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A Comparison with two semantic sensor data storages in total data transmission

Manaf saeid aragy2 Kaveh Bashash3 Shahram ,mehdi gheisari5 Sharifzadeh1 department of Department of Bashokian4 * varamin Department of computer, Computer,Damav School of university of Computer,Firooz Science and and Branch, Computer science and koohBranch,Isla research branch, Islamic Aazad Engineering,Iran technology, mic Azad Islamic Azad University, University of Email : University, University,Khom Damavand, Iran, Science and mehdi.gheisari61 Firoozkooh, IR, ein, Iran, Email : Email : Technology(IUS @gmail.com Email : saeed.aragy@gm kvb2002@yahoo. T), Email : manafsharif@gm ail.com com Bashokian@com ail.com p.iust.ac.ir

Abstract—The creation of small and cheap monitor and control environments of sensors promoted the emergence of large interest [1, 2]. WSN was identified as one scale sensor networks. Sensor networks of the ten emerging technologies that will allow monitoring a variety of physical change the world in MIT Technology phenomena, like weather conditions Review [3]. A wide variety of attractive (temperature, humidity, atmospheric applications with the use of WSN [4] pressure ...), traffic levels on highways or would come into reality, such as habitat rooms occupancy in public buildings. monitoring, [5] search and military Some of the sensors produce large volume industries, disaster relief, target tracking, of data such as weather temperature. These precision agriculture and smart data should be stored somewhere for user environments.WSN creates variant types queries. In this paper two known sensor of data like arrays and images. These data data storage methods that store data should be stored somewhere for variety of semantically has been compared and it has queries. The paper exemplifies how the use been shown that storing data in ontology of can enhance data form consumes more energy so the management in sensor networks. lifetime of sensor network would Semantics exploit underlying relationships decreases. The reason we choose them is between data captured by sensors [6- that they are useful and popular. 8].Section 2 describes some background knowledge like XML and RDFa. Section 3 Keywords- wireless, semsos, SWE describes SSW framework. Section 4 I. INTRODUCTION describes a semantic data storage. Progresses in wireless communications Section5provides an evaluation of the and micro electromechanical systems work. Finally in Section6we discuss our (MEMS) led to the deployment of large- conclusions. scale wireless sensor networks (WSN), in other words it revolutionized the way we II. Background Knowledge The core language and service interface This section describes some background includes the following: knowledge we should have. (1) Observations & Measurements (O&M) - Standard models and XML A. XML (Extensible Markup Schema for encoding observations and Language) measurements from a sensor, both archived and real-time. XML is the abbreviation of Extensible (2) Sensor Model Language (Sensor ML) .XML includes a set of - Standard models and XML Schema for rules for defining semantic tags that break describing sensors systems; in other words a document into different parts and defines it provides information needed for those different parts of the document [6]. discovery of sensors, location of sensor XML is a meta-markup language that observations. defines a syntax in which other domain- (3) Transducer Model Language specific markup languages can be written. (Transducer ML) – Standard models and Syntactically, XML documents look like XML Schema for supporting real-time HTML documents. A well-formed XML streaming of data to and from sensor document—one that conforms to the XML systems. syntax—contains exactly one element. (4) Sensor Observations Service (SOS) - Additionally an arbitrary number of Standard web service for requesting, comments and processing instructions can filtering, and retrieving observations and be included. sensor system information. This is the XML introduces some languages to allow intermediary between a client and an more semantic management of information observation source or near real-time sensor than HTML. XML is about the description channel. of data, with nothing said about its presentation.HTML combines some The following example shows a timestamp fundamental descriptive markup, plus a encoded in O&M and semantically great deal of mark up that describes the annotated with RDFa. presentation of the data [7]. The timestamp’s semantic annotation describes an instance of time: Instant (here, B. Sensor Web Enablement (SWE) time is the namespace for OWL-Time ontology): The Open Geospatial Consortium recently built the Sensor Web Enablement as a suite Seth and Hanson [10] discuss the idea of a This example generates two RDF triples. semantic sensor Web framework. SSW is The first, time_1 rdf: type time: Instant, used for providing enhanced meaning for describes time_1 as an instance of time: sensor observations so as to enable Instant (subject is time_1, predicate is rdf: situation awareness. It enhances meaning type, object is time: Instant). The second, by adding semantic annotations to existing time_1 xs: date-time “2010-03- standard sensor languages of the SWE. 08T05:00:00,”describes a data-type These annotations provide more property of time_1 specifying the time as a meaningful descriptions and enhance literal value (subject is time_1, predicate is access to sensor data than SWE alone, and xs: date-time, object is “2008-03- they act as a linking mechanism to bridge 08T05:00:00”)[10]. the gap between the primarily syntactic XML-based standards of the C. RDFa (or Resource Description SWE and the RDF/OWL-based metadata Framework - in - attributes): standards of the . In association with semantic annotation, Many languages can be used for ontologies and rules play an important role annotating sensor data, such as RDFa, in SSW for interoperability, analysis, and XLink, and SAWSDL (Semantic reasoning over heterogeneous multimodal Annotations for WSDL and XML sensor data. Schema). Here, we describe the use of RDFa, a W3C IV. ES3N proposed standard (www.w3.org/2006/07/SWD/RDFa/) and a ES3n uses Semantic Web techniques to markup language that enables the layering manage and query data collected from a of RDF information on any XHTML or mini dome Sensor Network. Our tool XML document. RDFa is a set of supports complex queries on both extensions to XHTML. RDFa uses continuous and archival data, by capturing attributes from XHTML's meta and link important associations among data, elements and generalizes them so that they collected and stored in a distributed are usable on all elements. This allows dynamic ontology [12]. annotating XHTML markup with semantics RDFa provides a set of V. Implementation, Evaluation and attributes that can represent semantic Comparison metadata within an XML language from which we can extract RDF triples using a At first we have evaluated these two simple mapping[11]. methods using j-sim[13,14] software that is a sensor network simulator in 10. For III. SSW (semantic sensor Web) evaluation of SSW we use the following After that we show above example in data: ontology form: Conditions> name=AirTemperature”> Schema# Double>35.1 hasUomIdentifierrdf:about= air “http://sweet.jpl.nasa.gov/ontology/units.o temperature wl#degreeC”/> urn:ogc:def:property: uble”>35.1 OGC:AIRTemperature > name=Winspeed”> L.Schema#anyURI>urn:ogc:def:property: about= Win “http://sweet.jpl.nasa.gov/ontology/units.o Speed wl#meter_persecond” code=”m/s”/> uble”>6.5 DataType=http://www.w3.org/2001/XML. Schema# Double>6.5 om:hasDoubleValue> This example generates two RDF. The first air temperature is 35.1 Celsius that data transmission. We should have a tradeoff in urn:ogc:def:property: mechanism to deal with link failures OGC:atmosphericConditions data more semantically will also be another step. Another step is evaluating Figure 1 shows a comparison with SSW this method when sensors send their data and ES3N: in stream.

References As we can see when we use ES3n, more data are transmitted through network in [1] I. F. Akyildiz, W. Su, Y. comparison with SSW. So the lifetime of Sankarasubramaniam, and E. Cayirci, network decreases more[15]. "Wireless VI. CONCLUSION Sensor Networks:A Survey," Computer In recent years progresses in energy Networks, vol. 38, pp. 393--422, 2002. efficient design and wireless technologies have enabled various new applications for [2] G. J. Pottie and W. J. Kaiser, "Wireless wireless devices .These applications span a integrated network sensors," ACM wide range including real time streaming Communications,vol. 43, pp. 51-58, video and audio delivery, remote 2000. monitoring using networked micro sensors, personal medical monitoring and [3] MIT Technology Review, Feb. 2003, home networking of everyday appliances. http://www.techreview.com. While these applications require high performance network, they suffer from [4] D. Estrin, G. P. L. Girod, and M. resource constraints that do not exist in Srivastava, "Instrumenting the world with traditional wired computing environments. wireless sensor networks," presented at In particular wireless spectrum is scarce ICASSP, Salt lake City, UT, 2001. limiting the bandwidth available to applications and making the channel error [5] A. Mainwaring, D. Culler, J. Polastre, prone and since the nodes are often battery R. Szewczyk, and J. Anderson, "Wireless operated and there is limited available Sensor networks for habitat monitoring," energy. If we can store sensors data more presented at the 1st ACM effectively, we have more effective and international workshop on Wireless lifetime sensor networks. In this paper, we sensor networks and applications, 2002. compared two methods of sensor data modeling to find better one in some aspect [6] W3C. Extensible markup language MobileSummit 2009, Conference () 1.0 (second edition). Technical Proceedings. Report 6 October 2000, Consortium, October 2000. W3C [13] M. Gheisari,” Design, Recommendation, Implementation, and Evaluation of http://www.w3.org/TR/2000/REC-xml- SemHD: A New 20001006. Semantic Hierarchical Sensor Data Storage”, Indian J. Innovations Dev., Vol. [7]W3C. Semantic web. Technical Report 1, No. 3 (Mar 2012) ISSN 2277 – 5390 17.October 2002, World Wide Web Consortium, [14] M. Gheisari, A.R. Bagheri 2000.http://www.w3.org/2001/sw/, no ,”Evaluation of two sensor data storages in pagination, verified on Oct total 17, 2002. data”5th international symposium on advances in science & technology, Iran [8] Mike Botts et al., .OGC Sensor Web ,2011 Enablement: Overview and High Level Architecture (OGC 07-165), Open [15] J.-H. Kim, H. Kwon, D-H.Kim, H- Geospatial Consortium whitepaper,28 Y.Kwak, and S.-J. Lee, “Building a Dec. 2007. serviceorientedontology for wireless sensor networks,” Computer and [9] Geography Markup Language (GML), Information Science,2008. ICIS 08.Seventh IEEE/ACIS International http://www.opengeospatial.org/standards/g Conference on, pp. 649–654, ml May2008

[10] , Cory Henson, and Satya Sahoo, "Semantic Sensor Web," IEEE Computing, July/August 2008, p. 78-83.

[11]http://www.w3.org/TR/xhtml-rdfa- primer/

[12] P.Barnaghi, S. Meissner, M. Presser, and K. Moessner,” Sense and Sens’ability: Semantic Data Modelling for Sensor Networks”, ICT-

Fig 1. Compares SSW and ES3N. X axis shows number of sensors and Y is the volume of data packets transmitted through network in KB.