Preface
During the past years, there has been a quickly rising interest in radio access technologies for providing
mobile as well as nomadic and fixed services for voice, video, and data. The difference in
design, implementation, and use between telecom and datacom technologies is also becoming more
blurred. One example is cellular technologies from the telecom world being used for broadband data
and wireless LAN from the datacom world being used for voice-over IP.
Today, the most widespread radio access technology for mobile communication is digital cellular,
with the number of users passing 5 billion by 2010, which is more than half of the world’s population.
It has emerged from early deployments of an expensive voice service for a few car-borne users,
to today’s widespread use of mobile-communication devices that provide a range of mobile services
and often include camera, MP3 player, and PDA functions. With this widespread use and increasing
interest in mobile communication, a continuing evolution ahead is foreseen.
This book describes LTE, developed in 3GPP (Third Generation Partnership Project) and providing
true 4G broadband mobile access, starting from the first version in release 8 and through the continuing
evolution to release 10, the latest version of LTE. Release 10, also known as LTE-Advanced,
is of particular interest as it is the major technology approved by the ITU as fulfilling the IMTAdvanced
requirements. The description in this book is based on LTE release 10 and thus provides a
complete description of the LTE-Advanced radio access from the bottom up.
Chapter 1 gives the background to LTE and its evolution, looking also at the different standards
bodies and organizations involved in the process of defining 4G. It also gives a discussion of the reasons
and driving forces behind the evolution.
Chapters 2–6 provide a deeper insight into some of the technologies that are part of LTE and its
evolution. Because of its generic nature, these chapters can be used as a background not only for LTE
as described in this book, but also for readers who want to understand the technology behind other
systems, such as WCDMA/HSPA, WiMAX, and CDMA2000.
Chapters 7–17 constitute the main part of the book. As a start, an introductory technical overview
of LTE is given, where the most important technology components are introduced based on
the generic technologies described in previous chapters. The following chapters provide a detailed
description of the protocol structure, the downlink and uplink transmission schemes, and the associated
mechanisms for scheduling, retransmission and interference handling. Broadcast operation and
relaying are also described. This is followed by a discussion of the spectrum flexibility and the associated
