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Software Radio (SR) is one of the most important emerging technologies for the
future of wireless communication services. By moving radio functionality into
software, it promises to give flexible radio systems that are multi-service, multi-
standard, multi-band, reconfigurable and reprogrammable by software.
Today’s radios are matched to a particular class of signals that are well defined
bytheircarrierfrequencies,modulationformatsandbandwidths.Aradiotransmitter
today can only up convert signals with well-defined bandwidths over defined center
frequencies, while, on the other side of the communication chain, a radio receiver
can only down convert well-defined signal bandwidths, transmitted over specified
carrier frequencies.
標簽：
Software
Radio
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2020-06-01
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Intensive development of digital technologies coincided in time with the beginning
of the new era in telecommunications. It made possible to formalize many proce-
dures of data exchange and to atomize some operations which made providing of
serviceandmakeworkofmanytelecommunicationworkersmucheasier. Somenew
telecommunication technologies were born out of the necessity for use of specific
configurations of network elements and networks, as well as for a possibility of
providing maximum characteristics of efficiency combined with high requirements
to the stability of operation, the overcoming of different catastrophic situations and
deadlockconditions,such as failuresand ”pending”of the networkandthe like. The
thresholdbetweeninformationsystems andtelecommunicationsystems has become
practically invisible. It resulted in such a new term as ”infocommunication”
標簽：
Telecommunication+Systems
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2020-06-01
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Rapid progress in information and communications technology (ICT) induces
improved and new telecommunications services and contributes greatly to society
in general and to vendors and network and service providers. In addition to existing
services such as telephony or leased line services, spread of the Internet, the Internet
Protocol (IP) phone, and new communications services like IPTV are making great
progress with the development of digital subscriber lines (DSL) and high - speed
communications technologies like fi ber to the home (FTTH).
標簽：
Telecommunications
Networks
上傳時間：
2020-06-01
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When 3GPP started standardizing the IMS a few years ago, most analysts expected the
number of IMS deploymentsto grow dramatically as soon the initial IMS specifications were
ready (3GPP Release 5 was functionallyfrozenin the first half of 2002and completedshortly
after that). While those predictions have proven to be too aggressive owing to a number of
upheavals hitting the ICT (Information and Communications technologies) sector, we are
now seeing more and more commercial IMS-based service offerings in the market. At the
time of writing (May 2008), there are over 30 commercial IMS networks running live traffic,
addingup to over10million IMS users aroundthe world; the IMS is beingdeployedglobally.
In addition, there are plenty of ongoing market activities; it is estimated that over 130 IMS
contracts have been awarded to all IMS manufacturers. The number of IMS users will grow
substantially as these awarded contracts are launched commercially. At the same time, the
number of IMS users in presently deployed networks is steadily increasing as new services
are introduced and operators running these networks migrate their non-IMS users to their
IMS networks.
標簽：
Multimedia
Subsystem
The
IMS
3G
IP
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2020-06-01
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Recent advances in wireless communication technologies have had a transforma-
tive impact on society and have directly contributed to several economic and social
aspects of daily life. Increasingly, the untethered exchange of information between
devices is becoming a prime requirement for further progress, which is placing an
ever greater demand on wireless bandwidth. The ultra wideband (UWB) system
marks a major milestone in this progress. Since 2002, when the FCC allowed the
unlicensed use of low-power, UWB radio signals in the 3.1–10.6GHz frequency
band, there has been significant synergistic advance in this technology at the cir-
cuits, architectural and communication systems levels. This technology allows for
devices to communicate wirelessly, while coexisting with other users by ensuring
that its power density is sufficiently low so that it is perceived as noise to other
users.
標簽：
Circuits
Wideband
Ultra
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2020-06-01
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In the two years since this book was first published, ultra wideband (UWB) has
advanced and consolidated as a technology, and many more people are aware of the
possibilities for this exciting technology. We too have expanded and consolidated
materials in this second edition in the hope that ‘Ultra Wideband: Signals and Systems
in Communication Engineering’ will continue to prove a useful tool for many students
and engineers to come to an understanding of the basic technologies for UWB.
標簽：
Wideband
Signals
Systems
Ultra
and
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2020-06-01
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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.
標簽：
Planning
Network
UMTS
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2020-06-01
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Today wireless is becoming the leader in communication choices among
users. It is not anymore a backup solution for nomadic travellers but really a
newmoodnaturallyusedeverywhereevenwhenthewiredcommunicationsare
possible. Many technologies evolve then continuously, changing the telecom-
munication world. We talk about wireless local area networks (WLANs), wire-
less personal area networks (WPANs), wireless metropolitan area networks
(WMANs), wireless wide area networks (WWANs), mobile ad hoc networks
(MANETs), wireless sensor networks (WSNs) and mesh networks. Since we
can find today a multitude of wireless technologies we decided to group a
numberofcomplementarytechnologiesintoonedocumenttomakeiteasierfor
areadertounderstandsomeofthetechnicaldetailsofeachmedia.
標簽：
TM
Bluetooth
Zigbee
Wi-Fi
WiMax
and
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2020-06-01
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Welcome to the world of wireless communications and the logical extension
to the broadband architectures that are emerging as the future of the
industry. No aspect of communications will be untouched by the wireless
interfaces;no part of our working environment will be left untouched either.
As the world changes and the newer technologies emerge, we can expect to
see more in the line of untethered communications than in the wired inter-
faces.
標簽：
Broadband
Wireless
Handbook
上傳時間：
2020-06-01
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Although the origins of radio frequency based wireless networking can be
traced back to the University of Hawaii’s ALOHANET research project
in the 1970s, the key events that led to wireless networking becoming
one of the fastest growing technologies of the early 21st century have
been the ratification of the IEEE 802.11 standard in 1997, and the
subsequent development of interoperability certification by the Wi-Fi
Alliance (formerly WECA).
標簽：
Networking
Technology
Wireless
上傳時間：
2020-06-01
上傳用戶：shancjb
