772 research outputs found
Indoor wireless communications and applications
Chapter 3 addresses challenges in radio link and system design in indoor scenarios. Given the fact that most human activities take place in indoor environments, the need for supporting ubiquitous indoor data connectivity and location/tracking service becomes even more important than in the previous decades. Specific technical challenges addressed in this section are(i), modelling complex indoor radio channels for effective antenna deployment, (ii), potential of millimeter-wave (mm-wave) radios for supporting higher data rates, and (iii), feasible indoor localisation and tracking techniques, which are summarised in three dedicated sections of this chapter
Identification of key research topics in 5G using co-word analysis
Project Work presented as the partial requirement for obtaining a Master's degree in Information Management, specialization in Knowledge Management and Business IntelligenceThe aim of this research is to better understand the field of 5G by analyzing the more than 10000 publications found in the Web of Science database. To achieve this, a co-word analysis was performed to identify research topics based on the author keywords and a strategic diagram was used to measure their level of maturity and relevance to the field. In total this analysis identified that all the articles can be grouped into seven topics, from which, two are mature but peripheral, one is both well developed and central to the field, and the rest are central, but underdeveloped. The value of this research, was the usage of a well-established technique that has been used in many fields, but never in the field of 5G which is growing in relevance
Satellite Clustering for Non-Terrestrial Networks: Concept, Architectures, and Applications
Recently, mega-constellations with a massive number of low Earth orbit (LEO)
satellites are being considered as a possible solution for providing global
coverage due to relatively low latency and high throughput compared to
geosynchronous orbit satellites. However, as the number of satellites and
operators participating in the LEO constellation increases, inter-satellite
interference will become more severe, which may yield marginal improvement or
even decrement in network throughput. In this article, we introduce the concept
of satellite clusters that can enhance network performance through satellites'
cooperative transmissions. The characteristics, formation types, and
transmission schemes for the satellite clusters are highlighted. Simulation
results evaluate the impact of clustering from coverage and capacity
perspectives, showing that when the number of satellites is large, the
performance of clustered networks outperforms the unclustered ones. The viable
network architectures of the satellite cluster are proposed based on the 3GPP
standard. Finally, the future applications of clustered satellite networks are
discussed.Comment: 7 pages, 7 figures, 1 table, submitted to IEEE Vehicular Technology
Magazin
Seven Defining Features of Terahertz (THz) Wireless Systems: A Fellowship of Communication and Sensing
Wireless communication at the terahertz (THz) frequency bands (0.1-10THz) is
viewed as one of the cornerstones of tomorrow's 6G wireless systems. Owing to
the large amount of available bandwidth, THz frequencies can potentially
provide wireless capacity performance gains and enable high-resolution sensing.
However, operating a wireless system at the THz-band is limited by a highly
uncertain channel. Effectively, these channel limitations lead to unreliable
intermittent links as a result of a short communication range, and a high
susceptibility to blockage and molecular absorption. Consequently, such
impediments could disrupt the THz band's promise of high-rate communications
and high-resolution sensing capabilities. In this context, this paper
panoramically examines the steps needed to efficiently deploy and operate
next-generation THz wireless systems that will synergistically support a
fellowship of communication and sensing services. For this purpose, we first
set the stage by describing the fundamentals of the THz frequency band. Based
on these fundamentals, we characterize seven unique defining features of THz
wireless systems: 1) Quasi-opticality of the band, 2) THz-tailored wireless
architectures, 3) Synergy with lower frequency bands, 4) Joint sensing and
communication systems, 5) PHY-layer procedures, 6) Spectrum access techniques,
and 7) Real-time network optimization. These seven defining features allow us
to shed light on how to re-engineer wireless systems as we know them today so
as to make them ready to support THz bands. Furthermore, these features
highlight how THz systems turn every communication challenge into a sensing
opportunity. Ultimately, the goal of this article is to chart a forward-looking
roadmap that exposes the necessary solutions and milestones for enabling THz
frequencies to realize their potential as a game changer for next-generation
wireless systems.Comment: 26 pages, 6 figure
SpaceRIS: LEO Satellite Coverage Maximization in 6G Sub-THz Networks by MAPPO DRL and Whale Optimization
Satellite systems face a significant challenge in effectively utilizing
limited communication resources to meet the demands of ground network traffic,
characterized by asymmetrical spatial distribution and time-varying
characteristics. Moreover, the coverage range and signal transmission distance
of low Earth orbit (LEO) satellites are restricted by notable propagation
attenuation, molecular absorption, and space losses in sub-terahertz (THz)
frequencies. This paper introduces a novel approach to maximize LEO satellite
coverage by leveraging reconfigurable intelligent surfaces (RISs) within 6G
sub-THz networks. The optimization objectives encompass enhancing the
end-to-end data rate, optimizing satellite-remote user equipment (RUE)
associations, data packet routing within satellite constellations, RIS phase
shift, and ground base station (GBS) transmit power (i.e., active beamforming).
The formulated joint optimization problem poses significant challenges owing to
its time-varying environment, non-convex characteristics, and NP-hard
complexity. To address these challenges, we propose a block coordinate descent
(BCD) algorithm that integrates balanced K-means clustering, multi-agent
proximal policy optimization (MAPPO) deep reinforcement learning (DRL), and
whale optimization (WOA) techniques. The performance of the proposed approach
is demonstrated through comprehensive simulation results, exhibiting its
superiority over existing baseline methods in the literature
A Vision of Self-Evolving Network Management for Future Intelligent Vertical HetNet
Future integrated terrestrial-aerial-satellite networks will have to exhibit
some unprecedented characteristics for the provision of both communications and
computation services, and security for a tremendous number of devices with very
broad and demanding requirements in an almost-ubiquitous manner. Although 3GPP
introduced the concept of self-organization networks (SONs) in 4G and 5G
documents to automate network management, even this progressive concept will
face several challenges as it may not be sufficiently agile in coping with the
immense levels of complexity, heterogeneity, and mobility in the envisioned
beyond-5G integrated networks. In the presented vision, we discuss how future
integrated networks can be intelligently and autonomously managed to
efficiently utilize resources, reduce operational costs, and achieve the
targeted Quality of Experience (QoE). We introduce the novel concept of
self-evolving networks (SENs) framework, which utilizes artificial
intelligence, enabled by machine learning (ML) algorithms, to make future
integrated networks fully intelligent and automated with respect to the
provision, adaptation, optimization, and management aspects of networking,
communications, and computation. To envisage the concept of SEN in future
integrated networks, we use the Intelligent Vertical Heterogeneous Network
(I-VHetNet) architecture as our reference. The paper discusses five prominent
communications and computation scenarios where SEN plays the main role in
providing automated network management. Numerical results provide an insight on
how the SEN framework improves the performance of future integrated networks.
The paper presents the leading enablers and examines the challenges associated
with the application of SEN concept in future integrated networks
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