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The rapid growth in mobile communications has led to an increasing demand for wide-
band high data rate communications services. In recent years, Distributed Antenna
Systems (DAS) has emerged as a promising candidate for future (beyond 3G or 4G)
mobile communications, as illustrated by projects such as FRAMES and FuTURE. The
architecture of DAS inherits and develops the concepts of pico- or micro-cell systems,
where multiple distributed antennas or access points (AP) are connected to and con-
trolled by a central unit.
標簽：
Distributed
Antenna
Systems
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A series of features makes the mobile telecommunications industry an
interesting field of investigation for economists: the industry is experi-
encing veryfastmarketgrowthcombinedwithrapidtechnological change;
regulatory design in setting market structure is playing a very important
role; and oligopolistic competition is unfolding under various forms. The
number of subscribers to mobile networks is growing at a rapid rate on a
worldwide basis, as shown in figure 1.1.
標簽：
Telecommunications
Economics
Mobile
of
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2020-05-27
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The telecommunications industry is undoubtedly in a period of radical change with
the advent of mobile broadband radio access and the rapid convergence of Internet
and mobile services. Some of these changes have been enabled by a fundamental
shift in the underlying technologies; mobile networks are now increasingly based
on a pure Internet Protocol (IP) network architecture. Since the first edition of this
book was published in 2009, a multitude of connected devices from eBook readers
to smartphones and even Machine-to-Machine (M2M) technologies have all started
to benefit from mobile broadband. The sea change over the last few years is only the
beginning of a wave of new services that will fundamentally change our economy, our
society, and even our environment. The evolution towards mobile broadband is one of
the core underlying parts of this revolution and is the focus of this book.
標簽：
Networks
Packet
EPC
and
4G
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2020-05-27
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With the rapid growth in the number of wireless applications, services and devices,
using a single wireless technology such as a second generation (2G) and third gener-
ation (3G) wireless system would not be efficient to deliver high speed data rate and
quality-of-service (QoS) support to mobile users in a seamless way. The next genera-
tion wireless systems (also sometimes referred to as Fourth generation (4G) systems)
are being devised with the vision of heterogeneity in which a mobile user/device will
be able to connect to multiple wireless networks (e.g., WLAN, cellular, WMAN)
simultaneously.
標簽：
Heterogeneous
Wireless
Networks
Access
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2020-05-27
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With the rapid expansion of wireless consumer products,there has been a con-
siderable increase in the need for radio-frequency (RF) planning, link plan-
ning, and propagation modeling.A network designer with no RF background
may find himself/herself designing a wireless network. A wide array of RF
planning software packages can provide some support, but there is no substi-
tute for a fundamental understanding of the propagation process and the lim-
itations of the models employed. Blind use of computer-aided design (CAD)
programs with no understanding of the physical fundamentals underlying the
process can be a recipe for disaster. Having witnessed the results of this
approach, I hope to spare others this frustration.
標簽：
Introduction
Propagation
to
RF
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2020-05-27
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With the rapid growth of the wireless mobile applications, wireless voice has
begun to challenge wireline voice, whereas the desire to access e-mail, surf the
Web or download music (e.g., MP3) wirelessly is increasing for wireless data.
While second generation (2G) cellular wireless systems, such as cdmaOne1,
GSM2 and TDMA3, introduced digital technology to wireless cellular systems
to deal with the increasing demand for wireless applications, there is still the
need for more spectrally efficient technologies for two reasons. First, wireless
voice capacity is expected to continue to grow. Second, the introduction of
high-speed wireless data will require more bandwidth.
標簽：
Wireless
Systems
Mobile
Beyond
and
3G
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2020-05-30
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The last decade proved to be hugely successful for the mobile communications industry,
characterised by continued and rapid growth in demand, spurred on by new technological
advances and innovative marketing techniques. Of course, when we refer to mobile commu-
nications, we tend to implicitly refer to cellular systems, such as GSM. The plight of the
mobile-satellite industry over the last decade, although eventful, has, at times, been more akin
to an out of control roller coaster ride.
標簽：
Communication
Satellite
Networks
Mobile
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2020-05-30
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The telecommunications industry has seen a rapid boost within the last decade. New realities
and visions of functionalities in various telecommunications networks have brought forward the
concept of next-generation networks (NGNs). The competitions among operators for support-
ing various services, lowering of the cost of having mobile and cellular phones and smartphones,
increasing demand for general mobility, explosion of digital traffic, and advent of convergence
network technologies added more dynamism in the idea of NGNs. In fact, facilitating con-
vergence of networks and convergence of various types of services is a significant objective of
NGNs.
標簽：
Next-Generation
Converged
Networks
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2020-05-31
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rapid growth of wireless communication services in recent decades has created
a huge demand of radio spectrum. Spectrum scarcity and utilization inefficiency
limit the development of wireless networks. Cognitive radio is a promising tech-
nology that allows secondary users to reuse the underutilized licensed spectrum of
primary users. The major challenge for spectrum sharing is to achieve high spectrum
efficiency while making non-intrusive access to the licensed bands. This requires in-
formation of availability and quality of channel resources at secondary transmitters,
however, is difficult to be obtained perfectly in practice.
標簽：
Opportunistic
Spectrum
Sharing
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2020-05-31
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The ever-increasing demand for private and sensitive data transmission over wireless net-
works has made security a crucial concern in the current and future large-scale, dynamic,
and heterogeneous wireless communication systems. To address this challenge, computer
scientists and engineers have tried hard to continuously come up with improved crypto-
graphic algorithms. But typically we do not need to wait too long to find an efficient way
to crack these algorithms. With the rapid progress of computational devices, the current
cryptographic methods are already becoming more unreliable. In recent years, wireless re-
searchers have sought a new security paradigm termed physical layer security. Unlike the
traditional cryptographic approach which ignores the effect of the wireless medium, physi-
cal layer security exploits the important characteristics of wireless channel, such as fading,
interference, and noise, for improving the communication security against eavesdropping
attacks. This new security paradigm is expected to complement and significantly increase
the overall communication security of future wireless networks.
標簽：
Communications
Physical
Security
Wireless
Layer
in
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2020-05-31
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