This thesis is about wireless communication in shared radio spectrum. Its origin and
motivation is ideally represented by the two quotations from above. In this thesis, the
support of Quality-of-Service (QoS) in cognitive radio networks is analyzed. New
approaches to distributed coordination of cognitive radios are developed in different
spectrum sharing scenarios. The Wireless Local Area Network (WLAN) 802.11 proto-
col of the Institute of Electrical and Electronics Engineers (IEEE) (IEEE, 2003) with
its enhancement for QoS support (IEEE, 2005d) is taken as basis. The Medium Access
Control (MAC) of 801.11(e) is modified to realize flexible and dynamic spectrum
assignment within a liberalized regulation framework.
Over the past ten years there has been a revolution in the devel-
opment and acceptance of mobile products. In that period, cel-
lular telephony and consumer electronics have moved from the
realm of science fiction to everyday reality. Much of that revolu-
tion is unremarkable – we use wireless, in its broadest sense, for
TV remote controls, car keyfobs, travel tickets and credit card
transactions every day. At the same time, we have increased the
number of mobile devices that we carry around with us. However,
in many cases the design and function of these and other static
products are still constrained by the wired connections that they
use to transfer and share data.
Over the past ten years there has been a revolution in the devel-
opment and acceptance of mobile products. In that period, cel-
lular telephony and consumer electronics have moved from the
realm of science fiction to everyday reality. Much of that revolu-
tion is unremarkable – we use wireless, in its broadest sense, for
TV remote controls, car keyfobs, travel tickets and credit card
transactions every day.
Wireless communication has become increasingly important not only for professional appli-
cations but also for many fields in our daily routine and in consumer electronics. In 1990,
a mobile telephone was still quite expensive, whereas today most teenagers have one, and
they use it not only for calls but also for data transmission. More and more computers use
wireless local area networks (WLANs), and audio and television broadcasting has become
digital.
The need to develop reliable microelectronic devices capable of operating at high
speeds with complex functionality requires a better understanding of the factors
that govern the thermal performance of electronics. With an increased demand
on system reliability and performance combined with miniaturization of the
devices, thermal consideration has become a crucial factor in the design of elec-
tronic packages, from chip to system levels.
The use of light to send messages is not new. Fires were used for signaling in
biblical times, smoke signals have been used for thousands of years and flashing
lights have been used to communicate between warships at sea since the days of
Lord Nelson.
The idea of using glass fibre to carry an optical communications signal originated
with Alexander Graham Bell. However this idea had to wait some 80 years for
better glasses and low-cost electronics for it to become useful in practical
situations.
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.
This book on electrostatic discharge phenomena is essentially a translation and
update ofa Swedish edition from 1992.
The book is intended for people working with electronic circuits and
equipments, in application and development. All personnel should be aware of the
ESD-hazards, especially those responsible for quality. ESD-prevention is a part of
TQM (Total Quality Management). The book is also usable for courses on the
subject.
For more than three decades, Micro Electro Mechanical Systems (MEMS) have
steadily transitioned out of research labs and into production forming a more than $10 billion
market [1]. MEMS devices such as accelerometers, pressure sensors and microphones, to name
a few, have seen immense utilization, particularly in the consumer electronics market, because
of their compact sizes and minute power consumptions. In addition, these devices benefit from
batch fabrication, which has enabled year-over-year reductions in cost [2]. In recent years,
You probably have heard all about what you can do with the Raspberry Pi. This credit-
card sized computer can be plugged into your TV or any HDMI monitor to replace a
typical computer. This little device is used in many computer projects, DIY electronics
projects and even as a learning tool for kids who want to learn the basics of computer
programming.
