Papers by Jaume Segura Garcia
IEEE Internet of Things Journal
Proceedings of the Euro American Conference on Telematics and Information Systems
The evaluation of QoS in mobile multipath environments is an interesting topic in modern communic... more The evaluation of QoS in mobile multipath environments is an interesting topic in modern communications. The use of Raspberry Pi as a low cost microcomputer board developed in the United Kingdom by the Raspberry Pi Foundation can be helpful in onsite deployments. The Pi3 model has integrated WiFi and Bluetooth connectivity and also 4 USB ports to expand the device with all kinds of peripheral. Under the premise of offering the power of a computer at low prices, this device is one of the most affordable ways to have a particularly efficient and dynamic hardware accessible at a low price to develop a Wireless Sensor Netwok (WSN). The use of the Raspberry Pi3 permits the development of a powerful and hight efficient mote in the development of a WSN, where data is highly processed in each mote and transmissions between motes and the sink or base station (BS) can be keep at minimum. We develop an experimental setup to analyse the quality of transmission between these devices in order to a further modelization of the channel. We program the Raspberry Pi3 to evaluate the quality of the transmission between two devices within a controlled multipath environment, particularly within an anechoic chamber.
Proceedings of the 10th Euro-American Conference on Telematics and Information Systems
Wireless sensor networks (WSN) are groups of small devices that contain a microcontroller in whic... more Wireless sensor networks (WSN) are groups of small devices that contain a microcontroller in which a large number of sensors can be added. They transmit data and communicate to each other in the ISM band, standard IEEE 802.15.4, exchanging packets using a multi-hop routing. These devices are named motes and are nodes of the WSN. They are very simple and easy to program, powered by batteries of 1.5Volts (AA and AAA). The nodes are autonomous elements that can be deployed implementing any type of network. In a typical deployment the nodes communicate with each other and with a master node or Base Station (BS), which in turn transmits the information to an external server, which collects the environmental and any type of parameters collected by each sensor. WSNs are used in a multitude of military, industrial and civil applications. They use a very low amount of power, and this fact limits the maximum communication distance between motes within the WSN, which is around 50m for civil current motes. The Stochastic Collaborative Beamforming (SCB), was proposed as a way to overcome the low range. in which we take advantage of the synchronization errors of the clocks. In SCB, it is possible to obtain the adequate time delay that permits the interference or sufficient gain in the direction of the receiver. However the dimensions of the WSN deployment are so large as to consider the effects of the near field. WSN with 200m diameter have Fresnel areas ranging to distances as far as 325Km. In the present work we present the theoretical background to analyze the SCB transmission of a cluster of radiating motes, and also the theoretical planning for a SCB long range communication in the Albufera de València natural reservation area, some preliminary simulations and measurements are also presented.
11 Euro American Conference on Telematics and Information Systems
2017 Fourth International Conference on Software Defined Systems (SDS), 2017
The increasing adoption of smart phones, the increased access to mobile broadband networks and th... more The increasing adoption of smart phones, the increased access to mobile broadband networks and the availability of public cloud infrastructures are aligning to the next generation of truly ubiquitous multimedia services, known as Cloud Mobile Media (CMM) services. Nevertheless, due to an inherit higher and variable end to end delay mainly as a result of the virtualization process, new challenges appear in particular for live video streaming applications in order to keep a good Quality of Experience of the delivered video. Thus, to keep client's satisfaction at good levels in terms of Mean Opinion Score (MOS), we propose an adaptive Software Defined Networking (SDN)-based architecture running on CMM. We estimate MOS using an statistical method based on Factor Analysis (FA) and then the SDN controller is able to schedule different actions. The MOS estimation is based on different measured variables throughout the CMM infrastructure. Finally, we compare the accuracy of the estimated MOS against well known publicly available video quality algorithms as well as we propose an algorithm to run at the SDN controller to meet these requirements.
2017 IEEE International Conference on Communications (ICC), 2017
Recent studies about the use of cloud platforms indicate that more than three-fourths of healthca... more Recent studies about the use of cloud platforms indicate that more than three-fourths of healthcare institutions apply these technologies in their daily lives. However, in most cases the cloud is based on “Infrastructure as a Service”, instead of developing new applications using the benefits that can bring us this type of technology. For these reasons, this paper shows a private cloud-based system to provide a new application based on thermographic video streaming. In this case, the cloud architecture is divided into three zones. The first zone is where the patient is under medical supervision through body temperature analysis using a global thermal camera. The second zone is the cloud itself, where the video is encoded, but taking into account that the received video must ensure a correct measurement of the temperature. The third zone is the access network, where people or processes receive and analyze these videos. Finally, a performance evaluation using several video codecs and bitrates is done in order to see which one is more accurate and fits better medical requirements. Finally, we conclude that the system works properly, indicating which video codecs are more suitable for each scenario.
Proceedings of the 10th Euro-American Conference on Telematics and Information Systems, 2020
The proliferation of commercial low-cost Small Board Computers (SBC) devices have allowed the dep... more The proliferation of commercial low-cost Small Board Computers (SBC) devices have allowed the deployment of many Wireless Sensor Networks (WSN) focused on different applications, mainly based on monitoring issues. These networks are characterized by a set of these SBCs devices working in a collaborative way where each device is sensing, processing and later sending out the data to the sink. These devices are equipped with power supply, a processing unit and communications capabilities (in particular WiFi), making themselves very interesting to fit in many topologies. However, their performance in terms of communications basically depends on the environment and usually heuristic techniques are used with any guarantee if they will succeed or not. To model the different scenarios there are theoretically several approaches, such as ray tracing technique, two-ray, as well as semi-empirical models, but it should be interesting to analyze them also from a experimental point of view. In this paper we carry out a thorough performance analysis, in particular using Raspberry Pi3 (RPi3) devices, in order to understand their behavior in terms of Quality of Services (throughput, delay, losses and jitter (delay variation) for different types of communications: indoor and outdoor environments, with and without multipath reflections in order to establish precisely the amount of signal required depending on the required througput. In the outdoor environments, we analyze the QoS over the links between two nodes in a deployment. We conclude that using this type of devices we can achieve a throughput of more than 45 Mbps in indoor within distances shorter than 50 m and 40 Mbps in outdoor till 100 m and then it starts decaying till 300 m in normal conditions.
Frontiers in Microbiology, 2020
workshop-swispain-2017-elprograma.html diverse extramural activities deemed to include a gender p... more workshop-swispain-2017-elprograma.html diverse extramural activities deemed to include a gender perspective and aimed at different age groups, were also carried out, obtaining very satisfactory results, increasing sensitivity and awareness to the global antibiotic crisis.
Computer Communications, 2018
Current mobile networks are providing high speed access to Internet at a rate of Gigabits per sec... more Current mobile networks are providing high speed access to Internet at a rate of Gigabits per second. In this scenario, traditional services over wired networks are an alternative, in particular those based on live video streaming. But in the transition, different issues should be considered due to the rapid changing network conditions and the limited resources of the mobile devices. These issues should be taken into account to keep a good Quality of Experience (QoE) of the video in terms of a high Mean Opinion Score (MOS), a subjective video quality. Our goal is to estimate and predict this subjective metric in a holistic manner. Thus, we have analyzed and measured different variables related to Quality of Service, bit stream and basic video quality metrics of live video streaming over LTE Advanced (4G) mobile networks, as well as server side. With these variables, we apply a statistical method, called Factor Analysis based on the correlation of the variables, which allows us to estimate MOS of the delivered video in a robust and reliable way, both in Full Reference and Non Reference approaches. The real MOS has been evaluated through surveys. Finally, we compare the accuracy of the estimated MOS for the different approaches and compare their performance with well known publicly available video quality algorithms.
Cluster Computing, 2018
Nowadays, more than 75% of Internet traffic is multimedia traffic, moreover mobile traffic is gro... more Nowadays, more than 75% of Internet traffic is multimedia traffic, moreover mobile traffic is growing at a rate of 50% each year. All these data together with the evolution of the cloud infrastructures lead us to develop Cloud Mobile Media (CMM) architectures to support the needs demanded by end users. Nevertheless, due to an inherit higher and variable end to end delay mainly as a result of the virtualization process, new challenges appear in particular for live video streaming applications in order to keep a good Quality of Experience (QoE) of the delivered video. Thus, to keep client's satisfaction within good levels in terms of Mean Opinion Score (MOS), we propose an adaptive QoE-based architecture running on CMM infrastructures for live streaming services. In order to carry out this goal, we propose an estimation of MOS values using an statistical method based on factor analysis. This estimation is based on different measured variables throughout the CMM infrastructure. In addition, we compare the accuracy of the estimated MOS against well-known publicly available video quality algorithms. With these estimations, our proposal is based on two added controllers to the CMM infrastructure: (a) the Software Defined Network controller that acts as a master and (b) the Media Streamer controller. Each one does different actions on the CMM infrastructure in order to maintain and improve the QoE at each end user. Finally, this architecture has been implemented over a fat tree topology in order to show their functionality. The results show that our proposal works properly and it adapts quickly to the network changes in order to deliver a good MOS.
Computer Communications, 2017
The adoption of smart phones, the increased access to mobile broadband networks and the availabil... more The adoption of smart phones, the increased access to mobile broadband networks and the availability of public cloud infrastructures are aligning to the next generation of truly ubiquitous multimedia services, known as Cloud Mobile Media (CMM) services offering mobile video. Nevertheless, due to an inherit higher and variable end to end delay mainly as a result of the virtualization process, new challenges appear. One challenge is given by live video streaming applications when trying to keep a good Quality of Experience of the delivered video, measured in terms of a subjective video quality metric, named Mean Opinion Score (MOS). Our goal is to estimate and predict this subjective metric in a holistic manner using different estimation techniques, such as Artificial Neural Networks, Factor Analysis and Multinomial Linear Regression, with Full Reference and Non Reference approaches. For this, we have analyzed and measured different variables related to Quality of Service, bit stream and basic video quality metrics, throughout the CMM infrastructure. With these variables, we apply the mentioned techniques which allows us to estimate MOS of the delivered video in a robust and reliable way, achieving an average estimation error between 0.46 and 15.94% depending on the technique used. The real MOS has been evaluated through surveys. Finally, we compare the accuracy of the estimated MOS against well known publicly available video quality algorithms, following the recommendations given by Video Quality Experts Group.
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RESUMEN La unión de los conceptos de realidad virtual y simulación acústica ha generado en los úl... more RESUMEN La unión de los conceptos de realidad virtual y simulación acústica ha generado en los últimos años un amplio campo de trabajo. En esta línea, presentamos la investigación que estamos desarrollando en el marco del proyecto de investigación (I+ ...
Lecture Notes in Computer Science, 2014
Archeological acoustics is a part of acoustics that studies ancient environments which were dedic... more Archeological acoustics is a part of acoustics that studies ancient environments which were dedicated (completely or partly) to sound performing. The combination of this acoustic area in conjunction with room acoustics enables the study of the acoustic evolution of existing buildings (in terms of the historical documentation) or even, make the acoustic reconstruction of rooms which were destroyed or they are in a bad state or in ruins. In this work, an acoustical reconstruction of the church of the Hieronymites' monastery of the Murta from the XIV century, in Alzira, Spain has been developed. This building was abandoned in 1836 and now is in ruins. The work develops a geometrical model, together with a proposal of materials which were common in the churches of the same area, an acoustical study and finally an auralization of a choral performance has been done (as this monastery had its own musical chappele).
Computer Communications, 2022
Proceedings XIII Jornadas de Ingenieria Telematica - JITEL2017, 2017
We present the results from a measurementbasedperformance evaluation of wireless networks basedon... more We present the results from a measurementbasedperformance evaluation of wireless networks basedon IEEE 802.11ac standard in an indoor environment, withthe aim to analyze their performance under high definitionstreaming video applications. We focus our study on analyzingthe highest performance of these standards using off-theshelfequipment as well as the behavior of Quality of Servicevariables and how they affect to the video quality. Thus, wehave analyzed and measured these variables and have applieda multivariate statistical technique, called Factor Analysis,and finally discuss their behavior.
Proceedings of the Euro American Conference on Telematics and Information Systems, 2018
Wireless Sensor Networks (WSNs) are composed of spatially distributed autonomous sensor devices, ... more Wireless Sensor Networks (WSNs) are composed of spatially distributed autonomous sensor devices, named motes. These devices are constituted by a microcontroller, sensors, and they have the ability to communicate in the ISM frequency band using the IEEE 802.15.4 standard. They have their own power supply, AA or AAA batteries, processing unit, sensors and wireless communications. Usually, the motes exchange packets using a multihop routing, and the maximum communication distance emitter-receiver is around 100m. At least one mote acts as a gateway, and the data gathered by the sensors of each mote have to be sent to this mote that is named sink or Base Station (BS). In a WSN the BS is within the area of the WSN in order to receive the information. The distance between the BS and the nearest mote must be at the most 100m to be able to receive the packets. If the BS distance is farther than this distance, the communication fails, because the motes have limited power. Some techniques are proposed to overcome this distance in order to achieve a long range communication to reach the BS, for instance to communicate to a low orbit satellite. The difficulties are related to synchronization errors in the clocks of the motes. We propose an alternative technique based in a collaborative beamforming scheme, named stochastic collaborative transmission or stochastic beamforming, in which we take advantage of the synchronization errors of the clocks to achieve a large gain in a limited number of trials.
7th International Conference on Higher Education Advances (HEAd'21), 2021
Digital Communications have been traditionally taught in laboratory sessions from a theoretical p... more Digital Communications have been traditionally taught in laboratory sessions from a theoretical point of view, using simulation platforms. However, current Academic Accreditation includes the dimension of “what students are expected to be able to do”, which poses the need of decreasing the gap between standard simulated laboratory sessions and more practical and realistic approaches. In this paper, we propose a methodology to enhance the learning of practical aspects related to Digital Communications courses, as well as increasing the student’s engagement, via the use of low-cost software defined radio devices. This methodology has been applied in the Degree in Telematics Engineering at the School of Engineering from the University of Valencia, Spain. With the aim of improving the engagement of both master and undergraduate students, a project based learning methodology has been implemented. In the paper, the methodology is described, several laboratory activities based on the 802.1...
Libro de Actas IN-RED 2021: VII Congreso de Innovación Edicativa y Docencia en Red, 2021
Los dispositivos de radio definida por software se han utilizado en los últimos 6 años como eleme... more Los dispositivos de radio definida por software se han utilizado en los últimos 6 años como elementos dinamizadores de las prácticas de laboratorio en las asignaturas de la materia de comunicaciones digitales del Grado en Ingeniería Telemática de la Universitat de València. Sin embargo, el desarrollo de estas prácticas requiere el acceso a unos dispositivos hardware que están localizados físicamente en los laboratorios de la Escuela Técnica Superior de Ingeniería. En esta contribución, atendiendo a la actual situación de docencia semipresencial y de un posible paso a docencia en línea debido a la pandemia de COVID-19, se plantea establecer un sistema que permita la interacción remota con los dispositivos de radio definida por software. Este sistema de acceso remoto, además de permitir que se sigan utilizando estos dispositivos en las prácticas de laboratorio aún en un contexto de docencia en línea, permitiría el acceso del alumnado a ellos fuera del horario de prácticas de laborator...
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Papers by Jaume Segura Garcia