Semantic Techniques to Support IoT Interoperability
233
One of the main characteristics of OWL-S, which makes it particularly adapt to
describe Services and compositions thereof, is its capability to describe a service’s
behaviour, considering all the possible interactions that a user is allowed to have
with it.
2.1.1 Application of Semantic Technologies to the IoT World
The use of Semantic Technologies in the IoT field is well documented, and several
ontologies have been developed in past years to efficiently describe sensors, in terms
of their capabilities and requirements, and of the data they exchange.
The work presented in [3] can be considered one of the first attempts to properly
apply semantics to sensor networks, by using an ontology-driven approach to increase
the network’s adaptability.
Among the first standard ontologies developed to tackle interoperability and adaptability issues in sensors networks, the one presented in [6] is surely worth citing. The
Semantic Sensor Network (SSN) ontology, developed by the W3C Semantic Sensor
Network Incubator Group is freely available
5 can be considered an Upper Ontology,
as it describes general sensor concepts, such as measurements, observations and sensors’ relations, but it does not provide any domain-related concepts. The work of the
incubation group also introduces the concept of Stimulus-Sensor-Observation (SSO)
pattern in their ontology description, trying to reduce all the described concepts to
three basic terms: Stimuli, that are detectable changes in the observed environment;
Sensors, in charge of the actual observation and of the transformation of the physical
stimulus to its digital representation; Observation representing the transformation of
the stimulus into the sensor’s output.
Other ontologies have been developed on top of SSN, such as the Sensor, Observation, Sample, and Actuator Ontology (SOSA) [10]
6 which can be considered
an lightweight update of the SSN, introducing a simplification of the original SSO
pattern and providing support to modern sensors descriptions.
Other recent standards include MyOntoSens [16], an ontology which describes
whole sensor measurement process including concepts like inputs, outputs, calibration, drift, latency, and precision. The ontology is being standardized as a Technical
Specification (TS) within the SmartBAN Technical Committee of the ETSI (European Telecommunications Standards Institute).
7
Since modern Smartphones contain numerous sensors that can be used to build
complex sensor networks, especially with the development of Edge and Fog Computing, specialized ontologies have been built to provide formal description thereof. The
work described in [2] presents the SmartOntoSensor ontology, based on previously
5 Semantic Sensor Network Ontology—https://www.w3.org/2005/Incubator/ssn/ssnx/ssn.
6 SOSA—https://www.w3.org/TR/vocab-ssn/.
7 Smart Body Area Networks (SmartBAN); Service and application standardized enablers and
interfaces, APIs and infrastructure for interoperability management—https://www.etsi.org/deliver/
etsi_ts/103300_103399/103327/01.01.01_60/ts_103327v010101p.pdf.
233
One of the main characteristics of OWL-S, which makes it particularly adapt to
describe Services and compositions thereof, is its capability to describe a service’s
behaviour, considering all the possible interactions that a user is allowed to have
with it.
2.1.1 Application of Semantic Technologies to the IoT World
The use of Semantic Technologies in the IoT field is well documented, and several
ontologies have been developed in past years to efficiently describe sensors, in terms
of their capabilities and requirements, and of the data they exchange.
The work presented in [3] can be considered one of the first attempts to properly
apply semantics to sensor networks, by using an ontology-driven approach to increase
the network’s adaptability.
Among the first standard ontologies developed to tackle interoperability and adaptability issues in sensors networks, the one presented in [6] is surely worth citing. The
Semantic Sensor Network (SSN) ontology, developed by the W3C Semantic Sensor
Network Incubator Group is freely available
5 can be considered an Upper Ontology,
as it describes general sensor concepts, such as measurements, observations and sensors’ relations, but it does not provide any domain-related concepts. The work of the
incubation group also introduces the concept of Stimulus-Sensor-Observation (SSO)
pattern in their ontology description, trying to reduce all the described concepts to
three basic terms: Stimuli, that are detectable changes in the observed environment;
Sensors, in charge of the actual observation and of the transformation of the physical
stimulus to its digital representation; Observation representing the transformation of
the stimulus into the sensor’s output.
Other ontologies have been developed on top of SSN, such as the Sensor, Observation, Sample, and Actuator Ontology (SOSA) [10]
6 which can be considered
an lightweight update of the SSN, introducing a simplification of the original SSO
pattern and providing support to modern sensors descriptions.
Other recent standards include MyOntoSens [16], an ontology which describes
whole sensor measurement process including concepts like inputs, outputs, calibration, drift, latency, and precision. The ontology is being standardized as a Technical
Specification (TS) within the SmartBAN Technical Committee of the ETSI (European Telecommunications Standards Institute).
7
Since modern Smartphones contain numerous sensors that can be used to build
complex sensor networks, especially with the development of Edge and Fog Computing, specialized ontologies have been built to provide formal description thereof. The
work described in [2] presents the SmartOntoSensor ontology, based on previously
5 Semantic Sensor Network Ontology—https://www.w3.org/2005/Incubator/ssn/ssnx/ssn.
6 SOSA—https://www.w3.org/TR/vocab-ssn/.
7 Smart Body Area Networks (SmartBAN); Service and application standardized enablers and
interfaces, APIs and infrastructure for interoperability management—https://www.etsi.org/deliver/
etsi_ts/103300_103399/103327/01.01.01_60/ts_103327v010101p.pdf.