CitySense A Vision for an Urban-Scale Sensor Network Testbed

1. CitySenseA Vision for an Urban-ScaleSensor Network Testbed Josh Bers†, Matt Welsh*, and Majid Ezzati‡ † BBN Technologies, Inc. * School of Engineering and Applied Sciences, Harvard University ‡ School of Public Health, Harvard University

2. Goals • Support experimentation with wireless sensor networks at scale • Simulations are valuable but inherently limited • Understanding characteristics of real sensor networks in diverse environments requires real testbeds and real applications • Testbeds should be open and easily shared by multiple research groups • Build a programmable testbed that supports • Wireless sensor research • Wireless networking research • Interface with larger GENI effort © 2007 BBN Technologies © 2007 Matt Welsh – Harvard University

3. CitySense Testbed • Deploy outdoor testbed of 100 embedded PCs across a city • Currently in negotiation with Cambridge, MA. • Linux-based embedded PCs with meteorological and air quality sensors • 802.11a/b/g interface with multihop wireless networking backbone: Use existing open-source standard: OLSR, HSLS • Current Status • Project began in Sept. 2006. • Have a 15 node dual-radio prototype testbed running at BBN and Harvard: 8 outdoor and 7 indoor nodes • 3 outdoor nodes continuously gathering weather sensor data (http://citysense.bbn.com/LiveMonitor/) • Time synchronization between nodes using NTP • Remote synchronization of baseline software over the air. © 2007 BBN Technologies © 2007 Matt Welsh – Harvard University

4. CitySense Overview © 2007 BBN Technologies © 2007 Matt Welsh – Harvard University

5. CitySense Node Design • Soekris net4826 embedded PC running Linux • 256 MB of RAM+flash, 1 GB USB flash drive • Two 802.11 radios b/g & 900 MHz, w/8 & 6 dBi omni antennas • Various sensors driven by app requirements • Vaisala Weather Sensor (temp, humidity, pressure, wind, rain, ...) • *Gas sensors (CO2, CO, O3...) • *Air particulate sensor (PM10 for air quality studies) • Microphones? Cameras? © 2007 BBN Technologies © 2007 Matt Welsh – Harvard University

6. BBN Network Topology © 2007 BBN Technologies © 2007 Matt Welsh – Harvard University

7. Cross-discipline Research Enabled • Sensor Networking • Spatio-temporal data fusion [Akyildiz ’04] • Distributed query processing / data routing [Sung ’07] • Wireless Networking (GENI) • Mesh routing protocols: geographic routing, Dynamic RF channel selection • Disruption Tolerant Networks (DTN) • Urban Monitoring • Public health studies: air pollution • Homeland security: bio-chem, toxic gas release tracking • Environmental impact: building efficiency, wind tunnel effects © 2007 BBN Technologies © 2007 Matt Welsh – Harvard University

8. Testbed Challenges • Resource management and sharing • How to support many applications? Fairness? Security? Sandboxing? • Programming models and languages • What is the right programming abstraction for a city-wide sensor network? ssh into every node? SQL? Something in between? • Robustness and administration • How to administer and maintain a network of 100+ nodes over a wireless mesh, without physical access? • Separate management/control radio • City Political Hurdles • Press coverage / City politics • Public acceptance / privacy issues • Benefits to City: K-12 summer workshop, using data to support green initiatives, commercial location based services.. © 2007 BBN Technologies © 2007 Matt Welsh – Harvard University

9. Acknowledgements / Questions? • CitySense team: • Abhimanyu Gosain (Tufts grad student), Bob Keyes, Geoff Mainland, Rohan Murty (Harvard grad students), Jon Hyman, Matt Tierney (Harvard undergrads) • For more information: • Josh Bers (jbers@bbn.com) and Matt Welsh (mdw@eecs.harvard.edu) • http://www.citysense.net © 2007 BBN Technologies © 2007 Matt Welsh – Harvard University