Long-Range Communications in Unlicensed Bands: the Rising Stars in the IoT and Smart City Scenarios

Connectivity is probably the most basic building block of the Internet of Things (IoT) paradigm. Up to know, the two main approaches to provide data access to the \emph{things} have been based either on multi-hop mesh networks using short-range communication technologies in the unlicensed spectrum, or on long-range, legacy cellular technologies, mainly 2G/GSM, operating in the corresponding licensed frequency bands. Recently, these reference models have been challenged by a new type of wireless connectivity, characterized by low-rate, long-range transmission technologies in the unlicensed sub-GHz frequency bands, used to realize access networks with star topology which are referred to a \emph{Low-Power Wide Area Networks} (LPWANs). In this paper, we introduce this new approach to provide connectivity in the IoT scenario, discussing its advantages over the established paradigms in terms of efficiency, effectiveness, and architectural design, in particular for the typical Smart Cities applications

Survey on wireless technology trade-offs for the industrial internet of things

Aside from vast deployment cost reduction, Industrial Wireless Sensor and Actuator Networks (IWSAN) introduce a new level of industrial connectivity. Wireless connection of sensors and actuators in industrial environments not only enables wireless monitoring and actuation, it also enables coordination of production stages, connecting mobile robots and autonomous transport vehicles, as well as localization and tracking of assets. All these opportunities already inspired the development of many wireless technologies in an effort to fully enable Industry 4.0. However, different technologies significantly differ in performance and capabilities, none being capable of supporting all industrial use cases. When designing a network solution, one must be aware of the capabilities and the trade-offs that prospective technologies have. This paper evaluates the technologies potentially suitable for IWSAN solutions covering an entire industrial site with limited infrastructure cost and discusses their trade-offs in an effort to provide information for choosing the most suitable technology for the use case of interest. The comparative discussion presented in this paper aims to enable engineers to choose the most suitable wireless technology for their specific IWSAN deployment

Integrated Satellite-terrestrial networks for IoT: LoRaWAN as a Flying Gateway

When the Internet of Things (IoT) was introduced, it causes an immense change in human life. Recently, different IoT emerging use cases, which will involve an even higher number of connected devices aimed at collecting and sending data with different purposes and over different application scenarios, such as smart city, smart factory, and smart agriculture. In some cases, the terrestrial infrastructure is not enough to guarantee the typical performance indicators due to its design and intrinsic limitations. Coverage is an example, where the terrestrial infrastructure is not able to cover certain areas such as remote and rural areas. Flying technologies, such as communication satellites and Unmanned Aerial Vehicles (UAVs), can contribute to overcome the limitations of the terrestrial infrastructure, offering wider coverage, higher resilience and availability, and improving user\u2019s Quality of Experience (QoE). IoT can benefit from the UAVs and satellite integration in many ways, also beyond the coverage extension and the increase of the available bandwidth that these objects can offer. This thesis proposes the integration of both IoT and UAVs to guarantee the increased coverage in hard to reach and out of coverage areas. Its core focus addresses the development of the IoT flying gateway and data mule and testing both approaches to show their feasibility. The first approach for the integration of IoT and UAV results in the implementing of LoRa flying gateway with the aim of increasing the IoT communication protocols\u2019 coverage area to reach remote and rural areas. This flying gateway examines the feasibility for extending the coverage in a remote area and transmitting the data to the IoT cloud in real-time. Moreover, it considers the presence of a satellite between the gateway and the final destination for areas with no Internet connectivity and communication means such as WiFi, Ethernet, 4G, or LTE. The experimental results have shown that deploying a LoRa gateway on board a flying drone is an ideal option for the extension of the IoT network coverage in rural and remote areas. The second approach for the integration of the aforementioned technologies is the deployment of IoT data mule concept for LoRa networks. The difference here is the storage of the data on board of the gateway and not transmitting the data to the IoT cloud in real time. The aim of this approach is to receive the data from the LoRa sensors installed in a remote area, store them in the gateway up until this flying gateway is connected to the Internet. The experimental results have shown the feasibility of our flying data mule in terms of signal quality, data delivery, power consumption and gateway status. The third approach considers the security aspect in LoRa networks. The possible physical attacks that can be performed on any LoRa device can be performed once its location is revealed. Position estimation was carried out using one of the LoRa signal features: RSSI. The values of RSSI are fed to the Trilateration localization algorithm to estimate the device\u2019s position. Different outdoor tests were done with and without the drone, and the results have shown that RSSI is a low cost option for position estimation that can result in a slight error due to different environmental conditions that affect the signal quality. In conclusion, by adopting both IoT technology and UAV, this thesis advances the development of flying LoRa gateway and LoRa data mule for the aim of increasing the coverage of LoRa networks to reach rural and remote areas. Moreover, this research could be considered as the first step towards the development of high quality and performance LoRa flying gateway to be tested and used in massive LoRa IoT networks in rural and remote areas