Indoor Location Using Wireless Sensor Networks

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Indoor Location Using Wireless Sensor Networks

• Tim Porter
• Jeremy Witmer
• CS 522 Fall 2006 Semester Project

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Why realtime indoor location?

• First responders
• Building security

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Wireless SENSOR Networks

• Self-forming mesh network
• Micropower processor and radio
• Highly configurable sensor capability

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TinyOS

• nesC
• Structured, component-based language
• Hardware access wrapped into components

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Hardware Diagram
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Motes
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Mote Software

• Fixed/Mobile mote
• Base mote

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Location Algorithm

• Trilateration
• Measurement ratio signal strength/distance

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Location Software
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Location Software
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Results

• Test network approx. square, approx. 120 inches
  to a side
• Locations found with error of approx. 5 inches
• Concurrency issues
• Algorithmic issues
• High power drain

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Further Research

• Attenuated signal testing
• Updated mote code
• Updated location software
• Querying/remote control of motes
• Extension to 3 dimensions

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Conclusions/Lessons Learned

• Proof of feasibility of signal-only location
• Requires further research on mote code and
  algorithm.
• Definite potential for various applications