Proactive measurement techniques for network monitoring in heterogeneous environments

Tesis doctoral inédita. Universidad Autónoma de Madrid, Escuela Politécnica Superior, Departamento de Tecnología Electrónica y de las Comunicaciones, 201

A Sensors System for Indoor Localisation of a Moving Target Based on Infrared Pattern Recognition

Estimating the position of a robot, a vehicle or a person in an indoor area is a significan

A context‐aware approach to defend against unauthorized reading and relay attacks in RFID systems

Radio frequency identification (RFID) systems are becoming increasingly ubiquitous in both public and private domains. However, because of the inherent weaknesses of underlying wireless radio communications, RFID systems are plagued with a wide variety of security and privacy threats. A large number of these threats arise because of the tag's promiscuous response to any reader requests. This renders sensitive tag information easily subject to unauthorized reading . Promiscuous tag response also incites different forms of relay attacks whereby a malicious colluding pair, relaying messages between a tag and a reader, can successfully impersonate the tag without actually possessing it. Because of the increasing ubiquity of RFID devices, there is a pressing need for the development of security primitives and protocols to defeat unauthorized reading and relay attacks. However, currently deployed or proposed solutions often fail to satisfy the constraints and requirements of the underlying RFID applications in terms of (one or more of) efficiency, security, and usability. This paper proposes a novel research direction, one that utilizes sensing technologies, to tackle the problems of unauthorized reading and relay attacks with a goal of reconciling the requirements of efficiency, security, and usability. The premise of the proposed work is based on a current technological advancement that enables many RFID tags with low‐cost sensing capabilities. The on‐board tag sensors will be used to acquire useful contextual information about the tag's environment (or its owner, or the tag itself). For defense against unauthorized reading and relay attacks, such context information can be leveraged in two ways. First, contextual information can be used to design context‐aware selective unlocking mechanisms so that tags can selectively respond to reader interrogations and thus minimize the likelihood of unauthorized reading and “ghost‐and‐leech” relay attacks. Second, contextual information can be used as a basis for context‐aware secure transaction verification to defend against special types of relay attacks involving malicious readers. Copyright © 2011 John Wiley & Sons, Ltd. This paper proposes a novel research direction, one that utilizes sensing technologies to tackle the challenging problems of unauthorized reading and relay attacks in radio frequency identification systems. First, contextual information is used to design context‐aware selective unlocking mechanisms, so that tags can selectively respond to reader interrogations and, thus, minimize the likelihood of unauthorized reading and “ghost‐and‐leech” relay attacks. Second, contextual information is used as a basis for context‐aware secure transaction verification to defend against special types of relay attacks involving malicious readers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109577/1/sec404.pd

On the Exploration of FPGAs and High-Level Synthesis Capabilities on Multi-Gigabit-per-Second Networks

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Escuela Politécnica Superior, Departamento de Tecnología Electrónica y de las Comunicaciones. Fecha de lectura: 24-01-2020Traffic on computer networks has faced an exponential grown in recent years. Both links and communication equipment had to adapt in order to provide a minimum quality of service required for current needs. However, in recent years, a few factors have prevented commercial off-the-shelf hardware from being able to keep pace with this growth rate, consequently, some software tools are struggling to fulfill their tasks, especially at speeds higher than 10 Gbit/s. For this reason, Field Programmable Gate Arrays (FPGAs) have arisen as an alternative to address the most demanding tasks without the need to design an application specific integrated circuit, this is in part to their flexibility and programmability in the field. Needless to say, developing for FPGAs is well-known to be complex. Therefore, in this thesis we tackle the use of FPGAs and High-Level Synthesis (HLS) languages in the context of computer networks. We focus on the use of FPGA both in computer network monitoring application and reliable data transmission at very high-speed. On the other hand, we intend to shed light on the use of high level synthesis languages and boost FPGA applicability in the context of computer networks so as to reduce development time and design complexity. In the first part of the thesis, devoted to computer network monitoring. We take advantage of the FPGA determinism in order to implement active monitoring probes, which consist on sending a train of packets which is later used to obtain network parameters. In this case, the determinism is key to reduce the uncertainty of the measurements. The results of our experiments show that the FPGA implementations are much more accurate and more precise than the software counterpart. At the same time, the FPGA implementation is scalable in terms of network speed — 1, 10 and 100 Gbit/s. In the context of passive monitoring, we leverage the FPGA architecture to implement algorithms able to thin cyphered traffic as well as removing duplicate packets. These two algorithms straightforward in principle, but very useful to help traditional network analysis tools to cope with their task at higher network speeds. On one hand, processing cyphered traffic bring little benefits, on the other hand, processing duplicate traffic impacts negatively in the performance of the software tools. In the second part of the thesis, devoted to the TCP/IP stack. We explore the current limitations of reliable data transmission using standard software at very high-speed. Nowadays, the network is becoming an important bottleneck to fulfill current needs, in particular in data centers. What is more, in recent years the deployment of 100 Gbit/s network links has started. Consequently, there has been an increase scrutiny of how networking functionality is deployed, furthermore, a wide range of approaches are currently being explored to increase the efficiency of networks and tailor its functionality to the actual needs of the application at hand. FPGAs arise as the perfect alternative to deal with this problem. For this reason, in this thesis we develop Limago an FPGA-based open-source implementation of a TCP/IP stack operating at 100 Gbit/s for Xilinx’s FPGAs. Limago not only provides an unprecedented throughput, but also, provides a tiny latency when compared to the software implementations, at least fifteen times. Limago is a key contribution in some of the hottest topic at the moment, for instance, network-attached FPGA and in-network data processing

The Combined Effects of Physical Exercise and Cognitive Training on Gait Speed and Primary Motor Cortex Metabolism in Individuals with Mild Cognitive Impairment: A 1H-MRS Analysis

Mild cognitive impairment (MCI) is a transitional stage before dementia. Altered gait in MCI has been associated with progression to dementia. Using magnetic resonance spectroscopy, a relationship between primary motor cortex (M1) neurochemistry and dual task gait speed has been reported in MCI. Interventional research suggests exercise, cognitive training, and vitamin D supplementation may benefit MCI, yet the combined effect of these treatments on gait speed and M1 metabolism is unknown. Participants with MCI (N=75) were assigned to one of five intervention arms and dual task cost on gait speed and M1 metabolism was assessed before and five months after intervention. Cognitive training paired with exercise increased M1 N-acetyl aspartate (NAA)/creatine concentrations compared to physical exercise alone. Additionally, those with greater changes in dual task cost on gait speed showed greater decreases in NAA and choline, further establishing a relationship between gait speed and M1 function in MCI

Sistema de medida de calidad de servicio de red basado en trenes de paquetes usando mensajes estándar de control

Trabajo de Fin de Grado en Ingeniería de Tecnologías y Servicios de TelecomunicaciónHoy en día, debido a la evolución de las tecnologías y a la mejora en la calidad de servicio, está teniendo lugar un proceso de digitalización en el ámbito empresarial sin precedentes. De hecho, durante este último año este proceso se ha acentuado aún más por la pandemia COVID-19 que impide viajes, reuniones… etc. En este contexto, las empresas demandan cada vez más recursos y calidad en el servicio, puesto que de ello depende el correcto funcionamiento de la compañía. Ante el aumento de esta demanda, las operadoras se han visto obligadas a ofrecer herramientas a sus clientes para que puedan comprobar que se está cumpliendo con el acuerdo de nivel de servicio. Sin embargo, estas herramientas utilizan habitualmente técnicas basadas en el protocolo TCP (por ejemplo, iperf) que han resultado ser poco eficientes en determinadas ocasiones, puesto que es necesario parar toda la actividad de la red para poder realizar las medidas. Esto se debe a que estas herramientas generalmente funcionan por inundación. Además, es necesario tener la aplicación tanto en el cliente como en el servidor para poder hacer las medidas. Consecuentemente, este Trabajo de Fin de Grado busca encontrar un método capaz de monitorizar la red de una forma más simple y eficiente. Para ello, se ha desarrollado un sistema de medida de calidad de servicio de red basado en trenes de paquetes usando mensajes estándar de control. Este sistema mide los parámetros habituales de calidad de servicio: pérdida de paquetes, retardo, variación del retardo(jitter), tasa de transferencia(throughput) y ancho de banda. Se han estudiado e implementado dos técnicas para realizar las estimaciones: una consiste en enviar y recibir paquetes ICMP de tipo eco, y la otra en transmitir paquetes UDP para generar mensajes de respuesta ICMP de puerto inalcanzable. Posteriormente, se ha desarrollado un programa en C capaz de enviar las ráfagas de paquetes y medir los parámetros de calidad de servicio. Gracias a este programa, se han puesto a prueba ambas técnicas, tanto en entornos reales como virtuales. Finalmente, se han analizado los resultados y se ha comprobado que la técnica basada en trenes de paquetes ICMP cumple con los requisitos mencionados anteriormente

Fully automated urban traffic system

The replacement of the driver with an automatic system which could perform the functions of guiding and routing a vehicle with a human's capability of responding to changing traffic demands was discussed. The problem was divided into four technological areas; guidance, routing, computing, and communications. It was determined that the latter three areas being developed independent of any need for fully automated urban traffic. A guidance system that would meet system requirements was not being developed but was technically feasible

Position, velocity and time measurement with multiple constellation data from GPS, GALILEO, GLONASS and BEIDOU

Il presente lavoro si propone di illustrare la teoria, il metodo e le modalità del calcolo della PVT, ovvero della posizione, della velocità e del sincronismo temporale, di un utente sulla Terra o di un satellite in orbita bassa (dotato di ricevitore multiGNSS), utilizzando un software integrato che sfrutti tutti i segnali provenienti da tutte le costellazioni a copertura globale in quel momento visibili. Nel caso presente si sono utilizzati i segnali da GPS, Galileo, GLONASS e BeiDou, rilevati grazie ad un ricevitore fornito dall'Università di Padova (STONEX S580), sia per la determinazione della posizione, sia per implementare il calcolo della velocità attraverso l'effetto Doppler. Questo lavoro, in futuro, potrebbe portare a contributi nello sviluppo di tecnologie innovative in molti settori, quali: navigazione autonoma e trasporti, difesa e aerospazio, agricoltura e molti altri.This work intends to outline the theory and the methods for the computation of position, velocity and time (PVT) of a user on the surface of the Earth or of a LEO satellite (Low Earth Orbit). An integrated software written in MATLAB and PERL has been used; it processes all the signals transmitted by all the constellations visible in that precise moment and in that precise place. The software's core uses the Weighted Least Squares algorithm, which permits the efficient computation of position, speed, timing and tropospheric delay in a few iterations. In this thesis, signals from GPS, Galileo, BeiDou and GLONASS have been used, specifically for the computation of the speed, which is calculated from the Doppler Effect. These signals were detected through a receiver STONEX Cube-a S580 provided by the University of Padua. A good precision in determination of both positioning and speed has been achieved and also the PNT of a LEO satellite (Sentinel 3A) has been determined successfully, using data also to study J2 perturbations on the orbit. The principal aim of this thesis is to provide an efficient and precise software able to process pseudorange and Doppler shift multi-constellation data, to enhance, in its future evolutions, the precise positioning of a receiver on Earth's surface and in orbit, with interesting applications in many different fields such as defence, transportations and automotive, attitude determination in space and many others

Internet traffic classification for high-performance and off-the-shelf systems

Tesis doctoral inédita, leída en la Universidad Autónoma de Madrid, Escuela Politécnica Superior, Departamento de Tecnología Electrónica y de las Comunicaciones, 2013

Lane keeping under cognitive distractions: performance and mechanisms

Cognitive distractions while driving often reduce the variability of lane position. However, data do not make clear whether smaller lane variability should be interpreted as a performance loss, indicating rigidified or unresponsive steering response to external stimuli, or a performance improvement in lane-keeping, indicating better lateral control. Four hypotheses, rigidified steering, visual enhancement, lateral prioritization, and automatic steering, debated on the performance implications and mechanisms of smaller lane variability under cognitive distractions. This dissertation project compares these hypotheses, and explores two important questions: first, whether the smaller lane variability under cognitive distraction indicates a performance loss or a performance gain in lane-keeping; second, what is the underlying cognitive mechanisms of lane variability reduction. Three studies have been carried out to assess drivers’ responsiveness to heavy lateral winds under varying levels of cognitive load. Data showed that cognitive load reduced the variability of lane position but increased the variability of vehicle speed, engendering more frequent steering activity but less frequent speed manipulation. Cognitive load also increased the coherence, or coupling between steering wheel position and lateral wind strength. More interestingly, distracted drivers produced quicker steering response time to the sudden onset of lateral wind. Results thus suggest that smaller lane variability under cognitive distractions is an indicator of better lane-keeping performance, and distracted drivers achieved better lane-keeping performance by actively prioritizing lateral control. Findings carry practical applications for mitigating driving risks and theoretical implications on the relationship between attention allocation and driving performance