Wireless technologies like GSM, UMTS, LTE, Wireless LAN and Bluetooth have revolu-
tionized the way we communicate and exchange data by making services like Telephony and
Internet access available anytime and from almost anywhere. Today, a great variety of techni-
cal publications offer background information about these technologies but they all fall short
in one way or another. Books covering these technologies usually describe only one of the
systems in detail and are generally too complex as a first introduction. The Internet is also a
good source, but the articles one finds are usually too short and superficial or only deal with
a specific mechanism of one of the systems. For this reason, it was difficult for me to recom-
mend a single publication to students in my telecommunication classes, which I have been
teaching in addition to my work in the wireless telecommunication industry. This book aims
to change this.
Communication has been one of the deepest needs of the human race throughout recorded
history. It is essential to forming social unions, to educating the young, and to expressing a
myriad of emotions and needs. Good communication is central to a civilized society.
The various communication disciplines in engineering have the purpose of providing technological
aids to human communication. One could view the smoke signals and drum rolls of primitive
societies as being technological aids to communication, but communication technology as we
view it today became important with telegraphy, then Telephony, then video, then computer
communication, and today the amazing mixture of all of these in inexpensive, small portable
devices.
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.
Rapid progress in information and communications technology (ICT) induces
improved and new telecommunications services and contributes greatly to society
in general and to vendors and network and service providers. In addition to existing
services such as Telephony or leased line services, spread of the Internet, the Internet
Protocol (IP) phone, and new communications services like IPTV are making great
progress with the development of digital subscriber lines (DSL) and high - speed
communications technologies like fi ber to the home (FTTH).
Public telephone operators and new independent wireless operators through-
out the world are deploying wireless access in an effort to drastically reduce
delivery costs in the most expensive part of the network?the local loop.
Available radio technology enables both existing and new entrants to access
subscribers in a rapid manner and deliver their basic Telephony products and
broadband-enhanced services.
Once upon a time, cellular wireless networks provided two basic services: voice
Telephony and low-rate text messaging. Users in the network were separated
by orthogonal multiple access schemes, and cells by generous frequency reuse
patterns [1]. Since then, the proliferation of wireless services, fierce competition,
andthe emergenceof new service classes such as wireless data and multimediahave
resulted in an ever increasing pressure on network operators to use resources in a
moreefficient manner.In the contextof wireless networks,two of the most common
resources are power and spectrum—and, due to regulations, these resources are
typically scarce. Hence, in contrast to wired networks, overprovisioning is not
feasible in wireless networks.
Mobile radio communications are evolving from pure Telephony systems to multimedia
platforms offering a variety of services ranging from simple file transfers and audio and
video streaming, to interactive applications and positioning tasks. Naturally, these services
have different constraints concerning data rate, delay, and reliability (quality-of-service
(QoS)). Hence, future mobile radio systems have to provide a large flexibility and scal-
ability to match these heterogeneous requirements.
