NEST Spy Tracker Demo

1
NEST Spy Tracker Demo

• Kane Kim
• Ray Klefstad
• UC Irvine

2
Demo Objective

• Track a spy through a room by detecting sound
• The room contains a grid of motes acting as
  smart sensors
• Focus is on real-time, fault tolerance, and
  scalability

3
Demo Hardware Configuration

• A grid of 16 motes (Tiny OS)
• Four super motes (iPAQs) acting as mote
  supervisors (Win CE)
• A laptop tracking the spy and displaying the
  track and network status in real-time (Win XP)

4
Demo Software Configuration

• 16 motes global time sync (GTS), sense and send
• 4 iPAQs GTS, collect and relay, H-SNS
• 1 laptop GTS, track and configure, GUI

5
Demo Key Services

• Global time synchronization
• Time-triggered functions on the motes
• TMO on the iPAQs and Laptop
• TDMA for mote radio communication
• Fault detection and Dynamic reconfiguration
  H-SNS

6
Metrics

• Track delay 1.25 seconds
• Global time error 10 milliseconds
• Fault detection time 5 seconds
• Supervisor mote reassignment 100 milliseconds

7
Difficulties

• Lack of documentation for Tiny-OS
• Hardware problems
• Stochastic microphone behavior
• Microphone saturation
• iPAQ to mote connector mismatch
• Lack of real-time support in Win CE and XP