No abstract

Meeting citizens' requirements economically and efficiently is the most important objective of Smart Cities. As a matter of fact, they are considered a key concept both for future Internet and information and communications technology. It is expected that a wide range of services will be made available for residential users (e.g. intelligent transportation systems, e-government, e-banking, e-commerce and smart management of energy demand), public administration entities, public safety and civil protection agencies and so on with increased quality, lower costs and reduced environmental impact. In order to achieve these ambitious objectives, new technologies should be developed such as non-invasive sensing, highly parallel processing, smart grids and mobile broadband communications. This paper considers the communication aspects of Smart City applications, specifically, the role of the latest developments of Long-Term Evolution-Advanced standard, which forecast the increase of broadband coverage by means of small cells. We shall demonstrate that the novel concept of small cell fully meets the emerging communication and networking requirements of future Smart Cities. To this aim, a feasible network architecture for future Smart Cities, based on small cells, will be discussed in the framework of a future smarter and user-centric perspective of forthcoming 4G mobile technologies.

Knowledge Graphs (KGs) that publish RDF data modelled using ontologies in a wide range of domains have populated the Web. The SHACL language is a W3C recommendation that has been endowed to encode a set of either value or model data restrictions that aim at validating KG data, ensuring data quality. Developing shapes is a complex and time consuming task that is not feasible to achieve manually. This article presents two resources that aim at generating automatically SHACL shapes for a set of ontologies: (1) Astrea-KG, a KG that publishes a set of mappings that encode the equivalent conceptual restrictions among ontology constraint patterns and SHACL constraint patterns, and (2) Astrea, a tool that automatically generates SHACL shapes from a set of ontologies by executing the mappings from the Astrea-KG. These two resources are openly available at Zenodo, GitHub, and a web application. In contrast to other proposals, these resources cover a large number of SHACL restrictions producing both value and model data restrictions, whereas other proposals consider only a limited number of restrictions or focus only on value or model restrictions.

With the constant growth of Internet of Things (IoT) ecosystems, allowing them to interact transparently has become a major issue for both the research and the software development communities. In this paper we propose a novel approach that builds semantically interoperable ecosystems of IoT devices. The approach provides a SPARQL query-based mechanism to transparently discover and access IoT devices that publish heterogeneous data. The approach was evaluated in order to prove that it provides complete and correct answers without affecting the response time and that it scales linearly in large ecosystems.

Wireless Metropolitan Area Networks based on IEEE 802.16d/e standards are soon to be deployed in several countries. However, there is lack of published literature with results from actual testbeds. This paper introduces the work done in the EU Sixth Framework Programme Project WEIRD to design and set up WiMAX testbeds in four EU countries. We describe the methodlogy followed, detail our implementation and present results from the testbeds, as deployed in the first phase of WEIRD. The testbeds are used to demonstrate how WiMAX technology can be used to extend the connectivity of the panEuropean data communications network (GEANT2) to isolated and impervious areas and, furthermore, to assure end-to-end quality of service to novel applications.

Blockchain has become a pervasive technology in a wide number of sectors like industry, research, and academy. In the last decade a large number of tailored-domain problems have been solved thanks to the blockchain. Due to this reason, researchers expressed their interest in combining the blockchain with other well-known technologies, like Semantic Web. Unfortunately, as far as we known, in the literature no one has presented the different scenarios in which Semantic Web and blockchain can be combined, and the further benefits for both. In this paper, we aim a providing an in-depth view of the beneficial symbiotic relation that these technologies may reach together and report the different scenarios that we have identified in the literature to combine Semantic Web and blockchain.

The foundations for the definition of the network of the future should be based on a correct user and community characterizations to minimize the fragmentation of the experiences during the global interactions with information communication infrastructures. This paper describes some of the complex objectives and main challenges that telecommunication solution and services have to deal with in order to respect both specific requirements of global user interactions, habits and personalization, and framework requirements about green environments.

Demand Response (DR) gains increasing attention as a core building block of smart grids. Advanced ICT systems have been made available in the last decades and have been employed already in commercial energy markets. As more and more hardware and software solutions are flooding the market, the need for interoperability among systems has become a necessity. Building upon OpenADR, a well-known standard for DR, this work presents its semantic enrichment towards transforming it into an ontology (publicly available), which ultimately enables semantic interoperability among various DR stakeholders and systems and other semantic-related features like data validation, reusing terms and integration with other standard ontologies. Following the Linked Open Terms methodology, a detailed description of the main OpenADR services is presented, encoded in OWL, along with needed extensions that derive from other well-known ontologies. By introducing an OpenADR ontology, the adoption and deployment of OpenADR in both research and industrial implementations is expected to expand, ultimately promoting significantly semantic interoperability in DR systems.