Emerging technologies, IoT/IIoT architectures and Edge/-Fog computing mechanisms for cybersecurity, energy efficiencyand decentralized/distributed communications

Abstract

The Internet of Things (IoT) is a paradigm in which various physical devices that communicate with each other can be capable of self-managing and exchanging information among them. These devices can be vehicles, household appliances, urban infrastructure, machinery or industrial tools. In order to enable this communication, it is necessary to integrate electronic components that allow for obtaining information from the environment (sensors), performing physical actions (actuators) and sending and receiving the necessary information (network communication interfaces). Additional processing may be required by remote devices (e.g., through a Cloud or Edge Computing system). The great expansion that the paradigm has undergone over the last two decades has led to the evolution and emergence of new technologies to overcome many of the present challenges. Throughout this thesis this evolution will be analyzed in several different lines, providing key aspects, improvements and future challenges of the current state-of-the-art technologies, as well as a practical approach that includes the design and implementation of different IoT systems. These research lines involve aspects such as IoT fundamentals, critical systems, processing and response capacity, security and energy consumption. One of the main drivers of the IoT evolution are distributed communication paradigms, which allow managing in a more efficient way the massive volume of information generated by the different sensor networks. In particular, solutions such as Fog or Edge Computing have proven to be an ideal complement in massive traffic situations. The requirements in terms of response time and Quality of Service (QoS) are another key aspect of the technology, in this respect, apart from being enhanced by these paradigms, they have also experienced a significant improvement thanks to the evolution of Wireless technologies as well as the processing capacity of the hardware itself. However, the implementation of these systems poses different challenges. Firstly, the diversity of the different technologies, as well as the heterogeneity of the different environments in which they are developed, presents a challenge from the point of view of standardization. Secondly, with respect to distributed communications, despite the advantages they offer, it is complex to apply appropriate security mechanisms, since their implementation differs considerably from centralized architectures. Thirdly, with the rising climate crisis, the sustainability of the technology is another key factor. In this regard, the inherent interconnection and automation capability of the technology enables efficiency improvements of the developments, while enhancing the sustainability of the technology itself with more efficient hardware and communication protocols as well as alternative energy sources. This thesis provides a practical analysis of the main state-of-the-art technologies that have enabled the IoT to date, with special focus on distributed communication paradigms, critical systems, security and energy efficiency. Due to the broad spectrum of technologies that the IoT encompasses, this thesis begins with an extensive analysis of the fundamentals of the IoT, followed by several practical use cases in different scenarios to provide a practical view of these fundamentals. Throughout the thesis, several use cases are analyzed within the context of critical systems, automatic processing and response capabilities, security and energy efficiency. In particular, different cases of use in different Industrial IoT (IIoT) environments are developed and empirically validated in real environments as well as different Critical IoT systems. Regarding the processing and response capacity, an edge solution is presented that involves the use of ML techniques, allowing its complete offline operation. In the field of cybersecurity, the state-of-the-art in security for distributed/decentralized systems is extensively analyzed. Finally, different energy optimization mechanisms are analyzed, both in wireless communications and Edge Intelligence solutions, as well as different energy harvesting mechanisms.