Paolo Barone

MUSIC: Middleware Support for Self-Adaptation in Ubiquitous and Service-Oriented Environments

Self-adaptive component-based architectures facilitate the building of systems capable of dynamically adapting to varying execution context. Such a dynamic adaptation is particularly relevant in the domain of ubiquitous computing, where numerous and unexpected changes of the execution context prevail. In this paper, we introduce an extension of the MUSIC component-based planning framework that optimizes the overall utility of applications when such changes occur. In particular, we focus on changes in the service provider landscape in order to plug in interchangeably components and services providing the functionalities defined by the component framework. The dynamic adaptations are operated automatically for optimizing the application utility in a given execution context. Our resulting planning framework is described and validated on a motivating scenario of the MUSIC project.

A Pluggable and Reconfigurable Architecture for a Context-Aware Enabling Middleware System

Context awareness is a core feature of modern mobile and ubiquitous computing systems. Although it has not reached its full potential yet, one can already observe significant activity in the area of software engineering for supporting the development of context-aware applications. An example of such an activity is the MUSIC project, which proposes a middleware featuring a generic and reusable context management system. This paper describes the pluggable architecture of this system, and explains how it advances the state of the art through its support for context heterogeneity and better resource utilization. The former is achieved with the use of a novel architecture, which enables the separation of low-level, platform-specific context plug-ins from higher-level application-specific ones. The improved resource utilization is achieved through intelligent activation and deactivation of context plug-ins based on the needs of the active applications. The proposed approach has been experimentally evaluated and the results indicate that it significantly improves the resource utilization in context-aware applications, especially when deployed on lightweight mobile devices.

ERMHAN: A multi-channel context-aware platform to support mobile caregivers in continuous care networks

Continuous care models for chronic diseases pose several technology-oriented challenges for home-based continuous care, where assistance services rely on a close collaboration among different stakeholders such as health operators, patient relatives and social community members. ERMHAN is a multi-channel context-aware service platform designed to support care networks in cooperating and sharing information with the common goal of improving patient quality of life. In order to meet extensibility and flexibility requirements, this platform has been developed through ontology-based context-aware computing and a service oriented approach.

Context Grouping Mechanism for Context Distribution in Ubiquitous Environments

Context distribution is a key aspect for successful applications within mobile and ubiquitous computing environments. In such environments, context information is acquired by several and multiple context sensors distributed over the environment. Applications collect and react to these data, according to predefined adaptation mechanisms. The success of these mechanisms depends on the availability of context information, which is disseminated over the network. However, in practice, only a fraction of the observable context information is required by the adaptation mechanisms. Moreover, for privacy reasons, it is important to delimitate a scope for context dissemination. In this work we address these issues by proposing a context grouping mechanism which allows the definition of groups based on the context characteristics. Each group is defined by these characteristics and delimitate a given context information set that can be distributed among group members. This approach of context grouping acts as a two-fold mechanism. On the one hand, it controls and organizes context distribution over a peer-to-peer network. On the other hand, it proposes a primary and low-level privacy mechanism for context distribution, which is an important aspect influencing context distribution.

A peer-to-peer based infrastructure for context distribution in mobile and ubiquitous environments

The increasing proliferation of mobile devices has raised the expectations for user-customized and environment-aware services. However, mobile context-aware systems inherently feature characteristics of distribution and heterogeneity which pose great challenges to their developers. This paper focuses on context distribution in mobile and ubiquitous computing environments. We propose a peer-to-peer based context distribution approach and evaluate it against the derived requirements.

Evaluation of context distribution methods via Bluetooth and WLAN: insights gained while examining battery power consumption

In a traditional context-aware system, most context information is local to a device. However, we may need access to context information from outside the device. Increasingly mobile electronic devices are equipped with Bluetooth and/or WLAN network interfaces. Both of these technologies enable ad hoc discovery & networking. In this paper we evaluate the use of these technologies for context distribution within a local area (i.e., limited to a single hop). Using Bluetooth, we begin by discovering devices using Bluetooths discovery protocol, collect their context information, create an XML file containing this information, and distribute this file to all discovered devices, such that every device now has the same context information. Next we perform the same discovery, collect, and distribute functions, but using WLAN. In each case we have performed the cycle of operations starting with a fully charged battery and continuing until the device was not able to utilize the selected wireless interface any longer. Finally we compare both approaches to context distribution in terms of battery power consumption. We observe that Bluetooth consumes 2-6 times more energy for transmission of a 1MB file to two devices than to discover these two devices. Furthermore, the transfer of this file is two times slower than WLAN, and we must unicast this file to each device. Multicasting via WLAN proved to be less energy consuming than the Bluetooth transmission, if data is to be sent to more than three users. In addition, the energy to discover 2 devices along with their services using Bluetooth consumed 52 times more energy than to receive the same amount of data via a WLAN multicast. Thus, this paper shows that it is more energy efficient to distribute context knowledge to other devices, than having each device learn this information itself. Finally, we give equations for calculating the battery power consumption of transmitting data using any protocol that runs over Bluetooth or over WLAN.

Hosting and using services with qos guarantee in self-adaptive service systems

In service-oriented computing, the vision is a market of services with alternative providers offering the same services with different cost and quality of service (QoS) properties, where applications form and adapt dynamically through dynamic service discovery and binding. To ensure decent and stable QoS to end users and efficient use of resources, it is required that both client applications and service implementations are able to adapt both their internal configuration and their binding to other actors in response to changes in the environment. To this end, service level negotiation and agreements (SLA) are important to ensure coordinated end to end adaptation. In this paper we propose a solution based on the integration of an SLA mechanism into a compositional adaptation planning framework and describe a simple yet powerful implementation targeted for resource constrained mobile devices. As validation we include a case study based on a peer-to-peer distributed mobile application.

An innovative platform to enhance the quality of life of people with mild dementia

ISISEMD project aims to provide a pilot of intelligent system to support independent living of persons with cognitive problems or mild dementia. The primary user of the system is the elderly but the services are also designed to support caregivers and relatives in patients daily care. Services and user scenario are analyzed together with four end-user organizations that participate in the project team. The solution is composed by different systems already available on the market, but not specifically focused on dementia management. All the systems are integrated under the ISISEMD platform that manages common functionalities (eg. login, reporting…) and the web interface for different users, too. Privacy and security are considered and the consortium assured these requirements by adopting commercially available solutions and compliance with all the applicable national and international regulations. Moreover, a market and business analysis is made before starting with the validation test.