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  • A multimetric, map-aware routing protocol for VANETs in urban areas

     Tripp Barba, Carolina; Urquiza Aguiar, Luis; Aguilar Igartua, Mónica; Rebollo Monedero, David; Cruz Llopis, Luis Javier de La; Mezher, Ahmad; Aguilar-Calderón, José Alfonso
    Sensors
    Date of publication: 2014-01-28
    Journal article

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    In recent years, the general interest in routing for vehicular ad hoc networks (VANETs) has increased notably. Many proposals have been presented to improve the behavior of the routing decisions in these very changeable networks. In this paper, we propose a new routing protocol for VANETs that uses four different metrics. which are the distance to destination, the vehicles¿ density, the vehicles¿ trajectory and the available bandwidth, making use of the information retrieved by the sensors of the vehicle, in order to make forwarding decisions, minimizing packet losses and packet delay. Through simulation, we compare our proposal to other protocols, such as AODV (Ad hoc On-Demand Distance Vector), GPSR (Greedy Perimeter Stateless Routing), I-GPSR (Improvement GPSR) and to our previous proposal, GBSR-B (Greedy Buffer Stateless Routing Building-aware). Besides, we present a performance evaluation of the individual importance of each metric to make forwarding decisions. Experimental results show that our proposed forwarding decision outperforms existing solutions in terms of packet delivery.

  • A collaborative protocol for anonymous reporting in vehicular ad hoc networks

     Tripp Barba, Carolina; Urquiza Aguiar, Luis; Aguilar Igartua, Mónica; Parra Arnau, Javier; Rebollo Monedero, David; Forné, Jordi; Pallares Segarra, Esteve
    Computer Standards & Interfaces
    Date of publication: 2013-11-01
    Journal article

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    Vehicular ad hoc networks (VANETs) have emerged to leverage the power of modern communication technologies, applied to both vehicles and infrastructure. Allowing drivers to report traffic accidents and violations through the VANET may lead to substantial improvements in road safety. However, being able to do so anonymously in order to avoid personal and professional repercussions will undoubtedly translate into user acceptance. The main goal of this work is to propose a new collaborative protocol for enforcing anonymity in multi-hop VANETs, closely inspired by the well-known Crowds protocol. In a nutshell, our anonymous-reporting protocol depends on a forwarding probability that determines whether the next forwarding step in message routing is random, for better anonymity, or in accordance with the routing protocol on which our approach builds, for better quality of service (QoS). Different from Crowds, our protocol is specifically conceived for multi-hop lossy wireless networks. Simulations for residential and downtown areas support and quantify the usefulness of our collaborative strategy for better anonymity, when users are willing to pay an eminently reasonable price in QoS.

  • A distributed, bandwidth-efficient accident prevention system for interurban VANETs

     García Lozano, Estrella; Tripp Barba, Carolina; Aguilar Igartua, Mónica; Campo, Celeste
    IEEE International Conference on Smart Communications in Network Technologies
    Presentation's date: 2013-06-18
    Presentation of work at congresses

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    Road safety has become a main issue for governments and car manufacturers in the last twenty years. The concept of Intelligent Transportation Systems (ITS) is used when talking about communication technologies between vehicles and infrastructure to improve, among others, road safety. In this paper, we propose a warning service to prevent accidents by alerting drivers about accidents and dangerous road conditions. This service includes the definition of a new broadcast dissemination mechanism. A VANET highway scenario is simulated to evaluate how the use of safety schemes decreases the driver¿s reaction time when an unexpected situation occurs.

  • Optimized path selection in a game-theoretic routing protocol for video-streaming services over MANETs

     Mezher, Ahmad; Tripp Barba, Carolina; Urquiza Aguiar, Luis; Aguilar Igartua, Mónica; Martin Faus, Isabel Victoria; Cruz Llopis, Luis Javier de La; Sanvicente Gargallo, Emilio
    Jornadas de Ingeniería Telemática
    Presentation's date: 2013-10-28
    Presentation of work at congresses

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    Mobile ad hoc networks (MANETs) are infrastructureless networks formed by wireless mobile devices. Recently, the demand over multimedia services such as video streaming has increased specially since the number of mobile end users is growing as well. MPEG-2 VBR is one of the most fitting video coding techniques for MANETs which improves the distribution of video streams specially when it is used with a proper multipath routing scheme. In this article, we aimed to design a routing scheme to dynamically select the forwarding paths using a game-theoretic approach over a multipath routing protocol. Our proposal seeks to describe an equation of the probability p of sending video frames through the best available path. p depends on network parameters that vary throughout time. The aim is that the most important video frames (I+P) will be sent through the best path with a certain probability p and will be sent through the second best path with a probability 1-p. To achieve that, we carried out simulations done with fixed values of p and after that we applied a lineal regression method to obtain the coefficients of the equation for p. Simulations have been done to show the benefits of our proposal where interfering traffic and mobility of the nodes are present.

  • Available bandwidth estimation in GPSR for VANETs

     Tripp Barba, Carolina; Aguilar Igartua, Mónica; Urquiza Aguiar, Luis; Mezher, Ahmad; Zaldivar Colado, Aníbal; Guérin-Lassous, Isabelle
    ACM international symposium on design and analysis of intelligent vehicular networks and applications
    Presentation's date: 2013-11-03
    Presentation of work at congresses

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    This paper proposes an adaptation of the collision probability used in the measure of the available bandwidth designed for Mobile Ad hoc Networks (MANETs) and which is described in ABE [12]. Instead, we propose a new ABE+ that includes a new function to estimate the probability of losses. This new function has been specially designed for Vehicular Ad hoc Networks, to be suited to the high mobility and variable density in vehicular environments. In this analysis we do not only consider the packet size, but also other metrics, such as, density and speed of the nodes. We include the ABE+ algorithm in the forwarding decisions of the GBSR-B protocol [14], which is an improvement of the well-known GPSR protocol. Finally through simulations, we compare the performance of our new ABE+ compared to the original ABE. These results show that ABE+ coupled with GBSR-B achieves a good trade-o in terms of packet losses and packet end-to-end delay.

  • Dimensionado dinámico de buffers para flujos de tráfico diferenciados no elásticos

     Vázquez Rodas, Andrés; Cruz Llopis, Luis Javier de La; Aguilar Igartua, Mónica; Sanvicente Gargallo, Emilio
    Jornadas de Ingeniería Telemática
    Presentation's date: 2013-10-30
    Presentation of work at congresses

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    El dimensionado del tamaño de los buffers de almacenamiento de paquetes en los equipos de red es un aspecto fundamental debido a sus consecuencias directas sobre la calidad de servicio observada por los usuarios finales. Dicho tamaño debe ser el más pequeño posible que cumpla con unos determinados requisitos respecto a algún parámetro de prestaciones de la red (caudal, tiempo extremo a extremo, probabilidad de pérdida de paquetes, etc.). En este artículo se propone un mecanismo de dimensionado que permite mantener la probabilidad de pérdida por debajo de un umbral determinado y que se adapta dinámicamente a las variaciones de carga en la red. El mecanismo, basado en una aproximación de máxima entropía, permite además el autodimensionado de buffers por parte de cada equipo, sin necesidad de la intervención de equipos especiales, y puede utilizarse también cuando se desea diferenciar diferentes flujos de tráfico y pedir para ellos distintas prestaciones.

  • On collaborative anonymous communications in lossy networks

     Rebollo Monedero, David; Forné, Jordi; Pallares Segarra, Esteve; Parra Arnau, Javier; Tripp Barba, Carolina; Urquiza Aguiar, Luis; Aguilar Igartua, Mónica
    Security and Communication Networks
    Date of publication: 2013-05-17
    Journal article

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    Message encryption does not prevent eavesdroppers from unveiling who is communicating with whom, when, or how frequently, a privacy risk wireless networks are particularly vulnerable to. The Crowds protocol, a well-established anonymous communication system, capitalizes on user collaboration to enforce sender anonymity. This work formulates a mathematical model of a Crowd-like protocol for anonymous communication in a lossy network, establishes quantifiable metrics of anonymity and quality of service (QoS), and theoretically characterizes the trade-off between them. The anonymity metric chosen follows the principle of measuring privacy as an attacker's estimation error. By introducing losses, we extend the applicability of the protocol beyond its original proposal. We quantify the intuition that anonymity comes at the expense of both delay and end-to-end losses. Aside from introducing losses in our model, another main difference with respect to the traditional Crowds is the focus on networks with stringent QoS requirements, for best effort anonymity, and the consequent elimination of the initial forwarding step. Beyond the mathematical solution, we illustrate a systematic methodology in our analysis of the protocol. This methodology includes a series of formal steps, from the establishment of quantifiable metrics all the way to the theoretical study of the privacy QoS trade-off. Copyright © 2013 John Wiley & Sons, Ltd.

  • Design and evaluation of GBSR-B, an improvement of GPSR for VANETs

     Tripp Barba, Carolina; Urquiza Aguiar, Luis; Aguilar Igartua, Mónica
    Revista IEEE América Latina
    Date of publication: 2013
    Journal article

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    Wireless vehicular communications are a key technology to provide drivers with novel services such as collision avoidance, safety warnings and real-time traffic information. Other services are high-speed toll collection, infotainment and wireless ubiquitous connectivity. It is clear that vehicular communications will be a cornerstone of the future transport systems which will significantly change our daily lives. Vehicular ad hoc networks (VANETs) have rapidly emerged and raised novel research challenges such as the design of network protocols adapted to the specific features of VANETs, e.g. the high speed of vehicles. Also, the design of realistic simulation frameworks is an important goal to speed up the development of VANETs. This paper presents the design and evaluation of GBSR-B, a routing protocol based on GPSR that seeks to improve the performance of VANETs over urban scenarios. Our proposal includes a novel algorithm to select the optimal next-hop forwarding node. This paper also presents an alternative to the perimeter mode used in GPSR. We compare our proposal GBSR-B to GPSR and AODV using the network simulator NCTUns 6.0, showing better results in terms of packet losses.

  • Contribution to design a communication framework for Vehicular Ad hoc Networks in urban scenarios  Open access

     Tripp Barba, Carolina
    Defense's date: 2013-06-20
    Department of Telematics Engineering, Universitat Politècnica de Catalunya
    Theses

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    The constant mobility of people, the growing need to be always connected, the large number of vehicles that nowadays can be found in the roads and the advances in technology make Vehicular Ad hoc Networks (VANETs) be a major area of research. Vehicular Ad hoc Networks are a special type of wireless Mobile Ad hoc Networks (MANETs), which allow a group of mobile nodes configure a temporary network and maintain it without the need of a fixed infrastructure. A vehicular network presents some specific characteristics, as the very high speed of nodes. Due to this high speed the topology changes are frequent and the communication links may last only a few seconds. Smart cities are now a reality and have a direct relationship with vehicular networks. With the help of existing infrastructure such as traffic lights, we propose a scheme to update and analyse traffic density and a warning system to spread alert messages. With this, traffic lights assist vehicular networks to take proper decisions. This would ensure less congested streets. It would also be possible that the routing protocol forwards data packets to vehicles on streets with enough neighbours to increase the possibility of delivering the packets to destination. Sharing updated, reliable and real-time information, about traffic conditions, weather or security alerts, increases the need of algorithms for the dissemination of information that take into account the main beneffits and constraints of these networks. For all this, routing protocols for vehicular networks have the difficult task to select and establish transmission links to send the data packets from source to destination through multiple nodes using intermediate vehicles efficiently. The main objective of this thesis is to provide improvements in the communication framework for vehicular networks to improve decisions to select next hops in the moment to send information, in this way improving the exchange of information to provide suitable communication to minimize accidents, reduce congestion, optimize resources for emergencies, etc. Also, we include intelligence to vehicles at the moment to take routing decisions. Making them map-aware, being conscious of the presence of buildings and other obstacles in urban environments. Furthermore, our proposal considers the decision to store packets for a maximum time until finding other neighbouring nodes to forward the packets before discarding them. For this, we propose a protocol that considers multiple metrics that we call MMMR (A Multimetric, Map-Aware Routing Protocol ). MMMR is a protocol based on geographical knowledge of the environment and vehicle location. The metrics considered are the distance, the density of vehicles in transmission range, the available bandwidth and the future trajectory of the neighbouring nodes. This allows us to have a complete view of the vehicular scenario to anticipate the driver about possible changes that may occur. Thus, a node can select a node among all its neighbours, which is the best option to increase the likelihood of successful packet delivery, minimizing time and offering a level of quality and service. In the same way, being aware of the increase of information in wireless environments, we analyse the possibility of offering anonymity services. We include a mechanism of anonymity in routing protocols based on the Crowd algorithm, which uses the idea of hiding the original source of a packet. This allowed us to add some level of anonymity on VANET routing protocols. The analytical modeling of the available bandwidth between nodes in a VANET, the use of city infrastructure in a smart way, the forwarding selection in data routing byvehicles and the provision of anonymity in communications, are issues that have been addressed in this PhD thesis. In our research work we provide contributions to improve the communication framework for Vehicular Ad hoc Networks obtaining benefits toenhance the everyday of the population.

    La movilidad constante de las personas y la creciente necesidad de estar conectados en todo momento ha hecho de las redes vehiculares un área cuyo interés ha ido en aumento. La gran cantidad de vehículos que hay en la actualidad, y los avances tecnológicos han hecho de las redes vehiculares (VANETS, Vehicular Ad hoc Networks) un gran campo de investigación. Las redes vehiculares son un tipo especial de redes móviles ad hoc inalámbricas, las cuales, al igual que las redes MANET (Mobile Ad hoc Networks), permiten a un grupo de nodos móviles tanto configurar como mantener una red temporal por si mismos sin la necesidad de una infraestructura fija. Las redes vehiculares presentan algunas características muy representativas, por ejemplo, la alta velocidad que pueden alcanzar los nodos, en este caso vehículos. Debido a esta alta velocidad la topología cambia frecuentemente y la duración de los enlaces de comunicación puede ser de unos pocos segundos. Estas redes tienen una amplia área de aplicación, pudiendo tener comunicación entre los mismos nodos (V2V) o entre los vehículos y una infraestructura fija (V2I). Uno de los principales desafíos existentes en las VANET es la seguridad vial donde el gobierno y fabricantes de automóviles han centrado principalmente sus esfuerzos. Gracias a la rápida evolución de las tecnologías de comunicación inalámbrica los investigadores han logrado introducir las redes vehiculares dentro de las comunicaciones diarias permitiendo una amplia variedad de servicios para ofrecer. Las ciudades inteligentes son ahora una realidad y tienen una relación directa con las redes vehiculares. Con la ayuda de la infraestructura existente, como semáforos, se propone un sistema de análisis de densidad de tráfico y mensajes de alerta. Con esto, los semáforos ayudan a la red vehicular en la toma de decisiones. Así se logrará disponer de calles menos congestionadas para hacer una circulación más fluida (lo cual disminuye la contaminación). Además, sería posible que el protocolo de encaminamiento de datos elija vehículos en calles con suficientes vecinos para incrementar la posibilidad de entregar los paquetes al destino (minimizando pérdidas de información). El compartir información actualizada, confiable y en tiempo real sobre el estado del tráfico, clima o alertas de seguridad, aumenta la necesidad de algoritmos de difusión de la información que consideren los principales beneficios y restricciones de estas redes. Así mismo, considerar servicios críticos que necesiten un nivel de calidad y servicio es otro desafío importante. Por todo esto, un protocolo de encaminamiento para este tipo de redes tiene la difícil tarea de seleccionar y establecer enlaces de transmisión para enviar los datos desde el origen hacia el destino vía múltiples nodos utilizando vehículos intermedios de una manera eficiente. El principal objetivo de esta tesis es ofrecer mejoras en los sistemas de comunicación vehicular que mejoren la toma de decisiones en el momento de realizar el envío de la información, con lo cual se mejora el intercambio de información para poder ofrecer comunicación oportuna que minimice accidentes, reduzca atascos, optimice los recursos destinados a emergencias, etc. Así mismo, incluimos más inteligencia a los coches en el momento de tomar decisiones de encaminamiento de paquetes. Haciéndolos conscientes de la presencia de edificios y otros obstáculos en los entornos urbanos. Así como tomar la decisión de guardar paquetes durante un tiempo máximo de modo que se encuentre otros nodos vecinos para encaminar paquetes de información antes de descartarlo. Para esto, proponemos un protocolo basado en múltiples métricas (MMMR, A Multimetric, Map-aware Routing Protocol ) que es un protocolo geográfio basado en el conocimiento del entorno y localización de los vehículos. Las métricas consideradas son la distancia, la densidad de vehículos en el área de transmisión, el ancho de banda disponible y la trayectoria futura de los nodos vecinos. Esto nos permite tener una visión completa del escenario vehicular y anticiparnos a los posibles cambios que puedan suceder. Así, un nodo podrá seleccionar aquel nodo entre todos sus vecinos posibles que sea la mejor opción para incrementar la posibilidad de entrega exitosa de paquetes, minimizando tiempos y ofreciendo un cierto nivel de calidad y servicio. De la misma manera, conscientes del incremento de información que circula por medios inalámbricos, se analizó la posibilidad de servicios de anonimato. Incluimos pues un mecanismo de anonimato en protocolos de encaminamiento basado en el algoritmo Crowd, que se basa en la idea de ocultar la fuente original de un paquete. Esto nos permitió añadir cierto nivel de anonimato que pueden ofrecer los protocolos de encaminamiento. El modelado analítico del ancho de banda disponible entre nodos de una VANET, el uso de la infraestructura de la ciudad de una manera inteligente, la adecuada toma de decisiones de encaminamiento de datos por parte de los vehículos y la disposición de anonimato en las comunicaciones, son problemas que han sido abordados en este trabajo de tesis doctoral que ofrece contribuciones a la mejora de las comunicaciones en redes vehiculares en entornos urbanos aportando beneficios en el desarrollo de la vida diaria de la población.

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    Available bandwidth-aware routing in urban vehicular ad-hoc networks  Open access

     Tripp Barba, Carolina; Mezher, Ahmad Mohamad; Aguilar Igartua, Mónica; Guérin-Lassous, Isabelle; Sarr, Cheikh
    IEEE Vehicular Technology Conference
    Presentation's date: 2012-09-03
    Presentation of work at congresses

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    Vehicular communication for intelligent transportation systems will provide safety, comfort for passengers, and more efficient travels. This type of network has the advantage to warn drivers of any event occurred in the road ahead, such as traffic jam, accidents or bad weather. This way, the number of traffic accidents may decrease and many lives could be saved. Moreover, a better selection of non-congested roads will help to reduce pollution. Some other interesting services, such as downloading of multimedia services, would be possible and available through infrastructure along the roadside. Providing multimedia services over VANETs may require a QoS-aware routing protocol that often need to estimate available resources. In this paper, we study the performance, in realistic VANET urban scenarios, of an extension of AODV that includes the available bandwidth estimator ABE [1]. AODV-ABE establishes forwarding paths that satisfy the bandwidth required by the applications. The results, obtained on the NCTUns simulator [2], show that AODVABE could be used in urban-VANETs where vehicles’ speed is moderate.

    Postprint (author’s final draft)

  • Smart city for VANETs using warning messages, traffic statistics and intelligent traffic lights

     Tripp Barba, Carolina; Mateos, Miguel Ángel; Regañas Soto, Pablo; Mezher, Ahmad Mohamad; Aguilar Igartua, Mónica
    IEEE Intelligent Vehicles Symposium
    Presentation's date: 2012-06-04
    Presentation of work at congresses

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  • Load splitting in clusters of video servers

     Cruz Llopis, Luis Javier de La; Vázquez Rodas, Andrés; Sanvicente Gargallo, Emilio; Aguilar Igartua, Mónica
    Computer communications
    Date of publication: 2012-03-07
    Journal article

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    Nowadays, video on demand is one of the services more highly appreciated and demanded by customers. As the number of users increases, the capacity of the system that provides these services must also be increased to guarantee the required quality of service. An approach to that end is to have available several videoservers at various distribution points in order to satisfy the different incoming demands (videoservercluster). When a movie demand arrives to such a cluster, a load balancing device must assign the request to a specific server according to a procedure that must be fast, easy to implement and scalable. In this article we consider the problem of appropriately splitting this load to improve on the system performance. After an analysis of the video packet generation, we point out the similarity between this problem and that of optimally routing packets in data networks. With this similarity in mind, a new mechanism to select the appropriate videoserver is proposed. The purpose of this mechanism is to minimize the average packet transfer time (waiting time plus transmission time) at the videoservercluster. In this way, we are able to obtain a dynamic load balancing policy that performs satisfactorily and that is very easy to implement in practice. The results of several experiments run with real data are shown and commented to substantiate our claims. A description of a practical implementation of the system is also included.

  • Dynamic framework with adaptive contention window and multipath routing for video-streaming services over mobile ad hoc networks

     Aguilar Igartua, Mónica; Carrascal Frías, Víctor; Cruz Llopis, Luis Javier de La; Sanvicente Gargallo, Emilio
    Telecommunication systems
    Date of publication: 2012-01-24
    Journal article

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    The number of portable electronic devices capable of maintaining wireless communications increases day by day. Such mobile nodes may easily self-configure to form a Mobile Ad Hoc Network (MANET) without the help of any established infrastructure. As the number of mobile devices grows, the demand of multimedia services such as video-streaming from these networks is foreseen to increase as well. This paper presents a proposal which seeks to improve the experience of the end users in such environment. The proposal is called dCW-MMDSR (dynamic Contention Window-Multipath Multimedia Dynamic Source Routing), a cross-layer multipath routing protocol which includes techniques to achieve a dynamic assignment of the Contention Window of the IEEE 802.11e MAC level. In addition, it includes multipath routing suitable for layered coded video to improve the performance of the service. The operation is simple and suitable for low capacity wireless devices. Simulations show the benefits under different scenarios.

  • A game-theoretic multipath routing for video-streaming services over mobile Ad Hoc networks

     Aguilar Igartua, Mónica; Cruz Llopis, Luis Javier de La; Carrascal Frías, Víctor; Sanvicente Gargallo, Emilio
    Computer networks
    Date of publication: 2011-09-15
    Journal article

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    The number of portable devices capable of maintaining wireless communications has increased considerably in the last decade. Such mobile nodes may form a spontaneous self-configured network connected by wireless links to constitute a Mobile Ad Hoc Network (MANET). As the number of mobile end users grows the demand of multimedia services, such as video-streaming, in such networks is envisioned to increase as well. One of the most appropriate video coding technique for MANETs is layered MPEG-2 VBR, which used with a proper multipath routing scheme improves the distribution of video streams. In this article we introduce a proposal called g-MMDSR (game theoretic-Multipath Multimedia Dynamic Source Routing), a cross-layer multipath routing protocol which includes a game theoretic approach to achieve a dynamic selection of the forwarding paths. The proposal seeks to improve the own benefits of the users whilst using the common scarce resources efficiently. It takes into account the importance of the video frames in the decoding process, which outperforms the quality of the received video. Our scheme has proved to enhance the performance of the framework and the experience of the end users. Simulations have been carried out to show the benefits of our proposal under different situations where high interfering traffic and mobility of the nodes are present.

  • Continuity of Service, Security and QoS for Transportation Systems

     Rebollo Monedero, David; Pallares Segarra, Esteve; Aguilar Igartua, Mónica; Parra Arnau, Javier; Tripp Barba, Carolina; Forné, Jordi
    Participation in a competitive project

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  • Evaluación de prestaciones de una red híbrida vehicular y de sensores para mejorar la seguridad vial

     Tripp Barba, Carolina; Ornelas, Karen; Diaz Delgado, Guillermo; Aguilar Igartua, Mónica
    Jornadas de Ingeniería Telemática
    Presentation's date: 2010-09-29
    Presentation of work at congresses

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    En los últimos años las redes inalámbricas se han convertido en una tecnología de comunicación ampliamente difundida así como en un reto en cuanto a investigación se refiere. Se han presentado muchas contribuciones sobre redes ad hoc, tales como redes inalámbricas de sensores (WSN, Wireless Sensor Networks) y redes vehiculares (VANET, Vehicular Ad hoc Networks). Recientemente, la cantidad de coches que transitan en nuestras calles, carreteras y autopistas ha ido en aumento, dando pie a un gran interés en las tecnologías de comunicación vehicular. Un nuevo tipo de red ha sido desarrollada, denominada Red Híbrida Vehicular y de Sensores (HSVN, Hybrid Sensor and Vehicular Network) en la cual WSNs y VANETs cooperan entre sí con el objetivo común de mejorar la seguridad vial. Existen proyectos recientes, tales como CVIS y COMeSafety , que se han enfocado en estos aspectos. Este tipo de propuesta prevendrá al conductor y al copiloto sobre cualquier evento que ocurra en la ruta por la que circulan, tales como accidentes que han sucedido en la carretera, densidad de tráfico, condiciones climatológicas de las rutas, etc. De esta manera el número de accidentes de tráfico podrá decrecer significativamente y se podrán salvar muchísimas vidas. Así mismo, otros servicios de entretenimiento como el acceso a Internet y las descargas multimedia podrán estar disponibles fácil y económicamente con el despliegue de infraestructura a lo largo de las carreteras. Además, el sistema navegador de a bordo podrá elegir la ruta que esté realmente menos congestionada, ayudando así a disminuir la contaminación. Transportarse en coche será más fácil, seguro y más cómodo para los pasajeros. En el presente artículo se presenta una plataforma de HSVN, así como la descripción y evaluación de un protocolo de comunicación entre VANETs y WSNs usando como simulador NCTUns para su evaluación.

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    AVISS: Aplicación Adaptativa de Streaming de Vídeo  Open access

     Díaz Delgado, Guillermo; Muñoz Jaime, Cristina; Tripp Barba, Carolina; Aguilar Igartua, Mónica
    Jornadas de Ingeniería Telemática
    Presentation's date: 2010-09-29
    Presentation of work at congresses

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    En este trabajo presentamos AVISS (Adaptive VIdeo-Streaming Application), una aplicación para la transmisión adaptativa de streaming de vídeo en redes móviles ad-hoc (MANET, Mobile Ad-hoc Networks). AVISS pretende ofrecer una mejor Calidad de Experiencia (QoE, Quality of Experience) al usuario final mediante la auto-adaptación a las condiciones cambiantes de operación de la red. Para medir la calidad del vídeo recibido, también se ha definido una nueva métrica llamada Calidad del GoP (QoG, Quality of GoP). Esta métrica se calcula en el destino final en tiempo real y depende de la cantidad y tipo de cuadros de vídeo recibidos por cada GoP (Group of Pictures) transmitido, por lo que está relacionada con la QoE que el usuario final podría percibir. AVISS ha sido implementado utilizando la versión de RTP/RTCP del simulador de redes NCTUns, y sus prestaciones se han evaluado bajo diferentes condiciones de operación en redes MANET, reconocidas por ser altamente dinámicas.------ In this paper we present AVISS (Adaptive VIdeo-Streaming Application), an adaptive Client-Server application for video-streaming over Mobile Ad-hoc NETworks (MANETs). AVISS pretends to offer a better Quality of Experience (QoE) to the end user of the video-streaming system by adapting itself to time-varying operating conditions of the network. In order to measure the quality of the received video, we also define a new metric called Quality of GoP (QoG), which is easy to measure at the destination node, it does not require the original transmitted video as reference and it is related to the QoE end-user could perceive. As a proof of concept, AVISS has been implemented over a modified version of the RTP/RTCP implementation included with the NCTU network simulator (NCTUns) and we have evaluated its performance on simulated MANETs under several different operating conditions.

  • Access to the full text
    Performance evaluation of a hybrid sensor and vehicular network to improve road safety  Open access

     Tripp Barba, Carolina; Ornelas, Karen; Aguilar Igartua, Mónica
    ACM Symposium on Performance Evaluation of Wireless Ad Hoc, Sensor, and Ubiquitous Networks
    Presentation's date: 2010-10-18
    Presentation of work at congresses

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    In the last years, wireless networks have become a widely spread type of communication technology and also a challenging scientific area for new fields of research. Many contributions in ad hoc networks, such as WSNs (Wireless Sensor Networks) and VANETs (Vehicular Ad Hoc Networks), have been proposed. Nowadays, the huge amount of cars in transit has raised a big interest in vehicular communication technologies. A new type of network has been developed, named HSVN (Hybrid Sensor and Vehicular Network) in which WSNs and VANETs cooperate with the aim of improving road safety. Recent projects, such as CVIS [1] and COMeSafety [2], are focused on improving the road driving. This type of approaches will warn the driver and the co-pilot of any event occurred in the road ahead, such as traffic jam, accidents, bad weather, etc. This way, the number of traffic accidents may decrease and many lives might be saved. Besides, a better selection of non-congested roads will help to reduce pollution. In addition, other attractive services, such as downloading of multimedia services or Internet browsing, would be easily available through infrastructure along the roadside. Transportation in motorways will be easier, safer and more comfortable for passengers. In this paper a HSVN platform is presented, also a communications protocol between VANETs and WSNs is described and evaluated using the NCTUns [3] simulator.

  • RDSR-V. Reliable dynamic source routing for video-streaming over mobile ad hoc networks

     Muñoz Tapia, Jose Luis; Esparza Martin, Oscar; Aguilar Igartua, Mónica; Carrascal Frias, F. Javier; Forné, Jordi
    Computer networks
    Date of publication: 2010-01
    Journal article

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    Mobile ad hoc networks (MANETs) are infrastructureless networks formed by wireless mobile devices with limited battery life. In MANETs for civilian applications, the network nodes may not belong to a single authority and they may not have a common goal. These MANETs are particularly vulnerable to selfish behavior, as some nodes may prefer saving resources to forward data. There are a few generic reputation-based systems for MANETs which could be used to enforce cooperation among nodes. However, we envision that the system performance can be highly improved by using cross-layer techniques that take into account the specific characteristics of each particular service. In this article, we propose a distributed and easy-to-implement routing mechanism based on reputation for the provision of MPEG-2 video-streaming services over MANETs. The main novelty that we introduce regarding the existent literature is that our proposal is service aware, that is to say, we consider the video-streaming service characteristics to develop a cross-layer design with the routing protocol. In addition, we do not introduce extra signaling overhead to monitor reputation because we use the standard video-streaming end-to-end signaling. Finally, simulation results show that our proposal clearly outperforms both standard Dynamic Source Routing (DSR) and OCEAN (a generic reputation-based mechanism).

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    Self-configured multipath routing using path lifetime for video-streaming services over Ad Hoc networks  Open access

     Aguilar Igartua, Mónica; Carrascal Frías, Víctor
    Computer communications
    Date of publication: 2010-06
    Journal article

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    The increasing spread of mobile nodes along with the technical advances in multi-hop MANETs (Mobile Ad hoc NETworks) make this kind of networks an important type of access network of next generation. The demand of multimedia services from these networks is expected to significantly grow in the next years. Multimedia services, though, require the provision of Quality of Service (QoS). Nevertheless, the highly dynamic nature of MANETs, the energy constraints, the lack on centralized infrastructure and the variable link capacity, makes the QoS provision over MANETs a matter that challenges attention. These features make self-configuration and system adaptation questions of major importance when developing a QoS-aware framework. To tackle this issue, we have designed a-MMDSR (adaptive-Multipath Multimedia Dynamic Source Routing), a multipath routing protocol able to self-configure dynamically depending on the state of the network. The approach includes cross-layer techniques especially designed to improve the end-to-end performance of video-streaming services over IEEE 802.11e Ad Hoc networks. Besides, a straightforward analytical model to estimate the path error probability is presented. This model is used by the routing scheme to estimate the lifetime of the paths. In this way, proper proactive decisions can be made before the paths get broken. The model simplicity is appropriate for low capacity wireless devices. Simulation results validate the proposal and show the improvement on standard DSR (Dynamic Source Routing) and on a previous static version.

  • Transmisión de datos: problemas resueltos

     Aguilar Igartua, Mónica; Forné, Jordi; Mata Diaz, Jorge; Rico Novella, Francisco Jose; Rojas Espinosa, Alfonso; Soriano Ibáñez, Miguel
    Date of publication: 2010-11
    Book

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  • Contribution to provide QoS over Mobile Ad Hoc Networks for Video-Streaming Services based on Adaptive Cross-Layer Architecture.

     Carrascal Frías, Víctor
    Defense's date: 2009-03-02
    Department of Telematics Engineering, Universitat Politècnica de Catalunya
    Theses

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  • Modelado y análisis transitorio de un sistema de distribución de vídeo bajo demanda

     Martin Faus, Isabel Victoria
    Defense's date: 2008-07-21
    Department of Telematics Engineering, Universitat Politècnica de Catalunya
    Theses

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  • Dynamic cross-layer framework to provide QoS for video streaming services over ad hoc networks

     Carrascal Frías, Víctor; Díaz Delgado, Guillermo; Zavala Ayala, Aída; Aguilar Igartua, Mónica
    International ICST Conference on Heterogeneous Networking for Quality, Reliability, Security and Robustness
    Presentation's date: 2008-07-28
    Presentation of work at congresses

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    In recent years the growing proliferation of small wireless devices able to maintain wireless communications using IEEE 802.11 technologies has enabled the deployment of ANETs (Mobile Ad Hoc Networks). This fact as stimulated the demand of multimedia services over this type of networks, such as video-streaming services. Providing QoS in this environment is a challenging task due to the inherent dynamic characteristics of these networks. In this paper we propose a-MMDSR (adaptable-Multipath Multimedia ynamic Source Routing), a dynamic framework for video streaming services which improves the user perceived quality. We have erfected our previous approach s-MMDSR (static- MMDSR), a multipath routing protocol based on DSR which works multaneously with a cross-layer algorithm. hrough simulations, we demonstrate that the performance of our proposal framework outperforms DSR and s-MMDSR.

  • Cross-Layer Optimization for Video-streaming Transmission with QoS over Ad hoc Networks: A Holistic Approach

     Delgado, Díaz; Carrascal, Frías; Aguilar Igartua, Mónica
    Journal of communications software and systems
    Date of publication: 2007-09
    Journal article

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  • MM-DSR: Encaminamiento multicamino con QoS para múltiples fuentes multimedia sobre redes móviles Ad Hoc (MM-DSR: Multipath QoS routing for multiple multimedia sources over Ad Hoc mobile networks)

     Carrascal Frías, Víctor; Delgado, G Díaz; Zavala, Aida Ayala; Aguilar Igartua, Mónica
    Revista IEEE América Latina
    Date of publication: 2007-10
    Journal article

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  • Modelo Analítico para el diseño de servicios video-streaming sobre redes MANET con QoS

     Zavala, A Ayala; Carrascal Frías, Víctor; Delgado, G Díaz; Aguilar Igartua, Mónica
    Jornadas de Ingeniería Telemática
    Presentation of work at congresses

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  • Diccionari de Telecomunicacions

     Aguilar Igartua, Mónica; Alcober Segura, Jesus Angel; Altes Bosch, Jorge; Aragones Cervera, Xavier; Artigas Garcia, David; Bardes Llorensi, Daniel; Barlabe Dalmau, Antoni; Bragos Bardia, Ramon; Calderer Cardona, Josep; Cardama Aznar, Angel; Casademont Serra, Jordi; Casals Ibañez, Lluis; Comeron Tejero, Adolfo; Cotrina Navau, Josep; Cruz Llopis, Luis Javier de La; Dios Otin, Victor Federico; Duxans Barrobes, Helena; Esparza Martin, Oscar; Esquerra Llucià, Ignasi; Garcia Vizcaino, David; Garcies Salva, Pau; Gomez Montenegro, Carlos; Gorricho Moreno, Juan Luis; Guinjoan Gispert, Francisco; Hesselbach Serra, Xavier; Liria Righetti, Antoni; Lopez Salcedo, Jose Antonio; Madrenas Boadas, Jordi; Madueño Ruiz, María Isabel; Mestre Pons, Francesc Xavier; Monte Moreno, Enrique; Morros Rubió, Josep Ramon; Muñoz Tapia, Jose Luis; Pallares Segarra, Esteve; Pons Nin, Joan; Recolons Martos, Jaume; Rincon Rivera, David; Riu Costa, Pere Joan; Ruiz Vela, Inmaculada; Pradell Cara, Lluis; Pascual Iserte, Antonio; Prat Viñas, Luis; Rey Micolau, Francesc; Villares Piera, N. Javier
    Date of publication: 2007-03
    Book

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  • Diseño de Diferentes Clases de Usuarios en un Servicio Video-Streaming Adaptativo

     Isabel, V Martín; Aguilar Igartua, Mónica; Mata Diaz, Jorge
    Jornadas de Ingeniería Telemática
    Presentation of work at congresses

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  • ITACA. Inquiry-based, with a Trustness model support, semantic Annotations and Communities formation Assistance

     Aguilar Igartua, Mónica; Forné, Jordi; Pallares Segarra, Esteve; Muñoz Tapia, Jose Luis; Hinarejos Campos, M. Francisca; Parra Arnau, Javier
    Participation in a competitive project

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  • MM-DSR: Encaminamiento multicamino con QoS para múltiples fuentes multimedia sobre redes móviles Ad Hoc

     Carrascal Frías, Víctor; Delgado, G Díaz; Zavala, A Ayala; Aguilar Igartua, Mónica
    Jornadas de Ingeniería Telemática
    Presentation of work at congresses

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  • Design of an Adaptive-Rate Video-Streaming Service with Different Classes of Users

     Martin Faus, Isabel Victoria; Aguilar Igartua, Mónica; Mata Diaz, Jorge
    IFIP International Federation for Information Processing
    Date of publication: 2006-08
    Journal article

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  • Multipath Routing with Layered Coded Video to Provide QoS for Video-streaming applications over MANETs

     Carrascal Frías, Víctor; Guillermo, Díaz Delgado; Aguilar Igartua, Mónica
    International conference on computer communications and networks. Proceedings
    Date of publication: 2006-09
    Journal article

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  • Multipath Routing for Video-Streaming Services over IEEE 802.11e Ad Hoc Networks

     Carrascal, Frías; Delgado, Díaz; Aguilar Igartua, Mónica
    Symposium on QoS in Wireless Multimedia Networks, co-located with the 14th IEEE International Conference on Software, Telecommunications and Computer Networks
    Presentation of work at congresses

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  • ViStA-XL: Diseño Cross-Layer para Video-Streaming con QoS en Redes Móviles Ad hoc

     Delgado, Díaz; Carrascal, Frías; Aguilar Igartua, Mónica
    Simposium Nacional de la Unión Científica Internacional de Radio
    Presentation of work at congresses

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  • Multipath Routing with Layered Coded Video to Provide QoS for Video-streaming applications over MANETs

     Carrascal Frías, Víctor; Guillermo, Díaz Delgado; Aguilar Igartua, Mónica
    14th IEEE International Conference on Communication Networks (ICON 2006)
    Presentation's date: 2006-09-14
    Presentation of work at congresses

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  • Design of an Adaptive-Rate Video-Streaming Service with Different Classes of Users

     Martin Faus, Isabel Victoria; Aguilar Igartua, Mónica; Mata Diaz, Jorge
    IFIP 19th World Computer Congress, TC-6, 5th IFIP International Conference on Network Control and Engineering for QoS, Security and Mobility
    Presentation of work at congresses

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  • ViStA-XL: A Cross-Layer Design for Video-Streaming over Ad hoc Networks

     Delgado, Díaz; Carrascal, Frías; Aguilar Igartua, Mónica
    International Symposium on Wireless Communication Systems
    Presentation of work at congresses

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  • Eurasip Journal on Wireless Communications and Networking

     Aguilar Igartua, Mónica
    Collaboration in journals

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  • Video-Streaming Transmission with QoS over Cross-Layered Ad hoc Networks

     Delgado, Díaz; Carrascal, Frías; Aguilar Igartua, Mónica
    Symposium on QoS in Wireless Multimedia Networks, co-located with the 14th IEEE International Conference on Software, Telecommunications and Computer Networks
    Presentation of work at congresses

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  • Moderació 3 sessions de comunicacions

     Aguilar Igartua, Mónica
    Jornadas Telecom I+D
    Presentation's date: 2006-11-30
    Presentation of work at congresses

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  • Performability Analysis of an Adaptive-Rate Video-Streaming Service in End-to-End QoS Scenarios

     Martin Faus, Isabel Victoria; Alins Delgado, Juan Jose; Aguilar Igartua, Mónica; Mata Diaz, Jorge
    Lecture notes in computer science
    Date of publication: 2005-10
    Journal article

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  • QoS Provision for Video-Streaming Applications over Ad Hoc Networks

     Carrascal Frías, Víctor; Alins Delgado, Juan Jose; Aguilar Igartua, Mónica; Mata Diaz, Jorge
    The International Conference on "Computer as a tool"
    Presentation of work at congresses

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  • Distribución de Información Segura con Qos en Entornos Telemáticos

     Soriano Ibáñez, Miguel; Aguilar Igartua, Mónica; Esparza Martin, Oscar; Fernandez Muñoz, Marcel; Forné, Jordi; Hernández Serrano, Juan Bautista; Isabel, Martín; Pallares Segarra, Esteve; Pegueroles Valles, Josep Rafel; Postigo Boix, Marcos; Jordi, Forné
    Jornadas de Ingeniería Telemática
    Presentation of work at congresses

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  • Performability Analysis of an Adaptive-Rate Video-Streaming Service in End-to-End QoS scenarios

     Martín, I V; Alins Delgado, Juan Jose; Aguilar Igartua, Mónica; Mata Diaz, Jorge
    16th IFIP/IEEE International Workshop on Distributed Systems: Operations and Management
    Presentation of work at congresses

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  • SECONNET. Plataforma Distribuida Para Comercio Electronico Seguro De Contenidos Multimedia Sobre Redes Heterogeneas De Banda Ancha

     Soriano Ibáñez, Miguel; Aguilar Igartua, Mónica; Mata Diaz, Jorge; Esparza Martin, Oscar; Muñoz Tapia, Jose Luis; Pegueroles Valles, Josep Rafel; Postigo Boix, Marcos; Hernández Serrano, Juan Bautista; Fernandez Muñoz, Marcel
    Participation in a competitive project

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  • Computer communications

     Aguilar Igartua, Mónica
    Collaboration in journals

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  • Modelling an Adaptive-Rate Video-Streaming Service Using Markov-Rewards Models

     Martin Faus, Isabel Victoria; Alins Delgado, Juan Jose; Aguilar Igartua, Mónica; Mata Diaz, Jorge
    First International Conference on Quality of Service in Heterogeneous Wired and Wireless Networks
    Presentation of work at congresses

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  • Adquisición y Revocación de Privilegios en esquemas de Autorización (ARPA).

     Forné, Jordi; Aguilar Igartua, Mónica; Esparza Martin, Oscar; Postigo Boix, Marcos
    Participation in a competitive project

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  • Evaluación de un Servicio Video-Streaming Utilizando Modelos Markovianos con Recompensas

     Martin Faus, Isabel Victoria; Alins Delgado, Juan Jose; Aguilar Igartua, Mónica; Mata Diaz, Jorge
    Simposium Nacional de la Unión Científica Internacional de Radio
    Presentation of work at congresses

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