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250 A Common Architectural Approach for IoT Empowerment
domain model. The communication stack proposed is similar to the ISO OSI
7-layer model for networks, mapping the needed features of the domain model
onto communication paradigms. As well, the description of how communication
schemes can be applied to different types of networks in IoT belongs to
this model.
6.2.2 The IoT-A Reference Architecture
The Reference Model is however too abstract to be used for building directly
concrete architectures. In order to implement a compliant IoT solutions, Reference
Architectures must be defined, describing essential building blocks as
well as design choices able to select specific constructs able to deal with converging
requirements regarding functionality, performance, deployment and
security, to name a few. Interfaces among different technological functional
blocks should be standardised, best practices in terms of functionality and
information usage need to be provided.
Existing literature provides methodologies for dealing with system
architectures (hereafter called Concrete Architectures) based on Views and
Perspectives. The way that the IoT-A project illustrates the Reference Architecture
(RA) is through a matrix that provides clear technological choices in
order to develop concrete architectures. To establish the contents of this matrix
we need to analyse all possible functionalities, mechanisms and protocols that
can be used for building any concrete IoT-related architecture and to show how
interconnections could take place between selected design and technological
choices. A system architect should then have a tool to make a rational selection
of protocols, functional components, and architectural options, needed to
build specific IoT systems.
The IoT-A project sees views as a representation of one or more structural
aspects of an architecture that illustrates how the architecture addresses one
or more concerns held by one or more of its stakeholders.
Viewpoints aggregate several concepts to make the work with views easier.
The IEEE Standard 1471 defines viewpoints as follows:
“A viewpoint is a collection of patterns, templates, and conventions
for constructing one type of view. It defines the
stakeholders whose concerns are reflected in the viewpoint
and the guidelines, principles, and template models for constructing
its views.“