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. ari/

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. s294-1/

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

Signal Strength vs. Distance

Noise Vs. Distance

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 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 The authors claim no right. All quoted products/work belong to the respective companies working on it.