-
Your Cisco Networking Academy Course Booklet is designed as a study resource you can easily read, high-
light, and review on the go, wherever the Internet is not available or practical:
■ The text is extracted directly, word-for-word, from the online course so you can highlight important
points and take notes in the “Your Chapter Notes” section.
■ Headings with the exact page correlations provide a quick reference to the online course for your class-
room discussions and exam preparation.
■ An icon system directs you to the online curriculum to take full advantage of the images, labs, Packet
Tracer activities, and dynamic Flash-based activities embedded within the Networking Academy online
course interface.
標簽：
Switching
Wireless
LAN
and
上傳時間：
2020-05-27
上傳用戶：shancjb
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By definition, the term “mobile-radio communications” describes any
radio communication link between two terminals of which one or both
are in motion or halted at unspecified locations and of which one may
actually be a fixed terminal such as a base station. This definition
applies to both mobile-to-mobile and mobile-to-fixed radio communica-
tion links. The mobile-to-mobile link could in fact consist of a mobile-
to-fixed-to-mobile radio communication link.The term “mobile” applies
to land vehicles, ships at sea, aircraft, and communications satellites.
In tactical situations, mobile-radio systems may include any or all of
these types of mobile terminals.
標簽：
Communications
Engineering
Mobile
上傳時間：
2020-05-30
上傳用戶：shancjb
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Ever since ancient times, people continuously have devised new techniques and
technologies for communicating their ideas, needs, and desires to others. Thus,
many forms of increasingly complex communication systems have appeared
over the years. The basic motivations behind each new one were to improve the
transmission fidelity so that fewer errors occur in the received message, to
increase the transmission capacity of a communication link so that more infor-
mation could be sent, or to increase the transmission distance between relay sta-
tions so that messages can be sent farther without the need to restore the signal
fidelity periodically along its path.
標簽：
Communications
Essentials
Optical
上傳時間：
2020-05-31
上傳用戶：shancjb
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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
上傳時間：
2020-05-31
上傳用戶：shancjb
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Wireless means different things to different people. For this book, it refers
to the radio systems that provide point-to-point, point-to-multipoint, and
Earth-space communications over transmission links that propagate outside
buildings through the lower atmosphere. Wireless systems are being built
that provide data transmission between computers and other devices on
one’s own desk. These are part of the wireless world but not the part where,
except for interference perhaps, the atmosphere has any influence. The intent
of this book is to provide a description of the physical phenomena that can
affect propagation through the atmosphere, present sample measurements
and statistics, and provide models that system designers can use to calculate
their link budgets and estimate the limitations the atmosphere may place on
their design.
標簽：
Communication
Propagation
Handbook
Wireless
for
上傳時間：
2020-05-31
上傳用戶：shancjb
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Radio propagation measurements and channel modelling continue to be of fundamental importance
to radio system design. As new technology enables dynamic spectrum access and higher data rates,
radio propagation effects such as shadowing, the presence of multipath and frequency dispersion
are the limiting factors in the design of wireless communication systems. While there are several
books covering the topic of radio propagation in various frequency bands, there appears to be no
books on radio propagation measurements, which this book addresses at length.
標簽：
Propagation
Measurement
Radio
上傳時間：
2020-06-01
上傳用戶：shancjb
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The book is written for those concerned with the design and performance of satellite
communications systems employed in fixed point-to-point, broadcasting, mobile, radio-
navigation,data-relay,computercommunications,andrelatedsatellite-basedapplications.The
recentrapidgrowthinsatellitecommunicationshascreatedaneedforaccurateinformationon
both satellite communications systems engineering and the impact of atmospheric effects on
satellite link design and system performance. This book addresses that need for the first time
in a single comprehensive source.
標簽：
Communications
Satellite
Systems
上傳時間：
2020-06-01
上傳用戶：shancjb
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The radio spectrum is one of the most precious resources which must be managed
to ensure efficient access for the wireless communication services which use it. The
allocation and management of spectrum are administered by the regulatory
authorities. Traditionally, spectrum allocation is carried out exclusively of its use in
large geographic areas and assigning frequency bands to specific users or service
providers is proved to be inefficient. Recently, substantial knowledge about
dynamic spectrum access scheme has been accumulated to enable efficient spectrum
sharing.
標簽：
Management
Spectrum
Access
and
上傳時間：
2020-06-01
上傳用戶：shancjb
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A wireless communication network can be viewed as a collection of nodes, located in some domain, which
can in turn be transmitters or receivers (depending on the network considered, nodes may be mobile users,
base stations in a cellular network, access points of a WiFi mesh etc.). At a given time, several nodes
transmit simultaneously, each toward its own receiver. Each transmitter–receiver pair requires its own
wireless link. The signal received from the link transmitter may be jammed by the signals received from
the other transmitters. Even in the simplest model where the signal power radiated from a point decays in
an isotropic way with Euclidean distance, the geometry of the locations of the nodes plays a key role since
it determines the signal to interference and noise ratio (SINR) at each receiver and hence the possibility of
establishing simultaneously this collection of links at a given bit rate. The interference seen by a receiver is
the sum of the signal powers received from all transmitters, except its own transmitter.
標簽：
Stochastic
Geometry
Networks
Wireless
Volume
and
II
上傳時間：
2020-06-01
上傳用戶：shancjb
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T
his book covers basic communications theory and practical imple-
mentation of transmitters and receivers. In so doing, I focus on dig-
ital modulation, demodulation methods, probabilities, detection of
digital signals, and spread spectrum system design and analysis. This book
was written for those who want a good understanding of the basic prin-
ciples of digital wireless communication systems, including spread spec-
trum techniques. This book also provides a good intuitive and practical
approach to digital communications. Therefore it is a valuable resource for
anyoneinvolvedinwirelesscommunicationsandtransceiverdesignfordig-
ital communications. The reader will gain a broad understanding of basic
communication principles for transceiver design, digital communications,
and spread spectrum, along with examples of many types of commercial
and military data link systems.
標簽：
Transceiver
System
Design
上傳時間：
2020-06-01
上傳用戶：shancjb
