Joint Uplink and Downlink Coverage Analysis of Cellular-based RF-powered IoT Network

Ambient radio frequency (RF) energy harvesting has emerged as a promising solution for powering small devices and sensors in massive Internet of Things (IoT) ecosystem due to its ubiquity and cost efficiency. In this paper, we study joint uplink and downlink coverage of cellular-based ambient RF energy harvesting IoT where the cellular network is assumed to be the only source of RF energy. We consider a time division-based approach for power and information transmission where each time-slot is partitioned into three sub-slots: (i) charging sub-slot during which the cellular base stations (BSs) act as RF chargers for the IoT devices, which then use the energy harvested in this sub-slot for information transmission and/or reception during the remaining two sub-slots, (ii) downlink sub-slot during which the IoT device receives information from the associated BS, and (iii) uplink sub-slot during which the IoT device transmits information to the associated BS. For this setup, we characterize the joint coverage probability, which is the joint probability of the events that the typical device harvests sufficient energy in the given time slot and is under both uplink and downlink signal-to-interference-plus-noise ratio (SINR) coverage with respect to its associated BS. This metric significantly generalizes the prior art on energy harvesting communications, which usually focused on downlink or uplink coverage separately. The key technical challenge is in handling the correlation between the amount of energy harvested in the charging sub-slot and the information signal quality (SINR) in the downlink and uplink sub-slots. Dominant BS-based approach is developed to derive tight approximation for this joint coverage probability. Several system design insights including comparison with regularly powered IoT network and throughput-optimal slot partitioning are also provided

Direct communication radio Iinterface for new radio multicasting and cooperative positioning

Cotutela: Universidad de defensa UNIVERSITA’ MEDITERRANEA DI REGGIO CALABRIARecently, the popularity of Millimeter Wave (mmWave) wireless networks has increased due to their capability to cope with the escalation of mobile data demands caused by the unprecedented proliferation of smart devices in the fifth-generation (5G). Extremely high frequency or mmWave band is a fundamental pillar in the provision of the expected gigabit data rates. Hence, according to both academic and industrial communities, mmWave technology, e.g., 5G New Radio (NR) and WiGig (60 GHz), is considered as one of the main components of 5G and beyond networks. Particularly, the 3rd Generation Partnership Project (3GPP) provides for the use of licensed mmWave sub-bands for the 5G mmWave cellular networks, whereas IEEE actively explores the unlicensed band at 60 GHz for the next-generation wireless local area networks. In this regard, mmWave has been envisaged as a new technology layout for real-time heavy-traffic and wearable applications. This very work is devoted to solving the problem of mmWave band communication system while enhancing its advantages through utilizing the direct communication radio interface for NR multicasting, cooperative positioning, and mission-critical applications. The main contributions presented in this work include: (i) a set of mathematical frameworks and simulation tools to characterize multicast traffic delivery in mmWave directional systems; (ii) sidelink relaying concept exploitation to deal with the channel condition deterioration of dynamic multicast systems and to ensure mission-critical and ultra-reliable low-latency communications; (iii) cooperative positioning techniques analysis for enhancing cellular positioning accuracy for 5G+ emerging applications that require not only improved communication characteristics but also precise localization. Our study indicates the need for additional mechanisms/research that can be utilized: (i) to further improve multicasting performance in 5G/6G systems; (ii) to investigate sideline aspects, including, but not limited to, standardization perspective and the next relay selection strategies; and (iii) to design cooperative positioning systems based on Device-to-Device (D2D) technology

Bayesian Estimation and Quality Monitoring for Personal Positioning Systems

Personal positioning is a dynamic estimation problem where the ability to assess the quality of the positioning service is as important as obtaining accurate position estimates. When estimating the position of a person, as opposed to e.g. an airplane, the type of motion can change at any time as a pedestrian can board a bus, or a cyclist can board a train. Also the changing surroundings in urban navigation influence the observation noise as tall buildings blocking the line of sight to satellites are full of reflecting surfaces. First we investigate classic robust estimation methods applied to the positioning problem, but then we focus on the Bayesian framework, as its generality allows us to take into account the abrupt changes in the state-space system. Gaussian mixture distributions and Markov chain indicator processes are used to model the changing systems. We evaluate the resulting systems mainly with sequential Monte Carlo methods, as this approach gives us an approximative joint posterior distribution of the errors and the state. We propose a general framework for the Bayesian receiver autonomous integrity monitoring in urban navigation based on the posterior probabilities. We also use the Bayesian framework to solve the explicit effect of the sensor errors in a nominal system that estimates the state with the assumption of no changes in the models. We use the estimated cumulated effect of the errors in the time series to determine whether error is present in the system at any time. Finally, a variational Bayes algorithm is developed for detecting changes in the system noise covariances

The genetic mating system and analyses of reproductive success in Allobates femoralis

Das Bild von Froschpopulationen, die als Brutgemeinschaften während kurzer reproduktiver Perioden an einzelnen Wasserstellen große Mengen an Laich ablegen, ist weit verbreitet. Innerhalb der Anuren finden wir jedoch ein breites Spektrum an verschiedenen reproduktiven Strategien. Neotropische Pfeilgiftfrösche (Dendrobatidae und Aromobatidae in der Überfamilie Dendrobatoidea) nehmen hinsichtlich ihres aufwändigen Reproduktionsverhaltens eine Sonderstellung innerhalb der Amphibien ein. Charakteristische Attribute aller Arten in dieser Gruppe sind lange Brutperioden, Territorialität zumindest bei einem der Geschlechter und obligate Brutpflege. Folglich kann man erwarten, dass sich Dendrobatoidae im Bezug auf ihre Populationsgenetik und reproduktiven Dynamiken erheblich von „temperaten Explosivlaichern“ unterscheiden. Die Kenntnisse über reproduktives Verhalten von Pfeilgiftfröschen basieren Großteils auf detaillierten Verhaltensbeobachtungen, und wurden bisher nur durch wenige molekulare Studien belegt. Die über ganz Amazonien verbreitete Pfeilgiftfroschart Allobates femoralis eignet sich sehr gut für Studien auf Individuen- bzw. Populationsniveau. Während der langen Fortpflanzungsperiode, die mit der Regenzeit einhergeht, sind die Männchen hoch territorial; die Weibchen sind iteropar und standorttreu. Balz und Paarung findet in den Territorien der Männchen statt. Das genetische Paarungssystem zu erfassen und die Verteilung des Fortpflanzungserfolges bei Männchen und Weibchen innerhalb einer A. femoralis Population zu untersuchen war das Ziel meiner Dissertation. Diese Arbeit trägt somit zum Wissen über Paarungssysteme, Parameter der Partnerwahl und über Effekte der elterlichen Verwandtschaft auf individuellen Fortpflanzungserfolg, insbesondere in Dendrobatoidea, bei. Die untersuchte A. femoralis Population befindet sich in der Nähe der Forschungsstation ‘Saut Pararé’ im Naturschutzgebiet ‘Les Nouragues’, in Französisch Guyana. Anhand molekularer Elternschaftsanalysen zweier aufeinanderfolgender Generationen adulter Individuen konnte ein hoch polygynandrisches Paarungssystem identifiziert werden. Trotz erheblicher Unterschiede im reproduktiven Verhalten von Männchen und Weibchen, hatten erfolgreiche Individuen in beiden Geschlechtern sowohl eine ähnliche Anzahl von Fortpflanzunspartnern als auch adulte Nachkommen pro Individuum. Auch der Prozentsatz an Männchen und auch Weibchen in der Population, die erfolgreich Nachkommen produzierten, die bis zum Adultstadium überlebten, war sehr hoch. Der individuelle Reproduktionserfolg war signifikant höher für Männchen, welche ein Territorium besaßen, jedoch unabhängig von der Größe des Territoriums oder Körpergröße beider Geschlechter. Elternschaftszuordnungen von Nachkommen zu zwei unterschiedlichen Zeitpunkten in der Entwicklung zu ihrer Parentalgeneration wurden verwendet, um die Effekte von genetischer Verwandtschaft auf individuellen Fortpflanzungserfolg in A. femoralis zu identifizieren. Die schrittweise räumliche Einengung der potentiellen männlichen Fortpflanzungspartner in unserer Analyse ermöglichte zwischen räumlichen und genetischen Effekten bei der Partnerwahl zu differenzieren. Räumliche und genetische Distanzen wiesen keinerlei Korrelation auf. Weibchen wählten ihre Fortpflanzungspartner meist (in 72%) innerhalb eines Radius von 20m. Unsere Analysen lieferten keinen Hinweis auf Inzuchtvermeidung bei A. femoralis, jedoch war die Varianz der genetischen Divergenz der erfolgreichen Fortpflanzungspaare signifikant kleiner, als bei Zufallsverpaarungen zu erwarten gewesen wäre. DNA Proben für die molekularen Analysen wurden gesammelt, in dem wir von allen adulten männlichen und weiblichen A. femoralis Phalangenamputationen durchführten. Nach wenigen Monaten, konnte die Größenzunahme dieser Phalangenstümpfe beobachtet werden, ein Phänomen, das bisher nur fallweise bei einzelnen Froscharten beschrieben wurde. Außerdem wiesen die rasch nachgewachsenen Zehenscheiben in fast ausnahmslos allen Individuen, die nach einem bzw. zwei Jahren wiedergefangen wurden, eine schwarze statt der ursprünglichen weißen Färbung auf. Der Besitz eines Territoriums, nicht jedoch dessen Größe, ist ein signifikanter Bestimmungsfaktor für den Fortpflanzungserfolg in A. femoralis Männchen. Jedoch resultiert der Unterschied zwischen der Kernzone, die ein Männchen während des Rufend okkupiert, und dem Raum, den ein Männchen aktiv verteidigt, in zwei möglichen Definitionen für „Territorium“. Das Ergebnis, dass in A. femoralis die Ausdehnung des verteidigten Areales nicht mir der Kernzone korreliert, ist von spezieller Relevanz für zukünftige Studien, die Effekte von Territorialität auf Fortpflanzungserfolg untersuchen. Schließlich dokumentieren wir die Prädation eines A. femoralis Männchen durch eine Schlange der Art Xenopholis scalaris (Colubridae).Anuran amphibians are often portrayed as generally congregating at confined aquatic sites to deposit rather large egg clutches during short reproductive bouts, but they actually show a remarkably wide array of different reproductive strategies. Neotropical poison frogs and their relatives (Dendrobatidae and Aromobatidae in the superfamily Dendrobatoidea), for example, hold an extraordinary position within amphibians due to their elaborate reproductive behaviour which is found across the whole taxon. Dendrobatoid frogs are characterised by prolonged breeding, territoriality of at least one sex, and uni- or biparental care. Hence, it can be expected that in this taxonomic group population genetics and reproductive dynamics also differ considerably from the ‘temperate explosive breeding’ situation. Dendrobatoid reproductive behaviour is well documented from behavioural observations, but very few molecular studies have been performed in this taxon so far. The pan-Amazonian dendrobatoid frog Allobates femoralis is a highly suitable species for studies at the individual and also population level. Throughout the prolonged breeding period, which corresponds to the rainy season, males are highly territorial. Females are iteroparous and show strong site fidelity. Courtship and mating takes place inside the male territories. The aim of my dissertation was to assess the genetic mating system and to investigate the distribution and determinants of male and female reproductive success across an entire A. femoralis population. This thesis hence contributes to the knowledge about mating systems, parameters of mate choice, and effects of parental relatedness on reproductive success, particularly in Dendrobatoid frogs. The A. femoralis population under study is located near the research station ‘Saut Pararé’ in the nature reserve ‘Les Nouragues’, French Guiana. Through molecular parentage analyses of two successive generations of adult individuals a highly polygynandrous mating system was identified. Despite significant differences in the reproductive behaviour of males and females, successful individuals of both sexes had similar numbers of mating partners and produced similar numbers of adult progeny. Furthermore, a high percentage of the males and females in the population produced progeny which survived until adulthood. Reproductive success was significantly higher in territorial males, but not related to territory size in males or body size in both sexes. Parentage assignments of one offspring generation at two different life history stages were used to identify patterns of parental relatedness on reproductive success in Allobates femoralis. The stepwise spatial restriction of candidate males in our analysis allowed us to discern between spatial and genetic effects of mate choice. There was no correlation between genetic and spatial distance. Females mainly (in 72%) chose their mating partners within a radius of 20 m. Our results show no evidence of behavioral inbreeding avoidance in A. femoralis but indicate a selective benefit of matings between partners of intermediate genetic divergence. For the molecular analyses, we removed toe clips to gain sufficient DNA from all adult male and female A. femoralis. After a few months, the regrowth of the clipped toes was observed, a phenomenon, which was so far only occasionally reported from few anuran species. Furthermore, in almost all one- and two-year recaptured individuals the regrown toe discs showed a black instead of the original white colouration. Territory occupancy, but not territory size, was identified as a significant determinant of reproductive success in A. femoralis males. Given the distinct difference between the core area that is occupied during calling and the area a male is willing to defend, results in two possible definitions of male territory size. Our finding that the extension of the defended area did not correlate with the area occupied during calling is of particular relevance to studies that investigate the effect of territory size on reproductive success. Finally, we document a predation event on an A. femoralis male by a colubrid snake

Presence 2005: the eighth annual international workshop on presence, 21-23 September, 2005 University College London (Conference proceedings)

OVERVIEW (taken from the CALL FOR PAPERS) Academics and practitioners with an interest in the concept of (tele)presence are invited to submit their work for presentation at PRESENCE 2005 at University College London in London, England, September 21-23, 2005. The eighth in a series of highly successful international workshops, PRESENCE 2005 will provide an open discussion forum to share ideas regarding concepts and theories, measurement techniques, technology, and applications related to presence, the psychological state or subjective perception in which a person fails to accurately and completely acknowledge the role of technology in an experience, including the sense of 'being there' experienced by users of advanced media such as virtual reality. The concept of presence in virtual environments has been around for at least 15 years, and the earlier idea of telepresence at least since Minsky's seminal paper in 1980. Recently there has been a burst of funded research activity in this area for the first time with the European FET Presence Research initiative. What do we really know about presence and its determinants? How can presence be successfully delivered with today's technology? This conference invites papers that are based on empirical results from studies of presence and related issues and/or which contribute to the technology for the delivery of presence. Papers that make substantial advances in theoretical understanding of presence are also welcome. The interest is not solely in virtual environments but in mixed reality environments. Submissions will be reviewed more rigorously than in previous conferences. High quality papers are therefore sought which make substantial contributions to the field. Approximately 20 papers will be selected for two successive special issues for the journal Presence: Teleoperators and Virtual Environments. PRESENCE 2005 takes place in London and is hosted by University College London. The conference is organized by ISPR, the International Society for Presence Research and is supported by the European Commission's FET Presence Research Initiative through the Presencia and IST OMNIPRES projects and by University College London