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Adeunis is about to launch a new range of NB-IoT and LTE-Cat-M1 IoT sensors dedicated to SMART BUILDING applications.
In order to reduce power consumption but also to facilitate the remote operational management of this new range of cellular IoT sensors, Adeunis has chosen to integrate the Lightweight M2M communication protocol.
In this article, you will be able to discover a definition, an example of architecture, as well as the advantages of the Lightweight M2M protocol.
WHAT IS THE LIGHTWEIGHT M2M PROTOCOL?
Lightweight Machine-to-Machine
LWM2M is a communication protocol for operational management, data feedback, provisioning and lifecycle management of machine-to-machine (M2M) and Internet of Things (IoT) devices.
This protocol was defined in 2012 by the Open Mobile Alliance (OMA) SpecWorks.
It is specifically designed for connected devices with constraints (computing capacity, memory space) and is based on :
- A secure data transfer standard called Constrained Application Protocol (CoAP).
- A variety of ready-to-use standard objects such as the IPSO Alliance Smart Objects, for standardised management of data models.
AVANTAGES DU PROTOCOLE LIGHTWEIGHT M2M
Bootstrapping
Mechanism to securely connect a sensor to a platform and manage all necessary keys and certificates
Configuration
Possibility to configure a sensor remotely
Performing certain functions (activation, deactivation, etc.)
Software update
Execution of firmware updates by air (FOTA) in order to implement new functions in the sensor or to correct bugs
Diagnostics
Remote diagnosis of the sensor (battery level, sw/hw version, etc.)
Connectivity management
APN identification, activation, device reboot
Report
Retrieval of sensor configuration parameters
Device error reporting (status change)
Security
Encryption and authentication at device, application and data transport level (PSK, certificates, etc.)
LIGHTWEIGHTM2M PROTOCOL SPECIFICATIONS
Transport
COAP
Security
Native support for DTLS, TLS and Oscore protocols with no performance impact
Native support for certificates and key-based authentication methods
Interoperability
Builds on the Ipso specification to standardise the semantics of data, i.e. how it should be structured to be interoperable
Data encoding
Supports a variety of data encoding formats for device-to-platform and platform-to-device communication, including TLV, JSON and CBOR.
Data management
IPSO or Custom data model
Client registration: Register/Update/De-register
Remote management: Read/Write/Execute/Create/Delete/Write attribute/Discover
Feedback: Observe/Cancel observation/Notify
Consumption
Can work in UDP
Exchanges are optimised
Offers composite operations
Compression of frame headers
Provisioning
Integrated bootstrap process. Automated registration and provisioning.
Device Management
Standard Objects and Resources (IPSO) to perform various sensor management tasks, such as updating parameters.
Firmware update
Integrated and defined by the LWM2M standard.
LWM2M ARCHITECTURE
This diagram describes the 4 logical interfaces (API) used to establish a communication between an LWM2M server and an LWM2M client (an Adeunis sensor for example):
- Bootstrapping: this interface allows the LWM2M bootstrap server to provide the LWM2M Client with information allowing it to register with an LWM2M server: security key, access control and product configuration.
- Registration: this interface allows an LWM2M Client to register with the LWM2M server and report product functionality to the LWM2M server.
Object/Resource access: this interface allows the LWM2M server to access the LWM2M Client’s OIR (Object/Instance/Resource).
Reporting: this interface allows the LWM2M Client to report to the LWM2M Server periodic or event-based changes to the RTI.
LWM2M DATA MODEL
For the exchange of information between an IoT sensor and a server, the LWM2M protocol uses a standardised data model. This data model is hierarchically divided into 3 levels: Object, Instance, Resource
- An LWM2M Object is a specified collection of resources used (and reusable) for a specific purpose, e.g. a software update.
- Before using its functions, an object must be instanced An object can have several Instances, numbered from 0 in ascending order.
- The reusable Resources that constitute an Object represent the static and dynamic properties of the connected IoT product and the embedded software it contains. A resource is exposed by an LWM2M client for use by an application. A resource is read, written or executed.
This standardised set of objects, resources, properties, attributes and operations enables extensibility while maintaining product and application interoperability.
The OMA has predefined a set of standard Objects based on the OMA LWM2M standard. Other standardised objects have been registered by standards bodies or third-party alliances such as the IP for Smart Objects alliance (IPSO).
Some players in the IoT ecosystem, including Adeunis, have also specified so-called CUSTOM objects to address the functional specificities of their products.
In total, more than 300 objects and resources have been specified. The complete list is available on the website
https://technical.openmobilealliance.org/OMNA/LwM2M/LwM2MRegistry.html
The diagram below shows the relationship between an LWM2M Client, an Object and Resources
Thanks to these characteristics, LWM2M is the most suitable protocol for the device management of battery-powered connected objects such as Adeunis SMART BUILDING sensors.
26/09/2022
20 years
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