Network mobility allows nodes to maintain their connections whilst attaching to different access networks. These access networks may be based on different access technologies. The NEMO Basic Support protocol is a generic protocol that can be used in different mobile environments such as bus or train. Yet, access control mechanisms and Authentication, Authorization and Accounting (AAA) architecture have to be set up according to these specific contexts. The fundamental difference, from an operator’s point of view, for access control and AAA considerations, is the ownership of the Mobile Router which is the centric device for network mobility. As such, three deployment scenarios are studied. AAA architectures are proposed and security problems are highlighted for each scenario.