From the Characterization of Ranging Error to the Enhancement of Nodes Localization for Group of Wireless Body Area Networks

International audienceTime-based localization in Wireless Body Area Networks (WBANs), has attracted growing research interest for the last past years. Nodes positions can be estimated based on peer-to-peer radio transactions between devices. Indeed, the accuracy of the localization process could be highly affected by different factors , such as the WBAN channels where the signal is propagating through, as well as the nodes mobility that bias the peer-to-peer range estimation, and thus, the final achieved localization accuracy. The goal of this paper consists in characterizing the impact of mobility and WBAN channel on the ranging and localization estimation, based on real mobility traces acquired through a motion capture system. More specifically, the ranging error is evaluated over all the WBANs links (i.e. on-body, off-body and body-to-body links), while an impulse Radio Ultra-Wideband (IR-UWB) physical layer, as well as a TDMA-based Medium Access Control (MAC) are playing on. The simulation results show that the range measurement error can be modeled as a Gaussian distribution. To deal with the gaus-sianity observation of ranging error and to provide high positioning accuracy, an adjustable extended Kalman Filter (EKF) is proposed

Proceedings of the 7th Sound and Music Computing Conference

Proceedings of the SMC2010 - 7th Sound and Music Computing Conference, July 21st - July 24th 2010

The Wireless Craze, The Unlimited Bandwidth Myth, The Spectrum Auction Faux Pas, and the Punchline to Ronald Coase's 'Big Joke': An Essay on Airwave Allocation Policy

In 1959 the Federal Communications Commission invited economist Ronald Coase to testify about his proposal for market allocation of radio spectrum rights. The FCC's first question: 'Is this all a big joke'' Today, however, leading policy makers, including the current FCC Chair, decry the 'spectrum drought' produced by administrative allocation and call for the creation of private bandwidth markets. This essay examines marketplace trends driving regulators' change of humor, and considers the path of spectrum policy liberalization in light of emerging technologies, theories of unlimited bandwidth, reforms such as FCC license auctions, and recent progress in deregulating wireless markets in the U.S. and around the globe.

Human Body Scattering Effects at Millimeter Waves Frequencies for Future 5G Systems and Beyond

[ES] Se espera que las futuras comunicaciones móviles experimenten una revolución técnica que vaya más allá de las velocidades de datos de Gbps y reduzca las latencias de las velocidades de datos a niveles muy cercanos al milisegundo. Se han investigado nuevas tecnologías habilitadoras para lograr estas exigentes especificaciones. Y la utilización de las bandas de ondas milimétricas, donde hay mucho espectro disponible, es una de ellas. Debido a las numerosas dificultades técnicas asociadas a la utilización de esta banda de frecuencias, se necesitan complicados modelos de canal para anticipar las características del canal de radio y evaluar con precisión el rendimiento de los sistemas celulares en milimétricas. En concreto, los modelos de propagación más precisos son los basados en técnicas de trazado de rayos deterministas. Pero estas técnicas tienen el estigma de ser computacionalmente exigentes, y esto dificulta su uso para caracterizar el canal de radio en escenarios interiores complejos y dinámicos. La complejidad de la caracterización de estos escenarios depende en gran medida de la interacción del cuerpo humano con el entorno radioeléctrico, que en las ondas milimétricas suele ser destructiva y muy impredecible. Por otro lado, en los últimos años, la industria de los videojuegos ha desarrollado potentes herramientas para entornos hiperrealistas, donde la mayor parte de los avances en esta emulación de la realidad tienen que ver con el manejo de la luz. Así, los motores gráficos de estas plataformas se han vuelto cada vez más eficientes para manejar grandes volúmenes de información, por lo que son ideales para emular el comportamiento de la propagación de las ondas de radio, así como para reconstruir un escenario interior complejo. Por ello, en esta Tesis se ha aprovechado la capacidad computacional de este tipo de herramientas para evaluar el canal radioeléctrico milimétricas de la forma más eficiente posible. Esta Tesis ofrece unas pautas para optimizar la propagación de la señal en milimétricas en un entorno interior dinámico y complejo, para lo cual se proponen tres objetivos principales. El primer objetivo es evaluar los efectos de dispersión del cuerpo humano cuando interactúa con el canal de propagación. Una vez evaluado, se propuso un modelo matemático y geométrico simplificado para calcular este efecto de forma fiable y rápida. Otro objetivo fue el diseño de un reflector pasivo modular en milimétricas, que optimiza la cobertura en entornos de interior, evitando la interferencia del ser humano en la propagación. Y, por último, se diseñó un sistema de apuntamiento del haz predictivo en tiempo real, para que opere con el sistema de radiación en milimétricas, cuyo objetivo es evitar las pérdidas de propagación causadas por el cuerpo humano en entornos interiores dinámicos y complejos.[CA] S'espera que les futures comunicacions mòbils experimenten una revolució tècnica que vaja més enllà de les velocitats de dades de Gbps i reduïsca les latències de les velocitats de dades a nivells molt pròxims al milisegundo. S'han investigat noves tecnologies habilitadoras per a aconseguir estes exigents especificacions. I la utilització de les bandes d'ones millimètriques, on hi ha molt espectre disponible, és una d'elles. A causa de les nombroses dificultats tècniques associades a la utilització d'esta banda de freqüències, es necessiten complicats models de canal per a anticipar les característiques del canal de ràdio i avaluar amb precisió el rendiment dels sistemes cellulars en millimètriques. En concret, els models de propagació més precisos són els basats en tècniques de traçat de rajos deterministes. Però estes tècniques tenen l'estigma de ser computacionalment exigents, i açò dificulta el seu ús per a caracteritzar el canal de ràdio en escenaris interiors complexos i dinàmics. La complexitat de la caracterització d'estos escenaris depén en gran manera de la interacció del cos humà amb l'entorn radioelèctric, que en les ones millimètriques sol ser destructiva i molt impredicible. D'altra banda, en els últims anys, la indústria dels videojocs ha desenrotllat potents ferramentes per a entorns hiperrealistes, on la major part dels avanços en esta emulació de la realitat tenen a veure amb el maneig de la llum. Així, els motors gràfics d'estes plataformes s'han tornat cada vegada més eficients per a manejar grans volums d'informació, per la qual cosa són ideals per a emular el comportament de la propagació de les ones de ràdio, així com per a reconstruir un escenari interior complex. Per això, en esta Tesi s'ha aprofitat la capacitat computacional d'este tipus de ferramentes per a avaluar el canal radioelèctric millimètriques de la manera més eficient possible. Esta Tesi oferix unes pautes per a optimitzar la propagació del senyal en millimètriques en un entorn interior dinàmic i complex, per a la qual cosa es proposen tres objectius principals. El primer objectiu és avaluar els efectes de dispersió del cos humà quan interactua amb el canal de propagació. Una vegada avaluat, es va proposar un model matemàtic i geomètric simplificat per a calcular este efecte de forma fiable i ràpida. Un altre objectiu va ser el disseny d'un reflector passiu modular en millimètriques, que optimitza la cobertura en entorns d'interior, evitant la interferència del ser humà en la propagació, per a així evitar pèrdues de propagació addicionals. I, finalment, es va dissenyar un sistema d'apuntament del feix predictiu en temps real, perquè opere amb el sistema de radiació en millimètriques, l'objectiu del qual és evitar les pèrdues de propagació causades pel cos humà en entorns interiors dinàmics i complexos.[EN] Future mobile communications are expected to experience a technical revolution that goes beyond Gbps data rates and reduces data rate latencies to levels very close to a millisecond. New enabling technologies have been researched to achieve these demanding specifications. The utilization of mmWave bands, where a lot of spectrum is available, is one of them. Due to the numerous technical difficulties associated with using this frequency band, complicated channel models are necessary to anticipate the radio channel characteristics and to accurately evaluate the performance of cellular systems in mmWave. In particular, the most accurate propagation models are those based on deterministic ray tracing techniques. But these techniques have the stigma of being computationally intensive, and this makes it difficult to use them to characterize the radio channel in complex and dynamic indoor scenarios. The complexity of characterizing these scenarios depends largely on the interaction of the human body with the radio environment, which at mmWaves is often destructive and highly unpredictable. On the other hand, in recent years, the video game industry has developed powerful tools for hyper-realistic environments, where most of the progress in this reality emulation has to do with the handling of light. Therefore, the graphic engines of these platforms have become more and more efficient to handle large volumes of information, becoming ideal to emulate the radio wave propagation behavior, as well as to reconstruct a complex interior scenario. Therefore, in this Thesis one has taken advantage of the computational capacity of this type of tools to evaluate the mmWave radio channel in the most efficient way possible. This Thesis offers some guidelines to optimize the signal propagation in mmWaves in a dynamic and complex indoor environment, for which three main objectives are proposed. The first objective has been to evaluate the scattering effects of the human body when it interacts with the propagation channel. Once evaluated, a simplified mathematical and geometrical model has been proposed to calculate this effect in a reliable and fast way. Another objective has been the design of a modular passive reflector in mmWaves, which optimizes the coverage in indoor environments, avoiding human interference in the propagation, in order to avoid its harmful scattering effects. And finally, a real-time predictive beam steering system has been designed for the mmWaves radiation system, in order to avoid propagation losses caused by the human body in dynamic and complex indoor environments.Romero Peña, JS. (2022). Human Body Scattering Effects at Millimeter Waves Frequencies for Future 5G Systems and Beyond [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/19132

Interactive Visualization and Exploration of High-Dimensional Data

Visualizing data is an essential part of good statistical practice. Plots are useful for revealing structure in the data, checking model assumptions, detecting outliers and finding unanticipated patterns. Post-analysis visualization is commonly used to communicate the results of statistical analyses. The availability of good statistical visualization software is key in effectively performing data analysis and in exploring and developing new methods for data visualization. Compared to static visualization, interactive visualization adds natural and powerful ways to explore the data. With interactive visualization an analyst can dive into the data and quickly react to visual clues by, for example, re-focusing and creating interactive queries of the data. Further, linking visual attributes of the data points such as color and size allows the analyst to compare different visual representations of the data such as histograms and scatterplots. In this thesis, we explore and develop new interactive data visualization and exploration tools for high-dimensional data. The original focus of our research was a software implementation of navigation graphs. Navigation graphs are navigational infrastructures for controlled exploration of high-dimensional data. As part of this thesis, we developed the first interactive implementation of these navigation graphs called RnavGraph. With RnavGraph we explored various features for enhancing the usability of navigation graphs. We concluded that a powerful interactive scatterplot display and methods to deal with large graphs were two areas that would add great value to the navigation graph framework. RnavGraph's scatterplot display proved to be particularly useful for data analysis and we continued our research with the design and implementation of a general-purpose interactive visualization toolkit called loon. The core contributions of loon are as follows. loon implements a general design for interactive statistical graphic displays that supports layering of visual information such as point objects, lines and polygons. These displays further support zooming, panning and selection, and modification and deactivation of plot elements and layers. Interactions with plots are provided with mouse and keyboard gestures as well as via command line control and with inspectors. These inspectors provide graphical user interfaces for modifying and overseeing the plots. loon also implements a novel dynamic linking mechanism that can be used to assign the plots that are to be linked and the linking rules at run time. Additionally, loon's design provides several different types of event bindings to add and customize functionality of loon's displays. In this thesis, we discuss loon's design and framework by giving concrete examples that show how these design choices can be used to efficiently explore and visualize data interactively. These examples revolve around loon's statistical interactive displays such as histograms, scatterplots and graph displays. We also illustrate how loon's design can be used to layer on plots relevant statistical information and model fits such as density estimates, contours, regression lines and geographical maps for spatial data analysis. loon is implemented in Tcl and Tk and we explore the integration of loon's framework into a complete statistical computing environment such as R. We show examples of statistical analyses performed in R that are enhanced with interactivity using loon. loon also implements a number of new tools for high-dimensional data exploration. The serialaxes display represents the data using parallel or radial coordinates. The scatterplot display supports high-dimensional point glyphs such as serialaxes glyphs, polygons and images. loon's navigation graphs allow for multiple navigators and for direct manipulation of a graph which includes deactivating nodes and their adjoining edges. To deal with large graphs, we propose and implement environments for creating navigation graphs interactively by filtering the nodes with respect to some node-associated relevant measures. Such measures include the correlation of variable pairs and the graph-based scagnostics measures. We use sliders, histograms and scatterplot matrices to interactively filter the nodes based on the value of their associated measure. Measures are kept generic and can be recalculated for the subset of selected data points. As another tool for exploring high-dimensional data, we introduce a setup that allows the analyst to select points and have their k-nearest neighboring points highlighted automatically. The space to calculate the inter-point distances that determine the k-nearest neighbors can be chosen dynamically. Finally, we propose a new high-dimensional point glyph called the spiro glyph. While some of loon's interaction features have appeared in part or in whole in statistical systems in the past 40 years (e.g. brushing, panning, zooming, linking plots, etc.), no other equally rich system has provided (or continues to provide) an interactive data visualization system integrated with a widely available and stable statistical system like R. Both Tcl and R are well suited for rapid prototyping of software and statistical methods; with loon rapid prototyping of interactive data visualization tools and methods become possible as well

Proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress

Published proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress, hosted by York University, 27-30 May 2018

Constrained LMDS technique for human motion and gesture estimation

International audienceBody Area Networks is an emerging domain taking a big interest from developers and system designers. On the other hand, the need to localize is becoming necessary in diverse applications. Within this context, the aim of this paper is to estimate the different gestures and motions of the human body. Initially, we use information, about human motion, extracted from C3D files. In fact, these files provide us with the exact 3D coordinates of the sensors on a moving body. In a second step the IEEE 802.15.6 channel model is used to estimate the distances between sensors which are the input of the locomotion technique based on Multidimensional Scaling. Basically, this technique did not present satisfying results, that's why we have improved our results by an SVD reconstruction algorithm and by adding distance constraints

Queensland University of Technology: Handbook 2014

The Queensland University of Technology handbook gives an outline of the faculties and subject offerings available that were offered by QUT