To develop our techniques for intra service interoperability, we intend to explore commonality in the implementation of this service in various collaboration systems. This work will be based on the research done by Dewan [ Dewan Characterizing ] and by Olson et al, [ Olson Trends ] which has explored the design space of some of these services we plan to support in the bus. We propose to extend this work by identifying the design space for the remaining services, and defining translations among the different points in these spaces provided by our clients system. We expect many of these design spaces to be characterized by hierarchical domains. For instance, session management would be classified as implicit and explicit session management, implicit session management would be further classified according to which actions trigger session management functions: entering a room, editing an artifact, and so on. Translations between different domains will typically involve abstracting operations to a common parent domain. For instance, converting between implicit and explicit session management will involve converting specific operations performed by these schemes to an abstract set of session management operations. When an operation in one domain has no counterpart in the other other, the system may ``coerce'' the operation to a different form. For instance, it may transform a fine-grained lock request in one system to a coarse-grained request in another and a series of ``insert line'' events in a text editing user-interface may correspond to a single ``insert structure'' event in a structure editing user interface. Similarly, if one system allows its users to exchange changes incrementally and another allows its users to exchange them only at the end of each day, then the bus will transmit events to the latter at the end of each day instead of incrementally. It may not always be possible to coerce an operation, in which case it may be disallowed. For instance, if two users are are view coupled, and one is using a structure-editor while the other is using a text editor, then the first user would not be allowed elide a substructure,
requires the two users to see the same view.
In the first year, we propose to finish our work on inter and intra-service interoperability for for session management, in the second year for user-interface and networking support; and in the third year for sharing, concurrency/access control, real-time support, and awareness.