71 research outputs found

    Applications

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    Volume 3 describes how resource-aware machine learning methods and techniques are used to successfully solve real-world problems. The book provides numerous specific application examples: in health and medicine for risk modelling, diagnosis, and treatment selection for diseases in electronics, steel production and milling for quality control during manufacturing processes in traffic, logistics for smart cities and for mobile communications

    Performance Evaluation of Wireless Medium Access Control Protocols for Internet of Things

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    The Internet of Things makes the residents in Smart Cities enjoy a more efficient and high-quality lifestyle by wirelessly interconnecting the physical and visual world. However, the performance of wireless networks is challenged by the ever-growing wireless traffic data, the complexity of the network structures, and various requirements of Quality of Service (QoS), especially on the Internet of Vehicle and wireless sensor networks. Consequently, the IEEE 802.11p and 802.11ah standards were designed to support effective inter-vehicle communications and large-scale sensor networks, respectively. Although their Medium Access Control protocols have attracted much research interest, they have yet to fully consider the influences of channel errors and buffer sizes on the performance evaluation of these Medium Access Control (MAC) protocols. Therefore, this thesis first proposed a new analytical model based on a Markov chain and Queuing analysis to evaluate the performance of IEEE 802.11p under imperfect channels with both saturated and unsaturated traffic. All influential factors of the Enhanced Distributed Channel Access (EDCA) mechanism in IEEE 802.11p are considered, including the backoff counter freezing, Arbitration Inter-Frame Spacing (AIFS) defers, the internal collision, and finite MAC buffer sizes. Furthermore, this proposed model considers more common and actual conditions with the influence of channel errors and finite MAC buffer sizes. The effectiveness and accuracy of the developed model have been validated through extensive ns-3 simulation experiments. Second, this thesis proposes a developed analytical model based on Advanced Queuing Analysis and the Gilbert-Elliot model to analyse the performance of IEEE 802.11p with burst error transmissions. This proposed analytical model simultaneously describes transmission queues for all four Access Categories (AC) queues with the influence of burst errors. Similarly, this presented model can analyse QoS performance, including throughputs and end-to-end delays with the unsaturated or saturated load traffics. Furthermore, this model operates under more actual bursty error channels in vehicular environments. In addition, a series of simulation experiments with a natural urban environment is designed to validate the efficiency and accuracy of the presented model. The simulation results reflect the reliability and effectiveness of the presented model in terms of throughput and end-to-end delays under various channel conditions. Third, this thesis designed and implemented a simulation experiment to analyse the performance of IEEE 802.11ah. These simulation experiments are based on ns-3 and an extension. These simulation experiments' results indicate the Restricted Access Window (RAW) mechanism's influence on the throughputs, end-to-end delays, and packet loss rates. Furthermore, the influences of channel errors and bursty errors are considered in the simulations. The results also show the strong impact of channel errors on the performance of IEEE 802.11ah due to urban environments. Finally, the potential future work based on the proposed models and simulations is analysed in this thesis. The proposed models of IEEE 802.11p can be an excellent fundamental to optimise the QoS due to the precise evaluation of the influence of factors on the performance of IEEE 802.11p. Moreover, it is possible to migrate the analytical models of IEEE 802.11p to evaluate the performance of IEEE 802.11ah

    Introducing reinforcement learning in the Wi-Fi MAC layer to support sustainable communications in e-Health scenarios

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    The crisis of energy supplies has led to the need for sustainability in technology, especially in the Internet of Things (IoT) paradigm. One solution is the integration of Energy Harvesting (EH) technologies into IoT systems, which reduces the amount of battery replacement. However, integrating EH technologies within IoT systems is challenging, and it requires adaptations at different layers of the IoT protocol stack, especially at Medium Access Control (MAC) layer due to its energy-hungry features. Since Wi-Fi is a widely used wireless technology in IoT systems, in this paper, we perform an extensive set of simulations in a dense solar-based energy-harvesting Wi-Fi network in an e-Health environment. We introduce optimization algorithms, which benefit from the Reinforcement Learning (RL) methods to efficiently adjust to the complexity and dynamic behaviour of the network. We assume the concept of Access Point (AP) coordination to demonstrate the feasibility of the upcoming Wi-Fi amendment IEEE 802.11bn (Wi-Fi 8). This paper shows that the proposed algorithms reduce the network&amp;#x2019;s energy consumption by up to 25% compared to legacy Wi-Fi while maintaining the required Quality of Service (QoS) for e-Health applications. Moreover, by considering the specific adjustment of MAC layer parameters, up to 37% of the energy of the network can be conserved, which illustrates the viability of reducing the dimensions of solar cells, while concurrently augmenting the flexibility of this EH technique for deployment within the IoT devices. We anticipate this research will shed light on new possibilities for IoT energy harvesting integration, particularly in contexts with restricted QoS environments such as e-Healthcare.</p

    Low-Power Wide-Area Networks: A Broad Overview of its Different Aspects

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    Low-power wide-area networks (LPWANs) are gaining popularity in the research community due to their low power consumption, low cost, and wide geographical coverage. LPWAN technologies complement and outperform short-range and traditional cellular wireless technologies in a variety of applications, including smart city development, machine-to-machine (M2M) communications, healthcare, intelligent transportation, industrial applications, climate-smart agriculture, and asset tracking. This review paper discusses the design objectives and the methodologies used by LPWAN to provide extensive coverage for low-power devices. We also explore how the presented LPWAN architecture employs various topologies such as star and mesh. We examine many current and emerging LPWAN technologies, as well as their system architectures and standards, and evaluate their ability to meet each design objective. In addition, the possible coexistence of LPWAN with other technologies, combining the best attributes to provide an optimum solution is also explored and reported in the current overview. Following that, a comparison of various LPWAN technologies is performed and their market opportunities are also investigated. Furthermore, an analysis of various LPWAN use cases is performed, highlighting their benefits and drawbacks. This aids in the selection of the best LPWAN technology for various applications. Before concluding the work, the open research issues, and challenges in designing LPWAN are presented.publishedVersio

    Five Facets of 6G: Research Challenges and Opportunities

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    Whilst the fifth-generation (5G) systems are being rolled out across the globe, researchers have turned their attention to the exploration of radical next-generation solutions. At this early evolutionary stage we survey five main research facets of this field, namely {\em Facet~1: next-generation architectures, spectrum and services, Facet~2: next-generation networking, Facet~3: Internet of Things (IoT), Facet~4: wireless positioning and sensing, as well as Facet~5: applications of deep learning in 6G networks.} In this paper, we have provided a critical appraisal of the literature of promising techniques ranging from the associated architectures, networking, applications as well as designs. We have portrayed a plethora of heterogeneous architectures relying on cooperative hybrid networks supported by diverse access and transmission mechanisms. The vulnerabilities of these techniques are also addressed and carefully considered for highlighting the most of promising future research directions. Additionally, we have listed a rich suite of learning-driven optimization techniques. We conclude by observing the evolutionary paradigm-shift that has taken place from pure single-component bandwidth-efficiency, power-efficiency or delay-optimization towards multi-component designs, as exemplified by the twin-component ultra-reliable low-latency mode of the 5G system. We advocate a further evolutionary step towards multi-component Pareto optimization, which requires the exploration of the entire Pareto front of all optiomal solutions, where none of the components of the objective function may be improved without degrading at least one of the other components

    Analisis Perbandingan Performa serta Efisiensi Energi Routing Protocol Data Centric SPIN dengan Directed Diffusion Wireless Sensor Network

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    Wireless Sensor Network (WSN) merupakan suatu jaringan multi hop nirkabel yang terdiri dari beberapa node yang tersebar di suatu area yang mengatur dirinya sendiri. Dalam pengaplikasian WSN memiliki suatu masalah yang sering muncul yaitu tingkat konsumsi energi dan performanya. Dalam upaya memecahkan masalah tersebut, diperkenalkan routing protocol berbasis data centric yang bertujuan untuk meminimalisir penggunaan energi. Salah satu routing protocol berbasis data centric yaitu SPIN dan directed diffusion. Berdasarkan hal tersebut dilakukannya penelitian untuk mengetahui perbandingan performa dan penggunaan energi. Penelitian ini menggunakan metode simulasi jaringan dengan bantuan software Network Simulator 2 (NS 2) untuk mendapatkan hasil berupa parameter jaringan. Parameter yang dibandingkan yaitu throughput, end-to-end delay, packet delivery ratio, konsumsi energi dan node life time. Hasil penelitian didapatkan bahwa directed diffusion lebih baik dalam hal performa berdasarkan parameter throughput bernilai 1281,184 Kbps, end-to-end delay bernilai 65,8975 ms dan packet delivery ratio bernilai 100%. SPIN lebih unggul dalam hal efisiensi energi yang bernilai 28,91%

    Medium access control protocol design for wireless communications and networks review

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    Medium access control (MAC) protocol design plays a crucial role to increase the performance of wireless communications and networks. The channel access mechanism is provided by MAC layer to share the medium by multiple stations. Different types of wireless networks have different design requirements such as throughput, delay, power consumption, fairness, reliability, and network density, therefore, MAC protocol for these networks must satisfy their requirements. In this work, we proposed two multiplexing methods for modern wireless networks: Massive multiple-input-multiple-output (MIMO) and power domain non-orthogonal multiple access (PD-NOMA). The first research method namely Massive MIMO uses a massive number of antenna elements to improve both spectral efficiency and energy efficiency. On the other hand, the second research method (PD-NOMA) allows multiple non-orthogonal signals to share the same orthogonal resources by allocating different power level for each station. PD-NOMA has a better spectral efficiency over the orthogonal multiple access methods. A review of previous works regarding the MAC design for different wireless networks is classified based on different categories. The main contribution of this research work is to show the importance of the MAC design with added optimal functionalities to improve the spectral and energy efficiencies of the wireless networks

    Συγκριτική παρουσίαση των τεχνολογιών 5G και WiFi 6.0

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    Τα τελευταία χρόνια, μεγάλη σημασία έχει δοθεί στην πέμπτη γενιά ασύρματης ευρυζωνικής συνδεσιμότητας γνωστής ως 5G, η οποία υπόσχεται μια σημαντική αναβάθμιση στη ποιότητα και στη χωρητικότητα των κινητών ευρυζωνικών υπηρεσιών αλλά και ένα γενικότερο τεχνολογικό άλμα με τη παροχή μιας πληθώρας νέων δυνατοτήτων. Παραδόξως, έχει δοθεί λιγότερη προσοχή στο Wi-Fi 6, το νέο πρότυπο 802.11ax της IEEE στην οικογένεια τεχνολογιών ασύρματου τοπικού δικτύου, με χαρακτηριστικά που στοχεύουν στα ιδιωτικά, ακραία δίκτυα, υποστηρίζοντας υψηλές ταχύτητες, χαμηλή καθυστέρηση και χαμηλή ενεργειακή κατανάλωση. Αυτή η εργασία εξετάζει την καταλληλότητα των κυψελωτών και των Wi-Fi δικτύων στην παροχή υψηλής ταχύτητας ασύρματης σύνδεσης στο διαδίκτυο. Και οι δύο τεχνολογίες φιλοδοξούν να προσφέρουν σημαντικά βελτιωμένη απόδοση, πολύ πιο γρήγορη ασύρματη ευρυζωνική σύνδεση και περαιτέρω υποστήριξη για το διαδίκτυο των πραγμάτων (IoT) και τις επικοινωνίες τύπου μηχανής, τοποθετώντας τις ως τεχνικά υποκατάστατες σε πολλά σενάρια χρήσης. Και οι δύο είναι πιθανό να διαδραματίσουν σημαντικό ρόλο στο μέλλον και ταυτόχρονα να αξιοποιηθούν ως ανταγωνιστικές και συμπληρωματικές τεχνολογίες. Το 5G αναμένεται να παραμείνει η προτιμώμενη τεχνολογία για την κάλυψη μιας ευρείας περιοχής, ενώ η τεχνολογία Wi-Fi θα παραμείνει κυρίαρχη για εσωτερική χρήση, χάρη στο πολύ χαμηλότερο κόστος ανάπτυξης. Ωστόσο, τα παραδοσιακά όρια που διέκριναν τις προηγούμενες γενιές κινητών και Wi-Fi δικτύων θολώνουν, με τη παρουσία πλέον αυτών των δυο τεχνολογιών να συμβάλει στην επίτευξη του στόχου της παροχής προσιτών, αξιόπιστων, και αδιάλειπτων ασύρματων ευρυζωνικών συνδέσεων υψηλής χωρητικότητας.In recent years, significant attention has been directed toward the fifth generation of wireless broadband connectivity known as ‘5G’, currently being deployed by Mobile Network Operators. 5G promises a significant upgrade in the quality and capacity of mobile broadband services but also a more general technological leap by providing a plethora of new capabilities Surprisingly, there has been considerably less attention paid to ‘Wi-Fi 6’, the new IEEE 802.1ax standard in the family of Wireless Local Area Network technologies with features targeting private, edge-networks, supporting high speeds, low latency and low energy consumption. This work revisits the suitability of cellular and Wi-Fi in delivering high-speed wireless Internet connectivity. Both technologies aspire to deliver significantly enhanced performance, enabling each to deliver much faster wireless broadband connectivity, and provide further support for the Internet of Things and Machine-toMachine communications, positioning the two technologies as technical substitutes in many usage scenarios. We conclude that both are likely to play important roles in the future, and simultaneously serve as competitors and complements. 5G is anticipated to remain the preferred technology for wide-area coverage, while Wi-Fi 6 will remain the preferred technology for indoor use, thanks to its much lower deployment costs. However, the traditional boundaries that differentiated earlier generations of cellular and Wi-Fi are blurring. The presence of both technologies should contribute to achieving the goal of providing affordable, reliable, and seamless high-bandwidth wireless broadband connections

    Estudio de tecnologías y protocolos de comunicación para redes de sensores inalámbricos aplicados a la agricultura: revisión bibliográfica

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    La agricultura es un sector importante de la economía brasilera y mundial, y así como otros sectores, se beneficia por el uso de la tecnología. Sin embargo, existen barreras tecnológicas, principalmente cuando se trata de la infraestructura de las redes de comunicación, lo que permitiría que las automatizaciones agrícolas sean más intensificadas. Con base en estos desafíos y para minimizarlos, este artículo tiene como finalidad, mediante una búsqueda bibliográfica, describir las características de las principales tecnologías WSN utilizadas en soluciones IoT, analizando variables importantes en estas aplicaciones, con el objetivo de resolver problemas comunes en el área agrícola, principalmente, donde la comunicación requiere mayores alcances y donde existen limitaciones de alimentación de la red eléctrica, para de esta forma, indicar las tecnologías y protocolos de comunicación para las redes de sensores inalámbricos (WSN) usados para comunicación máquina a máquina (M2M) en diferentes escenarios de automatización de actividades agrícolas. Dentro de estas metodologías, fueron escogidas como objeto de este estudio: WiFi (ah), ZigBee, SigFox e LoRa. La realización de este estudio será fundamental para la realización de trabajos futuros, donde serán realizadas pruebas con estas tecnologías en escenarios propuestos.Sociedad Argentina de Informática e Investigación Operativ
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