5 research outputs found

    Software defined wireless network (sdwn) for industrial environment: case of underground mine

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    Avec le développement continu des industries minières canadiennes, l’établissement des réseaux de communications souterrains avancés et sans fil est devenu un élément essentiel du processus industriel minier et ceci pour améliorer la productivité et assurer la communication entre les mineurs. Cette étude vise à proposer un système de communication minier en procurant une architecture SDWN (Software Defined Wireless Network) basée sur la technologie de communication LTE. Dans cette étude, les plateformes les plus importantes de réseau mobile 4G ont été étudiées, configurées et testées dans deux zones différentes : un tunnel de mine souterrain et un couloir intérieur étroit. Également, une architecture mobile combinant SDWN et NFV (Network Functions Virtualization) a été réalisée

    Developing an SDWN Architecture for Wireless Network Engineering to Support a Quality of Experience Aware Handover

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    The massive growth of data consumption and the variety of wireless technology emergence has made the handover (HO) an attractive research topic nowadays, mainly due to the popularity of Wireless Local Area Networks (WLANs), which allow users to reach high-speed data communication while they are in movement. Moreover, mobile devices such as tablets and smartphones have also become increasingly popular due to their low cost and ease of use, and an increase in mobile device use is expected to accelerate in the coming years, along with the availability and use of applications such as real-time services and online gaming. The traditional HO methods will likely not meet the requirements of mobile devices for modern applications due to the lack of intelligence, lack of awareness Quality of Service (QoS) and Quality of Experience (QoE) requirements of mobile users. We, therefore, introduce a novel architecture that supports horizontal HO in homogenous networks. This architecture is based on the Software-Defined Wireless Networking (SDWN) concept, where the wireless network is controlled centrally and the wireless Access Points (APs) are programmable. In this architecture, HO algorithms will assist wireless users to find the network that could best support the application requirements through Quality of Service (QoS) and Quality of Experience (QoE) management policies. The first HO algorithm proposed in this thesis is called Quality of Experience Oriented Handover Algorithm. This algorithm will guarantee the best possible connectivity to the users in terms of their QoE and QoS requirements and outperforms the traditional methods in a sparse network environment. The second contribution is called Optimised Handover Algorithm for Dense WLAN Environments. This algorithm has been designed to address dense network environments via taking into consideration the Adaptive Hysteresis Value (AHV). The AHV will help the Optimised Handover Algorithm via reducing the so-called ping-pong effect. This contribution shows promising performance results by selecting the best candidate AP, decreasing the number of redundant HO and avoiding the ping-pong effect. The final contribution is called Priority Based Handover Algorithm. We extended our proposed SDWN architecture in order to include the concept of prioritising users and make a smart decision during the process of HO. This algorithm will prioritise a certain class of users to avoid the effect of the over-congestion. The results show that the approach based on priority outperforms the state of the art and provides better QoE to the high priority users despite the over-congestion situation

    Managing Mobility for Distributed Smart Cities Services

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    The IoT refers to the idea of internetworking physical devices, vehicles, buildings, and any other item embedded with the appropriate electronics, software, sensors, actuators, and network connectivity to allows them to interchange data and to provide highly effective new services. In this thesis we focus on the communications issues of the IoT in relation to mobility and we provide different solutions to alleviate the impact of these potential problems and to guarantee the information delivery in mobile scenarios. Our reference context is a Smart City where various mobile devices collaboratively participate, periodically sending information from their sensors. We assume that these services are located in platforms based in cloud infrastructures where the information is protected through the use of virtualisation ensuring their security and privacy. This thesis is structured into seven chapters. We first detail our objectives and identify the current problems we intend to address. Next, we provide a thorough review of the state of the art of all the areas involved in our work, highlighting how we improved the existing solutions with our research. The overall approach of the solutions we propose in this thesis use prototypes that encompasses and integrates different technologies and standards in a small infrastructure, using real devices in real scenarios with two of the most commonly used networks around the world: WiFi and 802.15.4 to efficiently solve the problems we originally identified. We focussed on protocols based on a producer/consumer paradigm, namely AMQP and particularly MQTT. We observed the behaviour of these protocols using in lab experiments and in external environments, using a mesh wireless network as the backbone network. Various issues raised by mobility were taken into consideration, and thus, we repeated the tests with different messages sizes and different inter-message periodicity, in order to model different possible applications. We also present a model for dimensioning the number of sources for mobile nodes and calculating the number of buffers required in the mobile node as a function of the number of sources and the size of the messages. We included a mechanism for avoiding data loss based on intermediate buffering adapted to the MQTT protocol that, in conjunction with the use of an alternative to the Network Manager in certain contexts, improves the connection establishment for wireless mobile clients. We also performed a detailed study of the jitter behaviour of a mobile node when transmitting messages with this proposal while moving through a real outdoor scenario. To emulate simple IoT networks we used the Cooja simulator to study and determine the effects on the probability of delivering messages when both publishers and subscribers were added to different scenarios. Finally we present an approach that combines the MQTT protocol with DTN which we specifically designed for constrained environments and guarantees that important information will never be lost. The advantage of our proposed solutions is that they make an IoT system more resilient to changes in the point of attachment of the mobile devices in an IoT network without requiring IoT application & service developers to explicitly consider this issue. Moreover, our solutions do not require additional support from the network through protocols such as MobileIP or LISP. We close the thesis by providing some conclusions, and identifying future lines of work which we unable to address here.Internet de las cosas (IoT) se refiere a la idea de interconectar sensores, actuadores, dispositivos físicos, vehículos, edificios y cualquier elemento dotado de la electrónica, así como del software y de la conectividad de red que los hace capaces de intercambiar datos para proporcionar servicios altamente efectivos. En esta tesis nos centramos en temas relacionados con la comunicación de sistemas IoT, específicamente en situaciones de movilidad y en los problemas que esto conlleva. Con este fin ofrecemos diferentes soluciones que alivian su impacto y garantizan la entrega de información en estas situaciones. El contexto de referencia es una ciudad inteligente donde varios dispositivos móviles participan de forma colaborativa enviando periódicamente información desde sus sensores hacia servicios ubicados en plataformas en la nube (cloud computing) donde mediante el uso de virtualización, la información está protegida garantizando su seguridad y privacidad. Las soluciones propuestas en esta tesis se enfocan en probar sobre una pequeña infraestructura un prototipo que abarca e integra diferentes tecnologías y estándares para resolver eficientemente los problemas previamente identificados. Hemos enfocado nuestro esfuerzo en el uso de dispositivos sobre escenarios reales con dos de las redes más extendidas en todo el mundo: WiFi y enlaces 802.15.4. Nos enfocamos en protocolos que ofrecen el paradigma productor/consumidor como el protocolo avanzado de colas de mensajes (AMQP) y particularmente el protocolo de transporte de mensajes telemétricos (MQTT), observamos su comportamiento a través de experimentos en laboratorio y en pruebas al aire libre, repitiendo las pruebas con diferentes tamaños de mensajes y diferente periodicidad entre mensajes. Para modelar las diferentes posibles aplicaciones de la propuesta, se tomaron en consideración varias cuestiones planteadas por la movilidad, resultando en un modelo para dimensionar eficientemente el número de fuentes para un nodo móvil y para calcular el tamaño requerido del buffer, en función del número de fuentes y del tamaño de los mensajes. Proponemos un mecanismo adaptado al protocolo MQTT que evita la pérdida de datos en clientes móviles, basado en un buffer intermedio entre la producción y publicación de mensajes que, en conjunto con el uso de una alternativa al gestor de conexiones inalámbricas "Network Manager", en ciertos contextos mejora el establecimiento de las conexiones. Para la evaluación de esta propuesta se presenta un estudio detallado de un nodo móvil que se mueve en un escenario real al aire libre, donde estudiamos el comportamiento del jitter y la transmisión de mensajes. Además, hemos utilizado emuladores de redes IoT para estudiar y determinar los efectos sobre la probabilidad de entrega de mensajes, cuando se agregan tanto publicadores como suscriptores a diferentes escenarios. Finalmente, se presenta una solución totalmente orientada a entornos con dispositivos de recursos limitados que combina los protocolos MQTT con redes tolerantes a retardos (DTN) para garantizar la entrega de información. La ventaja de las soluciones que proponemos reside en el hecho de que los sistemas IoT se vuelven resilientes a la movilidad y a los cambios de punto de acceso, permitiendo así que los desarrolladores creen fácilmente aplicaciones y servicios IoT evitando considerar estos problema. Otra ventaja de nuestras soluciones es que no necesitan soporte adicional de la red como sucede con protocolos como MobileIP o el protocolo que separa el identificador del localizador (LISP). Se destaca cómo hemos mejorado las soluciones existentes hasta el momento de la escritura de esta disertación, y se identifican futuras líneas de actuación que no han sido contempladas.Internet de les coses (IoT) es refereix a la idea d'interconnectar sensors, actuadors, dispositius físics, vehicles, edificis i qualsevol element dotat de l'electrònica, així com del programari i de la connectivitat de xarxa que els fa capaces d'intercanviar dades per proporcionar serveis altament efectius. En aquesta tesi ens centrem en temes relacionats amb la comunicació de sistemes IoT, específicament en situacions de mobilitat i en els problemes que això comporta. A aquest efecte oferim diferents solucions que alleugeren el seu impacte i garanteixen el lliurament d'informació en aquestes situacions. El context de referència és una ciutat intel·ligent on diversos dispositius mòbils participen de forma col·laborativa enviant periòdicament informació des dels seus sensors cap a serveis situats en plataformes en el núvol (cloud computing) on mitjançant l'ús de virtualització, la informació està protegida garantint la seva seguretat i privadesa. Les solucions proposades en aquesta tesi s'enfoquen a provar sobre una xicoteta infraestructura un prototip que abasta i integra diferents tecnologies i estàndards per a resoldre eficientment els problemes prèviament identificats. Hem enfocat el nostre esforç en l'ús de dispositius sobre escenaris reals amb dos de les xarxes més esteses a tot el món: WiFi i enllaços 802.15.4. Ens enfoquem en protocols que ofereixen el paradigma productor/consumidor com el protocol avançat de cues de missatges (AMQP) i particularment el protocol de transport de missatges telemètrics (MQTT), observem el seu comportament a través d'experiments en laboratori i en proves a l'aire lliure, repetint les proves amb diferents grandàries de missatges i diferent periodicitat entre missatges. Per a modelar les diferents possibles aplicacions de la proposta, es van prendre en consideració diverses qüestions plantejades per la mobilitat, resultant en un model per a dimensionar eficientment el nombre de fonts per a un node mòbil i per a calcular la grandària requerida del buffer, en funció del nombre de fonts i de la grandària dels missatges. Proposem un mecanisme adaptat al protocol MQTT que evita la pèrdua de dades per a clients mòbils, basat en un buffer intermedi entre la producció i publicació de missatges que en conjunt amb l'ús d'una alternativa al gestor de connexions sense fils "Network Manager'', en certs contextos millora l'establiment de les connexions. Per a l'avaluació d'aquesta proposta es presenta un estudi detallat d'un node mòbil que es mou en un escenari real a l'aire lliure, on estudiem el comportament del jitter i la transmissió de missatges. A més, hem utilitzat emuladors de xarxes IoT per a estudiar i determinar els efectes sobre la probabilitat de lliurament de missatges, quan s'agreguen tant publicadors com subscriptors a diferents escenaris. Finalment, es presenta una solució totalment orientada a entorns amb dispositius de recursos limitats que combina els protocols MQTT amb xarxes tolerants a retards (DTN) per a garantir el lliurament d'informació. L'avantatge de les solucions que proposem resideix en el fet que els sistemes IoT es tornen resilients a la mobilitat i als canvis de punt d'accés, permetent així que els desenvolupadors creuen fàcilment aplicacions i serveis IoT evitant considerar aquests problema. Un altre avantatge de les nostres solucions és que no necessiten suport addicional de la xarxa com succeeix amb protocols com MobileIP o el protocol que separa l'identificador del localitzador (LISP). Es destaca com hem millorat les solucions existents fins al moment de l'escriptura d'aquesta dissertació, i s'identifican futures línies d'actuació que no han sigut contemplades.Luzuriaga Quichimbo, JE. (2017). Managing Mobility for Distributed Smart Cities Services [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/84744TESI

    Gestion de la mobilité dans les réseaux denses de cinquième génération (5G)

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    Les réseaux de communications mobiles ont connu de profondes avancées technologiques au cours des deux dernières décénnies. La croissance du nombre d’abonnés mobiles ainsi que l’accès à des forfaits de données illimitées, souvent à des tarifs préférentiels, ont engendré une demande de bande passante, de vidéo et de données en forte croissance. Ces progrès significatifs ont favorisé le déploiement de nouveaux services et de nouveaux cas d’utilisation tels que l’Internet-des-objets (IoT), la réalité augmentée et virtuelle, les réseaux de villes intelligentes, les véhicules autonomes et l’automatisation industrielle. Aux technologies existantes, s’ajouteront de nouveaux modes de communication dans le but de répondre à plusieurs cas d’utilisation des réseaux mobiles qui sont encore difficiles à satisfaire à ce jour. Le résultat à long terme de cette nouvelle tournure dans le monde de la réseautique mobile est désigné sous le vocable de réseaux de cinquième génération (5G). Au-delà du déploiement d’applications avancées, les réseaux 5G offriront de nouvelles opportunités de revenus aux fournisseurs de services lorsqu’ils seront combinés aux fonctionnalités avancées telles que l’analyse de données, l’apprentissage automatique et à l’intelligence artificielle. Dans ce contexte, un large consensus est aujourd’hui établit sur la nécessité d’accroître la capacité du réseau par un déploiement massif de cellules de petite taille (Small Cell, SCs), d’un rayon de couverture réduit et à faible puissance. On parle alors d’une ultra-densification du réseau dont le but essentiel est de favoriser la proximité des points d’accès des utilisateurs finaux. Cependant, la densification du réseau implique des relèves fréquentes des usagers mobiles (MNs) entre les SCs et les zones de service. En effet, le rayon de couverture réduit des SCs rend plus complèxe la phase de sélection des relèves en plus d’accroître la fréquence de celles-ci. Ces relèves entraînent des dégradations, des perturbations et des déconnexions qui peuvent entraver l’objectif d’un accès transparent aux services du réseau. En outre, la fréquence des relèves engendre une latence et une charge de signalisation élevées dans le reseau. De plus, l’omniprésence d’applications temps réel exige une latence faible du réseau. Dans ce contexte, la gestion de la mobilité demeure encore un enjeux et il s’avère donc indispensable de concevoir de nouveaux protocoles de gestion de la mobilité capables répondre aux exigences de performances strictes des réseaux 5G.----------ABSTRACT : Mobile communications networks have experienced tremendous technological advances in the last two decades. The growth of the number of mobile subscribers and access to unlimited data plans, often at very affordable prices, have led to an increased demand for bandwidth, video and high-growth data. These significant advances have facilitated the deployment of new services and use cases such as Internet-of-things (IoT), augmented and virtual reality, smart city networks, autonomous vehicles, and industrial automation. On top of the existing technologies, new communication modes will arise to respond to several uses cases of mobile systems that are still difficult to meet today. The long-term result of this new trend in the world of mobile networking gives birth to a new paradigm called the fifth generation networks (5G). Beyond deploying advanced applications, 5G networks will offer new revenue opportunities to service providers, when combined with advanced features such as data analytics, machine learning, and artificial intelligence. In this context, a broad consensus is now established on the need to increase the network capacity through a massive deployment of small cells (Small Cell, SCs), with reduced coverage and low power. This requirement led to the ultra-densification of the network whose primary purpose is to promote the proximity of access points to the end-users. However, the densification of the cellular networks involves many mobile nodes (MNs) going through several handovers between the SCs and the service areas. The shorter SC’s radius makes the handover selection phase more complex while increasing its frequency. These handovers lead to service disruptions and disconnections that may hinder the provision of seamless mobility of network services. Moreover, the frequency of the handovers generates a high latency and signaling load in the network. Besides, the ubiquity of real-time applications requires low network latency. In this context, mobility management is still an issue, and it is, therefore, essential to design new mobility management protocols that can meet the stringent performance requirements of 5G networks

    Flexible network management in software defined wireless sensor networks for monitoring application systems

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    Wireless Sensor Networks (WSNs) are the commonly applied information technologies of modern networking and computing platforms for application-specific systems. Today’s network computing applications are faced with high demand of reliable and powerful network functionalities. Hence, efficient network performance is central to the entire ecosystem, more especially where human life is a concern. However, effective management of WSNs remains a challenge due to problems supplemental to them. As a result, WSNs application systems such as in monitored environments, surveillance, aeronautics, medicine, processing and control, tend to suffer in terms of capacity to support compute intensive services due to limitations experienced on them. A recent technology shift proposes Software Defined Networking (SDN) for improving computing networks as well as enhancing network resource management, especially for life guarding systems. As an optimization strategy, a software-oriented approach for WSNs, known as Software Defined Wireless Sensor Network (SDWSN) is implemented to evolve, enhance and provide computing capacity to these resource constrained technologies. Software developmental strategies are applied with the focus to ensure efficient network management, introduce network flexibility and advance network innovation towards the maximum operation potential for WSNs application systems. The need to develop WSNs application systems which are powerful and scalable has grown tremendously due to their simplicity in implementation and application. Their nature of design serves as a potential direction for the much anticipated and resource abundant IoT networks. Information systems such as data analytics, shared computing resources, control systems, big data support, visualizations, system audits, artificial intelligence (AI), etc. are a necessity to everyday life of consumers. Such systems can greatly benefit from the SDN programmability strategy, in terms of improving how data is mined, analysed and committed to other parts of the system for greater functionality. This work proposes and implements SDN strategies for enhancing WSNs application systems especially for life critical systems. It also highlights implementation considerations for designing powerful WSNs application systems by focusing on system critical aspects that should not be disregarded when planning to improve core network functionalities. Due to their inherent challenges, WSN application systems lack robustness, reliability and scalability to support high computing demands. Anticipated systems must have greater capabilities to ubiquitously support many applications with flexible resources that can be easily accessed. To achieve this, such systems must incorporate powerful strategies for efficient data aggregation, query computations, communication and information presentation. The notion of applying machine learning methods to WSN systems is fairly new, though carries the potential to enhance WSN application technologies. This technological direction seeks to bring intelligent functionalities to WSN systems given the characteristics of wireless sensor nodes in terms of cooperative data transmission. With these technological aspects, a technical study is therefore conducted with a focus on WSN application systems as to how SDN strategies coupled with machine learning methods, can contribute with viable solutions on monitoring application systems to support and provide various applications and services with greater performance. To realize this, this work further proposes and implements machine learning (ML) methods coupled with SDN strategies to; enhance sensor data aggregation, introduce network flexibility, improve resource management, query processing and sensor information presentation. Hence, this work directly contributes to SDWSN strategies for monitoring application systems.Thesis (PhD)--University of Pretoria, 2018.National Research Foundation (NRF)Telkom Centre of ExcellenceElectrical, Electronic and Computer EngineeringPhDUnrestricte
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