Library of Congress Cataloging-in-Publication Data applied for
HB ISBN: 9780470683996
Cover Design & Image: © Peter Gregson
In memory of my father, the unshakeable optimist.
Foreword
First: But, Why?
Why should one dare to write a relatively long book in a digital age, where everything seems to be quickly found online and watching video tutorials is used as a substitute for reading? Why read, let alone write, a long text when a single tweet results in thousands of workers getting laid off or somebody becoming a millionaire in a day? And, last, but not least, why put in so much effort, knowing that, eventually, despite all the measures, the PDF of the book will be available for illegal download at a phony website?
A book or a textbook still has its role in the digital age, but this role is significantly different from the times when books were the ultimate source of information and knowledge. It should rather be understood as a gateway to knowledge, a gadget that helps to make sense of the massive amount of online data, a hitchhiker's guide for receiving, filtering, and learning from the overwhelming waves of information. As for the illegal copies: if you are reading this on an illegal copy, then it is fair to tell you that it is getting really boring from now on, so you can stop reading.:)
Wireless became Huge and Complex
This role of a “gateway to knowledge” was one of the motivations behind writing this book. The area of wireless communications has developed immensely over the last three decades, generating a large number of concepts, ideas, articles, patents, and even myths. Identifying the crucial ideas and their interconnection becomes increasingly difficult. The area of wireless connectivity grew to be very complex, to the level where the specialists working in one part of the system, say hardware, did not know much about the functioning of the high layer protocols, and vice versa. In the extreme case, this ignorance about the concepts and functioning of the other parts of the communication system led to the “only-my-part-of-the-system-matters” attitude, sometimes resulting in disastrously sub-optimal designs.
In order to see how much wireless communication has developed in volume and complexity, here is an ultra-short overview of the generations of wireless mobile communication systems. It started with the “modest” ambition of 2G being reachable for a phone call wherever you are moving, but the unlikely hero was the short message service (SMS) that brought texting as a new social phenomenon. It was perhaps this unlikely hero that planted the obsession with the “killer application” during the development of 3G. The advent of the smartphone has shown that there was not a single killer application, but a gateway to the internet, a gadget with many apps, a hitchhiker's guide to multiple applications [sic]. Only with the data speeds offered by 4G did the smartphone start to reach its full potential, completely transforming work and play. At the time of writing, we are at the dawn of the deployment of 5G, still with a lot of predictions, enthusiasm, and skepticism. The working version of the 5G ambition is to offer truly ubiquitous and reliable coverage to the humans, but also wirelessly connect machines and physical objects.
Note that this ultra-short overview is unfair to a lot of other wireless technologies that are omnipresent and play a crucial role in daily life, such as Wi-Fi and Bluetooth. The tone in the book is leaning towards mobile wireless cellular networks, but the overall discussion is kept generic, not tied to a particular wireless system or technology.
How this Book is Structured
The book does not follow the established, linear structure in which one starts from the propagation and channels and then climbs up the protocol layers. Here the approach has been somewhat nonlinear in an attempt to follow the intuition used when one creates a new technology to solve a certain problem. With this approach, we state a problem from the real world and create a model that reflects the features of the problem. The model is a simplification, a caricature of the reality, but as every good caricature, it captures the essential features. A certain model (for example, a collision model of a wireless channel), allows the system designer to propose solutions that reside within a subspace of the space of all possible solutions to the real communication problem. By enriching the model (for example, adding a capture and interference cancellation to the collision model), the system designer can devise solutions that go beyond the boundaries of the previously mentioned subspace. Practically each new chapter brings enrichment of the models, presenting system/algorithm designs that extend the ones developed for the simpler system models.
Each chapter starts with a cartoon that carries the main message of the chapter. The narrative in the book uses characters as it facilitates the discussion about communication between different parties. This is inspired by the security literature, which deals with Alice, Bob, etc. Here I have started from the other side of the alphabet, which is populated by the letters commonly used in communication theory. The characters are Zoya, Yoshi, Xia, Walt, Victoria (which happens to be the name of my mom) and Umer, and, yes, they are more international compared to Alice and Bob. The base stations are named Basil and Bastian for obvious reasons.
Among the references in “further reading”, I have inserted references to some of the research works co-authored by me. This is not to boost my citations by a self-citation (which is, righteously, often not counted in the academic record), but rather to offer a reference that shows that I, the author, have made an actual research contribution to the area. This can only increase the credibility of what is written in the chapter.
Objectives and Target Audience
When I started the book, the objective was to make it suitable for casual reading and use almost no equations. In the meantime, the number of equations increased, but still far below the number in standard textbooks on wireless communications, such that there is still hope that the reader can read it casually. Yet, the fact that there are five problems after each chapter indicates that the book can also be used as a textbook. However, for in depth reading, the reader should rely on the literature in “further reading”.
The target audience is:
Students in electronics, communication and networking. Some of the problems at the end of the chapters are actually mini-projects, which the students can do over an extended time. This is suitable for both graduate and undergraduate courses. Clearly, if used as a graduate course, then there is more reliance on external literature.
Wireless engineers that are specialists in one area who want to know how the whole system works, without going through all the detail and math.
Computer scientists that want to understand the fundamentals of wireless connectivity, the requirements. and, most importantly, the limitations.
As wireless connectivity starts to play a big role in a large number of cyber-physical systems, such as smart grids, transport, logistics or similar, the engineers specializing in those areas can obtain