ARC R02 Modelling operations – problem statement and proposal Group Name: ARC#19.3 Source: Joerg Swetina, NEC, Meeting Date: Agenda Item:

Problem 1: The Cleaning Robot’s Dilemma I have 2 s for – destination X coordinate – destination Y coordinate CREATing a new starts me moving.. (my AE gets notified) – But you cannot “CREATE” the two at the same time How do I avoid going first to X and later to Y ? (and get bitten by the dog) Problem to be solved: Write multiple application specific variables into the resource in a single operation X Y (X/Y)

Problem 2: Light weight variables Currently AE specific data ( = variables) are stored in s of of the resource. – This allows multiple instances of data, but Is heavy weight Might not be needed Problem to be solved Specify how AE specific data ( = variables) can be stored in the resource with the option to: – allow multiple instances of data of the variable (as currently specified in the / mechanism) – allow storing data of a variable in a simple, application defined, attribute (that can simply be “UPDATE”d). © 2014 oneM2M Partners 3

Problem 3: Associating output to input Consider a “multiplier” AE that – Receives values “3” and “4” for two input variables X and Y of the resource – multiplies the two input variables … this might take some time … – Returns the result “12” in a variable Z In the meantime X and Y may be overwritten with “5” and “6” Problem to be solved When the result “12” becomes available in the variable Z: – How to make sure that “12” is the result of multiplying “3” and “4” and not “5” and “6”? – A single CRUD operation does not allow to write input data into the resource and also receive the result output data.

Problem 4: How to avoid interfering with an operation that is ongoing in the AE? Problem to be solved – Has the operation been triggered in the AE? Has the AE received the input data from the resource? – Has the AE finished sending output data to the resource? – Has the AE finished the operation and is ready for a new operation invocation (even when no input- or output data are involved)? An operationStatus can provide such information and also can serve as a semaphore for oneM2M entities that want to invoke a new operation

Middle Node MN-CSE MN-AE Mca attribute CRUDN input / output data Communication between AEs (example of a MN-AE sending input data to ADN-AE) resource of ADN ADN-AE Application Dedicated Node Mca Step 1 Step 2 … and ADN-AE creating output data that can be retrieved / subscribed by MN-AE Operation invoking oneM2M entity Step 3 Step 4

Area Network Area Network native Device Middle Node MN-CSE MN-AE Mca IPE attribute CRUDN Interworking with non-oneM2M Nodes (example of a MN-AE sending input data to native device via IPE) resource of proxied device IPE proxies native Device into proxied Device input / output data Step 1Step 2 Mca (Non-oneM2M Node – NoDN ) … similarly output data are created / retrieved in the other direction Operation invoking oneM2M entity

Types of features for operations (I) 1.Simple operation setting / reading out a single variable  E.g. CREATE / RETRIEVE of a Child resource of the  E.g. UPDATE a particular attribute (e.g for “Reboot”)  Works well for the simplest case but  does not allow setting / reading out multiple variables  does not allow associating output to input  does not allow to keep a status of the operation  Invoking requires just a single CRUD operation

Improvement: light weight variables (application specific attributes) AE specific attribute AE specific attribute … Needs to have Name (unique within the resource) Value Type (optional) Can be UPDATEd to trigger action in the AE / same as in Rel-1 Note: the Name and Type of an AE specific attribute may also be provided through the information contained in a child-resource of the

Types of features for operations (II) 2.Simple operation setting / reading out multiple variables  Proposal to create new resource type AE specific attribute AE specific attribute … Attributes of an can be UPDATEd at once

Further improvement: references AE specific attribute AE specific attribute … Reference to AE Specific attribute Name (unique within resource) Value = link to Type (optional) Name (unique within resource) Value Type (optional) … 1.) CREATE containing the value of the variable 2.) UPDATE with the reference Note: the Name and Type of an AE specific attribute may also be provided through the information contained in a child-resource of the

Types of features for operations (IIIa) 3.Correlated (2…n) input- or output attributes - no operation state 1.The invoking entity or the AE UPDATEs the resource: Values of input attributes or references are set by the invoking entity. Values of output attributes or references are set by the AE. 2.UPDATE by the invoking entity triggers the action in the AE (AE either gets notified on the UPDATE or polls the ) 3.As a result attributes within the are correlated.

Types of features for operations (IIIb) 3.(0…n) input attributes and correlated (0…n) output attributes _with_ operation state – Similar to previous but contains a standardized operationState attribute. – Invoking entity sets operationState to "Operation_Initiated“ during UPDATE – When AE was triggered and possibly received input (step 2 in figures 5 and 6) the CSE [or AE ???] sets operationState to "Operation_Ongoing“ – When the action of the AE is finished (and the AE had its last UPDATE of the output) the AE sets the operationState to "Operation_Ended“ – Only when Operation_Ended“ the CSE allows an invoking entity to UPDATE the resource again. – Further operationState values (communication errors…) are possible AE specific attribute … operationState Reference to AE Specific attribute …

Types of features for operations (VI) 4.Stack of instances – Multiple instances of an can be put on a stack. – Depending on the capabilities of the AE the individual s could be handled sequentially or in parallel by the AE.

Proposal Introduce light weight variables (application specific attributes) and references (slides 9 and 11) Introduce a new resource type Specify service flows for (slides 12 and 13) Specify the operationState attribute and its minimal number of states: "Operation_Initiated“, "Operation_Ongoing“, "Operation_Ended“ … comments welcome !!!