  Over the past two decades, the Internet of Things (IoT) has become an
underlying concept to a variety of solutions and technologies that it is now
hardly possible to enumerate and describe all of them. The concept behind the
Internet of Things is as powerful as it is complex, and for the components in
the IoT solution tomesh together perfectly, they all have to be part of a
well-thought-out structure. That is where understanding the IoT architecture
becomes paramount. Because of the vast domain of IoT, there is no single
consensus on IoT architecture. Different researchers and organizations proposed
different architectures under a variety of classifications, mainly: conceptual,
standard and, industrial or commercial adoption. It is indispensable to make a
systematic analysis of IoT architecture to be able to compare the industrial
proposals and identify their similarities and their differences. In this work,
we summarize information about seven IoT industrial architectures in order to
propose an approach that makes possible a comparative analysis between
different IoT architectures. This work presents two main contributions: (i) an
approach for analyzing and comparing IoTarchitectures using Layer-Model; (ii) a
comparative study of seven industrial IoT architectures.
