Semantic Web of Things: an analysis of the application semantics for the IoT moving towards the IoT convergence

Abstract

The Internet of Things (IoT) is being applied for stovepipe solutions, since it presents a semantic description limited to a specific domain. IoT needs to be pushed towards a more open, interoperable and collaborative IoT. The first step has been the Web of Things (WoT). WoT evolves the IoT with a common stack based on web services. But, even when a homogeneous access is reached through web protocols, a common understanding is not yet acquired. For this purpose, the Semantic Web of Things (SWoT) is proposed for the integration of the semantic web on the WoT. This work analyses the SWoT, presenting its different levels to offer an IoT convergence. Specifically, we analyse the trends for capillary networks and for cellular networks with standards such as IPSO, ZigBee, OMA, and the oneM2M initiative. This work also analyses the impact of the semantic-annotations/metadata in the performance of the resources.

Interoperability in Internet of Things: Taxonomies and Open Challenges

“…The Semantic Web of Things (SWoT) [72] paradigm is proposed for the integration of the Semantic Web with the WoT, for realizing a common understanding of the various entities which form the IoT. Recent research has concluded that semantic web technologies are a major driver for interoperability across heterogenous environments [73]. The literature uses semantic web technologies to achieve semantic interoperability by using standards or agreements on the format and meaning of data or in a dynamic way by using shared vocabularies either in a schema form and/or in an ontology-driven approach.…”

Towards semantic interoperability in an open IoT ecosystem for connected vehicle services

“…However, interoperability in the IoT concerns various layers of the communication stack. The advancements of integrating smart things in the various layers are labelled with Internet of Things (network layer), Web of Things (application layer) and Semantic Web of Things (a common description of things) [7]. Since the underlying layers adopted standard technologies of the web (such as HTTP/HTML), leveraging semantic web technologies for the IoT is a promising approach to converge heterogeneous data sources in a smart ecosystem [8].…”

“…RDF provides a flexible approach to support and specify domain-dependent and independent vocabularies, and to define relations between terms from different vocabularies [7]. However, even though the vocabulary can be easily accessed, consumers must be able to understand the used vocabulary by the publisher, by either using the same or an aligned vocabulary.…”

“…In SSN, for instance, sensors, their setup, and their observations can be defined, which in turn could be combined with other vocabularies that define labels for specific sensor types, observations, attributes, and so forth. [7], [8] Figure 1 illustrates how these semantic models relate to existing messaging interfaces and thing description models in the IoT. Semantic models are not restricted to RDF, DATEX II 4 for example, is a EU initiative to define a vocabulary for the transportation domain in UML and the data models of the FIWARE 5 initiative are represented in JSON.…”

“…The layer below the semantic models is responsible for the definition of messaging interfaces and supporting the abstraction of smart things. Past and ongoing initiatives for this layer are, for example, IoT-A 6 , the OGC SensorThings API 7 , and the BIGIoT API [13]. The open messaging standards called Open-Messaging Interface (O-MI) 8 and Open-Data Format (O-DF) 9 are used in the open ecosystem to achieve interoperability on the application layer.…”