On the feasibility of unlicensed communications in the TV white space: Field measurements in the UHF band

In practical unlicensed communications in TV band, radio devices have to identify, at first, the transmission opportunities, that is, the portion of the spectrum licensed for broadcasting services unoccupied in a certain region at certain time, that is, the so-called TV white space. In this paper the outcome of field measurements in the UHF TV band (470-860 MHz) conducted in EU is presented. To obtain empirical values for the parameters upon which unlicensed radio devices are able to distinguish in a real scenario between empty and occupied TV channels, signal power measurements have been performed in Italy, Spain, and Romania on rural, suburban, and urban sites, at different heights over the ground by using different analysis bandwidths. The aim of this work is to provide a set of practical parameters upon which harmless unlicensed communication in the UHF TV white space is feasible. The results have been analyzed with respect to the hidden node margin problem, spectrum sensing bandwidth, and occupancy threshold

Exploiting social internet of things features in cognitive radio

Cognitive radio (CR) represents the proper technological solution in case of radio resources scarcity and availability of shared channels. For the deployment of CR solutions, it is important to implement proper sensing procedures, which are aimed at continuously surveying the status of the channels. However, accurate views of the resources status can be achieved only through the cooperation of many sensing devices. For these reasons, in this paper, we propose the utilization of the Social Internet of Things (SIoT) paradigm, according to which objects are capable of establishing social relationships in an autonomous way, with respect to the rules set by their owners. The resulting social network enables faster and trustworthy information/service discovery exploiting the social network of friend'' objects.We first describe the general approach according to which members of the SIoT collaborate to exchange channel status information. Then, we discuss the main features, i.e., the possibility to implement a distributed approach for a low-complexity cooperation and the scalability feature in heterogeneous networks. Simulations have also been run to show the advantages in terms of increased capacity and decreased interference probability

A Social Internet of Things Smart City Solution for Traffic and Pollution Monitoring in Cagliari

In the last years, the smart city (SC) paradigm has been deeply studied to support sustainable mobility and to improve human living conditions. In this context, a new SC based on the Social Internet of Things paradigm is presented in this article. Starting from the tracking of all vehicles (that is, private and public) and pedestrians, integrated with air quality measurements (that is, in real time by mobile and fixed sensors), the system aims to improve the viability of the city, both for pedestrian and vehicular users. A monitoring network based on sensors and devices hosted on board in local public transport allows real-time monitoring of the most sensitive areas both from traffic congestion and from an environmental point of view. The proposed solution is equipped with an appropriate intelligence that takes into account instantaneous speed, type of traffic, and instantaneous pollution data, allowing to evaluate the congestion and pollution condition in a specific moment. Moreover, specific tools support the decisions of public administration facilitating the identification of the most appropriate actions for the implementation of effective policies relating to mobility. All collected data are elaborated in real time to improve traffic viability suggesting new directions and information to citizens to better organize how to live in the city

Nonorthogonal Multiple Access and Subgrouping for Improved Resource Allocation in Multicast 5G NR

The ever-increasing demand for applications with stringent constraints in device density, latency, user mobility, or peak data rate has led to the appearance of the last generation of mobile networks (i.e., 5G). However, there is still room for improvement in the network spectral efficiency, not only at the waveform level but also at the Radio Resource Management (RRM). Up to now, solutions based on multicast transmissions have presented considerable efficiency increments by successfully implementing subgrouping strategies. These techniques enable more efficient exploitation of channel time and frequency resources by splitting users into subgroups and applying independent and adaptive modulation and coding schemes. However, at the RRM, traditional multiplexing techniques pose a hard limit in exploiting the available resources, especially when users' QoS requests are unbalanced. Under these circumstances, this paper proposes jointly applying the subgrouping and Non-Orthogonal Multiple Access (NOMA) techniques in 5G to increase the network data rate. This study shows that NOMA is highly spectrum-efficient and could improve the system throughput performance in certain conditions. In the first part of this paper, an in-depth analysis of the implications of introducing NOMA techniques in 5G subgrouping at RRM is carried out. Afterward, the validation is accomplished by applying the proposed approach to different 5G use cases based on vehicular communications. After a comprehensive analysis of the results, a theoretical approach combining NOMA and time division is presented, which improves considerably the data rate offered in each use case.This work was supported in part by the Italian Ministry of University and Research (MIUR), within the Smart Cities framework, Project Cagliari2020 ID: PON04a2_00381; in part by the Basque Government under Grant IT1234-19; and in part by the Spanish Government [Project PHANTOM under Grant RTI2018-099162-B-I00 (MCIU/AEI/FEDER, UE)]

Prevalence of IgG antibodies against Borrelia Burgdorferi s.l. and Ehrlichia Phagocytophila in sera of patients presenting symptoms of Lyme disease in a central region of Italy.

The aim of this study was to evaluate the prevalence (seroprevalence) of antibodies against Borrelia burgdorferi and Ehrlichia phagocytophila among patients resident in Lazio, a region of central Italy. Of a sample of 1,050 patients, which presented clinical manifestations related to Lyme disease, 34 (3.2%) were Borrelia-seropositive (Lyme index value ≥ 1.2). The sera of 25 out of the 34 patients that were Borrelia-positive were also analysed for the presence of antibodies against E. phagocytophila and 3 (12%) were found Ehrlichia-positive (titres >1:64). No Ehrlichia-positive samples were found among sera of 250 Borrelia-negative patients. Since both B. burgdorferi s.l. and Ehrlichia species share the same tick vector ( Ixodes ricinus), our results indicate that concurrent transmission of these microbial pathogens might have been occurred among the patients included in this study

Effects of meal timing on changes in circulating epinephrine, norepinephrine, and acylated ghrelin concentrations: A pilot study

Abstract Background Timing of food intake impacts on metabolic diseases. Few data are available about post-meal changes in epinephrine (E), norepinephrine (NE), and acylated ghrelin (AG) at different times of the day. Subjects and methods This randomized cross-over trial investigated E/NE/AG concentrations after identical meals consumed at 0800 or 2000 hours in 20 healthy volunteers, by standardizing diet, exercise, duration of fast, and resting. Participants randomly received the test meal at 0800 or 2000 hours, and vice versa after 1 week. Blood samples were collected before and up to 180-min post-meal, every 30 min, with participants supine, motionless, but awake. Results Median E levels increased at 30–60 min, then declined and rose again at 150 min; values at 60 min (19.0 vs. 15.0 ng/l, p = 0.03) and 180 min (25.0 vs. 11.0 ng/l, p < 0.001) were higher after the morning meals. NE rose at 30–60 min and then progressively declined; median values at 60 min (235.3 vs. 206.3 ng/l, p = 0.02) and 120 min (208.8 vs. 142.0 ng/l, p = 0.04) increased more after morning meals. AG progressively declined to increase again at 90 min after meal; median AG area-under-the-curve (AUC) values were lower at morning (7206.8 vs. 8828.3 pg/mL×h). AG-AUC was inversely associated with diet-induced thermogenesis (β = −121.6; 95% CI −201.0 to 42.2; p = 0.009 for each unit increase), while log NE-AUC was inversely associated with log-triglyceride AUC (β = −0.57; 95% CI −0.98 to 0.16; p = 0.015) in a multiple regression model, after multiple adjustments. Conclusions In conclusion, E/NE concentrations were higher after the morning meal, while AG showed an opposite behavior. These data, although requiring confirmation in larger samples, suggest an adjunctive possible mechanism explaining the unfavorable effects of evening eating on metabolic ris