Chapter 9
Recent Trends and Developments
There have been many new developments in the past decade as wireless technologies have continued to improve rapidly and have been providing higher data rates, optimizations for packet data traffic, and so on. Since this chapter is one of the chapters on wireless access technologies, we focus here on recent trends and developments in wireless access technologies. Recent trends and developments in other aspects (e.g., in the network) are covered in other chapters, especially Chapter 12, and in service architectures in Chapter 13.
In this chapter we begin in Section 9.1 with the third-generation systems WCDMA and cdma2000. Then in Section 9.2 we explore some emerging technologies in wireless, such as HARQ and multiple-antenna techniques. While WCDMA and cdma2000 can be said to be the last wireless air interfaces in the more voice-and circuit-centric traditional mold, a variety of enhancements and improvements to these systems were soon developed to support high-speed packet data more efficiently. These, called by various names, including HSPA and EV-DO, are discussed in Section 9.3. We wrap up the chapter by looking at aspects of WiMAX (Section 9.4) and LTE (Section 9.5).
9.1 Third-Generation CDMA-based Systems
There are two major third-generation (3G) systems: WCDMA (Section 9.1.1) and cdma2000 (Section 9.1.2). In general, these systems could be called “3G” because they addressed the ITU requirements for higher data rates, variable data rates, ...
