The present document identifies key mobility issues for access to IP-based enterprise information and communications services. It defines a taxonomy of mobility terms and then explores use cases and connectivity scenarios involving mobile enterprise users. From these it derives requirements for mobility management@ architecture and security. Mobility for enterprise communication is about making desktop communication and information resources available at different locations and while on the move. The Technical Report encompasses both wired and wireless connectivity using enterprise and public all-IP-networks for voice@ data and converged services. The present document is intended as an aid to analysing gaps in standardization that prevent or hinder mobility in enterprise communications and information access. More general interworking issues of enterprise communications are covered by a companion Technical Report ECMA TR/91.