resented some misconfigurations affecting the handling of QoS parameters that were under investigation). Additionally, this example also illustrates the necessity for an end-to-end approach to the QoS issues. Fourth Generation Mobile Networks Ajay R Mishra 5.1 Beyond 3G In previous chapters it was shown that all of the three previous generations of mobile network had their merits and demerits but none of them had the ability to completely replace the other. Even IMT-2000, a worldwide standard, was not able to break the bottleneck of high data rate and capacity, and SO this led to the formation of a new generation, referred to as the beyond 3G generation or 4G, but there is no clear definition for it. However, it was thought that instead of developing new radio interfaces and new technology it would be better to integrate existing and newly developed wireless systems like the GPRS, EDGE, Bluetooth, WLAN and Hiper-LAN. Hence, in the eighteenth TG-8/1, a new working group WP8F was established in 1999 to look into efforts to develop the systems beyond the IMT-2000. It was felt that the next generation networks would offer some exciting opportunities, such as: Performance. The 4G systems are intended to provide high quality video services providing data transfer speeds of about 100 Mbps. Bandwidth. The 4G technology offers transmission speeds of more than 20 Mbps and is capable of offering high bandwidth services within the reach of local area network (LAN) hotspots, installed in airports, homes and offices. Interoperability. The existence of multiple standards for 3G made it difficult to roam and interoperate across networks. There is therefore a need for a global standard providing global mobility and service portability SO that the single-system vendors of proprietary equipment do not bind the customers. Technology. Rather than being an entirely new standard, 4G basically resembles a conglomeration of existing technologies and is a convergence of more than one technology. 5.2 4G Network Architecture The exact netwo