FC are handled in more specific packages in ETSI M2M, such as SCL, ANW,
and SFW which each deal with specific functionalities that are subsumed under
Configuration in IoT-A. As the different architectures naturally have different
levels of abstraction, it is not surprising to not have a 1:1 relationship between
the two architectures, but a mapping can be performed easily in both directions.
Mapping to the IoT Communication Model
The ETSI M2M standard defines a Service Capability Layer in order to enable
seamless, secure, and reliable end-to-end communication in M2M networks.
The ETSI Service Capability Layer can therefore be mapped to the end-to-end
layer of the IoT Communication Model (see Section 3.6). (ETSI) applications,
communicating via the Service Capability Layer, would accordingly be
associated to the IoT-A Data Layer (see Section 3.6.2), although they do not
only exchange data, but also control and management information.
A Network and ID group (see Section 3.6.2) is not in the focus of ETSI M2M,
and the current bindings to HTTP and CoAP do not assume such a layer.
However, in cases where the Service Capability Layer enables a direct
connection of mobile Device applications to network applications, an ID layer
that describes the Device independently from its network location could assist
the Service Capability which provides seamless connectivity. The three
communication layers at the bottom of Figure 20 can be considered as identical
in ETSI M2M and IoT-A.
From the point of view of ETSI M2M, all actors making use of the Service
Capability Layer are applications. The model distinguishes between device
applications, gateway applications, and network applications. ETSI M2M also
considers so-called legacy Devices; these are Devices that have no own
Service Capability Layer and therefore need to be integrated via a gateway
application into the M2M system (M2M system is a term implicitly used in ETSI
M2M to refer to the overall architecture).
The IoT-A term IoT Device is used more or less in the same way in ETSI M2M,
but the concept of an IoT Application does not directly exist in ETSI M2M –
mainly because the concept of an application is more broadly defined in ETSI
M2M.
Mapping to the Security Model
One of the purposes of the ETSI M2M Service Capability Layer is to address all
security requirements of M2M communication. The standard defines a key
hierarchy of three levels. The ETSI M2M Root Key is used for mutual
authentication between device or gateway nodes and the M2M Service
Provider. It is also used for deriving and agreeing on the key of the next layer of
the hierarchy – the ETSI M2M Connection Key which is used for every service
connection procedure. Finally, the ETSI M2M Application Key is used for
securing sessions between specific applications. This largely maps to the IoT-A
Key exchange and management functionality, although the exact functionality in