See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/312113565 Ontologies and Semantic Web for the Internet of Things - a survey Conference Paper · October 2016 DOI: 10.1109/IECON.2016.7793744 CITATIONS READS 5 256 2 authors: Ioan Szilagyi Patrice Wira Université de Haute-Alsace Université de Haute-Alsace 10 PUBLICATIONS 17 CITATIONS 122 PUBLICATIONS 679 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: Physics of Solar Cells and Systems View project Artificial intelligence for renewable power generation and management: Application to wind and photovoltaic systems View project All content following this page was uploaded by Patrice Wira on 08 January 2018. The user has requested enhancement of the downloaded file. Ontologies and Semantic Web for the Internet of Things – A Survey Ioan Szilagyi, Patrice Wira MIPS Laboratory, University of Haute-Alsace, Mulhouse, France {ioan.szilagyi; patrice.wira}@uha.fr Abstract—The reality of Internet of Things (IoT), with its one of the most important task in an IoT system [6]. Providing growing number of devices and their diversity is challenging interoperability among the things is “one of the most current approaches and technologies for a smarter integration of fundamental requirements to support object addressing, their data, applications and services. While the Web is seen as a tracking and discovery as well as information representation, convenient platform for integrating things, the Semantic Web can storage, and exchange” [4]. further improve its capacity to understand things’ data and facilitate their interoperability. In this paper we present an There is consensus that Semantic Technologies is the overview of some of the Semantic Web technologies used in IoT appropriate tool to address the diversity of Things [4], [7]–[9]. systems, as well as some of the well accepted ontologies used to “Formal semantics enable the knowledge management and develop applications and services for the IoT. We finally present data exchange in a machine-interpretable way. This makes the Semantic Web Stack for the Internet of Things pointing out semantic technologies a key to overcome common modelling, some of its shortcomings in the development of an IoT model-exchange and interoperability problems that need to be application or service. solved across the life cycle of systems” [9]. Keywords—semantic web; internet of things; ontology; schema Without the objective of being exhaustive in our IoT; OWL presentation, we outline some of the works in the domain and provide a survey on existing ontologies. We finally propose a I. INTRODUCTION Semantic Web Stack for the IoT. The Internet of Things (IoT) is a technological evolution that, by interconnecting things, provides the basic structure for II. INTERNET OF THINGS the development of next generation everyday services and Defining the IoT is not an easy task. IEEE launched an applications. Cisco states that the IoT was born sometime invitation intended to establish a baseline definition for IoT, between 2008 and 2009 when the number of connected devices and in May 2015 they published a document that provides an on the Internet exceeded the number of world population. They overview of current definitions and concepts used in the estimate that by 2020 the IoT will feature around 50 billion domain of IoT. Depending on the environment scenario, which connected devices [1]. With the penetration and the can be small or large, the IoT is defined as follow: (1) for the convergence of the Internet, the IoT will eventually evolve small environment scenario the IoT is “a network that connects onto the Internet of Everything [2]. uniquely identifiable ‘Things’ to the Internet. The ‘Things’ have sensing/actuation and potential programmability An Internet of Things’ adapted Metcalf Law [3, p. 184] capabilities. Through the exploitation of unique identification would state that the value of a network is proportional to the and sensing, information about the ‘Thing’ can be collected square of the number of connected things (e.g. compatible and the state of the ‘Thing’ can be changed from anywhere, communicating devices, users). The value of the network will anytime, by anything.”, and (2) for the large environment determine its capacity to understand a situation or a context and scenario, the IoT is : “a self-configuring, adaptive, complex this understanding will “potentially enable services and network that interconnects ‘things’ to the Internet through the application to make intelligent decisions and to respond to the use of standard communication protocols. The interconnected dynamics of their environment” [4]. things have physical or virtual representation in the digital The capacity of the IoT to understand its environment is world, sensing/actuation capability, a programmability given by its interdisciplinary nature. Services in sectors like feature and are uniquely identifiable. The representation buildings, energy, consumers and homes, healthcare and life contains information including the thing’s identity, status, science, industry, transportation, retail, security/public safety location or any other business, social or privately relevant and, of course, IT and networks are represented in the IoT information. The things offer services, with or without through a variety of applications and over “300 different device human intervention, through the exploitation of unique types” [5]. However, the variety of devices that covers different identification, data capture and communication, and aspects of the environment has direct consequences on the data actuation capability. The service is exploited through the use that they produce and can limit the capacity of higher level of intelligent interfaces and is made available anywhere, systems to interpret and process the generated data. The anytime and for anything taking security into integration of data generated by the large diversity of things is consideration” [10]. The difference between a small and a I. Szilagyi and P. Wira, "Ontologies and semantic web for the internet of things," 42nd IEEE Industrial Electronics Conference (IECON 2016), Florence, Italy, October 24-27, 2016, pp. 6949-6954 (DOI: 10.1109/IECON.2016.7793744) large environment is given by its complexity defined in terms itself does not necessarily possess computational and of number of connected things and the thing’s communication capabilities. These capabilities are given by a ownership/management capabilities. The IERC (European chip that is attached and deeply integrated into the Thing. The Research Cluster on the Internet of Things) definition states things that form the IoT were not necessarily created with the that IoT is “a dynamic global network infrastructure with self- purpose of connecting them to the Internet (the first IoT thing configuring capabilities based on standards and interoperable was a toaster [13]). Generally, all kind of things can be communication protocols where physical and virtual ‘things’ connected to an IoT system. However, a Thing must possess have identities, physical attributes, and virtual personalities some interest for a service or an application; it must do and user intelligent interfaces, and are seamlessly integrated something useful in order to be considered for integration in an into the information network” [11]. The ITU (International IoT system. These things can be: Tags (e.g. QR Code, RFID); Telecommunication Union) defines IoT as “a global Devices (e.g. Arduino, Raspberry Pi), Machines (e.g. Smart infrastructure for the information society, enabling advanced Bulb, Smart Car), or even entire Environments (e.g. Smart services by interconnecting (physical and virtual) things based Building, Smart City)[14, p. 4]. on existing and evolving interoperable information and communication technologies” [12]. According to these When integrated into an IoT system, the Thing can be definitions IoT is primarily a network. characterized by three main capabilities: (1) communication; (2) programmability (data processing and storage); and (3) While an IoT system can become very complex, we present sensing and/or actuating capabilities. ITU defines the “device” in Fig. 1 a simple and basic architecture based on an IoT as a “piece of equipment with mandatory capabilities of system. The Thing, which has computational and communication and the optional capabilities of sensing, communication capabilities can exchange information with actuation, data capture, data storage and data processing” [12]. other things on the network in order to coordinate their actions Sensing and/or actuating capabilities allow the Thing to and/or they can simply produce data that will be used at a interact with its environment. A Thing may dispose of sensing higher level of the service or application (e.g. analytics, (e.g. thermometer), actuating (e.g. motors) or both capabilities business decisions). (e.g. thermostat). While the actuating capabilities are usually restricted and would require in most cases authorizations, Without re-considering here all the aspects and sensing capabilities can be shared to multiple services and characteristics defining an IoT system, we will emphasize on applications, and so contributing to the overall value of the IoT. some of its elements’ characteristics. While the network aspect is a core component and tight related to Internet standards and The programmable capability gives some autonomy