3,947 research outputs found
Multi-Gigabits Millimetre Wave Wireless Communications for 5G: From Fixed Access to Cellular Networks
With the formidable growth of various booming wireless communication services
that require ever-increasing data throughputs, the conventional microwave band
below 10 GHz, which is currently used by almost all mobile communication
systems, is going to reach its saturation point within just a few years.
Therefore, the attention of radio system designers has been pushed towards
ever-higher segments of the frequency spectrum in a quest for capacity
increase. In this article, we investigate the feasibility, advantages and
challenges of future wireless communications over the E-band frequencies. We
start from a brief review of the history of E-band spectrum and its light
licensing policy as well as benefits/challenges. Then we introduce the
propagation characteristics of E-band signals, based on which some potential
fixed and mobile applications at the E-band are investigated. In particular, we
analyze the achievability of non-trivial multiplexing gain in fixed
point-to-point E-band links and propose an E-band mobile broadband (EMB) system
as a candidate for the next generation mobile communication networks. The
channelization and frame structure of the EMB system are discussed in details.Comment: 25 pages, 4 figures, 2 tables, to appear in IEEE Communications
Magazin
A Survey of Millimeter Wave (mmWave) Communications for 5G: Opportunities and Challenges
With the explosive growth of mobile data demand, the fifth generation (5G)
mobile network would exploit the enormous amount of spectrum in the millimeter
wave (mmWave) bands to greatly increase communication capacity. There are
fundamental differences between mmWave communications and existing other
communication systems, in terms of high propagation loss, directivity, and
sensitivity to blockage. These characteristics of mmWave communications pose
several challenges to fully exploit the potential of mmWave communications,
including integrated circuits and system design, interference management,
spatial reuse, anti-blockage, and dynamics control. To address these
challenges, we carry out a survey of existing solutions and standards, and
propose design guidelines in architectures and protocols for mmWave
communications. We also discuss the potential applications of mmWave
communications in the 5G network, including the small cell access, the cellular
access, and the wireless backhaul. Finally, we discuss relevant open research
issues including the new physical layer technology, software-defined network
architecture, measurements of network state information, efficient control
mechanisms, and heterogeneous networking, which should be further investigated
to facilitate the deployment of mmWave communication systems in the future 5G
networks.Comment: 17 pages, 8 figures, 7 tables, Journal pape
MAC Protocols for Terahertz Communication: A Comprehensive Survey
Terahertz communication is emerging as a future technology to support
Terabits per second link with highlighting features as high throughput and
negligible latency. However, the unique features of the Terahertz band such as
high path loss, scattering and reflection pose new challenges and results in
short communication distance. The antenna directionality, in turn, is required
to enhance the communication distance and to overcome the high path loss.
However, these features in combine negate the use of traditional Medium access
protocols. Therefore novel MAC protocol designs are required to fully exploit
their potential benefits including efficient channel access, control message
exchange, link establishment, mobility management, and line-of-sight blockage
mitigation. An in-depth survey of Terahertz MAC protocols is presented in this
paper. The paper highlights the key features of the Terahertz band which should
be considered while designing an efficient Terahertz MAC protocol, and the
decisions which if taken at Terahertz MAC layer can enhance the network
performance. Different Terahertz applications at macro and nano scales are
highlighted with design requirements for their MAC protocols. The MAC protocol
design issues and considerations are highlighted. Further, the existing MAC
protocols are also classified based on network topology, channel access
mechanisms, and link establishment strategies as Transmitter and Receiver
initiated communication. The open challenges and future research directions on
Terahertz MAC protocols are also highlighted.Comment: Submitted to IEEE Communication Surveys and Tutorials Journa
Ultra-Dense 5G Small Cell Deployment for Fiber and Wireless Backhaul-Aware Infrastructures
In this paper, we study the cell planning problem for a two-tier cellular
network containing two types of base stations (BSs)-- i.e. with fiber backhaul,
referred to as wired BSs (W-BSs), and BSs with wireless backhaul, referred to
as unwired-BSs (U-BSs). In-band full-duplex wireless communications is used to
connect U-BSs and W-BSs. We propose an algorithm to determine the minimum
number of W-BSs and U-BSs to satisfy given cell and capacity coverage
constraints. Furthermore, we apply our proposed non-dominated sorting genetic
algorithm II (NSGA-II) to solve both cell planning and joint cell and backhaul
planning problem to minimize the cost of planning, while maximizing the
coverage simultaneously. Additionally, the considered cell planning program is
developed into an optimization by including the problem of minimizing the cost
of fiber backhaul deployment. In order to analyze the performance of the
proposed algorithm, we study three different deployment scenarios based on
different spatial distributions of users and coverage areas. The results show
the superiority of our proposed NSGA-II algorithm for both cell planning and
joint cell and backhaul planning to other well-known optimization algorithms.
The results also reveal that there is a trade-off between cell deployment costs
and SINR/rate coverage, and W-BSs are placed in congested areas to consume less
resources for wireless backhauls. Similarly, a trade-off between cell and fiber
deployment costs and SINR/rate coverage is observed in planning. We show that
for realistic scenarios desirable solutions can be selected from the Pareto
front of the introduced multi-objective problem based on given cellular
operator policies
A Comparative Survey of Optical Wireless Technologies: Architectures and Applications
New high-data-rate multimedia services and applications are evolving
continuously and exponentially increasing the demand for wireless capacity of
fifth-generation (5G) and beyond. The existing radio frequency (RF)
communication spectrum is insufficient to meet the demands of future
high-datarate 5G services. Optical wireless communication (OWC), which uses an
ultra-wide range of unregulated spectrum, has emerged as a promising solution
to overcome the RF spectrum crisis. It has attracted growing research interest
worldwide in the last decade for indoor and outdoor applications. OWC offloads
huge data traffic applications from RF networks. A 100 Gb/s data rate has
already been demonstrated through OWC. It offers services indoors as well as
outdoors, and communication distances range from several nm to more than 10000
km. This paper provides a technology overview and a review on optical wireless
technologies, such as visible light communication, light fidelity, optical
camera communication, free space optical communication, and light detection and
ranging. We survey the key technologies for understanding OWC and present
state-of-the-art criteria in aspects, such as classification, spectrum use,
architecture, and applications. The key contribution of this paper is to
clarify the differences among different promising optical wireless technologies
and between these technologies and their corresponding similar existing RF
technologie
All Technologies Work Together for Good: A Glance to Future Mobile Networks
The astounding capacity requirements of 5G have motivated researchers to
investigate the feasibility of many potential technologies, such as massive
multiple-input multiple-output, millimeter wave, full-duplex, non-orthogonal
multiple access, carrier aggregation, cognitive radio, and network
ultra-densification. The benefits and challenges of these technologies have
been thoroughly studied either individually or in a combination of two or
three. It is not clear, however, whether all potential technologies operating
together lead to fulfilling the requirements posed by 5G. This paper explores
the potential benefits and challenges when all technologies coexist in an
ultra-dense cellular environment. The sum rate of the network is investigated
with respect to the increase in the number of small-cells and results show the
capacity gains achieved by the coexistence.Comment: Accepted for publication in IEEE Wireless Communication, Special
Issue-5G mmWave Small Cell Networks: Architecture, Self-Organization and
Managemen
Optical Communication in Space: Challenges and Mitigation Techniques
In recent years, free space optical communication has gained significant
importance owing to its unique features: large bandwidth, license-free
spectrum, high data rate, easy and quick deployability, less power and low mass
requirements. FSO communication uses the optical carrier in the near infrared
band to establish either terrestrial links within the Earth's atmosphere or
inter-satellite or deep space links or ground-to-satellite or
satellite-to-ground links. However, despite the great potential of FSO
communication, its performance is limited by the adverse effects viz.,
absorption, scattering, and turbulence of the atmospheric channel. This paper
presents a comprehensive survey on various challenges faced by FSO
communication system for ground-to-satellite or satellite-to-ground and
inter-satellite links. It also provides details of various performance
mitigation techniques in order to have high link availability and reliability.
The first part of the paper will focus on various types of impairments that
pose a serious challenge to the performance of optical communication system for
ground-to-satellite or satellite-to-ground and inter-satellite links. The
latter part of the paper will provide the reader with an exhaustive review of
various techniques both at physical layer as well as at the other layers i.e.,
link, network or transport layer to combat the adverse effects of the
atmosphere. It also uniquely presents a recently developed technique using
orbital angular momentum for utilizing the high capacity advantage of the
optical carrier in case of space-based and near-Earth optical communication
links. This survey provides the reader with comprehensive details on the use of
space-based optical backhaul links in order to provide high-capacity and
low-cost backhaul solutions.Comment: 41 pages, 13 Figures and 8 Tables. arXiv admin note: substantial text
overlap with arXiv:1506.0483
Cloud Computing - Architecture and Applications
In the era of Internet of Things and with the explosive worldwide growth of
electronic data volume, and associated need of processing, analysis, and
storage of such humongous volume of data, it has now become mandatory to
exploit the power of massively parallel architecture for fast computation.
Cloud computing provides a cheap source of such computing framework for large
volume of data for real-time applications. It is, therefore, not surprising to
see that cloud computing has become a buzzword in the computing fraternity over
the last decade. This book presents some critical applications in cloud
frameworks along with some innovation design of algorithms and architecture for
deployment in cloud environment. It is a valuable source of knowledge for
researchers, engineers, practitioners, and graduate and doctoral students
working in the field of cloud computing. It will also be useful for faculty
members of graduate schools and universities.Comment: Edited Volume published by Intech Publishers, Croatia, June 2017. 138
pages. ISBN 978-953-51-3244-8, Print ISBN 978-953-51-3243-1. Link:
https://www.intechopen.com/books/cloud-computing-architecture-and-application
Communicating Using Spatial Mode Multiplexing: Potentials, Challenges and Perspectives
Time, polarization, and wavelength multiplexing schemes have been used to
satisfy the growing need of transmission capacity. Using space as a new
dimension for communication systems has been recently suggested as a versatile
technique to address future bandwidth issues. We review the potentials of
harnessing the space as an additional degree of freedom for communication
applications including free space optics, optical fiber installation,
underwater wireless optical links, on-chip interconnects, data center indoor
connections, radio frequency and acoustic communications. We focus on the
orbital angular momentum (OAM) modes and equally identify the challenges
related to each of the applications of spatial modes and the particular OAM
modes in communication. We further discuss the perspectives of this emerging
technology. Finally, we provide the open research directions and we discuss the
practical deployment of OAM communication links for different applications
Feasibility, Architecture and Cost Considerations of Using TVWS for Rural Internet Access in 5G
The cellular technology is mostly an urban technology that has been unable to serve rural areas well. This is because the traditional cellular models are not economical for areas with low user density and lesser revenues. In 5G cellular networks, the coverage dilemma is likely to remain the same, thus widening the rural-urban digital divide further. It is about time to identify the root cause that has hindered the rural technology growth and analyse the possible options in 5G architecture to address this issue. We advocate that it can only be accomplished in two phases by sequentially addressing economic viability followed by performance progression. We deliberate how various works in literature focus on the later stage of this ‘two-phase’ problem and are not feasible to implement in the first place. We propose the concept of TV band white space (TVWS) dovetailed with 5G infrastructure for rural coverage and show that it can yield cost-effectiveness from a service provider’s perspective
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