Mobile communication systems beyond 3G will comprise cellular and self-organizing networks. In this paper an appropriate migration path towards the convergence of these two network types is highlighted and the resulting common radio network architecture is presented. By means of example scenarios the way to beneficially combine both network types will be described. Thereby, transport oriented aspects, especially resource allocation, multihop communication, routing, and special frequency reuse will be the focus of attention. Moreover, it will be described how other network types, like satellite systems, will complement and support cellular and self-organizing networks. Furthermore, we will present results of our research and show the challenges to be met in the design of future radio architectures.