A transparent network handover for nomadic CORBA users

This paper introduces a generic disconnection handling and network handover mechanism for nomadic CORBA applications. The disconnection handling provides a transparent or explicit mode. In the explicit mode, a special class provided by the user or application is informed if a disconnection occurs and can take appropriate actions. The handover mechanism supports an active handover, where the handover decision is based on application and user needs as well as a passive handover which is needed if after a disconnection the original network is not available. Both mechanisms provide a solution for the lost reply problem occurring if the mobile node is disconnected before the reply to an outstanding request has arrived. The presented mechanisms are integrated into the generic proxy platform Π². Π² transparent encapsulates the wireless link and splits the connection between the client on the mobile node and the server into separate parts. Π² can be transparently integrated into existing distributed systems without changes to clients or servers using a generic interface and dynamic type determination