Summary This chapter reviews the trends in the end-to-end (E2E) architectural design for 5th generation (5G) networks. It describes the high-level ideas behind the common architectural trends, with a first definition of their common capabilities and how they can be leveraged to provide the enhanced key performance indicators (KPIs) expected by 5G networks. The chapter describes the common requirement and design principles that drive the current efforts in both standardization and research. It explains how the E2E architecture looks like, with the description of the main modules and which fundamental technical problems they will solve. The chapter explores the open issues on E2E architecture and a possible migration path. It introduces some of the novel enablers that will be a fundamental part of future 5G networks and the associated requirements. The chapter talks about how the current radio access network (RAN) and core architectures can be migrated to the future architectures.