Conceptual diagram ... of novel service features, spectrum management, radio access technologies, wired access integration, core network, and mobile terminal . The focus of the article is to define the scope and features of the 4G system in an overall system/network viewpoint. ... 3GPP (Third Generation Partnership Project) and 3GPP2 [l]-. The 3GPP and 3GPP2 Manuscript received July 31. 2002.