60 research outputs found

    Combining Web 2.0 and Web Services in Collaborative Working Environments

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    Collaborative applications offer significant benefits in business sector. Usually, team members need to use several systems to carry out their tasks. What these users need is an environment which permits them to carry out these tasks automatically, considering the flow of information between the different systems and offering interoperability and composition features. Nowadays, Web Services have gained their prominence in providing these both features. On the other hand, the use of Web 2.0 allows to create web applications in which the user constitutes a key element. What we propose in this paper is the combination of both approaches for creating a Collaborative Working Environment (CWE)

    Architecture and evaluation of a unified V2V and V2I communication system based on cellular networks

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    Vehicle communications are becoming the cornerstone in the future vehicle equipment. More specifically, vehicle to vehicle communications (V2V) are the main object of researching nowadays, because vehicle to infrastructure (V2I) approximations are already being developed as commercial solutions. Cellular networks (CN) are usually applied in V2I solutions, whereas ad hoc networks are practically the only technology considered in V2V communications. Due to fact that CN are currently a reality and the operators are continuously improving the network, this communication technology could be considered as a candidate to deal with V2V necessities as well. The present paper defends the applicability of CN in the V2V field, and presents a novel communication paradigm for vehicles which unifies both V2V and V2I paradigms into one system. A peer to peer network technology has been used over the CN basis to create a group-based communication infrastructure which enables the message propagation among vehicles and between the car and the road side infrastructure. The architecture has been implemented in both hardware and software terms, and multitude of field tests have been carried out, whose main performance results are shown in the paper.The authors would like to thank the Spanish Ministerio the Educacion y Ciencia for sponsoring the research activities under the grant AP2005-1437, in frames of the FPU program, and to the financial support given by the European Spatial Agency (ESA) under the GIROADS 332599 project. Special thanks as well to the Spanish Ministerio the Fomento for its continuous support in vehicular researching

    Experimental Analysis of Multi-hop Routing in Vehicular Ad-hoc Networks

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    International audienceEvaluation of vehicular ad-hoc networks (VANETs) over real environments is still a remaining issue for most re- searchers. There are some works dealing with common 802.11 anal- ysis over real vehicular environments, which carry out performance tests to measure the quality of the communication channel and justify results according to physical and MAC conditions. There are only a few works regarding multi-hop experimentation in this field, and even less (if not none) testing multi-hop protocols. In this paper an integral VANET testbed is evaluated, using 802.11b and a multi-hop network managed by the Optimized Link State Routing protocol (OLSR). Up to four vehicles are used over urban and highway environments to study the VANET performance, and different metrics are used to analyse the results in terms of delay, bandwidth, packet loss and distance between nodes. Furthermore, a deeper analysis is carried out to study the route followed by packets end to end, which enables us to count the number of hops and detect the links where packets are lost. Because a routing protocol is used, results differ from traditional two-hop and static- route tests, presenting a more realistic study. OLSR is considered as a good reference point for the research community, although it is not the most suitable protocol for vehicular environments, as results show

    Assessment of VANET multi-hop routing over an experimental platform

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    International audienceEvaluation of vehicular ad-hoc networks (VANETs) over real environments is still a remaining issue for most researchers. There are some works which carry out performance tests to evaluate the communication channel according to physical and MAC conditions. Only a few works deal with multi-hop experimentation in this field, and practically none tests multi- hop protocols. In this paper an integral VANET testbed is evaluated, using 802.11b and a multi-hop network managed by the Optimized Link State Routing protocol (OLSR). Up to four vehicles are used to study the VANET performance over different traffic environments and different metrics are considered to analyse the results in terms of delay, bandwidth, packet loss and distance between nodes. Furthermore, a deeper analysis is carried out to track the routes followed by packets end to end. Since a routing protocol is used, results differ from traditional one-hop and static-route tests, presenting a more realistic study

    Propuesta de implementación de los Servicios de Información (MIIS) de 802.21 como soporte al Handover en redes vanet

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    AbstractVehicular networks, both schemes vehicle to vehicle (V2V) and vehicleinfrastructure (V2I), are specially considered in different research and development processes nowadays. The SEISCIENTOS project focuses its work on studying the feasibility of these technologies in the field of vehicles, exploring new strategies for network modeling in VANETs and directing all the development to an integrated environment that provides a common interface for communication; isolating the user from transfers or changes that may occur between different network technologies. This article presents a proposal for implementation on NS2, the Media Independent Information Service (MIIS) of IEEE 802.21 [1], so that it allows to assess aspects of its impact in the test scenario defined for the development of the SEISCIENTOS project.ResumenLas redes vehiculares tanto en esquemas vehículo a vehículo (V2V) como vehículo a infraestructura (V2I) configuran actualmente un gran campo de investigacion y desarrollo. El proyecto SEISCIENTOS centra su trabajo en estudiar la viabilidad de estas tecnologías en el ámbito de los vehículos, explorar nuevas estrategias para el modelado de redes VANETs y dirigir el desarrollo hacia un entorno integrado que proporcione una interfaz común de comunicación, aislando al usuario de las transferencias que puedan producirse entre las diferentes tecnologías de red. Este artículo presenta una propuesta de implementación sobre NS2, del Media Independent Information Service (MIIS) de IEEE 802.21 [1], de tal forma que permita evaluar los aspectos relacionados con su incidencia en el escenario de prueba definido para el proyecto SEISCIENTOS

    Experiencia con la herramienta de virtualización VNUML para la enseñanza de redes de computadores

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    La virtualización permite disponer y configurar infraestructuras de red con un coste asumible para un laboratorio y, a diferencia de los simuladores, muestra un comportamiento real del sistema. Este artículo presenta la metodología que seguimos en la asignatura de Redes de la Facultad de Informática de la Universidad de Murcia para la enseñanza práctica de conceptos tales como encaminamiento, movilidad IP, balanceo de carga y alta disponibilidad por medio de la herramienta de virtualización de código abierto VNUML. Para mostrar estos conceptos hemos añadido diversas utilidades al sistema de ficheros utilizado en VNUML. Gracias a estas herramientas, los alumnos han podido mejorar el aprendizaje de estos conceptos como lo refutan las encuestas realizadas.Peer Reviewe

    High integrity IMM-EKF based road vehicle navigation with low cost GPS/INS.

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    User requirements for the performance of GlobaL Navigation Satellite System (GNSS)-based road applications have been significantly increasing in recent years. Safety systems based on vehicle localization, electronic fee-collection systems, and traveler information services are just a few examples of interesting applications requiring onboard equipment (OBE) capable of offering a high available accurate position, even in unfriendly environments with low satellite visibility such as built-up areas or tunnels and at low cost. In addition to that, users and service providers demand from the OBEs not only accurate continuous positioning but integrity information of the reliability of this position as well. Specifically, in life-critical applications, high-integrity monitored positioning is absolutely required. This paper presents a solution based on the fusion of GNSS and inertial sensors (a Global Positioning System/Satellite-Based Augmentation System/Inertial Navigation System integrated system) running an extended Kalman filter combined with an interactive multimodel method (IMM-EKF). The solution developed in this paper supplies continuous positioning in marketable conditions and a meaningful trust level of the given solution. A set of tests performed in controlled and real scenarios proves the suitability of the proposed IMM-EKF implementation as compared with lowcost GNSS-based solutions, dead reckoning systems, single-model EKF, and other filtering approaches of the current literature.This work was supported in part by the Spanish Ministerio de Fomento under Grant FOM/3929/2005 and by the Galileo Joint Undertaking (GJU) under Grant GIROADS 332599. The Associate Editor for this paper was Y. Wang

    Smart farming IoT platform based on edge and cloud computing

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    Precision Agriculture (PA), as the integration of information, communication and control technologies in agriculture, is growing day by day. The Internet of Things (IoT) and cloud computing paradigms offer advances to enhance PA connectivity. Nevertheless, their usage in this field is usually limited to specific scenarios of high cost, and they are not adapted to semi-arid conditions, or do not cover all PA management in an efficient way. For this reason, we propose a flexible platform able to cope with soilless culture needs in full recirculation greenhouses using moderately saline water. It is based on exchangeable low-cost hardware and supported by a three-tier open source software platform at local, edge and cloud planes. At the local plane, Cyber-Physical Systems (CPS) interact with crop devices to gather data and perform real-time atomic control actions. The edge plane of the platform is in charge of monitoring and managing main PA tasks near the access network to increase system reliability against network access failures. Finally, the cloud platform collects current and past records and hosts data analytics modules in a FIWARE deployment. IoT protocols like Message Queue Telemetry Transport (MQTT) or Constrained Application Protocol (CoAP) are used to communicate with CPS, while Next Generation Service Interface (NGSI) is employed for southbound and northbound access to the cloud. The system has been completely instantiated in a real prototype in frames of the EU DrainUse project, allowing the control of a real hydroponic closed system through managing software for final farmers connected to the platform.This work has been sponsored by the Spanish Ministry of Economy and Competitiveness, through the HIDROLEAF project (ref. RTC-2016-4827-2) and the Torres Quevedo program (grant TQ-15-08073), and the European Commission, through the DrainUse (ref. LIFE14 ENV/ES/000538) and ANASTACIA (contract 731558) projects. The authors would also like to thank the colleagues from OdinS company for their support in the prototype deployment

    An analysis of communication and navigation issues in collision avoidance support systems

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    Collision avoidance support systems (CASS) are nowadays one of the main fields of interest in the area of road transportation. Among the different approaches, those systems based on vehicle cooperation to avoid collisions present the most promising perspectives. Works available in the current literature have in common that the performance of such solutions strongly relies on the operation of two on-board subsystems: navigation and communications. However, the performance of these two subsystems is usually underestimated when the whole solution is evaluated. Collision avoidance support applications can be considered among the most critical vehicular services, and this is the reason why this paper focuses on the performance issues of these two subsystems. Main issues regarding navigation and communication performance are discussed along the paper, and a study of the literature in the field is completed with the evaluation of different system prototypes. Communication and navigation tests in real environments yield further conclusions discussed in the paper.The Authors would like to thank the Spanish Ministerio de Fomento and the Ministerio de Ciencia e Innovacion for sponsoring these research activities under the grants FOM/2454/2007, TIN2008-06441-C02-02 and AP2005-1437. Last one in frames of the FPU program. This work has been carried out inside the Intelligent Systems group of the University of Murcia, awarded as an excellence researching group in frames of the Spanish Plan de Ciencia y Tecnologıa de la Region de Murcia (04552/GERM/06)

    Evaluation of a zone encryption scheme for vehicular networks

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    Vehicular communications are bringing a new wave of applications under the umbrella of the Cooperative Intelligent Transportation Systems (C-ITS). To this end, on-board units are expected to send messages periodically or upon the appearance of a relevant event, to feed an awareness ecosystem that enables safety or traffic efficiency services. This is the case of Cooperative Awareness Messages (CAMs) in Europe, which contain basic vehicle information such as its position or speed, among other parameters. From a network security perspective, CAMs are broadcasted unencrypted over an unprotected radio channel, hence enabling their potential interception and the disclosure of sensitive data. Although public key infrastructures (PKI)-like solutions have been proposed, high computational cost of asymmetric cryptography to cipher application data remains a challenge and a confidentiality alternative is needed. In this work, we present the implementation and evaluation of a symmetric encryption scheme based on disjoint security domains distributed in geographical areas. In the solution, vehicles are able to coordinate and agree on common keys to be used in different security zones. Simulation results show the validity of the zone encryption scheme in diverse vehicular scenarios with different traffic densities. A potential issue in the zone key redistribution consisting in the propagation of wrongly-generated duplicated keys is also detected, which is discussed in detail and a reliable solution based on the support of third-party data-forwarders is proposed and tested. Evaluations reveal good performance of the zone encryption mechanism in terms of robustness and latency, guaranteeing the efficient access to a secured channel while maintaining low computing load.This work has been supported by the Spanish Ministry of Science, Innovation and Universities, under the Ramon y Cajal Program (Grant No. RYC2017-23823) and the projects PERSEIDES (Grant No. TIN2017-86885-R with ERDF funds) and Go2Edge (RED2018-102585-T); and by the European Commission, under the projects 5G-MOBIX (Grant No. 825496) and INSPIRE-5Gplus (Grant No. 871808)
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