An Ontology-based Framework for Describing Discoverable Data Services

Abstract

Data-services are applications whose main concern is to provide data to their client applications. Data-services play a key role in areas like the Internet of Things (IoT), where smart objects might want to offer/consume data through Internet, and thus, providing/discovering such data-services automatically. To make data-services discoverable, the usual strategy is to register dataservices in some kind of service-broker, i.e., a marketplace where data-services are publicly offered. Then, smart objects query the service-broker, and the servicebroker is responsible to match the request with its data-services. How to perform this matching automatically is still an open problem in IoT. In this paper, we propose a framework for specifying data-services so that they can be automatically discovered. To achieve it, we provide unambiguous descriptions of the data-services and the request, together with a mechanism capable of interpreting these descriptions and check whether they match. Our solution is grounded on ontology-based data integration and can be applied in the IoT context, altought it can also be used in any other domain involving the discovery of applications retrieving data. In essence, our idea is based on, given a domain ontology describing the real world our data-services speaks about, consider each data-service as a new association in that ontology. Indeed, a data-service consuming some input objects and retrieving some output objects can be modelled as an association from the proper to the latter. As expected, ontology constraints must be used to restrict the instances of the association to the input-output instances our data-service expects/provides. Hence, the problem of matching data-services is reduced to that of automatic reasoning on ontologies (and in particular, association subsumption). Thus, contributions on this last field can be directly used for the data-services discovering problem.