The Semantic Sensor Web (SSW) is a marriage of sensor web and semantic Web technologies. The encoding of sensor descriptions and sensor observation data with Semantic Web languages enables more expressive representation, advanced access, and formal analysis of sensor resources. The SSW annotates sensor data with spatial, temporal, and thematic semantic metadata. This technique builds on current standardization efforts within the

Open Geospatial Consortium The Open Geospatial Consortium (OGC), an international voluntary consensus standards organization for geospatial content and location-based services, sensor web and Internet of Things, GIS data processing and data sharing. It originated in 1994 ...

's Sensor Web Enablement (SWE) and extends them with Semantic Web technologies to provide enhanced descriptions and access to sensor data.

Semantic modeling and annotation of sensor data

Ontologies and other semantic technologies can be key enabling technologies for sensor networks because they will improve semantic interoperability and integration, as well as facilitate reasoning, classification and other types of assurance and automation not included in the Open Geospatial Consortium (OGC) standards. A semantic sensor network will allow the network, its sensors and the resulting data to be organised, installed and managed, queried, understood and controlled through high-level specifications. Ontologies for sensors provide a framework for describing sensors. These ontologies allow classification and reasoning on the capabilities and measurements of sensors, provenance of measurements and may allow reasoning about individual sensors as well as reasoning about the connection of a number of sensors as a macroinstrument. The sensor ontologies, to some degree, reflect the OGC standards and, given ontologies that can encode sensor descriptions, understanding how to map between the ontologies and OGC models is an important consideration. Semantic annotation of sensor descriptions and services that support sensor data exchange and sensor network management will serve a similar purpose as that espoused by semantic annotation of Web services. This research is conducted through th
W3C Semantic Sensor Network Incubator Group (SSN-XG)
activity.

W3C Semantic Sensor Networks

The

World Wide Web Consortium The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web. Founded in 1994 and led by Tim Berners-Lee, the consortium is made up of member organizations that maintain full-time staff working to ...

(W3C) initiated th
Semantic Sensor Networks Incubator Group (SSN-XG)
to develop the Semantic Sensor Network (SSN) ontology, intended to model sensor devices, systems, processes, and observations. The Incubator Group later transitioned into th
Semantic Sensor Networks Community Group
It was then picked up in the join
OGC
an
W3CSpatial Data on the Web Working Group
and published as a W3C Recommendation. The Semantic Sensor Network (SSN) ontology enables expressive representation of sensor observations, sampling, and actuation. The SSN ontology is encoded in the

Web Ontology Language The Web Ontology Language (OWL) is a family of knowledge representation languages for authoring ontologies. Ontologies are a formal way to describe taxonomies and classification networks, essentially defining the structure of knowledge for variou ...

(OWL2). A number of projects have used it for improved management of sensor data on the Web, involving annotation, integration, publishing, and search.

Context

Sensors A sensor is a device that produces an output signal for the purpose of sensing a physical phenomenon. In the broadest definition, a sensor is a device, module, machine, or subsystem that detects events or changes in its environment and sends ...

around the globe currently collect avalanches of data about the world. The rapid development and deployment of sensor technology is intensifying the existing problem of too much data and not enough knowledg

With a view to alleviating this glut, sensor data can be annotated with semantic

metadata Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive metadata – the descriptive ...

to increase interoperability between heterogeneous sensor networks, as well as to provide contextual information essential for

situation awareness Situational awareness or situation awareness (SA) is the perception of environmental elements and events with respect to time or space, the comprehension of their meaning, and the projection of their future status. An alternative definition is tha ...

. Semantic web techniques can greatly help with the problem of data integration and discovery as it helps map between different metadata schema in a structured way.

Uses

Semantic Sensor Web (SSW) technologies are utilized in fields such as

agriculture Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to ...

disaster management Emergency management or disaster management is the managerial function charged with creating the framework within which communities reduce vulnerability to hazards and cope with disasters. Emergency management, despite its name, does not actuall ...

building management Building management (in the UK) is a discipline that comes under the umbrella of facility management. Hard services usually relate to physical, structural services such as fire alarm systems, lifts, and so on whereas soft services allude to cleaning ...

and laboratory management.

Agriculture

Monitoring various

environmental A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale f ...

attributes is critical to the growth of

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...

s. Environmental attributes that are critical for growers are mainly

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measurement, measured with a thermometer. Thermometers are calibrated in various Conversion of units of temperature, temp ...

, moisture, pH,

electric conductivity Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allows ...

(EC), and more. Real-time monitoring in addition to setting alerts for the mentioned sensors was never possible. With the creation of SSW,

growers A farmer is a person engaged in agriculture, raising living organisms for food or raw materials. The term usually applies to people who do some combination of raising field crops, orchards, vineyards, poultry, or other livestock. A farmer mi ...

can now track their plant growing conditions in real-time. An example of such advancement in agriculture through utilization of SSW is the research conducted in 2008 on Australian

farm A farm (also called an agricultural holding) is an area of land that is devoted primarily to agricultural processes with the primary objective of producing food and other crops; it is the basic facility in food production. The name is used f ...

s where temperature, humidity,

barometric pressure Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, ...

, wind speed, wind direction and rainfall were monitored using SSW methodology. The architecture of this research project consists of personal integration needs, Semantic web, and more in addition to semantic data integration, i.e. where data is centralized to make sensor semantic web technologies meaningful and useful.

Building management (smart buildings)

Managing buildings can be quite sophisticated, as the cost of fixing damages is significantly higher than having proper monitoring tools in place to prevent damages from happening. SSW allows for getting notified of water leaks, controlling apartment temperature via

smartphone A smartphone is a portable computer device that combines mobile telephone and computing functions into one unit. They are distinguished from feature phones by their stronger hardware capabilities and extensive mobile operating systems, which ...

, and more.

Laboratory management

Managing

laboratory A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratory services are provided in a variety of settings: physicia ...

tests can be quite challenging, especially if tests take place over a long time, across multiple locations, or in infrastructures where many tests occur. Such tests include creep tests for a material, reaction tests of a certain chemical or wireless transmission tests of a circuit. Advancements in SSW allow for real-time monitoring of laboratory variables via sensors. Such sensors can take more than one factor into consideration before alerting. For example, an alert can go off when pressure and temperature both exceed a certain limit, or an alert can go off when pressure in one building drops, yet pressure in another building remains the same.

Notable contributions

Standardization is a lengthy and difficult process, as players in a field that have existing solutions would see any standardization as an additional cost to their activities.

(OGC), an international voluntary consensus standards organization that was founded in 1994, is making efforts to enhance and accelerate the growth of the SSW community and standardize sensor information across web. Most OGC standards depend on generalized architecture that is collectively captured in set of

document A document is a written, drawn, presented, or memorialized representation of thought, often the manifestation of non-fictional, as well as fictional, content. The word originates from the Latin ''Documentum'', which denotes a "teaching" or ...

s. The goal of OGC is to provide enhancements in description and meaning of sensor data. Also, OGC had enabled Sensor Web communication. OGC is in charge of creating open

geospatial Geographic data and information is defined in the ISO/TC 211 series of standards as data and information having an implicit or explicit association with a location relative to Earth (a geographic location or geographic position). It is also call ...

standards. Moreover, OCG is supported by

industry Industry may refer to: Economics * Industry (economics), a generally categorized branch of economic activity * Industry (manufacturing), a specific branch of economic activity, typically in factories with machinery * The wider industrial sector ...

government A government is the system or group of people governing an organized community, generally a state. In the case of its broad associative definition, government normally consists of legislature, executive, and judiciary. Government is a ...

, and

academic An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary or tertiary higher learning (and generally also research or honorary membership). The name traces back to Plato's school of philosophy, ...

partners to allow for easy creation of geo-processing technologies known as “plug and play”.

Current challenges

Current challenges in the SSW field include a lack of standardization, which slows down the growth rate of sensors created to measure things. For the semantic sensor web to be meaningful, the languages, tags, and labels across various applications, developed by various developers, must be the same. Unfortunately, due to scattered development of various architectures, such standardization is not possible. This problem is called vastness. There is also the problem of inconsistency, such that when changing the architecture of an existing solution, the system logic will no longer hold. In order to resolve this problem, there is a need for an extensive amount of resources (depending on the size and complexity of system). For example, many existing systems use twelve bits to transfer temperature data to a local computer. However, in a SSW 16 bits of data is acceptable. This inconsistency results in higher

data traffic Network traffic or data traffic is the amount of data moving across a network at a given point of time. Network data in computer networks is mostly encapsulated in network packets, which provide the load in the network. Network traffic is the main ...

with no additional accuracy improvement. In order for the old system to improve, there is a need of allocating extra bits and changing the buffer requirements, which is costly. Assuming the resources required to make the tag requirement are available, there is still the existence of unnecessary data that requires additional storage space in addition to creating confusion for other SSW members. The only solution remaining is changing the hardware requirements, which requires a lot of resources.

References

External links

W3C Semantic Sensor Network Incubator Group

Semantic Sensor Web Project @ Knoesis Center
— Research project at Knoesis bringing semantics to sensor networks.
SemSensWeb2009
- 1st International Workshop on Semantic Sensor Web
The Web of Things
European Semantic Web Conference 2011.
Videk
- A Mash-up for Environmental Intelligence, AI Mash-up challenge @ ESWC 2011. * 5th International Workshop on Semantic Sensor Networks
SSN 2012
, in conjunction with the 11th International Semantic Web Conference
ISWC 2012
Information science Semantic Web Sensor networks Sensors