In this work, a flexible and extensive digital platform for Smart Homes is presented, exploiting the most advanced technologies of the Internet of Things, such as Radio Frequency Identification, wearable electronics, Wireless Sensor Networks, and Artificial Intelligence. Thus, the main novelty of the paper is the system-level description of the platform flexibility allowing the interoperability of different smart devices. This research was developed within the framework of the operative project HABITAT (Home Assistance Based on the Internet of Things for the Autonomy of Everybody), aiming at developing smart devices to support elderly people both in their own houses and in retirement homes, and embedding them in everyday life objects, thus reducing the expenses for healthcare due to the lower need for personal assistance, and providing a better life quality to the elderly users.

This paper presents a publish-subscribe architecture designed to support information level interoperability in smart space applications in the Internet of Things (IoT). The architecture is built on top of a generic SPARQL endpoint where publishers and subscribers use standard SPARQL Updates and Queries. Notifications about events [i.e., changes in the resource description framework (RDF) knowledge base] are expressed in terms of added and removed SPARQL binding results since the previous notification, limiting the network overhead and facilitating notification processing at subscriber side. A novel event detection algorithm, tailored on the IoT specificities (i.e., heterogeneous events need to be detected and continuous updates of few RDF triples dominate with respect to more complex updates), is presented along with the envisioned application design pattern and performance evaluation model. Eventually, a reference implementation is evaluated against a benchmark inspired by a smart city lighting case. The performance evaluation results show the capability to process up to 68k subscriptions/s triggered by simple single-lamp updates and up to 3.8k subscriptions/s triggered by more complex updates (i.e., 10 to 100 lamps).

This paper presents a decentralized Web-based architecture designed to support the development of distributed, dynamic, context-aware and interoperable services and applications. The architecture enables the detection and notification of changes over the Web of Data by means of a content-based publish-subscribe mechanism where the W3C SPARQL 1.1 Update and Query languages are fully supported and used respectively by publishers and subscribers. The architecture is built on top of the W3C SPARQL 1.1 Protocol and introduces the SPARQL 1.1 Secure Event protocol and the SPARQL 1.1 Subscribe Language as a means for conveying and expressing subscription requests and notifications. The reference implementation of the architecture offers to developers a design pattern for a modular, scalable and effective application development.

The Internet of Things (IoT) envisions a global market in which it would be possible to easily get data from IoT devices across the globe. However, the potential of this idea still needs to be unlocked. Centralized architectures fall short due to their lack of transparency and tendency to create silos. On the other hand, blockchain technology enables the creation of distributed and trustworthy systems, but its integration with the IoT is still a matter of research. IoT-based scenarios often employ numerous devices for the same sensing task, which may be heterogeneous and unreliable by purpose. In our vision, IoT applications should rely on data and its quality rather than on single providers. For this purpose, we propose an architecture that enables a decentralized IoT global market in which clients pay for data and device owners are rewarded for providing it. Our solution employs a distributed oracle layer on top of smart contracts powered by a distributed global network of IoT devices. The system supports IoT data source decoupling since the end-user can perform semantic queries bounded to specific locations and data types without specifying the target devices. In addition, it features automatic discovery, interoperability mechanisms, and reputation algorithms for the selection of trustworthy data sources. Our results show that the proposed system is robust and consistently provides quality data, even with multiple malicious data sources.

The Internet of Energy (IoE) for Electric Mobility is an European research project that aims at deploying a communication infrastructure to facilitate and support the operations of Electric Vehicles (EVs). In this paper, we present three research contributions of IoE. First, we describe a software architecture to support the deployment of mobile and smart services over an Electric Mobility (EM) scenario. The proposed architecture relies on an ontology-based data representation, on a shared repository of information (Service Information Broker), and on software modules (called Knowledge Processors -KPs) for standardized data access/management. As a result, information sharing among the different stakeholders of the EM scenario (i.e. EVs, EVSEs, City Services, etc) is enabled, and the interoperability of smart services offered by heterogeneous providers is guaranteed by the common ontology. Second, we rely on the proposed architecture to develop a remote charging reservation system, that runs on top of mobile smarthphones, and allows drivers to monitor the current state-of-charge of their EV, and to reserve a charging slot at a specific EVSE. Finally, we validate our architecture through a benchmark framework, that supports the embedding of mobile EV applications and of real KPs into a simulated vehicular scenario, including realistic traffic, wireless communication and battery models. Evaluation results confirm the scalability of our architecture, and the ability to support EVs charging operations on a large-scale scenario (i.e. the downtown of Bologna).

The design of applications that may benefit from the data gathered from the surrounding physical environment represents a challenging and promising research field. Because of the heterogeneity of such systems interoperability is becoming more difficult to achieve at the service, information and device levels. In this paper, we report on the first attempt to design an interoperability platform by integrating a “Semantic Web” information sharing infrastructure, namely Smart-M3 (Multi-part, Multi-device and Multi-vendor), within the OSGi (Open Service Gateway initiative) framework, enhancing the information level interoperability of the former with the service level interoperability of the latter. Such an interoperability platform can grant the unanticipated evolution of existing Information and Communication Technology (ICT) systems by providing a generic and simple solution to develop what are generally called “Smart Space Applications”. As proof of concept a maintenance scenario will be discussed and detailed.