Softbank Mobile Softbank Telecom Individual Sprint DJ China Mobile Virtualization and cloud services have evolved significantly in the last few years. Additionally trends in virtualization like Network Function Virtualiztion and Softward Defined Networking are bound to have implications to mobile network architectures of cellular systems (3G/4G), WiFi and others. IETF has developed a number of mobility protocols that are used in the industry today. Mobility network architectures continue to evolve and it is likely that they will embrace virtualization and cloud services trends as well. The IETF can play a role in defining the mobility protocols that support architectures which leverage virtualization and cloud technologies. This document captures several use cases and requirements for a virtualized mobile network architecture.