Introduction

We start our look at wireless technology with what are, to date, the most important wireless systems – the cellular communications networks. They are the most important because they create by far the greatest value from the use of wireless communications to date [1] (although some suggest that the role of short-range unlicensed communications will become increasingly valuable over the next decade).

Cellular communications has been one of the great success stories for wireless since the early 1990s. The number of subscribers, networks and mobile phones has grown very quickly and the networks have gone through three major generations of technology. However, this is now changing and network operators face the following key challenges.

• Growth in subscriber numbers is mostly at an end, except in developing countries, and for the first time annual revenue has started falling as competition has reduced prices.

• Traffic levels across wireless networks are growing rapidly as mobile broadband becomes popular, causing network congestion but not resulting in the increased revenue needed to invest in additional resources.

• Services and applications are increasingly being provided by others, sidelining the operators, who are becoming ‘bit pipes’, reducing their potential for increased revenue and changing the value chain.

Whether 4G, sometimes known as ‘long-term evolution’ (LTE), can help operators address these challenges and indeed how it might change the cellular industry is the focus of this chapter; other possible solutions such as femtocells are discussed in subsequent chapters.