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The Internet of Things is considered to be the next big opportunity, and challenge, for the
Internet engineering community, users of technology, companies and society as a whole. It
involves connecting embedded devices such as sensors, home appliances, weather stations
and even toys to Internet Protocol (IP) based networks. The number of IP-enabled embedded
devices is increasing rapidly, and although hard to estimate, will surely outnumber the
number of personal computers (PCs) and servers in the future. With the advances made over
the past decade in microcontroller,low-power radio, battery and microelectronic technology,
the trend in the industry is for smart embedded devices (called smart objects) to become
IP-enabled, and an integral part of the latest services on the Internet. These services are no
longer cyber, just including data created by humans, but are to become very connected to the
physical world around us by including sensor data, the monitoring and control of machines,
and other kinds of physical context. We call this latest frontier of the Internet, consisting of
wireless low-power embedded devices, the Wireless Embedded Internet. Applications that
this new frontier of the Internet enable are critical to the sustainability, efficiency and safety
of society and include home and building automation, healthcare, energy efficiency, smart
grids and environmental monitoring to name just a few.
標簽：
Embedded
Internet
Wireless
6LoWPAN
The
上傳時間：
2020-05-26
上傳用戶：shancjb
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Emerging technologies such as WiFi and WiMAX are profoundly changing the
landscape of wireless broadband. As we evolve into future generation wireless
networks, a primary challenge is the support of high data rate, integrated multi-
media type traffic over a unified platform. Due to its inherent advantages in
high-speed communication, orthogonal frequency division multiplexing (OFDM)
has become the modem of choice for a number of high profile wireless systems
(e.g., DVB-T, WiFi, WiMAX, Ultra-wideband).
標簽：
Broadband
Wireless
Networks
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2020-05-26
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In cellular networks, it is estimated that
2
3
of calls and over 90% of data services occur
indoors. However, some surveys show that many households and businesses experience
a poor indoor coverage problem. It has been identified that poor coverage is the main
reason for churn, which is very costly for operators in saturated markets. How to provide
good indoor coverage cost effectively is thus a demanding challenge for operators.
標簽：
Technologies
Femtocells
Deployment
and
上傳時間：
2020-05-27
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This book is intended for RF planners, to serve as a practical tool in their daily work
designing indoor radio distribution systems.
Based on feedback from readers of the first edition it was clear to me that I needed to add
more material and in depth description of the basics of indoor systems based on using
repeaters; this has grown into a new Section 4.7.
There was also a strong demand to add more detail and dedicate a full chapter to radio
planning in tunnels, for both rail and road tunnels; and redundancy principles in the design
focus for solving the challenge of handover zones. An entire Chapter 11 is now dedicated to
tunnel radio planning.
標簽：
Planning
Indoor
Radio
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2020-05-27
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Nature is seldom kind. One of the most appealing uses for radio-
telephone systems—communication with people on the move—must over-
come radio transmission problems so difficult they challenge the imagina-
tion. A microwave radio signal transmitted between a fixed base station
and a moving vehicle in a typical urban environment exhibits extreme
variations in both amplitude and apparent frequency.
標簽：
Communications
Microwave
Mobile
上傳時間：
2020-05-28
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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
上傳時間：
2020-05-30
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-
Emerging technologies such as WiFi and WiMAX are profoundly changing the
landscape of wireless broadband. As we evolve into future generation wireless
networks, a primary challenge is the support of high data rate, integrated multi-
media type traffic over a unified platform. Due to its inherent advantages in
high-speed communication, orthogonal frequency division multiplexing (OFDM)
has become the modem of choice for a number of high profile wireless systems
(e.g., DVB-T, WiFi, WiMAX, Ultra-wideband).
標簽：
OFDM-Based
Broadband
Networks
Wireless
上傳時間：
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
上傳時間：
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
上傳時間：
2020-05-31
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Before I can present design concepts or tactical wireless communications and network
challenges, I feel the need to mention the challenges of writing for a field where some
information is not available for public domain and cannot be included in this book’s context.
Another challenge is the use of military jargon and the extensive number of abbreviations
(and abbreviations of abbreviations!) in the field. Engineering books are naturally dry, and I
have attempted to make it light by presenting the concepts in layman’s terms before diving
into the technical details. I am structuring this book in such a way as to make it useful for
a specialized graduate course in tactical communications and networking, or as a reference
book in the field.
標簽：
Communications
Tactical
Networks
Wireless
and
上傳時間：
2020-06-01
上傳用戶：shancjb
