A Survey on Semantic Software Platforms for Sensor Networks' Interoperability
V. Kramar*
* Oulu University of Applied Sciences, Pehr Brahe Software Laboratory, Raahe, Finland
Abstract
A large number, variety, heterogeneity of sensor networks and their application areas are amazing at these days.Along with complicationof internetworking schemas interoperability issues are growing continuously. Processing data at higher levels of intelligence using metadata may increase interoperability significantly. In this paper a survey on platforms and frameworks that propose a way to form information or even knowledge out of sensor data by annotating it with semantic metadata is presented. An overview of relevant standards, specifications and community efforts is given along with a vision of Internet of Things, Semantic Sensor Web andSemantic Reality. Benefits of the use of semantic technologies, particularly, Semantic Web, in sensor network applications are discussed. The paper concludes withstatement of current situation and future forecast.
Keywords: semantic, sensor, web, network, platform, framework, interoperability
Introduction
In multi-networks environment, data exchange is not always seamless due to heterogeneity of networks, especially with increasing a number of those. A seamless data exchange is possible when it is not performed at a level of data (by data formatsthat are often different or not compliant) but at level of information (by a meaning of data). Semantic technologies allow meaningful data processing through metadata layer. In this paper a survey on platforms and frameworks that use semantic technologies to process and exchange data of sensor networks are presented and discussed.
Towards to integrating the physical world into self-organizing information space via sensor Web
Sensor networks are tools allowing human to cense our physical world. The Internet of Things deals with identified objects of the virtual world that reflect entities of the real world. To make this possible, the real world object can be defined as resource and annotated with data obtained from sensor networks. Semantic Web technologies, e.g. Resource Description Framework (RDF) are intended for that. In its turn, sensor data can also be defined and annotated. Such web is known as Semantic Sensor Web. Semantic Reality is a vision of information space that comprises the virtual and the real world and requires understanding of both for that purpose.
An effort of Semantic Web Activity ofthe World Wide Web Consortium (W3C), Open Geospatial Consortium (OGC), different academic institutions and industry players in standardization, developing practices, ontologies and taxonomies made it finally possible to have real implementations of projects likeNEMBES-FM, S-SOS, AAI, DOG, etc.
Results and Discussion
It is proved by practical experiments with software platforms and frameworks that semantic technologies bring sensor networks' interoperabilityto a higher level. Following the Semantic Web specifications allow developing applications with different level of abstraction and practically any complicated interoperability schemas or evennon-yet-existing schemas and a fuure of Web.
A drowback of such platforms and frameworks is a big effort required at the beginning of development process. This drowback can be partially reduced by growing number of open implementations and ontologies available. Another drowback is a low yet community acceptance of those technologies or their use in such an emerging way.
Conclusions
Currently we are at the beginning of an expansion into the Semantic Reality. Main technoloical enables exist, netwiork infrastructures are developed enough. Some standardisation is missing though. But even more than that a large community acceprtance is missing in both, industry and academia. Most of the moderrn platforms serving the sensor networks do not use semantic technologies. Thus a power of semantics is either unknown or underestimated.
Time will come though that a power of semantic technologies will be realized at its full potential and their benefits will become to be so clear that a wave of acceptance will be observed.