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arXiv 2023年

作者： Shamsabadi, Afsoon Alidadi Yadav, Animesh Yanikomeroglu, Halim Non-Terrestrial Networks Lab. Department of Systems and Computer Engineering Carleton University OttawaONK1S 5B6 Canada The School of Electrical Engineering and Computer Science Ohio University AthensOH45701 United States

Located in the stratospheric layer of Earth's atmosphere, high altitude platform station (HAPS) is a promising network infrastructure, which can bring significant advantages to sixth-generation (6G) and beyond wireless communications systems by forming vertical heterogeneous networks (vHetNets). However, if not dealt with properly, integrated networks suffer from several performance challenges compared to standalone networks. In harmonized spectrum integrated networks, where different tiers share the same frequency spectrum, interference is an important challenge to be addressed. This work focuses on an integrated HAPS-terrestrial network, serving users in an overlapped urban geographic area, and formulates a fairness optimization problem, aiming to maximize the minimum spectral efficiency (SE) of the network. Due to the highly nonconvex nature of the formulated problem, we develop a rapid converging iterative algorithm that designs the multiple-input multiple-output (MIMO) beamforming weights and the user association scheme such that the propagated inter- and intra-tier interference is managed. Simulation results demonstrate the proposed algorithm's superiority over standalone terrestrial networks and scenario where only the beamforming weights are optimized. © 2023, CC0.

关键词： Heterogeneous networks

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Routing in All-Optical LEO Constellations with High-Altitude Ground Stations

Routing in All-Optical LEO Constellations with High-Altitude...

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Communications and Networking (MECOM), IEEE Middle East Conference on

作者： Benoit Coeugnet Pablo G. Madoery Juan A. Fraire Jorge M. Finochietto Halim Yanikomeroglu Department of Systems and Computer Engineering Non-Terrestrial Networks Lab Carleton University Ottawa Canada Inria INSA Lyon CITI UR3720 Villeurbanne France CONICET Universidad Nacional de Cordoba Cordoba Argentina

ISBN: (数字)9798350376715

ISBN: (纸本)9798350376722

The recent proliferation of non-terrestrial networks (NTNs) utilizing low Earth orbit (LEO) satellites and high-altitude platform stations (HAPS) has garnered significant attention. Establishing an all-optical network in LEO constellations has been explored, leveraging HAPS used as high-altitude ground stations (HAGS) in conjunction with traditional ground stations (GS). This approach is appealing for Earth observation missions spanning a fully connected network between LEO satellites and a delay-tolerant stochastic partition between HAGS and GS. To address the emerging routing challenges arising from weather-related impairments, we first develop new routing solutions that mitigate these issues. Secondly, we compare the performance of our new routing solutions to the classic contact graph routing (CGR), demonstrating improved performance for NTN networks. Finally, we conclude by outlining future research directions.

关键词： Earth All-optical networks Satellites Clouds Prevention and mitigation Low earth orbit satellites Routing Robustness Optical fiber communication Meteorology

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Hemispherical Massive MIMO Architecture for High-Altitude Platform Station (HAPS)

Hemispherical Massive MIMO Architecture for High-Altitude Pl...

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IEEE Conference on Wireless Communications and Networking

作者： Omid Abbasi Halim Yanikomeroglu Georges Kaddoum Department of Systems and Computer Engineering Non-Terrestrial Networks (NTN) Lab Carleton University Ottawa ON Canada Department of Electrical Engineering École de Technologie Supérieure (ETS) Université du Québec Montréal QC Canada

ISBN: (数字)9798350303582

ISBN: (纸本)9798350303599

In this paper, we present a novel hemispherical antenna array (HAA) designed for High-Altitude Platform Stations (HAPS). Traditional rectangular antenna arrays for HAPS suffer from a significant limitation - their antenna elements are perpetually oriented downward, resulting in low gain for distant users. Meanwhile, cylindrical antenna arrays were introduced to mitigate this drawback, but they, in turn, exhibit a distinct problem: their antenna elements continually face the horizon, leading to suboptimal gain for users located beneath the HAPS. To address these challenges, we introduce the HAA. In the HAA configuration, antenna elements are strategically distributed across the surface of a hemisphere, ensuring that each user receives direct alignment with specific antenna elements, thereby maximizing the gain for all users. We derive the achievable data rates for users within this proposed scheme, employing an analog beamforming technique that leverages the steering vectors of the selected antenna elements for each user. We also formulate an op-timization problem focused on maximizing the minimum Signal-to-Interference-plus-Noise Ratio (SINR) for users. Additionally, we introduce an antenna selection algorithm based on the gains of the antenna elements. To further enhance system performance, we employ the Bisection method to determine the optimal power allocation for each user. Our simulation results substantiate the superior rate performance of the proposed HAA when compared to the conventional rectangular and cylindrical baseline arrays. The proposed approach demonstrates to reach sum data rates of up to 14 Gigabit/s. Furthermore, in contrast to the baseline schemes, the proposed scheme achieves more consistent spectral efficiencies across the entire coverage area.

关键词： Spectral efficiency Urban areas Receiving antennas Interference Bandwidth Vectors Resource management

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HAPS-Enabled Sustainability Provision in Cellular networks Through Cell-Switching

HAPS-Enabled Sustainability Provision in Cellular Networks T...

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International Black Sea Conference on Communications and Networking (BlackSeaCom)

作者： Görkem Berkay Koç Berk Çiloğlu Metin Öztürk Halim Yanikomeroglu Electrical and Electronics Engineering Ankara Yıldırım Beyazıt University Ankara Türkiye Non-Terrestrial Networks (NTN) Lab Systems and Computer Engineering Carleton University Ottawa Canada

There is a consensus in the literature that cell-switching is a viable solution to tackle the draconian increase in the energy consumption of cellular networks. High altitude platform station (HAPS) draws considerable attention with its massive footprint, high capacity, and ubiquitous connectivity. The aim of this study is to show the potential benefits of using HAPS in cell-switching methods by being a bountiful host for offloaded users from cell-switching operations. More specifically, HAPS is included in the network so that it can increase the switching off opportunities by providing extra coverage and capacity. In this regard, a vertical heterogeneous network scenario, wherein there are terrestrial small cells and a single HAPS, is considered in the simulations, and different user density cases are tested in order to analyze the impact of network density on the performance of HAPS-enabled cell-switching. The simulation results demonstrate that a significant amount of reduction in energy consumption (as high as 16%) is obtained while ensuring quality-of-service (QoS) requirements.

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UAV-based Maritime Communications: Relaying to Enhance the Link Quality

arXiv

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arXiv 2023年

作者： Çağan, Abdullah Taha Koç, Görkem Berkay Yakın, Handan Çiloğlu, Berk Ashgar, Muhammad Zeeshan Ersoy, Özgün Hämäläinen, Jyri Öztürk, Metin Ankara Yıldırım Beyazıt University Ankara Turkey School of Electrical Engineering Aalto University Espoo Finland Non-Terrestrial Networks Lab Systems and Computer Engineering Carleton University Ottawa Canada

Providing stable connectivity in maritime communications is of utmost importance to unleash the full potential of smart ports. nonetheless, due to the crowded nature of harbor environments, it is likely that some ships are shadowed by others, resulting in reduced received power that subsequently diminishes their data rates-even threatens basic connectivity requirements. Given that uncrewed aerial vehicles (UAVs) have been regarded as an integral part of future generations of wireless communication networks, they can be employed in maritime communications as well. In this paper, we investigate the use of UAV-mounted relays in order to help mitigate the reduced data rates of blocked links in maritime communications. Various communication architectures are considered based on the positioning mechanism of the UAV;in this regard, fixed, k-means algorithm-based, and landing spot-based positioning approaches are examined. Additionally, since UAVs are predominantly battery-operated, the energy consumption performances of these approaches are also measured. Results reveal that the landing spot-based UAV relay positioning approach finds the best trade-off between the data rate and energy consumption. Copyright © 2023, The Authors. All rights reserved.

关键词： Energy utilization

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Next-Generation Satellite IoT networks: A HAPS-Enabled Solution to Enhance Optical Data Transfer

Next-Generation Satellite IoT Networks: A HAPS-Enabled Solut...

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IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

作者： Ethan Fettes Pablo G. Madoery Halim Yanikomeroglu Gunes Karabulut Kurt Colin Bellinger Stéphane Martel Khaled Ahmed Sameera Siddiqui Department of Systems and Computer Engineering Non-Terrestrial Networks (NTN) Lab Carleton University Canada Department of Electrical Engineering Poly-Grames Research Center Polytechnique Montréal Montréal Canada National Research Council Canada Canada Satellite Systems MDA Canada Defence Research and Development Canada Canada

ISBN: (数字)9798350362244

ISBN: (纸本)9798350362251

For decades, satellites have facilitated remote internet of things (IoT) services. However, the recent proliferation of increasingly capable sensors and a surge in the number deployed, has led to a substantial growth in the volume of data that needs to be transmitted via satellites. In response to this growing demand, free space optical communication systems have been proposed, as they allow for the use of large bandwidths of unlicensed spectrum, enabling high data rates. However, optical communications are highly vulnerable to weather-induced disruptions, thereby limiting their high potential. This paper proposes the use of high altitude platform station (HAPS) systems in conjunction with delay-tolerant networking techniques to increase the amount of data that can be transmitted to the ground from satellites when compared to the use of traditional ground station network architectures. The architectural proposal is evaluated in terms of delivery ratio and buffer occupancy, and the subsequent discussion analyzes the advantages, challenges and potential areas for future research.

关键词： Limiting Satellite broadcasting Optical buffering Optical fiber networks Network architecture Internet of Things Optical sensors Proposals Surges Next generation networking

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A Novel non- terrestrial networks Architecture: All Optical LEO Constellations with High-Altitude Ground Stations

A Novel Non- Terrestrial Networks Architecture: All Optical ...

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IEEE International Conference on Communications Workshops, ICC

作者： Pablo G. Madoery Juan A. Fraire Jorge M. Finochietto Halim Yanikomeroglu Gunes Karabulut Kurt Department of Systems and Computer Engineering Non-Terrestrial Networks Lab Carleton University Ottawa Canada Inria INSA Lyon CITI UR3720 Villeurbanne France CONICET - Universidad Nacional de Cordoba Cordoba Argentina Department of Electrical Engineering Poly technique Montreal Poly-Grames Research Center Montreal Canada

ISBN: (数字)9798350304053

ISBN: (纸本)9798350304060

The emergence of low Earth orbit (LEO) satellite mega-constellations is dynamically transforming the space sector. While free-space optical (FSO) links efficiently facilitate inter-satellite data forwarding, they suffer from atmospheric/weather conditions in the space-to-ground link. This study delves into utilizing high-altitude platform stations (HAPS) as elevated relay stations strategically positioned above terrestrial ground stations. We introduce the concept of high-altitude ground stations (HAGS), an innovative approach to enabling the development of all optical LEO satellite constellations. The first contribution is an analysis of the HAGS-based network architecture where the LEO spacecraft only hosts FSO transceivers. Secondly, we execute an extensive simulation campaign to determine the gain of HAGS, including a new equivalency model with the traditional ground station approach. Finally, we examine the research challenges of implementing HAGS-based, all optical LEO mega-constellations.

关键词： Integrated optics All-optical networks Space vehicles Satellites Uncertainty Conferences Optical buffering

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A Novel non-terrestrial networks Architecture: All Optical LEO Constellations with High-Altitude Ground Stations

arXiv

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arXiv 2024年

作者： Madoery, Pablo G. Fraire, Juan A. Finochietto, Jorge M. Yanikomeroglu, Halim Kurt, Gunes Karabulut Non-Terrestrial Networks Lab Department of Systems and Computer Engineering Carleton University Ottawa Canada Inria INSA Lyon CITI UR3720 Villeurbanne69621 France CONICET - Universidad Nacional de Cordoba Cordoba Argentina Poly-Grames Research Center Department of Electrical Engineering Polytechnique Montréal Montréal Canada

关键词： Network architecture

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Smart Resource Allocation Model via Artificial Intelligence in Software Defined 6G networks

Smart Resource Allocation Model via Artificial Intelligence ...

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IEEE International Conference on Communications (ICC)

作者： Ali Nouruzi Atefeh Rezaei Ata Khalili Nader Mokari Mohammad Reza Javan Eduard A. Jorswieck Halim Yanikomeroglu Department of Electrical and Computer Engineering Tarbiat Modares University Tehran Iran Technical University of Berlin Germany Friedrich-Alexander-University Erlangen-Nurnberg Germany Department of Electrical Engineering Shahrood University of Technology Shahrood Iran Institute of Communications Technology Technische Universität Braunschweig Braunschweig Germany Department of Systems and Computer Engineering Non-Terrestrial Networks (NTN) Lab Carleton University

In this paper, we design a new flexible smart software-defined radio access network (Soft-RAN) architecture with traffic awareness for sixth generation (6G) wireless networks. In particular, we consider a hierarchical resource allocation model for the proposed smart soft-RAN model where the software-defined network (SDN) controller is the first and foremost layer of the framework. This unit dynamically monitors the network to select a network operation type on the basis of distributed or centralized resource allocation procedures to intelligently perform decision-making. In this paper, our aim is to make the network more scalab.e and more flexible in terms of conflicting performance indicators such as achievable data rate, overhead, and complexity indicators. To this end, we introduce a new metric, i.e, throughput-overhead-complexity (TOC), for the proposed machine learning-based algorithm, which supports a trade-off between these performance indicators. In particular, the decision making based on TOC is solved via deep reinforcement learning (DRL) which determines an appropriate resource allocation policy. Furthermore, for the selected algorithm, we employ the soft actor-critic (SAC) method which is more accurate, scalab.e, and robust than other learning methods. Simulation results demonstrate that the proposed smart network achieves better performance in terms of TOC compared to fixed centralized or distributed resource management schemes that lack dynamism. Moreover, our proposed algorithm outperforms conventional learning methods employed in recent state-of-the-art network designs.

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25th Annual Computational Neuroscience Meeting CNS-2016, Seogwipo City, South Korea, July 2-7, 2016 Abstracts

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BMC NEUROSCIENCE 2016年第1期17卷 1-112页

作者： [Anonymous] Computational Neurobiology Laboratory The Salk Institute for Biological Studies San Diego USA UNIC CNRS Gif sur Yvette France The European Institute for Theoretical Neuroscience (EITN) Paris France ATR Computational Neuroscience Laboratories Kyoto Japan Krembil Research Institute University Health Network Toronto Canada Department of Physiology University of Toronto Toronto Canada Department of Medicine (Neurology) University of Toronto Toronto Canada Department of Physics University of New Hampshire Durham USA Department of Neurophysiology Nencki Institute of Experimental Biology Warsaw Poland Department of Theory Wigner Research Centre for Physics of the Hungarian Academy of Sciences Budapest Hungary Department of Mathematical Sciences KAIST Daejoen Republic of Korea Department of Mathematics University of Houston Houston USA Department of Biochemistry & Cell Biology and Institute of Biosciences and Bioengineering Rice University Houston USA Department of Biology and Biochemistry University of Houston Houston USA Grupo de Neurocomputación Biológica Dpto. de Ingeniería Informática Escuela Politécnica Superior Universidad Autónoma de Madrid Madrid Spain Department of Biological Sciences University of Southern California Los Angeles USA Center for Neuroscience Korea Institute of Science and Technology Seoul South Korea Department of Neurology Albert Einstein College of Medicine Bronx USA Center for Neuroscience KIST Seoul South Korea Department of Neuroscience University of Science and Technology Daejon South Korea Systems Neuroscience Group QIMR Berghofer Medical Research Institute Herston Australia Department of Psychology Yonsei University Seoul South Korea Department of Psychiatry Kyung Hee University Hospital at Gangdong Seoul South Korea Department of Psychiatry Veterans Administration Boston Healthcare System and Harvard Medical School Brockton USA Department of Electrical and Electronic Engineering The University of Melbourne Parkvil

A1 Functional advantages of cell-type heterogeneity in neural circuits Tatyana O. Sharpee A2 Mesoscopic modeling of propagating waves in visual cortex Alain Destexhe A3 Dynamics and biomarkers of mental disorders Mitsuo Kawato F1 Precise recruitment of spiking output at theta frequencies requires dendritic h-channels in multi-compartment models of oriens-lacunosum/moleculare hippocampal interneurons Vladislav Sekulić, Frances K. Skinner F2 Kernel methods in reconstruction of current sources from extracellular potentials for single cells and the whole brains Daniel K. Wójcik, Chaitanya Chintaluri, Dorottya Cserpán, Zoltán Somogyvári F3 The synchronized periods depend on intracellular transcriptional repression mechanisms in circadian clocks. Jae Kyoung Kim, Zachary P. Kilpatrick, Matthew R. Bennett, Kresimir Josić O1 Assessing irregularity and coordination of spiking-bursting rhythms in central pattern generators Irene Elices, David Arroyo, Rafael Levi, Francisco B. Rodriguez, Pablo Varona O2 Regulation of top-down processing by cortically-projecting parvalbumin positive neurons in basal forebrain Eunjin Hwang, Bowon Kim, Hio-Been Han, Tae Kim, James T. McKenna, Ritchie E. Brown, Robert W. McCarley, Jee Hyun Choi O3 Modeling auditory stream segregation, build-up and bistability James Rankin, Pamela Osborn Popp, John Rinzel O4 Strong competition between tonotopic neural ensembles explains pitch-related dynamics of auditory cortex evoked fields Alejandro Tabas, André Rupp, Emili Balaguer-Ballester O5 A simple model of retinal response to multi-electrode stimulation Matias I. Maturana, David B. Grayden, Shaun L. Cloherty, Tatiana Kameneva, Michael R. Ibbotson, Hamish Meffin O6 Noise correlations in V4 area correlate with behavioral performance in visual discrimination task Veronika Koren, Timm Lochmann, Valentin Dragoi, Klaus Obermayer O7 Input-location dependent gain modulation in cerebellar nucleus neurons Maria Psarrou, Maria Schilstra, Neil Davey, Benjamin Torben-Ni

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