Internet of Things – Architecture © 26
The central choice of the IoT-A project was to base its work on the current state of
the art, rather than using a clean-slate approach. Due to this choice, common traits
are derived to form the base line of the IoT Architectural Reference Model (ARM).
This has the major advantage of ensuring backward-compatibility of the model and
also the adoption of established, working solutions to various aspects of the IoT.
With the help of end users, organised into a stakeholders group, new requirements
for IoT have been collected and introduced in the main model building process.
Figure 1 shows an overview of the process we used for defining the different parts
that constitute the ARM. Notice that definitions of terms such as reference
architecture, etc. can be found in an external glossary [IoT-A Project]. Starting
with existing architectures and solutions, generic baseline requirements can be
extracted and used as an input to the design. The IoT ARM consists of three parts:
The IoT Reference Model provides the highest abstraction level for the definition
of the IoT Architectural Reference Model. It promotes a common understanding
of the IoT domain. The description of the IoT Reference Model includes a general
discourse on the IoT domain, an IoT Domain Model as a top-level description, an
IoT Information Model explaining how IoT knowledge is going to be modelled,
and an IoT Communication Model in order to understand specifics about
communication between many heterogeneous IoT devices and the Internet as a
whole. The definition of the IoT Reference Model is conforming to the OASIS
reference model definition [Brown 2006]. A detailed description of the IoT
Reference Model is provided in Chapter 3 ;
The IoT Reference Architecture is the reference for building compliant IoT
architectures. As such, it provides views and perspectives on different
architectural aspects that are of concern to stakeholders of the IoT. The terms
view and perspectives are used according to the general literature and standards
[IEEE Architecture], [Woods 2005] Definitions of these terms are also
provided in Chapter 4. The creation of the IoT Reference Architecture focuses on
abstract sets of mechanisms rather than concrete application architectures;
The Guidelines: While the IoT Reference Model and Reference Architecture give
the needed models, views and perspectives for deriving a concrete architecture
out of it, it is of the utmost importance to guide the architect during this derivation
process. The ―Guidance‖ Chapter is therefore an extremely important part of this
work achieved by the IoT-A project. It discusses how those Models, Views and
Perspectives can be concretely used. Chapter 5 provides lot of details about the
derivation process, large list of Design Choices and concretes examples.