Device to Cloud General Info OMA LwM2M Objects

In this chapter you will learn about the basics of LwM2M objects, instances and resources. Further more you will find a list of currently (September 2025) registered LwM2M objects at the OMA (Open Mobile Alliance).

Open Mobile Alliance and Lightweight M2M Copied!

The Open Mobile Alliance OMA is the standards body that defines Lightweight M2M (LwM2M). OMA’s role is to develop, maintain, and publish the LwM2M specification. LwM2M itself is a standard protocol for device management and service enablement in IoT (e.g. configuration, firmware update, monitoring).

OMA also hosts the object registry , where all official LwM2M Objects are defined and publicly available (see https://github.com/OpenMobileAlliance/lwm2m-registry) .

By providing this framework, OMA ensures interoperability between IoT devices, servers, and ecosystems from different vendors.

👉 In short: OMA defines the rules and the shared “language” (LwM2M) so IoT devices and platforms can work together worldwide.

L2M2M Objects, Instances and Resources Copied!

Pieces of data or actions inside a device can be addressed in the LwM2M model by a triple of hierarchical ordered abstract entities Object, Object Instance, and Resource. This triple is handled in the LwM2M practice as a path in the form /<object-id>/<instance-id>/<resource-id>.

Object An Object can be understood as a template or type of thing that a device can expose. Each object represents a function or feature (for example: Device Information, Firmware Update, Temperature Sensor). Every object has a unique Object ID (e.g. 3 = Device, 5 = Firmware Update, 3303 = Temperature). An object defines what resources exist (like attributes or actions).

👉 Analogy: An Object is like a class in programming or a form template.

Object Instance An Object Instance is a concrete occurrence of an Object on a device. Some objects can exist only once (e.g. the Device object → only one device identity). Others may exist multiple times (e.g. multiple Temperature Sensor instances if a device has several sensors). Each instance has an Instance ID (starting at 0).

👉 Analogy: An Object Instance is like an object created from a class in OOP, or a filled-out form.

Resource A Resource is the smallest piece of data or action inside an object instance. Resources can be:

• Readable data (e.g. current temperature, device serial number)
• Writable settings (e.g. set reporting interval, Wi-Fi SSID)
• Executable actions (e.g. reboot, perform firmware update)

Each resource has a Resource ID within the object definition.

👉 Analogy: A Resource is like a field or method of a class, or an individual question/answer on a form.

LwM2M Object Registry Copied!

As mentioned above OMA publishes the registered LwM2M objects and resource specifications at https://github.com/OpenMobileAlliance/lwm2m-registry .

In the following you find the complete list of the registered objects (September 2025) with a link to its specification files at the OMA registery.