Motivation, Genesis & Evolution of the eXtreme Scale Mote (XSM)

Motivation, Genesis & Evolution of the eXtreme Scale Mote (XSM) Prabal Dutta <prabal@eecs>

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 Acknowledgements

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 Motivation: Data Collection vs. Event Detection vs.            

Differing Energy Usage Patterns

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

Magnetic Target Detected Radar Target Detected LITeS Concept of Operations

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 (> 30 days) • Latency: 10 – 30 seconds • Coverage: 10km^2 (could not meet given constraints) • Supportability • Adaptive: Dynamic reconfiguration of thresholds, etc.

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 < 100 hrs • Must lower power • Radio • Fix anisotropic radiation and impedance mismatch

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

The eXtreme Scale Mote • Key Differences between XSM and MICA2 • Low-power Sensors • Grenade Timer • Radio Performance

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)

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 Low-power Sensing through Duty-cycled Operation

Motivation Basic idea presented by Stajano and Anderson Once started You can’t turn it off You can only speed it up Our implementation: Reliability through the Grenade Timer

XSM RF Performance

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

Discussion

Motivation, Genesis & Evolution of the eXtreme Scale Mote (XSM)