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A decade ago, I first wrote that people moved, and networks needed to adapt to the
reality that people worked on the go. Of course, in those days, wireless LANs came
with a trade-off. Yes, you could use them while moving, but you had to trade a great
deal of throughput to get the mobility. Although it was possible to get bits anywhere,
even while in motion, those bits came slower. As one of the network engineers I worked
with put it, “We’ve installed switched gigabit Ethernet everywhere on campus, so I
don’t understand why you’d want to go back to what is a 25-megabit hub.” He un-
derestimated the allure of working on the go.
標(biāo)簽:
Survival
802.11
Guide
上傳時間:
2020-05-26
上傳用戶:shancjb
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This book presents, in a unitary and novel perspective, some of the research work
the authors have carried out over the last decade, along with several collaborators and
students. The roots of this book can be traced back to the design of adaptive sequence
detection algorithms for channels with parametric uncertainty. The explosion of turbo
codes and iterative decoding around the middle of the Nineties has motivated the
design of iterative (turbo and graph-based) detection algorithms.
標(biāo)簽:
Communications
Algorithms
Detection
Wireless
for
上傳時間:
2020-05-27
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Never have telecommunications operations and network management been so
important. Never has it been more important to move away from practices that date
back to the very beginning of the telecommunications industry. Building and con-
necting systems internally at low cost, on an as - needed basis, and adding software
for supporting new networks and services without an overall architectural design
will not be cost effective for the future. Defi ning operations and network manage-
ment requirements at the 11th hour for new technologies, networks, and services
deployments must also change.
標(biāo)簽:
Telecommunications
Generation
Networks
Next
上傳時間:
2020-05-31
上傳用戶:shancjb
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The first practical examples of mobile communications were used in many countries like
the USA, the UK and Germany in military services, and played a significant role in the
First World War to transfer important information from the front to headquarters to take
further actions. Good and secure wireless communications were an important need for all
military services – army, navy and air force. In this respect, the Second World War was a big
experimental battlefield for the development and evolution of mobile radio. It was in the
interests of governments that after the Second World War the military investment should
be paid back by civilian use, and all western European countries started their so-called first
generation of mobile communication networks.
標(biāo)簽:
Multimedia
Business
Mobile
The
上傳時間:
2020-06-01
上傳用戶:shancjb
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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(biāo)簽:
Networking
Technology
Wireless
上傳時間:
2020-06-01
上傳用戶:shancjb
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It has been said that the move from narrowband to broadband access is the second
revolution for the Internet — ‘broadband is more bandwidth than you can use’.
Once users have experienced broadband access there is no turning back. A whole
new world of applications and services becomes possible. No longer is it the ‘world-
wide wait’. The speed of response and visual quality enabled by broadband finally
allows the Internet to reach its true potential.
標(biāo)簽:
Digital
Home
上傳時間:
2020-06-06
上傳用戶:shancjb
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December 2007, San Jose, California: It seems a long time ago.
I walked into a big networking company to head their small
Power over Ethernet (PoE) applications team. Surprisingly,
I hardly knew anything about PoE prior to that day, having been a
switching-power conversion engineer almost all my life. But it
seemed a great opportunity to widen my horizons. As you can see,
one notable outcome of that seemingly illogical career choice five
years ago is the book you hold in your hands today. I hope this small
body of work goes on to prove worthy of your expectations and also
of all the effort that went into it. Because, behind the scenes, there is a
rather interesting story to relate—about its backdrop, intertwined
with a small slice of modern PoE history, punctuated by a rather res-
tive search for our roots and our true heroes, one that takes us back
almost two centuries
標(biāo)簽:
Ethernet
Power
Over
上傳時間:
2020-06-07
上傳用戶:shancjb
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RFID (radio-frequency identification) is the use of a wireless non-contact system
that uses radio-frequencyelectromagnetic fields to transfer datafrom a tag attached
to an object, for the purposes of automatic identification and tracking [38]. The
basic technologies for RFID have been around for a long time. Its root can be traced
back to an espionage device designed in 1945 by Leon Theremin of the Soviet
Union,whichretransmittedincidentradiowaves modulatedwith audioinformation.
After decades of development, RFID systems have gain more and more attention
from both the research community and the industry.
標(biāo)簽:
Infrastructure
RFID
as
an
上傳時間:
2020-06-08
上傳用戶:shancjb
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We are in the era of ubiquitous computing in which the use and development of Radio Frequency Iden-
tification (RFID) is becoming more widespread. RFID systems have three main components: readers,
tags, and database. An RFID tag is composed of a small microchip, limited logical functionality, and an
antenna. Most common tags are passive and harvest energy from a nearby RFID reader. This energy is
used both to energize the chip and send the answer back to the reader request. The tag provides a unique
identifier (or an anonymized version of that), which allows the unequivocal identification of the tag
holder (i.e. person, animal, or items).
標(biāo)簽:
Identification
Wireless
上傳時間:
2020-06-08
上傳用戶:shancjb
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I can remember buying my first electronic calculator. I was teaching a graduate level statistics course and I
had to have a calculator with a square root function. Back in the late 1960s, that was a pretty high-end
requirement for a calculator. I managed to purchase one at the “educational discount price” of $149.95!
Now, I look down at my desk at an ATmega2560 that is half the size for less than a quarter of the cost and
think of all the possibilities built into that piece of hardware. I am amazed by what has happened to
everything from toasters to car engines. Who-da-thunk-it 40 years ago?
標(biāo)簽:
Beginning
Arduino
for
上傳時間:
2020-06-09
上傳用戶:shancjb