-
Quality of Service ( QoS ) has always been in a world of its own, but as the technology
has been refi ned and has evolved in recent years, QOS usage has increased to the point
where it is now considered a necessary part of network design and operation. As with
most technologies, large - scale deployments have led to the technology becoming more
mature, and QOS is no exception.
標簽：
QOS-Enabled
Networks
上傳時間：
2020-05-31
上傳用戶：shancjb
-
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
-
By inventing the wireless transmitter or radio in 1897, the Italian physicist Tomaso
Guglielmo Marconi added a new dimension to the world of communications. This
enabled the transmission of the human voice through space without wires. For this
epoch-making invention, this illustrious scientist was honored with the Nobel Prize
for Physics in 1909. Even today, students of wireless or radio technology remember
this distinguished physicist with reverence. A new era began in Radio
Communications.
標簽：
Radio
Frequency
Modulation
上傳時間：
2020-06-01
上傳用戶：shancjb
-
Wireless communications and networking technology are advancing at a very rapid
pace. Newer technologies and standards are evolving to serve the ever-increasing num-
ber of users demanding different types of mobile applications and services. Research
and development activities on wireless technology constitute one of the most impor-
tant segments of research and development in the telecommunications area today.
標簽：
Management
Resource
Radio
上傳時間：
2020-06-01
上傳用戶：shancjb
-
Mobile and wireless communication systems are a prominent communications
technology of the twenty-first century with profound economic and social impacts
in practically all parts of the world. The current state of wireless communication
systems allows for a much wider scope of applications than what it used to be
originally, that is, to be a mobile extension of the public switched telephone
network.
標簽：
Allocation
Resource
MIMO
and
上傳時間：
2020-06-01
上傳用戶：shancjb
-
The unguided transmission of information using electromagnetic waves
at radio frequency (RF) is often referred to as wireless communications,
the first demonstration of which took place at the end of the 19th cen-
tury and is attributed to Hertz. The technology was, shortly thereafter,
commercialised by, amongst others, Marconi in one of the first wire-
less communication systems, i.e., wireless telegraphy. In the first half of
the 20th century the technology was developed further to enable more
than the mere transmission of Morse code. This first resulted in uni-
directional radio broadcasting and several years later also in television
broadcasting.
標簽：
Imperfections
RF
上傳時間：
2020-06-01
上傳用戶：shancjb
-
This book was born from the perception that there is much more to spectrum use
and sharing than one sees reflected in publications, whether academic, commercial
or political. the former – in good research style – tend towards reductionism and
concentrate on specific, detailed aspects. commercial publications tend to empha-
size the positive aspects and they tend to put promise above practice. Given the ever
increasing pace of technology development and recent successes of new wireless
technologies, some pundits predict large-scale spectrum scarcity, potentially lead-
ing to economic catastrophe. Although economic theory has a hard time explaining
recent events that shook the world economy, the notion of spectrum scarcity is intui-
tively acceptable, even if not correct or immediately relevant.
標簽：
Spectrum
Sharing
RF
上傳時間：
2020-06-01
上傳用戶：shancjb
-
Short-range communications is one of the most relevant as well as diversified fields of en-
deavour in wireless communications. As such, it has been a subject of intense research and
development worldwide, particularly in the last decade. There is no reason to believe that this
trend will decline. On the contrary, the rapidly crystallizing vision of a hyper-connected world
will certainly strengthen the role of short-range communications in the future. Concepts such
as wireless social networks, Internet of things, car communications, home and office network-
ing, wireless grids and personal communications heavily rely on short-range communications
technology.
標簽：
Communications
Short-Range
Wireless
上傳時間：
2020-06-01
上傳用戶：shancjb
-
Ultra-wideband (UWB) technology enables high data-rate short-range communica-
tion, in excess of hundredmegabit-per-secondsand up to multi-gigabit-per-seconds,
over a wide spectrum of frequencies, while keeping power consumption at low lev-
els. This low power operation results in a less-interfering co-existence with other
existed communication technologies (e.g., UNII bands).
In addition to carrying a huge amount of data over a distance of up to 230 feet
at very low power (less than 0.5mW), the UWB signal has the ability to penetrate
through the doors and other obstacles that tend to reflect signals at more limited
bandwidths and higher power densities.
標簽：
Silicon-Based
Front-Ends
RF
上傳時間：
2020-06-01
上傳用戶：shancjb
-
Software defined radio (SDR) is an exciting new field for the wireless indus-
try; it is gaining momentum and beginning to be included in commercial
and defense products. The technology offers the potential to revolutionize
the way radios are designed, manufactured, deployed, and used. SDR prom-
ises to increase flexibility, extend hardware lifetime, lower costs, and reduce
time to market
標簽：
Software
Defined
Radio
for
3G
上傳時間：
2020-06-01
上傳用戶：shancjb
