Rebecca Montanari

Context-aware middleware solutions for anytime and anywhere emergency assistance to elderly people

The growing percentage of elderly people in society calls for novel healthcare support services to enhance elders daily life independence in indoor and outdoor environments. Ubiquitous technologies create significant opportunities not only for indoor, but also for outdoor anytime and anywhere assistance. However, outdoor emergency assistance requires that we address several challenging aspects, from elder location tracking and health condition monitoring to the formation of ad hoc assistance groups capable of assisting elders in need of help. This article focuses on the creation and management of outdoor assistance teams and proposes a group management system, AGAPE, that exploits visibility of location and group/user/device profile information as a key principle to trigger and control the team formation and team member interactions required to coordinate emergency activities.

Context-aware semantic discovery for next generation mobile systems

A mass market of users with differentiated preferences and heterogeneous wireless terminals will increasingly access services dynamically introduced by competitor providers. In next-generation mobile systems, novel solutions for user-centric service discovery are crucial to provide personalized views of only the services of potential interest. The service view personalization should be based on user context, for example, user preferences, access device capabilities, and environment conditions, and should exploit semantic technologies to allow flexible matching between requirements and capabilities in open and dynamic deployment scenarios. Our MIDAS middleware exemplifies how to exploit context awareness based on user/device/service profile metadata and semantic-based matchmaking

Context-based access control for ubiquitous service provisioning

Pervasive user mobility, wireless connectivity and the widespread diffusion of portable devices raise new challenges for ubiquitous service provisioning. In particular, mobility of users/devices causes frequent and unpredictable changes in physical user location and in consequently available resources and services. Users can also change portable access devices, with different capabilities, even at runtime and during the same service session, thus forcing us to consider very dynamic aspects even due to client heterogeneity. Access control to resources is crucial to leverage the provision of ubiquitous services and calls for novel solutions based on various context information, e.g., user/device location, device properties, user needs, local resource visibility. This work presents a novel access control model built upon the concept of context as the first-class design principle to rule access to resources. As key features, this model allows to associate access control permissions with contexts where users operate and users acquire/lose their permissions when entering/leaving a specific context. Unlike traditional access control solutions where user identity/role triggers policy evaluation when requesting resource access, this model exploits the user context to fully determine the set of available permissions. In addition, the proposed model allows to express context-based access control policies at a high level of abstraction cleanly separate from service logic implementation, thus promoting dynamic policy modification with no impact on the service code. The paper shows the implementation of the proposed model in the UbiCOSM framework and presents a mobile office service provisioning scenario.

Context-based security management for multi-agent systems

Policies are being increasingly used for controlling the behavior of complex multi-agent systems. The use of policies allows administrators to specify both agent permissions and duties without changing source code or requiring the consent or cooperation of the agents being governed. However, policy-based control can encounter difficulties when applied to agents that act in pervasive environments characterized by frequent and unpredictable changes. In this case, policies cannot be all specified a priori to face any operative run time situation, but require continuous adjustments to allow agents to behave in a contextually appropriate manner. Current approaches to policy representation have been restrictive in many ways, as they typically follow a subject-centric model, which assigns agent permissions and obligations on the basis of agent role/identity information. However, in the new pervasive scenario the roles/identities of interacting agents may not be known a-priori and most important, may not be informative or sufficiently trustworthy. We claim that the design of policy-based agent systems for pervasive environments requires a paradigm shift from subject-centric to context-centric policy models. This paper discusses some issues concerning the specification and enforcement of context-driven policies and presents a novel context-based policy approach that considers context as a first-class principle to guide both policy specification and enforcement. In this perspective, context explicitly appears in the specification of security policies and context changes trigger the evaluation process of applicable agent permissions and obligations.

A context-centric security middleware for service provisioning in pervasive computing

Pervasive user mobility, wireless connectivity and the widespread diffusion of portable devices raise new challenges for ubiquitous service provisioning. An emerging architecture solution in the wireless Internet is based on mobile proxies (implemented as mobile agent-based middleware components) over the fixed network that follow the movements and act on behalf of the limited wireless clients. It is crucial that mobile proxies have full visibility of their context, i.e., the set of available and relevant resources, depending on access control rules, client location, user preferences, privacy requirements, terminal characteristics, and current state of hosting environments. The paper presents the design and implementation of a context-centric security middleware, called UbiCOSM, for MA-based service provisioning in pervasive computing. UbiCOSM dynamically determines the contexts of mobile proxies, and effectively rules the access to them, by taking into account different types of metadata (user profiles and authorization policies), expressed at a high level of abstraction and cleanly separated from the service logic. The paper also shows the functioning of UbiCOSM in the design and the development of a mobile context-centric airport business assistant.

A context-aware group management middleware to support resource sharing in MANET environments

Recent advances in Mobile Ad-hoc NETworks (MANET) technologies promote new opportunities for users to share resources from ubiquitous points of attachment, when changing physical locations and even when no statically deployed network infrastructure is available. However, the highly dynamic nature of Mobile Ad-Hoc environments causes users to experience continuous changes in the set of the locally accessible resources, thus increasing the complexity of resource sharing. Novel middleware solutions are required to support the various management issues involved in resource sharing in MANETs environments. In particular, it is crucial to handle and to propagate up to the application level the visibility of both the users that are willing to group together to share their resources and of the resources they decide to share. The paper proposes a group management middleware (AGAPE) that, as a key feature, exploits the visibility of context information, e.g., user location, user attributes and preferences, access device properties, to create and discover groups of interest for resource sharing, to monitor the availability of groups members, and to dynamically arrange/requalify group members bindings to shared resources as changes in context operating conditions occur. Application developers can exploit the AGAPE support to build on top of it various application-specific resource sharing strategies and mechanisms, such as Global Virtual Data Structures. Finally, the paper presents a MANET-enabled emergency rescue application scenario to show and to evaluate the functioning of AGAPE.

Enabling context-aware group collaboration in MANETs

Recent advances in mobile ad-hoc networks (MANET) technologies promote new opportunities for anytime and anywhere impromptu collaboration and leverage the provisioning of novel collaborative services, such as emergency rescue, e-care, and troop car management. However, the design and deployment of collaborative services in MANET environments raise new group management challenges. In particular, unpredictable users/devices mobility, frequent disconnection/reconnection of devices and continuous changes in network topology call for novel middleware solutions to handle properly the transient and dynamic formation of ad-hoc groups. The paper proposes a context-aware group membership middleware (AGAPE) that bases group management decisions depending on context information, such as user location, user attributes and preferences, and access device properties. User location determines the scope of group member visibility within a network locality, whereas user requirements and device properties govern the joining to a group and influence the played role of a user within a group. AGAPE provides a set of support services to arrange/dissolve and manage ad-hoc groups on demand and propagates the visibility of available group members and of their context up to the application level to allow applications to adapt collaborative decisions and actions accordingly. The paper also presents a MANET-enabled emergency rescue application scenario to show and to evaluate the functioning of AGAPE.

Context-Awareness for Impromptu Collaboration in MANETs

The growing diffusion of wireless-enabled portable devices and the recent advances in mobile ad-hoc networks (MANET) open a new scenario where users can benefit from anywhere/anytime impromptu collaboration. However, the development of collaborative services in MANET environments raises new challenges and calls for novel middleware solutions to handle properly the communication between transiently collaborating partners. The paper proposes AGAPE, a context-aware group communication middleware that permits to select collaborating partners, to schedule incoming messages and to tailor their presentation on the basis of group members context, e.g. depending on members location, attributes, and device properties.

Context-Aware Group Communication in Mobile Ad-Hoc Networks

The widespread availability of both fixed and wireless network connectivity and the growing market of portable devices are enabling anytime and anywhere impromptu collaboration. The emergence of Mobile Ad-Hoc Networks (MANET) further opens up new possibilities for the provisioning of advanced collaborative services, such as civil protection, e-care, and troop car management. However, the design and the deployment of collaborative applications in MANET scenarios raises new group management challenges. In particular, MANET characteristics, e.g., unpredictable and frequent mobility of users/devices, intermittent device connectivity, continuous variations of network topology, make it impossible any a-priori knowledge about group members availability and ask for novel solutions to handle properly the communication about group members. The paper proposes a context-aware communication model to govern communication on the basis of the characteristics of the communicating parties, such as their location and their profiling information. The model provides communication patterns with different semantics to address both point-to-point and point-to-multipoint communication needs. The paper shows the implementation of the proposed model in the AGAPE framework for the design, deployment, and support of collaborative applications in MANET environments and presents the functioning of the AGAPE communication support in the context of a civil protection application scenario.

Context-awareness for impromptu collaboration in MANETs

The growing diffusion of wireless-enabled portable devices and the recent advances in mobile ad-hoc networks (MANET) open a new scenario where users can benefit from anywhere/anytime impromptu collaboration. However, the development of collaborative services in MANET environments raises new challenges and calls for novel middleware solutions to handle properly the communication between transiently collaborating partners. The paper proposes AGAPE, a context-aware group communication middleware that permits to select collaborating partners, to schedule incoming messages and to tailor their presentation on the basis of group members context, e.g. depending on members location, attributes, and device properties.