Introduction

Cognitive radio is a topic of great interest and holds much promise as a technology that will play a strong role in communication systems of the future. This book focuses on the essential elements of cognitive radio technology and regulation. This is a challenging task in that cognitive radio is still very much an emerging technology. There is much debate over its exact definition, its potential role in communication systems, whether cognitive radios should in fact be permitted in the first place and if yes, what the regulatory policies should be. However, while acknowledging the flux in this field, the book aims to identify the core concepts that will remain central to the field irrespective of how precisely it develops. The aim of this first chapter is to briefly define cognitive radio and to then focus on the all important question of why cognitive radios are needed. This chapter therefore motivates all that is to come in the book.

Brief history and definition

The term cognitive radio was coined by Mitola in an article he wrote with Maguire in 1999 [1]. In that article, Mitola and Maguire describe a cognitive radio as a radio that understands the context in which it finds itself and as a result can tailor the communication process in line with that understanding.