Defeating jamming with the power of silence: a game-theoretic analysis

The timing channel is a logical communication channel in which information is encoded in the timing between events. Recently, the use of the timing channel has been proposed as a countermeasure to reactive jamming attacks performed by an energy-constrained malicious node. In fact, whilst a jammer is able to disrupt the information contained in the attacked packets, timing information cannot be jammed and, therefore, timing channels can be exploited to deliver information to the receiver even on a jammed channel. Since the nodes under attack and the jammer have conflicting interests, their interactions can be modeled by means of game theory. Accordingly, in this paper a game-theoretic model of the interactions between nodes exploiting the timing channel to achieve resilience to jamming attacks and a jammer is derived and analyzed. More specifically, the Nash equilibrium is studied in the terms of existence, uniqueness, and convergence under best response dynamics. Furthermore, the case in which the communication nodes set their strategy and the jammer reacts accordingly is modeled and analyzed as a Stackelberg game, by considering both perfect and imperfect knowledge of the jammer's utility function. Extensive numerical results are presented, showing the impact of network parameters on the system performance.Comment: Anti-jamming, Timing Channel, Game-Theoretic Models, Nash Equilibriu

Intra-Body Communications for Nervous System Applications: Current Technologies and Future Directions

The Internet of Medical Things (IoMT) paradigm will enable next generation healthcare by enhancing human abilities, supporting continuous body monitoring and restoring lost physiological functions due to serious impairments. This paper presents intra-body communication solutions that interconnect implantable devices for application to the nervous system, challenging the specific features of the complex intra-body scenario. The presented approaches include both speculative and implementative methods, ranging from neural signal transmission to testbeds, to be applied to specific neural diseases therapies. Also future directions in this research area are considered to overcome the existing technical challenges mainly associated with miniaturization, power supply, and multi-scale communications.Comment: https://www.sciencedirect.com/science/article/pii/S138912862300163

Opportunistic P2P Communications in Delay-Tolerant Rural Scenarios

Opportunistic networking represents a promising paradigm for support of communications, specifically in infrastructureless scenarios such as remote areas communications. In principle in opportunistic environments, we would like to make available all the applications thought for traditional wired and wireless networks like file-sharing and content distribution. In this paper, we present a delay-tolerant scenario for file sharing applications in rural areas, where an opportunistic approach is exploited. In order to support communications, we compare two peer-to-peer (P2P) schemes initially conceived for wireless networks and prove their applicability and usefulness to a DTN scenario, where replication of resources can be used to improve the lookup performance and the network can be occasionally connected by means of a data mule. Simulation results show the suitability of the schemes and allow to derive interesting design guidelines on the convenience and applicability of such approaches

An analytical model of information spreading through conjugation in bacterial nanonetworks

Molecular communications are a powerful tool to implement communication functionalities in environments where the use of electromagnetic waves becomes critical, e.g. in the human body. Molecules such as proteins, DNA, RNA sequences are used to carry information. To this aim a novel approach relies on the use of genetically modi ed bacteria to transport enhanced DNA strands, called plasmids, where information can be encoded and then transferred among bacterial cell using the so called conjugation process. Information transfer is thus based on bacteria motility, i.e. self-propelled motion which under appropriate circumstances is exhibited by certain bacteria, which is still not completely understood. In this paper we propose an analytical model to characterize information spreading in bacterial nanonetworks by employing an epidemic approach similar to the one used to model Delay Tolerant Networks (DTNs) and we show that such modeling can be pro tably used to represent information spreading in conjugation-based bacterial nanonetwork

Willage: A Two-Tiered Peer-to-Peer Resource Sharing Platform for Wireless Mesh Community Networks

The success of experiences such as Seattle and Houston Wireless has attracted the attention on the so called wireless mesh community networks. These are wireless multihop networks spontaneously deployed by users willing to share communication resources. Due to the community spirit characterizing such networks, it is likely that users will be willing to share other resources besides communication resources, such as data, images, music, movies, disk quotas for distributed backup, and so on. In other words, it is expected that peer-to-peer applications will be deployed in such type of networks. In this paper we propose Willage, a platform for resource localization in wireless mesh community networks with mobile users. The platform is based on a two-tiered architecture: resources are made available at the lower tier, which is composed of mobile terminals, whereas information on their localization is managed at the upper layer, which is composed of wireless mesh routers. We also introduce Georoy, an algorithm for the efficient retrieval of the information on resource localization based on the Viceroy algorithm. Simulation results show that Willage achieves its goal of enabling efficient and scalable peer-to-peer resource sharing in wireless mesh community networks

Covid-19 and the role of smoking: the protocol of the multicentric prospective study COSMO-IT (COvid19 and SMOking in ITaly).

The emergency caused by Covid-19 pandemic raised interest in studying lifestyles and comorbidities as important determinants of poor Covid-19 prognosis. Data on tobacco smoking, alcohol consumption and obesity are still limited, while no data are available on the role of e-cigarettes and heated tobacco products (HTP). To clarify the role of tobacco smoking and other lifestyle habits on COVID-19 severity and progression, we designed a longitudinal observational study titled COvid19 and SMOking in ITaly (COSMO-IT). About 30 Italian hospitals in North, Centre and South of Italy joined the study. Its main aims are: 1) to quantify the role of tobacco smoking and smoking cessation on the severity and progression of COVID-19 in hospitalized patients; 2) to compare smoking prevalence and severity of the disease in relation to smoking in hospitalized COVID-19 patients versus patients treated at home; 3) to quantify the association between other lifestyle factors, such as e-cigarette and HTP use, alcohol and obesity and the risk of unfavourable COVID-19 outcomes. Socio-demographic, lifestyle and medical history information will be gathered for around 3000 hospitalized and 700-1000 home-isolated, laboratory-confirmed, COVID-19 patients. Given the current absence of a vaccine against SARS-COV-2 and the lack of a specific treatment for -COVID-19, prevention strategies are of extreme importance. This project, designed to highly contribute to the international scientific debate on the role of avoidable lifestyle habits on COVID-19 severity, will provide valuable epidemiological data in order to support important recommendations to prevent COVID-19 incidence, progression and mortality

DOLOMITES WITHIN THE MESOZOIC CARBONATES OF SORRENTO PENINSULA (SOUTHERN APENNINES - ITALY): GENETIC MODELS AND RESERVOIR IMPLICATIONS

Dolomitization is undoubtedly the most intensively studied diagenetic process in carbonate rocks. It can induce porosity and permeability changes resulting from a complex interplay of intrinsic and extrinsic factors, which together with the variety of dolomitizing fluid circulation schemes, makes the prediction of the dolomite geometric distribution and of petrophysical features very challenging. In Southern Italy the dolomitization processes and the induced porosity/permeability changes have never been investigated in detail. Only the Upper Triassic interval of the Apenninic carbonate platform succession outcropping on the Monti Lattari Belt (Southern Apennines) has been studied by Iannace (1991) and Iannace & Frisia (1994), which demonstrated a fundamental difference in dolomitization style between Norian and Rhaetian-Lower Jurassic successions. The present research aims to a detailed genetical and petrophysical characterization of the dolomitized bodies outcropping along the Monti Lattari belt from the Lower Jurassic to the Lower Cretaceous. The goal was to complete the study of the dolomitization processes along the carbonate succession of the Monti Lattari belt, started by Iannace (1991), and to furnish also a complete characterization of the petrophysical properties of the observed different types of dolomites. The research approach was to combine detailed sampling and analysis of well exposed outcrops along road cuts and quarries with a large scale reconstruction along a transect showing platform domains alternating with intraplatform basins. The workflow has been the following: • Field work including geometric and stratigraphic observations and sampling. • Petrographic analysis of dolomite types and their porosity (Optical microscopy, SEM and catodoluminescence analyses). • Geochemical analyses on the separate dolomite phases (O, C, and Sr, trace elements, Ca% and fluid inclusions). • Petrophysical analyses including: Helium-porosimetry, Petrographyc and Digital Image Analysis, Mercury Injection porosimetry, Nitrogen Permeability and Sonic Velocity. The field study and the petrographic analyses have shown that the Lower-Middle Jurassic stratigraphic interval mainly consists of a widespread massive dolomite which irregularly replace the carbonate bodies in the Liassic interval and only partially replaces the Dogger facies. This dolomite (called Dolomite2), which affects also the Rhaetian portion of the succession, is made of coarse crystals with both planar-s and planar-e mosaic with low porosities and permeability. Its occurrence and geometry, together with the light oxygen isotopes signature and the Mg/Ca ratio close to the stochiometry, allow to ascribe this dolomite to a late diagenetic event related to a large scale circulation of marine fluids through the Jurassic carbonate platform driven by thermal convection. In this stratigraphic interval also another type of dolomite has been locally recognized (Dolomite1). It consists of fine grained crystals with a very low porosity which only partially replace the carbonate bodies. It shows sedimentary structures which indicate, together with the stable isotopes results and the XRD data, a very early diagenetic process, likely related to reflux and tidal pumping mechanisms of fluid circulation. At last, a third type of dolomite (saddle type dolomite, called Dolomite3) followed by precipitation of poikilotopic calcite has been discriminated. These last two diagenetic phases are concentrated along faults and fracture systems and their oxygen isotopes in addition to the fluid inclusions results, allow to relate them to a precipitation from warm fluids (about 130°C) raised along extensional faults during a very late stage of diagenesis. The Lower-Middle Cretaceous interval has been studied, in cooperation with Shell, because considered as possible analogue of Val D’Agri reservoirs. In fact, the high similarities between the most productive intervals of the Apulian Platform (Cretaceous in age) and the coeval rocks outcropping in the Apenninic Platform (Monti Lattari belt), allow the characterization of buried bodies via outcropping facies. This interval consists of partially dolomitized bodies, usually stratiform, alternated with low porosity micritic carbonates. Petrographically, it has been possible to distinguish two main different types of dolomites: Dolomite A made of fine crystals (10 to 50µm) with a low porosity mosaic and Dolomite B made of coarse crystals (70 to 130µm) with both a tight mosaic and a more porous one (planar-s and planar-e respectively). They are Ca enriched and have positive oxygen isotopes data which indicate an early diagenesis from a normal marine water. The invoked processes for their formation are a capillary rising of fluids in an evaporitic setting, for Dolomite A and a reflux of slightly saline water for Dolomite B. Finally, also in this stratigraphic interval, a third less abundant type of dolomite has been distinguished: Dolomite C (saddle type) followed by precipitation of poikilotopic calcite. Again, these last two diagenetic phases are concentrated along fractures and fault systems and can be related to warm fluids (130°C, as indicated by fluid inclusion microthermometry), raised along extensional faults. As a consequence, considering the similarity with the Jurassic, and also with some Raethian samples collected by Iannace (1991), these two last diagenetic phases can be ascribed to a unique late diagenetic event that is the rising of warm fluids along the extensional Neogenic faults, which represent the last tectonic phase affectiong the Apenninic fold and thrust belt. From a petrophysical point of view, the dolomites belonging to the two analyzed intervals show very low porosity values. The integration of petrophysics and petrography, show that the main factor affecting the porosity and permeability values is the crystal size and packing which is strictly related to the limestone precursor facies. In fact, both in the Jurassic and in the Cretaceous, the presence of two different textures (Planar-e and s), due to the facies variations of the host rock, strongly drives the porosity differences. As a result, considering an hypothetical hydrocarbon reservoir, both for the Jurassic and for the Cretaceous, the potential permeable horizons could have represented by the layers with the more porous Planar-e mosaic. Finally, in order to have a complete petrophysical characterization of the sampled dolomites, a detailed study on sonic velocity variations has been carried out. The investigation, aimed to analyze the influence of the intrinsic and extrinsic parameters on the sonic velocity variations in low porosity dolomites, involved the characterization of dolomites coming from the same succession but having different stratigraphic heights (Cretaceous and Jurassic from the Apenninic Platform, sharing the same burial and tectonic history) and also of dolomites having the same age but coming from two domains with different burial history (Cretaceous dolomites from the Apenninic and Apulia Platform). The main result of this part of the study has been that, in low porosity dolomites (<10%), the factors affecting the sonic velocity propagation drastically reduce. As a consequence, pore types and mostly crystals size result to be the main controlling factors on the sonic velocity variations. In conclusion, the data collected in this PhD thesis, together with the previous studies on the Sorrento Peninsula and on the Tethyan domain, demonstrate that there is a stratigraphic control on the observed different types of dolomites in terms of geometry, petrography and geochemistry. This control appears to be related to the different impact that surface-related, climatic controlled diagenesis and subsurface late diagenetic processes had in the different moments of the Mesozoic. The Norian and the Cretaceous appear as time favorable to the formation of early dolomites. On the other hand, the Rhaetian and the Lower-Middle Jurassic were times characterized by widespread fluid circulation episodes took place during the Jurassic and leaded to the formation of large discordant bodies of coarse grained dolomites. These processes have been active not only in the Lattari Mountain platform but likely affected also other platform domains of Apennines and Alps