Policy-Driven Binding to Information Resources in Mobility-Enabled Scenarios

Abstract

Abstract. 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 agentbased 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 mobilityenabled information services.

A critical evaluation of location based services and their potential

“…By contrast Bellavista et al (2003) developed the SCaLaDE system that implemented mobile proxies to follow the user and device around so that context-specific services would always be provided. Claude et al (2006) designed the Geo-Located Web Services Architecture to permit the satisfaction of client service requests at the geographically closest server.…”

Transparent Caching of Virtual Stubs for Improved Performance in Ubiquitous Environments

“…In this section we focus on providing related work in mobile environments and compare it with the proposed caching support. [19,20,21,22,23,26] target mobile environments and support disconnections, which enable mobile clients to carry on accessing services in case of disconnections. The system [19] provides support for caching of web services for supporting disconnections in mobile environments, where SOAP (Simple Object Access Protocol) requests / responses are cached.…”

Context-aware middleware for resource management in the wireless internet

“…In addition to the choice of the most suitable binding mechanism, however, a very complex aspect is the design of solutions to dynamically change binding strategies depending on the management requirements of service providers, on the runtime conditions of the execution environment, on user preferences, and on access device properties. Traditional middleware approaches embed a static binding strategy within the service logic, thus limiting the flexibility of binding management [16]. Novel middlewares should support binding strategies defined and modified at provision time, depending on dynamic conditions.…”

“…It is in charge of supporting the specification/update of profile information, and of dynamically installing/enforcing policies for access control and mobility handling. In the following, we focus on the aspects related to mobility handling policies (see [16], [19] for further details about the management of the other metadata types). The enforcement of mobility handling policies involves the detection of changes in the operating environment (via the Monitoring and Location facilities), the notification of event occurrence to the interested policy subjects (via the EM facility), and the MM interpretation of enforced policies so as to activate the specified management actions.…”

“…The resource descriptor is an object with the same methods and constructor interface of the needed resource, returned back to the proxy by the getResource() invocation. CARMEN supports different mechanisms for reference objects, from Jini-based stubs for rebinding to RMI stubs for remote reference; further details about CARMEN reference objects can be found in [16].…”