1,001 research outputs found

    Securing NextG networks with physical-layer key generation: A survey

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    As the development of next-generation (NextG) communication networks continues, tremendous devices are accessing the network and the amount of information is exploding. However, with the increase of sensitive data that requires confidentiality to be transmitted and stored in the network, wireless network security risks are further amplified. Physical-layer key generation (PKG) has received extensive attention in security research due to its solid information-theoretic security proof, ease of implementation, and low cost. Nevertheless, the applications of PKG in the NextG networks are still in the preliminary exploration stage. Therefore, we survey existing research and discuss (1) the performance advantages of PKG compared to cryptography schemes, (2) the principles and processes of PKG, as well as research progresses in previous network environments, and (3) new application scenarios and development potential for PKG in NextG communication networks, particularly analyzing the effect and prospects of PKG in massive multiple-input multiple-output (MIMO), reconfigurable intelligent surfaces (RISs), artificial intelligence (AI) enabled networks, integrated space-air-ground network, and quantum communication. Moreover, we summarize open issues and provide new insights into the development trends of PKG in NextG networks

    Mögliche gesundheitliche Auswirkungen verschiedener Frequenzbereiche elektromagnetischer Felder (HF-EMF). Endbericht zum TA-Projekt

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    Hochfrequente elektromagnetische Felder (HF-EMF) bilden die Grundlage aller digitalen, drahtlosen Kommunikation im gesamten öffentlichen Raum und in den privaten Haushalten. In den kommenden Jahren ist mit einer weiteren Zunahme von EMF-Quellen verschiedener Frequenzbereiche zu rechnen. Hauptgrund hierfür ist die rasant fortschreitende Digitalisierung nahezu aller Arbeits-, Lebens- und Wirtschaftsbereiche, die zugleich eng mit mobil zu nutzenden Technologien verbunden ist. Vor diesem Hintergrund stellt der vorliegende Bericht den aktuellen Wissensstand zu möglichen gesundheitlichen Risiken elektromagnetischer Felder – insbesondere des Mobilfunks – dar. Dazu wurde die neuere internationale wissenschaftliche Literatur umfassend gesichtet und die Ergebnisse aktueller nationaler und internationaler Forschungsprojekten daraufhin analysiert, ob relevante neue Erkenntnisse vorliegen, die die Diskussionen zu möglichen gesundheitlichen Risiken der HF-EMF substanziell verändern könnten. Ein weiterer Schwerpunkt lag auf Forschungsbemühungen, die einen substanziellen Beitrag zur verbesserten Risikobewertung der Exposition von jungen Menschen leisten wollen. Darüber hinaus diskutiert der Bericht relevante Aspekte der EMF-Risikogovernance (z.B. Öffentlichkeitsbeteiligung, Interessenkonflikte, Risikoinformation und -kommunikation) und beschreibt Optionen, wie im Kontext des EMF-Diskurses Barrieren für eine offene wechselseitige Kommunikation von Akteursgruppen – insbesondere zwischen Wissenschaft, Zivilgesellschaft und Politik – abgebaut werden können

    Throughput analysis of non-orthogonal multiple access and orthogonal multiple access assisted wireless energy harvesting K-hop relaying networks

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    This study introduces the non-orthogonal multiple access (NOMA) technique into the wireless energy harvesting K-hop relay network to increase throughput. The relays have no dedicated energy source and thus depend on energy harvested by wireless from a power beacon (PB). Recently, NOMA has been promoted as a technology with the potential to enhance connectivity, reduce latency, increase fairness amongst users, and raise spectral effectiveness compared to orthogonal multiple access (OMA) technology. For performance considerations, we derive exact throughput expressions for NOMA and OMA-assisted multi-hop relaying and compare the performance between the two. The obtained results are validated via Monte Carlo simulations

    Wireless Network Channel Interference for Mobile Communication: a Systematic Literature Review and Research Agenda

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    The development and renewal of wireless technology is currently a necessity. Wifi technology has now reached wifi 6. Network infrastructure is currently the main thing in the process of distributing data using wireless media to mobile phone or laptop users. By looking at the need for wireless in offices, schools, public places, hospitals, and indoor or outdoor buildings that use a large number of access point devices. Based on a review of existing research obtained problems and opportunities for development, this literature study taken from 25 journal articles aims to be able to plan the construction of wireless network infrastructure so that channel interference does not occur. Research on wireless network channel interference has been carried out in several scenarios, for example, by increasing the number of wireless networks in adjacent areas, providing obstacles, and managing different channels. The eight most common methods used in wireless network channel interference research are descriptive analysis, comparative study, method analysis, model development, case studies, regression models, literature studies, and optimization. Research related to wireless network channel interference can still be further developed by using the latest wireless technology which can simultaneously test existing channel interferenc

    Physical-Layer Reliability of Drones and Their Counter-Measures: Full vs. Half Duplex

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    In this article, we study the advantages and disadvantages that full-duplex (FD) radio technology brings to remote-controlled drone and counter-drone systems in comparison to classical half-duplex (HD) radio technology. We consider especially the physical-layer reliability perspective that has not yet been comprehensively studied. For establishing a solid analytical background, we first derive original closed-form expressions to evaluate demodulation and detection performance of frequency-hopped and frequency-shift keyed drone remote control signals under external or self-inflicted interference. The developed analytical tools are verified by comparison to simulated results and then used to study the impact that the operation mode has on the operable area of drones and effectiveness of counter-drone systems in different scenarios, linking the physical layer performance to practical safety. Analysis of the scenarios shows that FD operation compared to HD can improve the effectiveness of a counter-drone system and that in FD mode a drone can detect the attacks from the counter-drone system from a greater distance than in HD mode. However, two-way communication between the remote controller and drone in FD mode compared to HD significantly reduces the drone’s operable area when targeted by a smart counter-drone system.Peer reviewe

    Computational efficiency maximization for UAV-assisted MEC network with energy harvesting in disaster scenarios

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    Wireless networks are expected to provide unlimited connectivity to an increasing number of heterogeneous devices. Future wireless networks (sixth-generation (6G)) will accomplish this in three-dimensional (3D) space by combining terrestrial and aerial networks. However, effective resource optimization and standardization in future wireless networks are challenging because of massive resource-constrained devices, diverse quality-of-service (QoS) requirements, and a high density of heterogeneous devices. Recently, unmanned aerial vehicle (UAV)-assisted mobile edge computing (MEC) networks are considered a potential candidate to provide effective and efficient solutions for disaster management in terms of disaster monitoring, forecasting, in-time response, and situation awareness. However, the limited size of end-user devices comes with the limitation of battery lives and computational capacities. Therefore, offloading, energy consumption and computational efficiency are significant challenges for uninterrupted communication in UAV-assisted MEC networks. In this thesis, we consider a UAV-assisted MEC network with energy harvesting (EH). To achieve this, we mathematically formulate a mixed integer non-linear programming problem to maximize the computational efficiency of UAV-assisted MEC networks with EH under disaster situations. A power splitting architecture splits the source power for communication and EH. We jointly optimize user association, the transmission power of UE, task offloading time, and UAV’s optimal location. To solve this optimization problem, we divide it into three stages. In the first stage, we adopt k-means clustering to determine the optimal locations of the UAVs. In the second stage, we determine user association. In the third stage, we determine the optimal power of UE and offloading time using the optimal UAV location from the first stage and the user association indicator from the second stage, followed by linearization and the use of interior-point method to solve the resulting linear optimization problem. Simulation results for offloading, no-offloading, offloading with EH, and no-offloading no-EH scenarios are presented with a varying number of UAVs and UEs. The results show the proposed EH solution’s effectiveness in offloading scenarios compared to no-offloading scenarios in terms of computational efficiency, bits computed, and energy consumptio

    Distributed Intermittent Fault Diagnosis in Wireless Sensor Network Using Likelihood Ratio Test

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    In current days, sensor nodes are deployed in hostile environments for various military and commercial applications. Sensor nodes are becoming faulty and having adverse effects in the network if they are not diagnosed and inform the fault status to other nodes. Fault diagnosis is difficult when the nodes behave faulty some times and provide good data at other times. The intermittent disturbances may be random or kind of spikes either in regular or irregular intervals. In literature, the fault diagnosis algorithms are based on statistical methods using repeated testing or machine learning. To avoid more complex and time consuming repeated test processes and computationally complex machine learning methods, we proposed a one shot likelihood ratio test (LRT) here to determine the fault status of the sensor node. The proposed method measures the statistics of the received data over a certain period of time and then compares the likelihood ratio with the threshold value associated with a certain tolerance limit. The simulation results using a real time data set shows that the new method provides better detection accuracy (DA) with minimum false positive rate (FPR) and false alarm rate (FAR) over the modified three sigma test. LRT based hybrid fault diagnosis method detecting the fault status of a sensor node in wireless sensor network (WSN) for real time measured data with 100% DA, 0% FAR and 0% FPR if the probability of the data from faulty node exceeds 25%

    Performance analysis of multihop full-duplex NOMA systems with imperfect interference cancellation and near-field path-loss

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    Outage probability (OP) and potential throughput (PT) of multihop full-duplex (FD) nonorthogonal multiple access (NOMA) systems are addressed in the present paper. More precisely, two metrics are derived in the closed-form expressions under the impact of both imperfect successive interference cancellation (SIC) and imperfect self-interference cancellation. Moreover, to model short transmission distance from the transmit and receive antennae at relays, the near-field path-loss is taken into consideration. Additionally, the impact of the total transmit power on the performance of these metrics is rigorously derived. Furthermore, the mathematical framework of the baseline systems is provided too. Computer-based simulations via the Monte Carlo method are given to verify the accuracy of the proposed framework, confirm our findings, and highlight the benefits of the proposed systems compared with the baseline one.Web of Science231art. no. 52

    Statistical Performance Evaluation for Energy Harvesting Communications based on Large Deviation Theorem

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    Energy harvesting (EH) is a promising technology for enhancing a network’s quality of service (QoS). EH-based communication systems are studied by tackling the challenges of energy-outage probability and energy conditioning. These issues motivate this research to develop new solutions for increasing the lifetime of device batteries by leveraging renewable energy sources available in the surrounding environment, for instance, from solar and radio-frequency (RF) energy through harvesting. This dissertation studies an energy outage problem and user QoS requirements for energy harvesting communications. In the first part of this dissertation, the performance of an energy harvesting communication link is analysed by allowing a certain level of energy-outage. In EH systems, energy consumed from the battery depends on the QoS required by the end user and on the channel state information. At the same time, the energy arrival to the battery depends on the strength of the power source, solar in this case, and is independent of the fading channel conditions and the required QoS. Due to the independence between the energy arrival into the battery and the energy consumed from there, it is challenging to estimate the exact status of the available energy in the battery. An energy outage is experienced when there is no further energy for the system to utilise for data transmission. In this part, a thorough study was carried out to analyse the required energy harvesting (EH) rate for satisfying the QoS requirements when a level of energy-outage is allowed in a point-to-point EH-based communication system equipped with a finite-sized battery. Furthermore, an expression relating the rate of the incoming energy with the fading channel conditions and the minimum required QoS of the system was provided to analyse the performance of the EH-based communication system under energy constraints. Finally, numerical results confirm the proposed mechanism’s analytical findings and correctness. In the second part of this dissertation, the performance of point-to-point communications is investigated in which the source node can harvest and store energy from RF signals and then use the harvested energy to communicate with its end destination. The continuous availability of RF energy has proved advantageous as a wireless power source to support low-power devices, making RF-based energy harvesting an alternative and viable solution for powering next-generation wireless networks, particularly for Internet-of-Things (IoT) applications. Specifically, the point-to-point RF-based energy-harvesting communication is considered, where the transmitter, which can be an IoT sensor, implements a time-switching protocol between the energy harvesting and the information transfer, and we focus on analysing the system performance while aiming to guarantee the required QoS of the end user subject to system constraint energy outage. The time-switching circuit at the source node allows the latter to switch between harvesting energy from a distant RF energy source and transmitting data to its target destination using the scavenged energy. Using a duality principle between the physical energy queue and a proposed virtual energy queue and assuming that a certain level of energy outage can be tolerated in the communication process, the system performance was evaluated with a novel analytical framework that leverages tools for the large deviation principle. In the third and last part of this dissertation, an empirical study of the RF-EH model is presented for ensuring the QoS constraints during an energy-outage for Simultaneous Wireless Information and Power Transfer (SWIPT) network. We consider a relay network over a Rayleigh fading channel where the relay lacks a permanent power source. Thus, we obtain energy from wireless energy harvesting (EH) of the source’s signals to maintain operation. This process is performed using a time-switching protocol at the relay for enhancing the quality of service (QoS) in SWIPT networks. A numerical approach is incorporated to evaluate the performance of the proposed RF-EH model in terms of different evaluation parameters such as time-switching protocol, transmit power and outage. The assumptions of the large deviation principle are satisfied using a proposed virtual energy queuing model, which is then used for the performance analysis. We established a closed-form expression for the system’s probability of experiencing an energy outage and the energy consumed by the relay battery

    On the Road to 6G: Visions, Requirements, Key Technologies and Testbeds

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    Fifth generation (5G) mobile communication systems have entered the stage of commercial development, providing users with new services and improved user experiences as well as offering a host of novel opportunities to various industries. However, 5G still faces many challenges. To address these challenges, international industrial, academic, and standards organizations have commenced research on sixth generation (6G) wireless communication systems. A series of white papers and survey papers have been published, which aim to define 6G in terms of requirements, application scenarios, key technologies, etc. Although ITU-R has been working on the 6G vision and it is expected to reach a consensus on what 6G will be by mid-2023, the related global discussions are still wide open and the existing literature has identified numerous open issues. This paper first provides a comprehensive portrayal of the 6G vision, technical requirements, and application scenarios, covering the current common understanding of 6G. Then, a critical appraisal of the 6G network architecture and key technologies is presented. Furthermore, existing testbeds and advanced 6G verification platforms are detailed for the first time. In addition, future research directions and open challenges are identified for stimulating the on-going global debate. Finally, lessons learned to date concerning 6G networks are discussed
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