1. ESP: Embedded Sensor Packs
Wireless
Networks
1996-
2000
1997-
2000
Networked
Sensors
2000+

2. Sensor Packs 1996 Marathon Man 1997 Fort Benning 1998 Mount Everest
2000 Iceland/Greenland

3. Sensor Packs

4. Wireless Networks
Self Organizing
Low Power
Scalable
Lightweight

5. Wireless Networks GRAd: Exploits natural redundancy in RF Low Latency
Robust in the face of mobility
Strictly decentralized
Dynamic, loop free routing

6. GRAd demo

7. SNAP! Lessons Learned Processor power Memory constraints Wireless
In building a real system, we came to realize several limitations of the PIC based platform
- processing power- the PIC just doesn’t have the facilities, such as an RTOS, to make development easy
- memory- running out of program space and program memory- not expandable
- wireless- nodes not fundamentally wireless- useful for “localized” networking of sensors (ex- human body)- but not for most rapid deployment situations

8. Constellation Specs/Goals
Low Cost (< $20/node)
Low Power
< 50uA sleep current
< 20mA tx/rx
Good Development Platform
RSSI, A/D’s, I2C bus, variable power, spare logic

9. Constellation Platform
Analog Devices ADuC824
Waferscale Memory Device
RFM TR1000 Low Power Radio
-Goal is to provide a real platform to enable real-world testing of system
-insufficiencies in simulation for multi-path and real-world propagation effects
-platform hits a great power/price ratio
- ADuC824 has features that make it perfect for this application
- < 30uA sleep current
- < 20mA tx/rx
- < $20/node in volume

10. Constellation Applications
Robert Poor
Testbed for GRAd Evaluation
Andy Wheeler
Trail monitoring application
Mis-use and over-use of popular wilderness areas
Opportunity to deploy >100 nodes

11. MIT Media Laboratory Andy Wheeler <ajwheele@mit.edu>
Robert Poor