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Wide area, wireless, Internet of Things (IoT)-based, distributed sensor systems can be employed in mixed criticality solutions for measurement/detection/signaling of emergencies, dangers, accidents, and disasters. All these scenarios require reliability, security, and safety. This work introduces and characterizes a new proposal to enhance existing LoRaWAN applications by adding a transparent redundant channel just for critical traffic. Network survivability and delivery success of critical messages, even with low LoRaWAN signal quality (as in indoors), is increased. The proposal preserves the LoRaWAN backend structure (including end-to-end (E2E) security) using short-range radios to implement an underlying redundant mesh channel for transparently transporting LoRaWAN traffic of critical applications. Hybrid scenarios with legacy standard nodes coexisting are also permitted. The proof-of-concept combines LoRaWAN and, without losing generality, a redundant channel with Bluetooth mesh (BM). This work includes: metrics definition, evaluation of complex scenario by means of simulations, and real experiments demonstrating feasibility and integration with LoRaWAN-compliant backend using commercial hardware/firmware/software. In particular, results confirm that packet loss in the order of 1% on the BM side can be obtained and therefore the critical traffic delivery success is improved by almost two orders of magnitude.

Micromobility electric vehicles are steadily spreading and their impact on society, technology and industry will be remarkable. Most of the factors limiting their use, like, for example, range anxiety, are somehow related to the technical limitations of current charging stations. There is a gap in the literature regarding charging stations specifically devoted to micromobility. Actually, charging stations for e-bikes are characterized by specific critical points and opportunities, related to the lower power demand with respect to an electric cars and to the absence of consolidated standards for the requested output voltage. For this reason, this article aims at filling such gap through a comprehensive analysis of the different aspects characterizing these infrastructures. At first, the electrical features of the Electrical Micromobility Vehicles (EMVs) are surveyed through a market analysis. Then, an in depth analysis of the factors influencing the design of the charging stations is conducted and the scientific literature on the subject is discussed. Particular attention is devoted to the implication of the use or renewable sources for both grid-connected and off-grid applications. Furthermore, issues related to the architecture flexibility and the selection of the transformer technology are discussed. In general, it is argued that univocal guidelines are difficult to formulate, but a certain number of factors can be identified, which are to be evaluated depending on the context where the charging station is supposed to operate. Finally, emerging scientific and technological trends are discussed: fast charging; wireless power transfer; wide band gap power semiconductors, exploitation of EMVs charging stations in the context of renewable energy communities.