The document discusses several key issues for 4G networks including rapidly scaling capacity to meet demands of ubiquitous wireless and pervasive computing. It notes capacity challenges and limitations of 2G and 3G networks. Potential approaches for 4G networks include using WLAN hotspots, infostations, self-organizing ad-hoc networks, and content-based multicasting. Hierarchical, self-organizing networks with three tiers (cellular, WLAN, personal area) and automatic protocols are seen as a promising architecture.

3. 4G System Issues

7. 4G System Issues: Protocol Evolution

10. Self-organizing, ad-hoc networks for 4G

13. 4G Mobile Networks: “network of wireless networks”

14. 4G Mobile Networks: An Experimental Testbed