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The growth of mobile technologies is remarkable. At a recent Mobile World Congress Conference, Eric
Schmidt, CEO of Google predicted that within three years, smart phones will surpass Personal Com-
puter sales. The number of mobile phones used worldwide has exceeded 4.6 billion with continued
growth expected in the future. In fact, in the United States alone, the numbers of mobile phone users
comprise over 80% of the population.
標(biāo)簽:
Opportunities
Consumption
Technology
Mobile
上傳時間:
2020-05-30
上傳用戶:shancjb
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The insinuation of telecommunications into the daily fabric of our lives has been
arguably the most important and surprising development of the last 25 years. Before
this revolution, telephone service and its place in our lives had been largely stable
for more than a generation. The growth was, so to speak, lateral, as the global reach
of telecommunications extended and more people got telephone service. The
distinction between oversea and domestic calls blurred with the advances in
switching and transmission, undersea cable, and communication satellites. Traffic
on the network remained overwhelmingly voice, largely in analog format with
facsimile (Fax) beginning to make inroads.
標(biāo)簽:
Telecommunications
Modeling
Analysis
and
of
上傳時間:
2020-05-31
上傳用戶:shancjb
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In case you haven’t noticed, multimedia communication over IP and wireless net-
works is exploding. Applications such as BitTorrent, used primarily for video
downloads, now take up the lion’s share of all traffic on the Internet. Music file
sharing, once on the legal cutting edge of massive copyright infringement on col-
lege campuses around the world, has moved into the mainstream with signifi-
cant legal downloads of music and video to devices such as the iPod and nu-
merous other portable media players.
標(biāo)簽:
Multimedia
Over
IP
上傳時間:
2020-05-31
上傳用戶:shancjb
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Wireless communication is witnessing tremendous growth with great proliferation of different standards covering wide ,local and personal area networks
標(biāo)簽:
Multi-Standard
Receivers
Wireless
CMOS
上傳時間:
2020-05-31
上傳用戶:shancjb
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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(biāo)簽:
Opportunistic
Spectrum
Sharing
上傳時間:
2020-05-31
上傳用戶:shancjb
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This book provides the essential design techniques for radio systems that
operate at frequencies of 3 MHz to 100 GHz and which will be employed in
the telecommunication service. We may also call these wireless systems,
wireless being synonymous with radio, Telecommunications is a vibrant indus-
try, particularly on the ‘‘radio side of the house.’’ The major supporter of this
upsurge in radio has been the IEEE and its 802 committees. We now devote
? . an entire chapter to wireless LANs WLANs detailed in IEEE 802.11. We
also now have subsections on IEEE 802.15, 802.16, 802.20 and the wireless
? . ? metropolitan area network WMAN . WiFi, WiMax,, and UWB ultra wide-
. band are described where these comparatively new radio specialties are
demonstrating spectacular growth.
標(biāo)簽:
Telecommunication
Design
System
Radio
for
上傳時間:
2020-06-01
上傳用戶:shancjb
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Radio frequency spectrum is a scarce and critical natural resource that is utilized for
many services including surveillance, navigation, communication, and broadcast-
ing. Recent years have seen tremendous growth in the use of spectrum especially by
commercial cellular operators. Ubiquitous use of smartphones and tablets is one
of the reasons behind an all-time high utilization of spectrum. As a result, cellular
operators are experiencing a shortage of radio spectrum to meet bandwidth
demands of users. On the other hand, spectrum measurements have shown that
much spectrum not held by cellular operators is underutilized even in dense urban
areas. This has motivated shared access to spectrum by secondary systems with no
or minimal impact on incumbent systems. Spectrum sharing is a promising
approach to solve the problem of spectrum congestion as it allows cellular operators
access to more spectrum in order to satisfy the ever-growing bandwidth demands of
commercial users.
標(biāo)簽:
Spectrum
Sharing
Between
Radars
上傳時間:
2020-06-01
上傳用戶:shancjb
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The continuing explosive growth in mobile communication is demanding more spectrally
efficient radio access technologies than the prevalent second generation (2G) systems such as
GSM to handle just the voice traffic. We are already witnessing high levels of mobile
penetration exceeding 70% in some countries. It is anticipated that by 2010 more than half of
all communications will be carried out by mobile cellular networks. On the other hand, the
information revolution and changing life habits are bringing the requirement of commu-
nicating on a multimedia level to the mobile environment. But the data handling capabilities
and flexibility of the 2G cellular systems are limited.
標(biāo)簽:
Planning
Network
UMTS
上傳時間:
2020-06-01
上傳用戶:shancjb
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The information age is exploding around us,
giving us access to dizzying amounts of data the instant it becomes available.
Smart phones and tablets provide an untethered experience that offers stream-
ing video, audio, and other media formats to just about any place on the planet.
Even people who are not “computer literate” use Facebook to catch up with
friends and family, use Google to research a new restaurant choice and print
directions to get there, or Tweet their reactions once they have sampled the
fare. The budding Internet-of-things will only catalyze this data eruption.
The infrastructure supporting these services is also growing exponentially,
and the technology that facilitates this rapid growth is virtualization.
標(biāo)簽:
Virtualization
Essentials
上傳時間:
2020-06-01
上傳用戶:shancjb
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Visible light communications (VLC) is the name given to an optical wireless
communication system that carries information by modulating light in the visible spectrum
(400–700 nm) that is principally used for illumination [1–3]. The communications signal
is encoded on top of the illumination light. Interest in VLC has grown rapidly with the
growth of high power light emitting diodes (LEDs) in the visible spectrum. The
motivation to use the illumination light for communication is to save energy by exploiting
the illumination to carry information and, at the same time, to use technology that is
“green” in comparison to radio frequency (RF) technology, while using the existing
infrastructure of the lighting system.
標(biāo)簽:
Communication
Visible
Light
上傳時間:
2020-06-01
上傳用戶:shancjb