74 research outputs found

    Robotic Wireless Sensor Networks

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    In this chapter, we present a literature survey of an emerging, cutting-edge, and multi-disciplinary field of research at the intersection of Robotics and Wireless Sensor Networks (WSN) which we refer to as Robotic Wireless Sensor Networks (RWSN). We define a RWSN as an autonomous networked multi-robot system that aims to achieve certain sensing goals while meeting and maintaining certain communication performance requirements, through cooperative control, learning and adaptation. While both of the component areas, i.e., Robotics and WSN, are very well-known and well-explored, there exist a whole set of new opportunities and research directions at the intersection of these two fields which are relatively or even completely unexplored. One such example would be the use of a set of robotic routers to set up a temporary communication path between a sender and a receiver that uses the controlled mobility to the advantage of packet routing. We find that there exist only a limited number of articles to be directly categorized as RWSN related works whereas there exist a range of articles in the robotics and the WSN literature that are also relevant to this new field of research. To connect the dots, we first identify the core problems and research trends related to RWSN such as connectivity, localization, routing, and robust flow of information. Next, we classify the existing research on RWSN as well as the relevant state-of-the-arts from robotics and WSN community according to the problems and trends identified in the first step. Lastly, we analyze what is missing in the existing literature, and identify topics that require more research attention in the future

    Ubiquitous robust communications for emergency response using multi-operator heterogeneous networks

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    A number of disasters in various places of the planet have caused an extensive loss of lives, severe damages to properties and the environment, as well as a tremendous shock to the survivors. For relief and mitigation operations, emergency responders are immediately dispatched to the disaster areas. Ubiquitous and robust communications during the emergency response operations are of paramount importance. Nevertheless, various reports have highlighted that after many devastating events, the current technologies used, failed to support the mission critical communications, resulting in further loss of lives. Inefficiencies of the current communications used for emergency response include lack of technology inter-operability between different jurisdictions, and high vulnerability due to their centralized infrastructure. In this article, we propose a flexible network architecture that provides a common networking platform for heterogeneous multi-operator networks, for interoperation in case of emergencies. A wireless mesh network is the main part of the proposed architecture and this provides a back-up network in case of emergencies. We first describe the shortcomings and limitations of the current technologies, and then we address issues related to the applications and functionalities a future emergency response network should support. Furthermore, we describe the necessary requirements for a flexible, secure, robust, and QoS-aware emergency response multi-operator architecture, and then we suggest several schemes that can be adopted by our proposed architecture to meet those requirements. In addition, we suggest several methods for the re-tasking of communication means owned by independent individuals to provide support during emergencies. In order to investigate the feasibility of multimedia transmission over a wireless mesh network, we measured the performance of a video streaming application in a real wireless metropolitan multi-radio mesh network, showing that the mesh network can meet the requirements for high quality video transmissions

    A study of the applicability of software-defined networking in industrial networks

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    173 p.Las redes industriales interconectan sensores y actuadores para llevar a cabo funciones de monitorización, control y protección en diferentes entornos, tales como sistemas de transporte o sistemas de automatización industrial. Estos sistemas ciberfísicos generalmente están soportados por múltiples redes de datos, ya sean cableadas o inalámbricas, a las cuales demandan nuevas prestaciones, de forma que el control y gestión de tales redes deben estar acoplados a las condiciones del propio sistema industrial. De este modo, aparecen requisitos relacionados con la flexibilidad, mantenibilidad y adaptabilidad, al mismo tiempo que las restricciones de calidad de servicio no se vean afectadas. Sin embargo, las estrategias de control de red tradicionales generalmente no se adaptan eficientemente a entornos cada vez más dinámicos y heterogéneos.Tras definir un conjunto de requerimientos de red y analizar las limitaciones de las soluciones actuales, se deduce que un control provisto independientemente de los propios dispositivos de red añadiría flexibilidad a dichas redes. Por consiguiente, la presente tesis explora la aplicabilidad de las redes definidas por software (Software-Defined Networking, SDN) en sistemas de automatización industrial. Para llevar a cabo este enfoque, se ha tomado como caso de estudio las redes de automatización basadas en el estándar IEC 61850, el cual es ampliamente usado en el diseño de las redes de comunicaciones en sistemas de distribución de energía, tales como las subestaciones eléctricas. El estándar IEC 61850 define diferentes servicios y protocolos con altos requisitos en terminos de latencia y disponibilidad de la red, los cuales han de ser satisfechos mediante técnicas de ingeniería de tráfico. Como resultado, aprovechando la flexibilidad y programabilidad ofrecidas por las redes definidas por software, en esta tesis se propone una arquitectura de control basada en el protocolo OpenFlow que, incluyendo tecnologías de gestión y monitorización de red, permite establecer políticas de tráfico acorde a su prioridad y al estado de la red.Además, las subestaciones eléctricas son un ejemplo representativo de infraestructura crítica, que son aquellas en las que un fallo puede resultar en graves pérdidas económicas, daños físicos y materiales. De esta forma, tales sistemas deben ser extremadamente seguros y robustos, por lo que es conveniente la implementación de topologías redundantes que ofrezcan un tiempo de reacción ante fallos mínimo. Con tal objetivo, el estándar IEC 62439-3 define los protocolos Parallel Redundancy Protocol (PRP) y High-availability Seamless Redundancy (HSR), los cuales garantizan un tiempo de recuperación nulo en caso de fallo mediante la redundancia activa de datos en redes Ethernet. Sin embargo, la gestión de redes basadas en PRP y HSR es estática e inflexible, lo que, añadido a la reducción de ancho de banda debida la duplicación de datos, hace difícil un control eficiente de los recursos disponibles. En dicho sentido, esta tesis propone control de la redundancia basado en el paradigma SDN para un aprovechamiento eficiente de topologías malladas, al mismo tiempo que se garantiza la disponibilidad de las aplicaciones de control y monitorización. En particular, se discute cómo el protocolo OpenFlow permite a un controlador externo configurar múltiples caminos redundantes entre dispositivos con varias interfaces de red, así como en entornos inalámbricos. De esta forma, los servicios críticos pueden protegerse en situaciones de interferencia y movilidad.La evaluación de la idoneidad de las soluciones propuestas ha sido llevada a cabo, principalmente, mediante la emulación de diferentes topologías y tipos de tráfico. Igualmente, se ha estudiado analítica y experimentalmente cómo afecta a la latencia el poder reducir el número de saltos en las comunicaciones con respecto al uso de un árbol de expansión, así como balancear la carga en una red de nivel 2. Además, se ha realizado un análisis de la mejora de la eficiencia en el uso de los recursos de red y la robustez alcanzada con la combinación de los protocolos PRP y HSR con un control llevado a cabo mediante OpenFlow. Estos resultados muestran que el modelo SDN podría mejorar significativamente las prestaciones de una red industrial de misión crítica

    Secure and Privacy-Preserving Authentication Protocols for Wireless Mesh Networks

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    Wireless mesh networks (WMNs) have emerged as a promising concept to meet the challenges in next-generation wireless networks such as providing flexible, adaptive, and reconfigurable architecture while offering cost-effective solutions to service providers. As WMNs become an increasingly popular replacement technology for last-mile connectivity to the home networking, community and neighborhood networking, it is imperative to design efficient and secure communication protocols for these networks. However, several vulnerabilities exist in currently existing protocols for WMNs. These security loopholes can be exploited by potential attackers to launch attack on WMNs. The absence of a central point of administration makes securing WMNs even more challenging. The broadcast nature of transmission and the dependency on the intermediate nodes for multi-hop communications lead to several security vulnerabilities in WMNs. The attacks can be external as well as internal in nature. External attacks are launched by intruders who are not authorized users of the network. For example, an intruding node may eavesdrop on the packets and replay those packets at a later point of time to gain access to the network resources. On the other hand, the internal attacks are launched by the nodes that are part of the WMN. On example of such attack is an intermediate node dropping packets which it was supposed to forward. This chapter presents a comprehensive discussion on the current authentication and privacy protection schemes for WMN. In addition, it proposes a novel security protocol for node authentication and message confidentiality and an anonymization scheme for privacy protection of users in WMNs.Comment: 32 pages, 10 figures. The work is an extended version of the author's previous works submitted in CoRR: arXiv:1107.5538v1 and arXiv:1102.1226v

    Cross-layer optimizations in multi-hop ad hoc networks

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    Unlike traditional wireless networks, characterized by the presence of last-mile, static and reliable infrastructures, Mobile ad Hoc Networks (MANETs) are dynamically formed by collections of mobile and static terminals that exchange data by enabling each other's communication. Supporting multi-hop communication in a MANET is a challenging research area because it requires cooperation between different protocol layers (MAC, routing, transport). In particular, MAC and routing protocols could be considered mutually cooperative protocol layers. When a route is established, the exposed and hidden terminal problems at MAC layer may decrease the end-to-end performance proportionally with the length of each route. Conversely, the contention at MAC layer may cause a routing protocol to respond by initiating new routes queries and routing table updates. Multi-hop communication may also benefit the presence of pseudo-centralized virtual infrastructures obtained by grouping nodes into clusters. Clustering structures may facilitate the spatial reuse of resources by increasing the system capacity: at the same time, the clustering hierarchy may be used to coordinate transmissions events inside the network and to support intra-cluster routing schemes. Again, MAC and clustering protocols could be considered mutually cooperative protocol layers: the clustering scheme could support MAC layer coordination among nodes, by shifting the distributed MAC paradigm towards a pseudo-centralized MAC paradigm. On the other hand, the system benefits of the clustering scheme could be emphasized by the pseudo-centralized MAC layer with the support for differentiated access priorities and controlled contention. In this thesis, we propose cross-layer solutions involving joint design of MAC, clustering and routing protocols in MANETs. As main contribution, we study and analyze the integration of MAC and clustering schemes to support multi-hop communication in large-scale ad hoc networks. A novel clustering protocol, named Availability Clustering (AC), is defined under general nodes' heterogeneity assumptions in terms of connectivity, available energy and relative mobility. On this basis, we design and analyze a distributed and adaptive MAC protocol, named Differentiated Distributed Coordination Function (DDCF), whose focus is to implement adaptive access differentiation based on the node roles, which have been assigned by the upper-layer's clustering scheme. We extensively simulate the proposed clustering scheme by showing its effectiveness in dominating the network dynamics, under some stressing mobility models and different mobility rates. Based on these results, we propose a possible application of the cross-layer MAC+Clustering scheme to support the fast propagation of alert messages in a vehicular environment. At the same time, we investigate the integration of MAC and routing protocols in large scale multi-hop ad-hoc networks. A novel multipath routing scheme is proposed, by extending the AOMDV protocol with a novel load-balancing approach to concurrently distribute the traffic among the multiple paths. We also study the composition effect of a IEEE 802.11-based enhanced MAC forwarding mechanism called Fast Forward (FF), used to reduce the effects of self-contention among frames at the MAC layer. The protocol framework is modelled and extensively simulated for a large set of metrics and scenarios. For both the schemes, the simulation results reveal the benefits of the cross-layer MAC+routing and MAC+clustering approaches over single-layer solutions

    Mobile Ad Hoc Networks

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    Guiding readers through the basics of these rapidly emerging networks to more advanced concepts and future expectations, Mobile Ad hoc Networks: Current Status and Future Trends identifies and examines the most pressing research issues in Mobile Ad hoc Networks (MANETs). Containing the contributions of leading researchers, industry professionals, and academics, this forward-looking reference provides an authoritative perspective of the state of the art in MANETs. The book includes surveys of recent publications that investigate key areas of interest such as limited resources and the mobility of mobile nodes. It considers routing, multicast, energy, security, channel assignment, and ensuring quality of service. Also suitable as a text for graduate students, the book is organized into three sections: Fundamentals of MANET Modeling and Simulation—Describes how MANETs operate and perform through simulations and models Communication Protocols of MANETs—Presents cutting-edge research on key issues, including MAC layer issues and routing in high mobility Future Networks Inspired By MANETs—Tackles open research issues and emerging trends Illustrating the role MANETs are likely to play in future networks, this book supplies the foundation and insight you will need to make your own contributions to the field. It includes coverage of routing protocols, modeling and simulations tools, intelligent optimization techniques to multicriteria routing, security issues in FHAMIPv6, connecting moving smart objects to the Internet, underwater sensor networks, wireless mesh network architecture and protocols, adaptive routing provision using Bayesian inference, and adaptive flow control in transport layer using genetic algorithms
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