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This paper aims at proposing an augmented sensing method for estimating volumetric water content (VWC) in soil for Internet of Underground Things (IoUT) applications. The system exploits an IoUT sensor node embedding a low-cost, low-precision soil moisture sensor and a long-range wide-area network (LoRaWAN) transceiver sending relative measurements within LoRaWAN packets. The VWC estimation is achieved by means of machine learning (ML) algorithms combining the readings provided by the soil moisture sensor with the received signal strength indicator (RSSI) values measured at the LoRaWAN gateway side during broadcasting. A dataset containing such measurements was especially collected in the laboratory by burying the IoUT sensor node within a plastic case filled with sand, while several VWCs were artificially created by progressively adding water. The adopted ML algorithms are trained and tested using three different techniques for estimating VWC. Firstly, the low-cost, low-precision soil moisture sensor is calibrated by resorting to an ML model exploiting only its raw readings to estimate VWC. Secondly, a virtual VWC sensor is shown, where no real sensor readings are used because only LoRaWAN RSSIs are exploited. Lastly, an augmented VWC sensing method relying on the combination of RSSIs and soil moisture sensor readings is presented. The findings of this paper demonstrate that the augmented sensor outperforms both the virtual sensor and the calibrated real soil moisture sensor. The latter provides a root mean square error (RMSE) of 3.33%, a virtual sensor of 8.67%, and an augmented sensor of 1.84%, which improves down to 1.53% if filtered in post-processing.

This paper focuses on the comparison of transmission performances within critical environments (i.e., underwater, within metal enclosures and underground) for two of the most adopted enabling technologies for the Internet of Things (IoT): the Long Range Wide Area Network (LoRaWAN) protocol and the Narrowband Internet of Things (NB-IoT) standard. After a literature review, the two technologies are surveyed and compared. Then, the most exploited path loss models for the aforesaid application scenarios are presented. In order to assess and compare performances, a multi-protocol wireless sensor node prototype exploiting both the technologies for transmitting is described. Such prototype is then employed within field tests which consisted of underwater, through-metal and underground broadcasts with the aim of measuring losses only ascribed to the media. Eventually, tests results are analyzed and compared with the theoretical models.

The aim of this paper is to present the viability of an energy-harvesting system prototype, based on thermoelectric generators (TEGs), to be embedded in a Long-Range Wide Area Network (LoRaWAN)-based wireless sensor node, allowing continuous quasi-real-time data transmission even for low temperature gradients and for frequent transmissions. To this end, an RFM95x LoRa module is used in the system. The energy management of the entire node is achieved by exploiting a nano power boost charger buck converter integrated circuit, which allows power extraction from the energy-harvesting source and, at the same time, regulates the charging/discharging process of a Li-Po battery that supplies the wireless node. The first phase of the project was dedicated to understanding the electrical characteristics of the TEG. A series of tests were performed to study the open circuit voltage, the current and the power generated by the TEG at different temperature gradients. Following this first phase, tests were then set up to study the charging/discharging process of the battery by changing two crucial parameters: the temperature between the faces of the TEG and the frequency of the transmissions performed by the transceiver. Experimental results show a positive balance for the battery charging at different conditions, which suggests two important conclusions: first of all, with high temperature gradients, it is possible to set relatively high transmission frequencies for the LoRaWAN module without discharging the battery. The second important consideration concerns the operation of the system at extremely low temperature gradients, with a minimum of 5 °C reached during one of the measurements. This suggests the usability of thermoelectric energy-harvesting systems in a wide range of possible applications even in conditions of low temperature gradients.

This paper proposes a novel network architecture integrating a multi-hop Long Range (LoRa)-based thin linear network within a LoRa Wide Area Network (LoRaWAN) infrastructure, with the aim of proposing linear distributed measurement systems forwarding their collected data to a LoRaWAN server by means of a hybrid LoRa-LoRaWAN node. Such device is able to collect LoRa packets coming from the linear network and to encapsulate them in LoRaWAN packets transmitted to the remote server by means of standard LoRaWAN Gateways. The operation of the nodes is regulated by an ad-hoc routing protocol which aims at minimizing their active period, in order to reduce their power consumption increasing the overall system lifetime. Similarly, the synchronization of the nodes aims at increasing the robustness of the network reducing at minimum packet losses. The effectiveness of the proposed network architecture in terms of successful packet deliveries and reduction of active time is tested in different configurations, exploiting 2-node, 3-node and 4-node chains as well as adopting increasingly larger cycle periods. Results show that the proposed configuration ensures a noteworthy robustness in terms of packets delivery while maintaining the duty-cycling at levels that may guarantee long life times and autonomous operation to the overall infrastructure.

The aim of this paper is to study the usability of the Long Range (LoRa) Wide Area Network (LoRaWAN) protocol in the context of vehicular networks, in order to exploit it as enabling technology for the realization of Internet of Things (IoT) solutions within automotive contexts. Despite the critical requirements of this application scenario in terms of bandwidth and latency, LoRaWAN may be exploited for several purposes thanks to its excellent performances in terms of low power consumption and long transmission range. However, the vehicular context features some peculiar constraints that require a specific validation of this technology. One of this requirements concerns the fact that vehicles are actually in motion when transmitting data. Such motion can occur at different speeds that may affect in some way the transmission performances. To this aim, the performances of the LoRaWAN link are evaluated with the transmitter in motion at different speeds, from 20 km/h up to 90 km/h. In particular, received packets percentage, Received Signal Strength Indicator (RSSI) and Signal to Noise Ratio (SNR) are measured, with varying transmission setups in terms of Spreading Factor (SF). The measurement campaign is carried out in an elliptical track, with a LoRaWAN Gateway positioned exactly in its center, in order to limit the variations of the wireless link. Achieved results demonstrate the robustness of LoRaWAN also in case of transmissions taking place in motion, with limited signal degradation in the case of highest speed values.

This article presents the architecture and the performances of a long-range wide-area network (LoRaWAN) infrastructure used for data transmission from a floating sensor node placed in the middle of the sea to a multigateway structure positioned on the coast, whose purpose is the monitoring of offshore breeding cages within a fish farming plant. In particular, the sensor node is installed on a seamark buoy and it is interfaced with ad hoc sensors for the measurement of marine parameters. All sampled data are conveyed ashore to the Gateways by successfully covering the distance of 8.33 km. The article presents the results concerning the performances of the data transmission for a 70-day operating period, analyzing the radio parameters Signal-to-Noise Ratio (SNR) and Received Signal Strength Indicator (RSSI) in relation to the variations of environmental parameters, such as temperature, relative humidity and atmospheric pressure, as well as weather conditions. The proposed system demonstrates the usability of the LoRaWAN in all those cases where data collection from offshore monitoring structures is required; while this infrastructure focuses on the monitoring of fish farming plants, it may find application in several contexts, from navigational buoys to offshore oil plants.

Data transmission from the underground can be a relevant task for a wide range of Internet of Things (IoT) applications (e.g., from Smart Agriculture to environmental monitoring) thus paving the way to the recent paradigm of the Internet of Underground Things (IoUT). In this context, Low Power Wide Area Network (LPWAN) technologies proved to be reliable solutions for underground to aboveground (UG2AG) data transmission: Long Range (LoRa) modulation and LoRa Wide Area Network (LoRaWAN) protocol in particular, demonstrated to be able to transmit from depths down to 1.5 m. Nevertheless, the quality of the transmission channel may significantly vary due to several factors: ranging from soil composition to presence of water. Specifically, soil moisture may have an attenuating effect on the transmitted signal. The aim of this paper is to preliminary analyze the impact of different Volumetric Water Contents (VWCs) in soil on the LoRa transmission channel. Radio parameters are collected by burying a LoRaWAN transmitter inside a plastic case filled up with sand. The underground attenuation is measured reproducing different VWCs by progressively adding different quantities of water: this methodology allows to re-create in laboratory well-defined VWCs unlike a real environment where the actual VWC is due to a plethora of different factors. Results achieved in this paper demonstrate the correlation among VWC and losses though showing the potential feasibility of LoRa links also in case of elevate VWC levels.

The aim of this article is to discuss the usability of the long-range (LoRa) transmission technology together with the LoRa wide-area network (LoRaWAN) protocol for underground monitoring activities. In particular, this article focuses on the transmission performances in different soils (i.e., gravel, sand, and clay), for an underground-to-aboveground (UG2AG) communication. The three soils have been chosen in order to test the system behavior in case of pure soil compositions, in order to provide a general result that can be used to evaluate the transmission chances for any kind of soil. The performances of the transmission channel have been tested using an experimental setup for depths up to 50 cm, acquiring the values of the received signal strength indicator (RSSI) and the signal-to-noise ratio (SNR) for every transmission and analyzing the packet loss (PL). Such a kind of system may be crucial in several application scenarios, such as environmental monitoring or smart agriculture, where the real-time, remote acquisition of underground parameters at different depths is required.

The aim of this paper is to discuss the usability of the LoRa transmission technology together with the LoRaWAN protocol for underground monitoring activities. In particular, the paper focuses on the transmission performances in different conditions (i.e., different antennas, different Spreading Factors and different burial depths), for an underground-to-aboveground (UG2AG) communication. The theoretical achievable value for RSSI is calculated and is then compared with the real values achieved by means of field measurements. While the obtained results on field are slightly worse than the theoretical ones, due to additional unpredictable losses and attenuation, their trends are consistent with the estimated ones and demonstrate the feasibility of UG2AG LoRaWAN transmission channels. Such a kind of system may be crucial in several application scenarios, like for example environmental monitoring or smart agriculture, where the real-time, remote acquisition of underground parameters at different depths is required.

Fish farming is nowadays a crucial sector for food industry all around the world. While the total amount of captured fish production has remained almost constant in the last 30 years (around 90 millions tonnes according to the Food and Agriculture Organization (FAO) of the United States), in the same span of time the quantity of bred fish has increased tenfold, almost reaching the quantity of the captured one. What was once little more than a hand-crafted production, is now an actual industrial sector, employing around 60 million workers all around the world. Like all industrial sectors, aquaculture can considerably benefit by the introduction of Internet of Things (IoT) technologies, thus adopting them within the context of Industry 4.0 to optimize fish farming processes. In this context, this paper proposes a real-time monitoring infrastructure based on the use of Fixed Nodes and Mobile Sinks for the remote, real-time control of offshore sea farms. The proposed architecture exploits a LoRaWAN network infrastructure for data transmission: different configurations are tested on the field, proving the reliability of the communication channel in a worst case scenario up to a 8.33 km offshore distance. A complete real-time monitoring system is presented, allowing to measure in real time several parameters about the quality of water in the fish cages as well as their maintenance status.

In this paper the authors discuss the realization of a Long Range Wide Area Network (LoRaWAN) network infrastructure to be employed for monitoring activities within the marine environment. In particular, transmission ranges as well as the assessment of parameters like Signal to Noise Ratio (SNR) and Received Signal Strength Indicator (RSSI) are analyzed in the specific context of an aquaculture industrial plant, setting up a transmission channel from an offshore monitoring structure provided with a LoRaWAN transmitter, to an ashore receiving device composed of two LoRaWAN Gateways. A theoretical analysis about the feasibility of the transmission is provided. The performances of the system are then measured with different network parameters (in particular the Spreading Factor&mdash, SF) as well as with two different heights for the transmitting antenna. Test results prove that efficient data transmission can be achieved at a distance of 8.33 km even using worst case network settings: this suggests the effectiveness of the system even in harsher environmental conditions, thus entailing a lower quality of the transmission channel, or for larger transmission ranges.

In this work, a low-power IoT architecture for the monitoring of chemical emissions is presented. This system is expected to be employed to set up monitoring infrastructures in industrial plants or public buildings. The proposed system has been designed to embed different sensors. In particular, each sensor node manages a humidity sensor and an array of temperature and electrochemical gas sensors for the detection of carbon monoxide (CO), nitrogen oxides (NOx), and oxygen (O2). Moreover, it exploits some dedicated processing algorithms to mitigate the dependence of the sensor response on temperature. The sensor node has been designed to minimise power consumption as much as possible, and it is provided with LoRa LPWAN connectivity, which allows for wide-area data transmission. Tests carried out in urban areas proved that a 3 km communication range is achievable in noisy environments. A network architecture and a data acquisition and management structure are then described. A multilayer modular topology that combines the features of LoRa technology with shorter and larger range telecommunication channels in order to develop an IoT framework that can be customised according to the physical and technical features of the deployment scenario

Context: In premenopausal and older women, high testosterone and estradiol (E2) and low SHBG levels are associated with insulin resistance and diabetes, conditions characterized by low-grade inflammation. Objective: The aim of the study was to examine the relationship between SHBG, total testosterone, total E2, and inflammatory markers in older women. Design and Patients: We conducted a retrospective cross-sectional study of 433 women at least 65 yr old from the InCHIANTI Study, Italy, who were not on hormone replacement therapy or recently hospitalized and who had complete data on SHBG, testosterone, E2, C-reactive protein (CRP), IL-6, soluble IL-6 receptor (sIL-6r), and TNF-α. Relationships between sex hormones and inflammatory markers were examined by multivariate linear regression analyses adjusted for age, body mass index, smoking, insulin, physical activity, and chronic disease. Results: In fully adjusted analyses, SHBG was negatively associated with CRP (P = 0.007), IL-6 (P = 0.008), and sIL-6r (P = 0.02). In addition, testosterone was positively associated with CRP (P = 0.006), IL-6 (P = 0.001), and TNF-α (P = 0.0002). The negative relationship between testosterone and sIL-6r in an age-adjusted model (P = 0.02) was no longer significant in a fully adjusted model (P = 0.12). E2 was positively associated with CRP (P = 0.002) but not with IL-6 in fully adjusted models. In a final model including E2, testosterone, and SHBG, and all the confounders previously considered, SHBG (0.23 ± 0.08; P = 0.006) and E2 (0.21 ± 0.08; P = 0.007), but not testosterone (P = 0.21), were still significantly associated with CRP. Conclusion: In late postmenopausal women not on hormone replacement therapy, SHBG and E2 are, respectively, negative and positive, independent and significant correlates of a proinflammatory state.

This paper focuses on the realization of an Internet of Things (IoT) architecture to optimize waste management in the context of Smart Cities. In particular, a novel typology of sensor node based on the use of low cost and low power components is described. This node is provided with a single-chip microcontroller, a sensor able to measure the filling level of trash bins using ultrasounds and a data transmission module based on the LoRa LPWAN (Low Power Wide Area Network) technology. Together with the node, a minimal network architecture was designed, based on a LoRa gateway, with the purpose of testing the IoT node performances. Especially, the paper analyzes in detail the node architecture, focusing on the energy saving technologies and policies, with the purpose of extending the batteries lifetime by reducing power consumption, through hardware and software optimization. Tests on sensor and radio module effectiveness are also presented.

We describe the study and development of a 2-meter-wide HF RFID gate providing omnidirectional detection of transponders. Common commercial HF RFID gate structures provide a maximum reading range around 150 cm. Moreover, this value is in most cases guaranteed only for the maximum coupling direction, with lower values for the other 2 orientations. The proposed structure raises the value of the reading range up to 200 cm for every orientation of the transponder, with even better results (220 cm) when the transponder is in the position of maximum coupling. This result has been achieved through numerical simulations, focused on the study of the geometry of the antenna system and on the realization of the matching circuit and then confirmed with the physical implementation of the system.

Healthcare represents one of the most significant sectors where the diffusion of RFID technology is growing day by day. Many different applications have already been studied and developed, with both active and passive devices working at all the available operative frequencies. Sanitary environments are nowadays extremely complex structures employing several thousands of people with very strict safety requirements: in emergency situations for example 5 minutes can make the difference for a patient between survive and die. RFID is especially indicated to be employed in these scenarios for two main reasons: first of all because it’s a particularly reliable technology, with good performances, few errors and fast interaction, and secondly because, due to the presence of many different technological systems, ad-hoc solutions can be designed on the specific requirements of the application to be realized. At present the most common RFID applications in healthcare can be divided into two main categories: the items tracking and the tracking and identification of people, patients and sanitary operators. The items tracking is performed in order to avoid the loss of expensive devices and to reduce wasting of time during assistance operations: systems studied and realized for this purpose cover all the range of RFID systems and provide different services according to their different performances. Passive systems are mainly thought for the tracking of large amounts of items, providing identification also to low value items, and are mainly based on gate structures. Active systems are designed for the tracking of big and expensive items and use long range antennas located at specific key points. RFID systems for the identification of people probably represent the most interesting sector, due to the variety of different applications that can be studied and realized. The most common systems foresee the use of RFID for the tracking of sanitary operators or patients during their assistance operations: these solutions are very similar to the one described for the tracking of items and are already working in many structures around the world. Along with this many other applications have been implemented, including systems operating the unambiguous matching between the patient and his treatments (for example the medicine or the blood sack) or between the mother and the child in the paediatrics departments: these applications mainly foresee the use of passive technology, due to the lower costs, and ad-hoc items like electronic bracelets have already been realized and can be commonly found off the shelf. Finally the availability of a memory on the transponders fostered to the use of RFID technology also as a mean to promptly store and retrieve patient related information: for example electronic case history or electronic medical prescription applications have been studied and developed.

In this article we discuss the realization of antenna gate structures for Inductively Coupled Passive HF RFID Systems. Antenna gates are currently used in several applications, from industrial tracking to access control: in these structures the identification process is realized with the use of more antennas disposed in a configuration that makes them similar to doors. Nowadays these structures can reach a maximum width of 1.50–1.60 meters due to the limitations deriving from the CEPT ERC Recommendation 70-03 annex 9 on electromagnetic emissions from electronic devices. Next to this, limitations also derive from the decrease of the electromagnetic field with the distance and from physical constrains due to the fact that the field strength is proportional to the dimensions of the antennas. The purpose of this article is to describe a possible optimum configuration of antennas allowing the detection of tags across a 2 meters wide gate reducing as much as possible its dimensions.