Examinando por Autor "Iglesia Carril, Idoia de la"

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    Ítem
    Cross-layer cluster-based energy-efficient protocol for wireless sensor networks
    (MDPI AG, 2015-04-09) Koyamparambil Mammu, Aboobeker Sidhik; Hernández Jayo, Unai; Sainz Bedoya, Nekane Ione; Iglesia Carril, Idoia de la
    Recent developments in electronics and wireless communications have enabled the improvement of low-power and low-cost wireless sensors networks (WSNs). One of the most important challenges in WSNs is to increase the network lifetime due to the limited energy capacity of the network nodes. Another major challenge in WSNs is the hot spots that emerge as locations under heavy traffic load. Nodes in such areas quickly drain energy resources, leading to disconnection in network services. In such an environment, cross-layer cluster-based energy-efficient algorithms (CCBE) can prolong the network lifetime and energy efficiency. CCBE is based on clustering the nodes to different hexagonal structures. A hexagonal cluster consists of cluster members (CMs) and a cluster head (CH). The CHs are selected from the CMs based on nodes near the optimal CH distance and the residual energy of the nodes. Additionally, the optimal CH distance that links to optimal energy consumption is derived. To balance the energy consumption and the traffic load in the network, the CHs are rotated among all CMs. In WSNs, energy is mostly consumed during transmission and reception. Transmission collisions can further decrease the energy efficiency. These collisions can be avoided by using a contention-free protocol during the transmission period. Additionally, the CH allocates slots to the CMs based on their residual energy to increase sleep time. Furthermore, the energy consumption of CH can be further reduced by data aggregation. In this paper, we propose a data aggregation level based on the residual energy of CH and a cost-aware decision scheme for the fusion of data. Performance results show that the CCBE scheme performs better in terms of network lifetime, energy consumption and throughput compared to low-energy adaptive clustering hierarchy (LEACH) and hybrid energy-efficient distributed clustering (HEED).
  • Miniatura
    Ítem
    Diseño e implementación de una metodología de asignación de recursos radio eficiente para redes vehiculares donde co-existen usuarios celulares comunes y vehículos
    (Universidad de Deusto, 2019-01-18) Iglesia Carril, Idoia de la; Hernández Jayo, Unai; Facultad de Ingeniería; Ingeniería para la Sociedad de la Información y Desarrollo Sostenible
    La comunicación del vehículo con su entorno, conocida como V2X (Vehicle-to-Everything), se presenta como un paradigma emergente capaz de ser uno de los factores principales de la siguiente revolución en el mundo del automóvil. V2X es una tecnología inalámbrica que permite la comunicación entre los vehículos, la infraestructura, otro tipo de dispositivos (sensores, peatones, etc.) y la red de comunicaciones cableada presente. Este tipo de comunicaciones son la base sobre la que se sustenta el despliegue de los denominados Sistemas Inteligentes de Transporte Cooperativo, conocidos en inglés como C-ITS (Cooperative Intelligent Transport Systems), los cuales permiten aumentar la seguridad en las carreteras, mejorar la gestión y eficiencia del tráfico y proporcionar nuevas experiencias y servicios a los pasajeros durante sus viajes. Los sistemas V2X pueden desplegarse utilizando diferentes tecnologías inalámbricas, estando este trabajo centrado en la habilitación de sistemas C-ITS haciendo uso de tecnologías celulares, principalmente LTE o su evolución 5G. Uno de los grandes problemas surgidos en este tipo de comunicaciones es el ser capaz de satisfacer los exigentes requisitos de calidad de servicio demandados por las aplicaciones de seguridad y entretenimiento en entornos donde existe una alta densidad de vehículos. Además, es necesario tener en cuenta que hasta ahora los principales consumidores de las redes celulares eran los usuarios comunes. Por lo tanto, aunque a partir de ahora los vehículos formen parte del grupo de consumidores de la red celular, es imprescindible mantener y seguir mejorando la calidad de servicio que se ha ofrecido hasta ahora a los usuarios celulares comunes. Por tanto, en una red celular en la que ya de por sí cohabitan un gran número de usuarios celulares, si añadimos nuevos nodos como es el caso de los vehículos, una gestión de recursos radio eficiente es indiscutiblemente un elemento de suma importancia para desplegar aplicaciones cooperativas con diferentes requisitos de calidad de servicio. En la literatura actual puede encontrarse un vasto número de metodologías de asignación de recursos radio, cada una con sus propias características. Debido a que el espectro radio es un recurso limitado y a la alta complejidad del problema a solucionar, no hay una metodología definitiva que consiga resolver de forma ´optima todos los escenarios posibles. Este hecho hace que el campo de gestión y asignación de recursos radio sea un tema de investigación candente. Como resultado, el presente trabajo de tesis doctoral centra su esfuerzo en el diseño e implementación de una metodología de asignación de recursos radio para redes celulares en las que co-existen usuarios celulares comunes y vehículos. La metodología propuesta ofrece un valor añadido frente a las metodología existentes en la literatura, debido tanto a su originalidad como a los niveles de rendimiento que ofrece de igual manera a las comunicaciones de los usuarios comunes, como a los enlaces V2X creados. Con la intención de validar la metodología propuesta, se ha llevado a cabo una extensa experimentación en la cual se han comparado los resultados obtenidos con otras metodologías de referencia y previamente contrastadas en la literatura. Gracias a esta experimentación se ha podido afirmar de forma rigurosa que la técnica propuesta es competitiva en distintas métricas en base al throughput ofrecido a los usuarios, al rendimiento energético de las comunicaciones entre vehículos, la eficiencia energética de las comunicaciones del conjunto global de usuarios y es especialmente competitiva en términos de eficiencia espectral.
  • Miniatura
    Ítem
    Smart bandwidth assignation in an underlay cellular network for internet of vehicles
    (MDPI AG, 2017-09-27) Iglesia Carril, Idoia de la ; Hernández Jayo, Unai ; Osaba, Eneko; Carballedo Morillo, Roberto
    The evolution of the IoT (Internet of Things) paradigm applied to new scenarios as VANETs (Vehicular Ad Hoc Networks) has gained momentum in recent years. Both academia and industry have triggered advanced studies in the IoV (Internet of Vehicles), which is understood as an ecosystem where different types of users (vehicles, elements of the infrastructure, pedestrians) are connected. How to efficiently share the available radio resources among the different types of eligible users is one of the important issues to be addressed. This paper briefly analyzes various concepts presented hitherto in the literature and it proposes an enhanced algorithm for ensuring a robust co-existence of the aforementioned system users. Therefore, this paper introduces an underlay RRM (Radio Resource Management) methodology which is capable of (1) improving cellular spectral efficiency while making a minimal impact on cellular communications and (2) ensuring the different QoS (Quality of Service) requirements of ITS (Intelligent Transportation Systems) applications. Simulation results, where we compare the proposed algorithm to the other two RRM, show the promising spectral efficiency performance of the proposed RRM methodology.
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    A survey on vehicular communication for cooperative truck platooning application
    (Elsevier Inc., 2022-02-28) Balador, Ali ; Bazzi, Alessandro ; Hernández Jayo, Unai ; Iglesia Carril, Idoia de la ; Ahmadvand, Hossein
    Platooning is an application where a group of vehicles move one after each other in close proximity, acting jointly as a single physical system. The scope of platooning is to improve safety, reduce fuel consumption, and increase road use efficiency. Even if conceived several decades ago as a concept, based on the new progress in automation and vehicular networking platooning has attracted particular attention in the latest years and is expected to become of common implementation in the next future, at least for trucks. The platoon system is the result of a combination of multiple disciplines, from transportation, to automation, to electronics, to telecommunications. In this survey, we consider the platooning, and more specifically the platooning of trucks, from the point of view of wireless communications. Wireless communications are indeed a key element, since they allow the information to propagate within the convoy with an almost negligible delay and really making all vehicles acting as one. Scope of this paper is to present a comprehensive survey on connected vehicles for the platooning application, starting with an overview of the projects that are driving the development of this technology, followed by a brief overview of the current and upcoming vehicular networking architecture and standards, by a review of the main open issues related to wireless communications applied to platooning, and a discussion of security threats and privacy concerns. The survey will conclude with a discussion of the main areas that we consider still open and that can drive future research directions.
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    V-alert: description and validation of a vulnerable road user alert system in the framework of a smart city
    (MDPI AG, 2015-07-29) Hernández Jayo, Unai; Iglesia Carril, Idoia de la; Pérez Gómez, Jagoba
    V-Alert is a cooperative application to be deployed in the frame of Smart Cities with the aim of reducing the probability of accidents involving Vulnerable Road Users (VRU) and vehicles. The architecture of V-Alert combines short- and long-range communication technologies in order to provide more time to the drivers and VRU to take the appropriate maneuver and avoid a possible collision. The information generated by mobile sensors (vehicles and cyclists) is sent over this heterogeneous communication architecture and processed in a central server, the Drivers Cloud, which is in charge of generating the messages that are shown on the drivers’ and cyclists’ Human Machine Interface (HMI). First of all, V-Alert has been tested in a simulated scenario to check the communications architecture in a complex scenario and, once it was validated, all the elements of V-Alert have been moved to a real scenario to check the application reliability. All the results are shown along the length of this paper.