4G Wireless Video Communications

4

4G Wireless Communications and Networking

4.1 IMT-Advanced and 4G

Today, wireless technologies and systems which are claimed to be “4G” represent a market positioning statement by different interest groups. Such claims must be substantiated by a set of technical rules in order to qualify as 4G. Currently, the ITU (International Telecommunications Union) has been working on a new international standard for 4G, called IMT-Advanced, which is regarded as an evolutionary version of IMT-2000, the international standard on 3G technologies and systems.

With the rapid development of telecommunications technologies and services, the number of mobile subscribers worldwide has increased from 215 million in 1997 to 946 million (15.5% of global population) in 2001, as shown in Figure 4.1. It is predicted that by the year 2010 there will be 1700 million terrestrial mobile subscribers worldwide. A substantial portion of these additional subscribers is expected to be from outside the countries that already had substantial numbers of mobile users by the year 2001. Figure 4.1 shows the user trends of mobile and wireline telecommunications services and applications.

4G technologies can be thought of as an evolution of the 3G technologies which are specified by IMT-2000. The framework for the future development of IMT-2000 and IMT-Advanced and their relationship to each other are depicted in Figure 4.2. Systems beyond IMT-2000 will encompass the capabilities of previous systems. Other communication ...