OMA Lightweight M2M ontology

URL

https://sites.google.com/site/smartappliancesproject/ontologies/omalwm2m.ttl

Description

The OMA LWM2M architecture is based on a client component, which resides in the LWM2M Device, and a server component, which resides within the M2M Service Provider or the Network Service Provider. Each piece of information made available by the client is a resource. A client may have any number of resources and these resources are organized into objects. Each resource supports one or more operations. The Omalwm2m ontology describes the resources, objects and operations supported by the OMA LWM2M architecture.

An object (Object class) consists of one or more resources (Resource class). Different resources are organized into an object. Each Object has a unique identifier (hasObjectID property), and each Resource has a unique identifier within the object it belongs to (hasResourceID property). Both objects and resources can be mandatory or optional (isMandatory property). Both objects and resources can have a single instance (hasInstance min 0 and hasInstance max 1 constraints) or multiple instances (hasInstance min 0 constraint), represented by the ObjectInstance and ResourceInstance classes, respectively. Each object instance and resource instance have a unique identifier (hasObjectInstanceID and hasResourceInstanceID properties). A Resource supports one or more operations (hasOperation property). Examples of operations are Read, Write, and Execute.

According to the OMA Lightweight Machine-to-Machine Technical Specification, the Omalwm2m ontology defines several type of objects, namely the LWM2MSecurity, LWM2MServer, LWM2MAccessControl, LWM2MDevice, LWM2MConnectivityMonitoring, LWM2MFirmware, LWM2MLocation, and LWM2MConnectivityStatistics objects. Each object has a unique identifier (hasObjectID property). The ontology further details the LWM2MDevice object and its corresponding resources, such as, for example, the Manufacturer, PowerSourceCurrent, and AvailablePowerSource resources, among others. The LWM2MDevice object hasObjectID with value “3”, supports a single object instance, and is a mandatory object. The Manufacturer resource hasResourceID with value “0”, supports a single resource instance, supports the “Read” operation, and is optional for the LWM2MDevice object.

Observations

• Not all the OMA LWM2M objects defined in the 'OMA Lightweight Machine-to-Machine Technical Specification' are in the scope of our study. Therefore, we have chosen to describe in details in the ontology only the LWM2MDevice object and its corresponding resources. Following the same approach, the ontology can be extended with the details of the other objects (LWM2MSecurity, LWM2MServer, LWM2MAccessControl, LWM2MConnectivityMonitoring, LWM2MFirmware, LWM2MLocation, and LWM2MConnectivityStatistics), which are currently “open” classes, i.e., these classes are defined in the ontology, but they may be further detailed.