A concept to facilitate the integration of UAVs into controlled airspace using a datalink dialig with civil ATC and a military airspace control system is being pursued. To evaluate potential concepts of operation and the associated functions of the UAV mission management system and to refine the human-machine interface requirements, a UAV mission management simulation environment is being extended. The extensions are performed in three phases. Phase one has been completed and added the capability to perform a datalink-based dialog to the control station. The second phase will add the capability to network the control station with an ATC simulator and the MASE C2 system. The third phase will add the capability to operate in a network with multiple operator stations, allowing scenarios involving the (partial) handover of control to be evaluated. This paper provides the rationale for the datalink based integration and the current concept for the operator station user interface to support this idea. It discusses the planned simulation setup for phases I to II and the results from phase I.@en