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Study of Localization problem with Sensor Networks. By Jayanth Patil Ganesh Godavari. Localization. Localization “The process of determining or marking the location or site” Why is Localization a tough problem
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Study of Localization problem with Sensor Networks By Jayanth Patil Ganesh Godavari
Localization • Localization “The process of determining or marking the location or site” Why is Localization a tough problem • ubiquitous computing requires high security and high resolution indoors (MIT CRICKET) • military planning requires high security and low resolution outdoors …. Problem goals changes from one scenario to another
Localization for Sensor Networks • Sensor networks generally require • low security and low resolution • assume minimal infrastructure, hardware and deployment-time overhead. • Problem complexity increases?
Related Work • Calamari – Univ. of Berkeley • aims to explore the space of localization solutions in the sensor network domain • tries to give each sensor node in an ad-hoc wireless sensor network an (x,y) coordinate with respect to some known coordinate system. • http://www.cs.berkeley.edu/~kamin/calamari/
Mobi Loc • Mobility Enhanced Localization : Univ. of Berkeley • aims to study relationship between mobility, navigation, and localization in the context of wireless sensor networks and mobile objects. http://www.eecs.berkeley.edu/~prabal/projects/cs294-1/
Localization Questions • How to determine where the object is ? • Need some reference object to determine. • How to measure “how far is the object” ? • Use radio signal strength, Round Trip Time… Is the radio signal strength or RTT a good measure? * No Disruptive forces of Nature
How to determine Where the object is ? • Existing technologies • Global Positioning System • Designed for outdoor localization • High power consumption • Provides about 2-3 meter resolution • Not suitable for sensor networks • Cricket • Used for Ubiquitous computing. • Passive listeners self localization • Not scalable for ad-hoc needs
Contd.. • AHLoS: under development @ UCLA • Similar to cricket but uses Ultra sound • Millibots • Miniature robots • Use Leap Frog approach • Uses centralized approach, group leader • Not feasible for large ad-hoc deployment.
Lessons Learned • Could not get calamari to work • Calamari needs a separate ultrasonic transciever board. • Looked into calamari project and learnt a lot about tinyos, mica nodes • Currently working on repeating the testing of radio signal strength with distance
References • This document is prepared based on the thesis work done by Cameron Dean Whitehouse, • All information presented here is taken from http://www.cs.berkeley.edu/~kamin/calamari/ • The authors claim no right. All quoted products/work belong to the respective companies working on it.