The Reference Model for Open Distributed Processing provides a framework for building distributed heterogeneous applications and creates a good basis for building mobile (ubiquitous) computing applications. We analyse the requirements imposed by mobile computing on distributed environments and characterise adaptability strategies which can be applied in nomadic environments to cope with the quality of service changes due to user, computer or application mobility. We then describe the design of an architecture which extends the ODP architecture to provide support for mobile computing. We characterise the functionality of the architecture, the RPC semantics used for communication in this architecture as well as a prototype built in a CORBA environment.