[ETSI TS 102 690], this discussion within IoT-A also takes the later update
[ETSI TS 103 092] into account that was released in May 2012.
The purpose of the ETSI M2M functional architecture is to define a service-
capability layer which serves as middleware between applications in the Internet
and Devices or gateways residing in local-area networks. The current release is
mainly concerned with secure and reliable data transport.
In what follows, we give a more detailed description of a possible reverse
mapping of ETSI M2M to the IoT Domain Model and IoT Communication Model
as well as their management information model and how it maps to our
management model. We also have a brief look at the ETSI M2M security model
and how it compares to our threat analysis.
Mapping to the IoT Domain Model
As everything above the ETSI M2M Service Capability Layer is considered an
application, there is no explicit concept of a User in ETSI M2M. In particular,
Human Users are out of scope, as the standard focuses on machine-to-
machine communication. The role of an IoT-A User would typically be taken by
ETSI network applications, in some cases also by ETSI gateway applications,
because these applications use the information provided by sensing M2M
Devices and control the actuation capabilities of Devices.
ETSI M2M defines Sensors and Actuators in a similar way as the IoT Domain
Model. However, there is a subtle difference regarding the concept of a Device.
While in IoT-A there is a ―is-a‖ relationship between Sensor/Actuator and
Device, ETSI M2M defines a Device to be a unit comprising Sensors and
Actuators, as well as embedded processing and communication capabilities –
so here Sensors and Actuators are part of Devices.
The ETSI M2M defines a Service Capability Layer with standardised interfaces.
Since this layer includes similar functionalities to the IoT-A Service level (e.g.
registration), it is reasonable to map these functionalities to IoT Services. There
are also some differences between ETSI and IoT-A terminology. For example,
the ETSI Services are not only exposed towards actors which IoT-A would
consider as Users, but also towards (ETSI) applications residing on Devices.
Additionally, the concept of IoT Resource (IoT-A) as a native software interface
of Devices does not explicitly exist in ETSI M2M – although software
components on legacy Devices could be considered as IoT Resources. Instead
the term of Resources in ETSI is exclusively used to describe the RESTful
interface exposed by the Service Capability Layer.
The mapping of ETSI M2M concepts to the IoT Domain Model is shown in
Table 32.
ETSI M2M IoT Domain Model Comments