reminder : <contentInstance> resource cannot be updated strictly-sensu.
However :
in LWM2M Interworking context, parent <container> resource has maxNrOfInstances=1
clause : “when creating the <contentInstance> resource which violates the policy defined in the parent <container> resource (e.g. maxNrOfInstances) then the <oldest> resource shall be removed from the <container> resource to enable the creation of the new <contentInstance> resource (clause ).
=> so creating <latest> resource in the (LWM2M ) Interworking context , works as a <contentInstance> resource “update”

6. IW Proxy mechanisms improvements
IW Mechanisms (UPDATE)
0. Prerequisite : the <container> resource my MotorActuator has a subscription with the eventType ‘C’ :
Subscription Clause :: « Creation of a direct child of the subscribed-to resource  »
Originator Application sends a CREATE request over Mcc Ref Point
e.g. CREATE Hosting-CSE-Address/the-Hosting-CSE-ID/myMotorActuator/la <payload>
On the Receiver, the CREATE request triggers an event according
to eventType ‘C’ and a NOTIFICATION is sent to IPE
A LWM2M WRITE DATA request is launched by IPE
to update LWM2M context
LWM2M DATA status is back
IPE/AE (through Mca) is likely to transfer status
Status is sent back to the Originator Application
ARC TS-0001 modification :
=> CREATE <latest> procedure has to be added to already existing
RETRIEVE and DELETE procedure

7. IW Proxy mechanisms improvements
DELETE the LWM2M Interworked sensor/actuator
oneM2M request :
e.g. : DELETE Hosting-CSE-Address/the-Hosting-CSE-ID/myTemperatureReading
The Object Instance is removed (and de-registered from the LWM2M context)
IW Mechanism (DELETE)
0. Prerequisite : the <container> resource myTemperatureReading has a subscription
with the eventType ‘B’ set :
Subscription Clause :: «Deletion of the subscribed-to resource »
Originator Application sends a DELETE request over Mcc Ref Point
e.g. DELETE Hosting-CSE-Address/the-Hosting-CSE-ID/ myTemperatureReading
On the Receiver, the DELETE request, an event is triggered according
to eventType ‘B’ and NOTIFICATION is sent to IPE
A related Delete Object Instance is launched in LWM2M Context
Step 3 provokes in return a de-registration of this Instance in the IPE.
5. & 6. as usual

8. IW Proxy mechanisms improvements
Application to IW / LWM2M Contributions List
ARC : IW - LWM2M Retrieve latest
ARC : IW - LWM2M Create latest
ARC : TS-0014-LWM2M_IW Procedures