Policy-driven binding to information resources in mobility-enabled scenarios

The widespread diffusion of mobile computing and of portable devices with wireless connectivity identifies new challenging scenarios for the Internet provisioning of information services. The possible mobility of users, terminals, and even middleware/service components requires solutions to handle properly the links to information resources in response to the mobile entity migration. Binding decisions may depend on dynamic deployment conditions, e.g., local availability of resources, user preferences, and terminal hardware/software characteristics, and should be determined at service provision time. There is the need for novel middlewares capable of supporting mobility-enabled resource binding and of cleanly separating the application logic from binding strategies. The paper presents a middleware, called SCaLaDE, that supports the accessibility of mobile users/terminals to information services. SCaLaDE provides mobile clients with mobile agent-based proxies that can follow the user/terminal roaming and have their resource references transparently accommodated by the middleware depending on policy-driven binding strategies expressed in a high-level specification language and separated from the application logic. This separation of concerns is crucial to reduce the complexity and leverage the development of mobility enabled information services.