Model

LiveObjects Twin Model is a specification of object definitions.

A Twin Model is a tree of objectDefinitions where each objectDefinition includes attributeDefinitions.

Twin Model is compatible with the OMA LWM2M Specifications.

ObjectDefinitionowner:StringobjectDefinitionId:String pathSegment:Stringname:stringdescription:StringminOccurs:IntegermaxOccurs:Integertype:ObjectTypeoperations:List<ObjectOperation>attributes:List<AttributeDefinition>parent:Stringchildren:List<String>ObjectTypeOBJECT,OBJECT_MAPObjectOperationREAD,WRITEAttributeDefinitionpathSegment:Stringname:Stringdescription:StringminOccurs:IntegermaxOccurs:Integertype:AttributeTypeoperations:List<AttributeOperation>AttributeTypeSTRING,INTEGER,UNSIGNED_INTEGER,BOOLEAN,FLOAT,BASE_64,DATE_TIMEAttributeOperationREAD,WRITE,EXECUTEparentchildren*111*1*111*
Figure 1. Overview of Twin Model

  • an ObjectDefinition can have 0, 1 or more children,

  • a root ObjectDefinition has no parent,

  • there is one root Object definition for LwM2M model (objectDefinitionId=urn:oma:lwm2m)

  • direct children of urn:oma:lwm2m are normalized.

Children ObjectDefinition of urn:oma:lwm2m represents LwM2M Objects, where a Twin Model AttributeDefinition represents a LwM2M Object Resource.

For example the Firmware Update LwM2M Object (Object Id=5) has a Resource called PkgName (Id=6):

Firmware Update LwM2M Object 5

landing

Model - ObjectDefinition

Firmware Update Object is represented by the following ObjectDefinition:

Field Value Comment

owner

A public definition has no owner.

objectDefinitionId

urn:oma:lwm2m:5:1.1

Object-definition unique identifier.

For example, objectDefinitionId urn:oma:lwm2m:5:1.1 refers to Object Id 5 in version 1.1 of the oma lwm2m

pathSegment

5

Current segment of the path

name

Firmware Update

Original name

description

…​

Description of the object

minoccurs

0

Minimal occurrence (0 means optional, 1 means mandatory and at least 1 is required)

maxoccurs

1

Maximal occurrence (0 means infinite instances are allowed (unbounded), 1 means maximum 1 instance is allowed

type

OBJECT_MAP

Type of object. possible values are OBJECT, OBJECT_MAP.

- OBJECT means that this is a single object

- OBJECT_MAP means that this object is a map of objects, and that a path of such an object instance is always using a map index.

In LwM2M, every object is of type OBJECT_MAP (except the root node)

operations

[ "READ", "WRITE" ]

Array of possible operations on the object. Possible values are READ, WRITE.

- READ : when applied on an Object, it means a READ operation for all the available Attributes of the Object.

- WRITE when applied on an Object, it means a WRITE operation on all the Attributes of the Object

parent

urn:oma:lwm2m

The objectDefinitionId of the parent object. All LwM2M objects are direct children of urn:oma:lwm2m.

attributes

[…​, {"pathSegment" : "6", "name" : "PkgName", "minoccurs" : 0, "maxoccurs" : 1, "type" : "STRING", "operations" : [ "READ"] } ]

A list of AttributeDefinition. For example, list of Firmware Update attributes.

Model - AttributeDefinition

PkgName Resource is represented by the following AttributeDefinition:

Field Value Comment

pathSegment

6

Current segment of the path

name

PkgName

Original name

description

…​

Description of the attribute

minoccurs

0

Minimal occurrence (0 means optional, 1 means mandatory and at least 1 is required)

maxoccurs

1

Maximal occurrence (0 means infinite instances are allowed (unbounded), 1 means maximum 1 instance is allowed

type

STRING

Type of attribute. Supported values are : STRING, INTEGER, UNSIGNED_INTEGER, BOOLEAN, FLOAT, BASE64, DATETIME.

- STRING : represented as UTF-8 string.

- INTEGER : represented as ASCII signed integer 1, 2,4 or 8 bytes

- UNSIGNED_INTEGER : represented as ASCII unsigned integer 1, 2,4 or 8 bytes

- BOOLEAN : represented as ASCII value 0 or 1

- FLOAT : represented as a 32 or 64-bit floating point values

- BASE64 : represented as a sequence of binary octets

- DATETIME : represented as a Unix Time. A signed integer representing the number of seconds since Jan 1st, 1970 in the UTC time zone

operations

[ "READ", "WRITE", "EXECUTE" ]

Array of possible operations on the attribute. Possible values are READ, WRITE, EXECUTE.

- EXECUTE, only on an attribute, it means a EXECUTE operation on the Attribute of the Object

Model management

In the Twin Model, we distinguish two types of models:

  • public models that are defined for the entire LiveObjects platform. For LwM2M, the ObjectIDs can range from 0 to 32768.

  • custom models that are defined per LiveObjects account. For LwM2M, the ObjectIDs are restricted to the 10241 - 42800 range.

For a given ID, the custom model takes precedence over the public model if both exist.
For the LwM2M protocol, models with IDs between 10241 and 32768 are published by the OMA, so care should be taken when defining a custom model in this range as it may override a public model for the account.

More details on the different ObjectID classes defined by the OMA for LwM2M can be found in the LwM2M Registry.

Public model

Objects from public range are managed by LiveObjects.

A (managed) public object definition :

  • has an empty owner attribute.

Public object definitions can’t be removed.

Custom model

A customer can extend the model by importing new Custom Object definitions.

This extension is called "Customer defined twin model". This model will apply for all twin devices of the customer account.

Using Twin Model Management API you can import a custom LWM2M OMA compatible XML Files, or delete a given customer model.

See this chapter for examples of Twin Model Management API usage which give you how to manage your custom objects.

Custom model limits

Some limits on custom models apply :

  • The number of custom model per tenant is limited.

Version 2026.7.0 • Updated date 2026-08-11 12:37:29 UTC