Michele Girolami

On service discovery in mobile social networks

Mobile social networks represent a convergence between mobile communications and service-oriented paradigms, which are supported by the large availability and heterogeneity of resources and services offered by recent mobile devices. In particular, the service-oriented nature of MSN is in the capability of sharing resources and services among devices that lie in proximity and that opportunistically interact. Service discovery is thus of primary importance to sustain the most intimate mechanisms of MSN. Despite of their centrality, studies on service discovery in MSN are still in their youth. We contribute to frame the results achieved so far and to identify some possible perspectives of the research in this field, by giving a transversal review of the scientific outcomes in the different steps of service discovery, namely advertisement, query, selection and access.

SAIL: A Sensor Abstraction and Integration Layer for Context Awareness

Wireless Sensor Networks (WSN) are an important technological support for ambient assisted applications. Up to now most WSN applications are based on ad hoc solutions, and attempts to provide reusable applications are still in their youth. Under this trend of research we propose a layered architecture called SAIL (Sensor Abstraction and Integration Layers) to be used in context aware architectures, and aimed at integrating WSN as context information sources. In the proposed approach, the applications running on WSN can be exposed using either a node centric or a data centric paradigm, and they are interfaced with different access technologies. SAIL is currently encapsulated within the OSGi framework and has been tested on MICAz motes.

Empowering mobile crowdsensing through social and ad hoc networking

Mobile crowdsensing (MCS) enables collective data harvesting actions by coordinating citizens willing to contribute data collected via their sensor-rich smartphones that represent sources of valuable sensing information in urban environments nowadays. One of the biggest challenges in a real long-running MCS system lies in the capacity not only to attract new volunteers, but also, and most importantly, to leverage existing social ties between volunteers to keep them involved to build long-lasting MCS communities. In addition, the advent of high-performing devices and ad hoc communication technologies can help to further amplify the effect of sensing actions in proximity of the volunteer devices. This article originally describes how to exploit these socio-technical networking aspects to increase the performance of MCS campaigns in the ParticipAct living laboratory, an ongoing MCS real-world experiment that involved about 170 students of the University of Bologna for more than two years. The article also reports some significant experimental results to quantify the effectiveness of the proposed techniques.

The UniversAAL Platform for AAL (Ambient Assisted Living)

Abstract This article describes the UniversAAL platform, an open platform intended to facilitate the development, distribution, and deployment of technological solutions for Ambient assisted living (AAL). The platform is intended to benefit end users (i.e., assisted persons, their families, and caregivers), authorities with responsibility for AAL, and organizations involved in the development and deployment of AAL services. It consists of an extensive set of resources (some are software and some are models/architectures) aimed at these different groups. The resources are classified into three main groups: runtime support, development support, and community support. The article presents the benefits that can be expected from the widespread adoption of the platform. The article also describes progress on prototype implementations of some of the software resources, and the results of initial evaluations of the platform. The work is partially based on results from earlier European Union-funded research projects in the area.

A service-oriented ZigBee gateway for Smart Environments

In the recent past Smart Environments, and in particular Smart Homes, have attracted the attention of many researchers and industrial vendors. In such environments, according to the Ambient Intelligence paradigm, heterogeneous devices may operate collectively using context information and intelligence that is usually hidden in the home networks. The networks of ZigBee devices play an important role in this scenario. However they require an easier interaction model with IP-based networks. This work presents an open source platform that seamlessly integrates ZigBee devices with applications running on smart phones and other connected devices available at home. It can be deployed on low-cost devices, such as Plug-PC, and it exploits the OSGi execution environment to discover devices and to notify the smart home of new available services.

universAAL: Provisioning Platform for AAL Services

universAAL is a European research project that aims at creating an open platform and standards which will make it technically feasible and economically viable to develop Ambient Assisted Living (AAL) solutions. It defined hardware and software infrastructure for smart environments called AAL Spaces, which enable context sharing and reasoning about activities carried out by the assisted person. AAL Services developed with the universAAL platform may be a combination of hardware, software and human resources. Tools for the development, publishing and provisioning of such services have been defined to support the whole chain of stakeholders involved in the AAL domain. The paper focuses on the provisioning of AAL Services by describing the main components involved in the service life cycle.

Service discovery in mobile social networks

We present a new service discovery algorithm, termed SIDEMAN, which considers human mobility for service dissemination and discovery. SIDEMAN takes advantage of mobile social networking characteristics, such as user membership to a restricted number of communities and interest for similar services among users in the same community. We evaluated the performance of SIDEMAN via simulations in a scenario based on traces collected at the IEEE conference Infocom in 2006. Our algorithm has been compared to the social version of two popular data dissemination techniques, namely, flooding and gossiping. We have measured how proactive an algorithm is in distributing services of interest (Recall), how many services are already with a user when they are needed (Gain), the energy cost for service discovery, and the time needed to reply a service query. We show that SIDEMAN obtains perfect Recall and a Gain that is always comparable to that of the other algorithms. Furthermore, most services are retrieved in reasonable time and at a lower energy cost than that of the flooding and gossiping-based solutions.

Mobile crowd sensing management with the ParticipAct living lab

Abstract The widespread availability of smartphones have enabled the blossom of Mobile Crowd Sensing (MCS) projects, whose goal is to involve users in participatory tasks aimed at building large real-world datasets. In this framework, we present the large-scale experience of the ParticipAct Living Lab, an ongoing experiment at the University of Bologna, which involves about 170 students in MCS campaigns. Specifically, we originally present the analysis of the large set of ParticipAct collected results against some primary datasets in the literature; we present the evaluation and assessment of the original participatory sensing campaign management aspects of ParticipAct; and we report the lessons learned from this wide-scale deployment experience.

Detecting Social Interactions in Working Environments Through Sensing Technologies

The knowledge about social ties among humans is important to optimize several aspects concerning networking in mobile social networks. Generally, ties among people are detected on the base of proximity of people. We discuss here how ties concerning colleagues in an office can be detected by leveraging on a number of sociological markers like co-activity, proximity, speech activity and similarity of locations visited. We present the results from two data gathering campaigns located in Italy and Spain.

Signals from the depths: Properties of percolation strategies with the Argo dataset

Underwater communications through acoustic modems rise several networking challenges for the Underwater Acoustic Sensor Networks (UASN). In particular, opportunistic routing is a novel but promising technique that can remarkably increase the reliability of the UASN, but its use in this context requires studies on the nature of mobility in UASN. Our goal is to study a real-world mobility dataset obtained from the Argo project. In particular, we observe the mobility of 51 free-drifting floats deployed on the Mediterranean Sea for approximately one year and we analyze some important properties of the underwater network we built. Specifically, we analyze the contact-time, inter-contact time as well density and network degree while varying the connectivity degree of the whole dataset. We then consider three known routing algorithms, namely Epidemic, PROPHET and Direct Delivery, with the goal of measuring their performance in real conditions for USAN. We finally discuss the opportunities arising from the adoption of opportunistic routing in UASN showing that, even in a very sparse and strongly disconnected network, it is still possible to build a limited but working networking framework.