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.
Communication protocols – for short protocols – form the basis for the opera-
tion of computer networks and telecommunication systems. They are behavior
conventions which describe how communication systems interact with each other
in computer networks. Protocols define the temporal order of the interactions and
the formats of the data units exchanged. Communication protocols comprise a
wide range of different functions and mechanisms, such as the sending and receiv-
ing of data units, their coding/decoding, error control mechanisms, timer control,
flow control, and many others.
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.
The use of optical free-space emissions to provide indoor wireless commu-
nications has been studied extensively since the pioneering work of Gfeller
and Bapst in 1979 [1]. These studies have been invariably interdisciplinary in-
volving such far flung areas such as optics design? indoor propagation studies?
electronics design? communications systems design among others. The focus
of this text is on the design of communications systems for indoor wireless
optical channels. Signalling techniques developed for wired fibre optic net-
works are seldom efficient since they do not consider the bandwidth restricted
nature of the wireless optical channel.
LIKE SO MANY others , THIS BOOK WAS WRITTEN BECAUSE WE COULDN ’ T FIND ONE LIKE IT . We
needed something to hand to all of those people who have come to us asking for “a good
book to read on RFID.” When we looked for candidates we found some great books, but
most were aimed at electrical engineers or top-level managers, with very little for those of
us who are in between. This book is for developers, system and software architects, and
project managers, as well as students and professionals in all of the industries impacted by
Radio Frequency Identification (RFID) who want to understand how this technology
works. As the title suggests, this book is about RFID in general and not just the most
recent developments; however, because so much is going on in the area of RFID for the
supply chain and especially the Electronic Product Code (EPC), we have devoted consider-
able space to these topics. Regardless of the type of RFID work you may be doing, we
think you will find something useful here.
Fun. We (your authors) wanted a word to describe our ultimate goal for this book, as well as a word
we hope you (our reader) will use to describe it, and that’s the one we chose. There are others goals,
of course, but in the end, when you’ve finished the book, we’re hoping you’ll have enjoyed the
activities described in these pages.
Many books use the Introduction to explain exactly what the book is about, what the reader will
learn, what the reader needs (a skill or maybe an item or piece of software), and what the reader
will be left with when that last page is completed. And this Introduction will do those things, but …
hopefully it’ll make you excited to get started.
Artificial Intelligence (AI) has undoubtedly been one of the most important buz-
zwords over the past years. The goal in AI is to design algorithms that transform com-
puters into “intelligent” agents. By intelligence here we do not necessarily mean an
extraordinary level of smartness shown by superhuman; it rather often involves very
basic problems that humans solve very frequently in their day-to-day life. This can
be as simple as recognizing faces in an image, driving a car, playing a board game, or
reading (and understanding) an article in a newspaper. The intelligent behaviour ex-
hibited by humans when “reading” is one of the main goals for a subfield of AI called
Natural Language Processing (NLP). Natural language 1 is one of the most complex
tools used by humans for a wide range of reasons, for instance to communicate with
others, to express thoughts, feelings and ideas, to ask questions, or to give instruc-
tions. Therefore, it is crucial for computers to possess the ability to use the same tool
in order to effectively interact with humans.
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