Disconnected Operations in Mobile Environments

The execution of distributed applications involving mobile terminals and fixed servers connected by wireless links raises the need for handling network disconnections, both involuntary during unexpected connection breakdowns, and voluntary when the user wants to save money and energy. In this paper, we investigate how standard CORBA mechanisms (Objects By Value and Portable Interceptors) can be used for enhancing legacy CORBA-based distributed applications in order to support voluntary and involuntary disconnections. We show that the first mechanism can be used for handling easily voluntary disconnections by copying on the terminal all the data necessary for running the application in a disconnected mode. The second mechanism allows also to handle involuntary disconnections ; a switch between connected mode and disconnected mode can be performed transparently to the user.