Presentation On

Implementing Node LocalizationFor

Wireless Sensor Networks

Presented By :-Gaurav Dhaka

Dept. Of Comp. Science & Engg.

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ContentsContents

IntroductionLocalizationConclusion and Future WorkReferences

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Wireless Sensor NetworksWireless Sensor Networks

A sensor network is an infrastructure comprised of sensing, computing and communication elements [1].

Provides the ability of instrumenting, observing and reacting to events and phenomena in a specified environment [1].

Wireless Sensor Network consist of a large number of small, cheap, battery powered devices with limited resources, known as Sensor Nodes.

First major Implementation was done during cold war by USA for submarine surveillance [1].

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Application Areas of Wireless Sensor NetworksApplication Areas of Wireless Sensor Networks

Wireless Sensor Networks has a very vast range of applications [2,6].

Disaster relief applicationsMilitary ApplicationsIntelligent buildingsPrecision agricultureMedicine and health careLogisticsTraffic Monitoring

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Issues Related to Wireless Sensor Network [2]Issues Related to Wireless Sensor Network [2]

Quality of ServiceFault ToleranceEnergy Efficient OperationAuto ConfigurationCollaboration and in-network processingLocalization :- Estimating the position of sensor nodes in

random deployment applications.

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LocalizationLocalization• Localization in Wireless Sensor Networks• Terms Related to Localization• Design Objectives of Localization• Literature Review

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Localization in Wireless Sensor NetworksLocalization in Wireless Sensor Networks

Sensor networks may be deployed in inaccessible terrains or disaster relief operations, the position of sensor nodes may not be predetermined [3].

Localization system deals with the task of providing position information to the nodes [3].

Terms Related To Localization [3]Terms Related To Localization [3]

Unknown Nodes/Free Nodes/Dumb NodesNodes, Those Do not know their localization

information.Settled Nodes

Initially unknown nodes but now managed to get their location.

Beacon Nodes/Anchor Nodes/Landmark NodesDoesn’t require localization system to get their location.Location obtained by Manual placing or some external

means i.e. GPS.

Design Objectives of Localization [6]Design Objectives of Localization [6]

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Independence from Anchor Node placementRobustnessEnergy EfficiencySecuritySupport for Distributed AlgorithmsSimple Measurement Hardware

Literature ReviewLiterature Review

Localization systems for wireless sensor networks [3]

Paper provides basic introduction of Localization system, generic problem statement of a localization system and components of a localization system.

Problem Statement :- Given a multihop network G = (V, E), and a set of beacon nodes B and their positions (xb, yb), we want to find the position (xu, yu) of as many unknown nodes as possible, transforming these unknown nodes into settled nodes, S.

Contd…Components Of Localization System

Distance/Angle EstimationTime of Arrival and Time Difference of ArrivalRSSIAngle of Arrival

Position ComputationTrilateration and MultilaterationTriangulationBounding Box

Localization AlgorithmAd-Hoc Positioning SystemRecursive Positioning EstimationLocalization with a Mobile Beacon

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SerLoc : Robust Localization for Wireless Sensor Networks [4]

Computed location in four stepsStep 1: Listen to Beacon nodes.

Step 2: Calculate the search area.

Step 3: Overlapping region majority vote using Grid Score

Step 4: Position estimation as centroid of overlapping region

DV-Loc: A Scalable Localization Protocol Using Voronoi Diagrams For Wireless Sensor Networks [5]

Computed location in different phasesPhase 1: 4 Beacon nodes of Level 1 floods the

network with packets containing its location, number of hops and other details. Intermediate nodes saves its location and number of hops to each beacon and forwards the packet.

Contd…

Phase 2: Based on the data, Voronoi cells are created and nodes fix their voronoi cells. Each node computes a new Voronoi diagram inside its Voronoi cell.

Contd…Phase 3: Second level nodes computes average hop distance.Phase 4: When no new Beacon message is received for a long time, it converts hops into distances and computes its location using multilateration.

Conclusion and Future WorkConclusion and Future WorkDifferent localization algorithms focus on different issues

of localization such as errors, number of beacons, number of settled nodes, GPS usage or energy consumption.

In Ad-Hoc Positioning system, lesser number of Beacon nodes are required but the method of distance calculation i.e. DV-Hop and DV-Distance introduces some errors.

SerLoc uses locators equipped with a set of higher-power sectored antennas in place of anchor nodes. Fails in situations of jamming of the wireless medium.

The future work will be centralized towards the task of proposing an effective localization strategy keeping issues related to localization in mind and will try to resolve one or more issues.

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[1] Kazem Sohraby, Daniel Minoli and Taieb Znati, "Wireless Sensor Networks-Technology, Protocols, and Applications", John Wiley & Sons, Inc. Publication, 2007.

[2] Holger Karl, Andreas Willig, "Protocols and Architectures for Wireless Sensor Networks", John Wiley & Sons Ltd Publication, 2005.

[3] Azzedine Boukerche, Horacio A. B. F. Oliveira, Eduardo F. Nakamura and Antonio A. F. Loureiro, "Localization systems for wireless sensor networks", IEEE Wireless Communications, Volume 14, Issue 6, December 2007, Pages 6-12.

[4] Loukas Lazos and Radha Poovendran, “SeRLoc: Robust Localization for Wireless Sensor Networks”, ACM Transactions on Sensor Networks (TOSN), Volume 1 ,Issue 1, August 2005, Pages 73-100.

[5] Azzedine Boukerche, Horacio A. B. F. Oliveira, Eduardo F. Nakamura and Antonio A. F. Loureiro, “DV-Loc: A Scalable Localization Protocol Using Voronoi Diagrams For Wireless Sensor Networks”, IEEE Wireless Communications, Volume 16, Issue 2, April 2009, Pages 50-55.

[6] Baisakh, Nileshkumar Patel, Energy Saving and Survival Routing Protocol for Mobile Ad-hoc Networks in Internation Journal of Computer Applications, Volume 48, Issue 2, pp 13-17, June 2012.

ReferencesReferences

[7] Mohammed Ziaur Rahman and Lindsay Kleeman, “Paired Measurement Localization: A Robust Approach for Wireless Localization”, IEEE Transactions on Mobile Computing, Volume 8, Issue 8, August 2009, Pages 1087-1102.

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Thank You…