Detection, Classification and Tracking of Targets in Distributed Sensor Networks

1
Motivation, Genesis Evolution of the eXtreme
Scale Mote (XSM)
Prabal Dutta ltprabal_at_eecsgt
2
Acknowledgements

• Crossbow Technology
• Mike Grimmer
• Ohio State
• Emre Ertin
• Hui Cao
• U.C. Berkeley
• Joe Polastre
• Cory Sharp
• Rob Szewczyk
• Virginia
• Lin Gu
• MITRE
• Ken Parker
• DARPA

3
Motivation Data Collection vs. Event Detection

• Data Collection
• Signal Reconstruction
• Reconstruction Fidelity
• Data-centric
• Data-driven Messaging
• Periodic Sampling
• High-latency Acceptable
• Periodic Traffic
• Store Forward Messaging
• Aggregation
• Phenomena Omnichronic
• Absolute Global Time

• Event Detection
• Signal Detection
• Detection and False Alarm Rates
• Meta-data Centric (e.g. statistics)
• Decision-driven Messaging
• Continuous Passive Vigilance
• Low-latency Required
• Bursty Traffic
• Real-time Messaging
• Fusion, Classification
• Rare, Random, Short-lived
• Relative Local Time

vs. ? ? ? ? ? ? ? ? ? ? ? ?
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Differing Energy Usage Patterns
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Extreme Scale Requirements

• Biggie-size A Line in the Sand (like PEG)
• ? Network Scale by 100x (10,000 nodes)
• ? Detection range by 6x (10m)
• ? Lifetime 8x (720hrs ? 1000hrs)
• Other areas also affected, but not covered
• Topology
• Classification
• Tracking
• Routing
• Time Synchronization
• Localization
• Application
• Visualization

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LITeS Concept of Operations
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Requirements (of the hardware platform)

• Functional
• Detection, Classification (and Tracking) of
• Civilians, Soldiers and Vehicles
• Reliability
• Recoverable Even from a Byzantine program image
• Performance
• Intrusion Rate 10 intrusions per day
• Lifetime 1000 hrs of continuous operation (gt 30
  days)
• Latency 10 30 seconds
• Coverage 10km2 (could not meet given
  constraints)
• Supportability
• Adaptive Dynamic reconfiguration of thresholds,
  etc.

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Genesis The Case for a New Platform

• Cost
• Eliminate expensive parts from BOM
• Eliminate unnecessary parts from BOM
• Optimize for large quantity manufacturing and use
• ? Network Scale by 100x (10,000 nodes)
• Reliability How to deal with 10K nodes with bad
  image
• ? Detection range by 6x (10m)
• New sensors to satisfy range/density/cost
  tradeoff
• ? Lifetime 8x (720hrs ? 1000hrs)
• Magnetometer Tstartup 40ms, Pss 18mW
• UWB Radar Tstartup 30s, Pss 45mW
• Optimistic lifetime 6000mWh / 63mW lt 100 hrs
• Must lower power
• Radio
• Fix anisotropic radiation and impedance mismatch

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Hardware Evolution
Telos Low-power CPU 802.15.4 Radio Easy to
use Sleep-Wakeup-Active
MICAz MICA2 - CC1000 802.15.4
Radio Sleep-Wakeup-Active
XSM2 XSM Improvements Bug Fixes
XSM MICA2 Improved RF Low-power sensing
Recoverability Passive Vigilance-Wakeup-Active
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The eXtreme Scale Mote

• Key Differences between XSM and MICA2
• Low-power Sensors
• Grenade Timer
• Radio Performance

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Sensor Suite

• Passive infrared
• Long range (15m)
• Low power (10s of micro Watts)
• Wide FOV (360 degrees with 4 sensors)
• Gain 80dB
• Wakeup
• Microphone
• LPF fc 100Hz 10kHz
• HPF fc 20Hz 4.7kHz
• Gain 40dB 80dB (100-8300)
• Wakeup
• Magnetometer
• High power, long startup latency
• Gain 86dB (20,000)

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Low-power Sensing through Duty-cycled Operation

• Motivation
• Low-latency, high-power sensors
• High-latency, low-power signal conditioning
• Components
• Unbalanced clock
• Tsetup phase
• Tsampe phase
• Thold phase
• S/H switch
• S/H capacitor
• S/H unity-gain buffer

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Reliability through the Grenade Timer

• Motivation
• Basic idea presented by Stajano and Anderson
• Once started
• You cant turn it off
• You can only speed it up
• Our implementation

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XSM RF Performance
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Conclusions and Future Work

• Improve (or obviate) sensor wakeup circuits
• Lower false-alarm rate
• Low-power (zero-power?) wakeup
• Reduce sensing power (op amp ? FET ? ASIC)
• Decrease signal processing power consumption
• Consider space, time, message (and energy)
  complexity

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Discussion