Internet of Things – Architecture © - 39 -
2 Introduction
A commonly observed trend in the field of the Internet of Things (IoT) is the
emergence of a variety of communication solutions targeted at specific
application domains. Many popular ―umbrella‖ topics like Smart Cities pull a
large number of specific domains of applications like Transportation, Energy,
Environment, Assisted Living, most of time pre-fixed with ―Smart‖ in order to
emphasise the fact they embed a sort of intelligence and global awareness.
This new breed of application exploits the full potential of IoT related
technologies, however unfortunately, the resulting applications appear as
vertical silos only, meaning specific applications with specific architectures, with
little place left for inter-system communication and inter-operation. Actually that
is where the real issue stands: the smartness of those new applications can
only reach its pinnacle whenever full collaboration between those vertical silos
can eventually be achieved.
If we consider also the fact that IoT related technologies come with a high level
of heterogeneity, with specific protocols developed with specific applications in
mind, it results that the IoT landscape nowadays appears as highly fragmented.
Many IoT-enabled solutions exist with recognised benefits in terms of business
and social impact, however they form what we could call a set of Intranets of
things, not an Internet of things!
In the vision of the Internet of things IoT-A wants to promote, high level of
interoperability needs to be reached at the communication level as well as at
the service and even knowledge levels across different platforms established on
a common grounding. The IoT-A project reckons that achieving those goals
comes in two steps, first of all in establishing a common understanding of the
IoT domain and second in providing to IoT system developers a common
technical foundation and set of guidelines for deriving a concrete IoT system
architecture (both aspects being captured within the IoT Architectural Reference
Model).
While existing literature like [Rozanski 2005] provide methodologies for
dealing with system architectures (hereafter called concrete architectures)
based on Views and Perspectives for instance, establishing a reference
architecture is a quite different business, at least as far as describing Views and
Perspectives is concerned as we will see in the rest of this document.
An Architectural Reference Model (ARM) can be visualised therefore as the
matrix that eventually derives into a large set of concrete IoT architectures. For
establishing such a matrix, based on a strong and exhaustive analysis of the
State Of The Art (SOTA), a super-set of all possible functionalities, mechanisms
and protocols that can be used for building such concrete architecture has been
identified. Providing such a technical foundation along with a set of design-
choices, based on the characterisation of the targeted system w.r.t. various
dimensions (like distribution, security, real-time, semantics,...) it becomes