1. Reconfigurable Sensor Networks Chris Elliott Honours in Digital Systems Charles Greif and Nandita Bhattacharjee

2. Chris Elliott2 Reconfigurable Sensor Networks Aim of Project –Demonstrate a sensor network that reconfigures Via network and sensors Overview –Background –Hardware –Wireless Communication –TinyOS –How it will be done –Relevance of the research

3. Chris Elliott3 Background Smart Dust Project –Hill, Hollar, Culler, Pister and Katz at the University of California in Berkeley Funded by Intel and Department of Defense Research started in 1995 –Using the idea of processing, sensing, communications and power in one chip –Sensor Node also named Mote by people at Berkeley –Tiny Operating System Current research concentrating on size

4. Chris Elliott4 Background

5. Chris Elliott5 Background

6. Chris Elliott6 Experiments Wireless sensor networks have been used –Great Duck Island Habitat Monitoring Looked at habitat on this island –url: www.greatduckisland.net –COTS BOTS Motes were connected to mobile robots –url: www.eecs.berkeley.edu/~sbergbre/CotsBots/cotsbots.html –Palms Fixed Mobile Experiment Tracking vehicles on a road –url: robotics.eecs.berkeley.edu/~pister/20Palms0103/

7. Chris Elliott7 Hardware Processor –Atmel ATmega 128L –Low Power – 2.7V –RISC –A/D converter Memory – 128Kb program – 512Kb data Radio – 868/916Mhz – 150m range

8. Chris Elliott8 Hardware Sensors –Light – Temp – Acoustic –Magnetic – Acceleration –Microphone

9. Chris Elliott9 Wireless Communication Ad-hoc scheme –No organised connectivity before deployment –Still meets needs of application Broadcasting –Motes find out who neighbours are to discover topology –Periodic checks are performed Multi-hop route –Allows for easy reconfiguration of network Flooding –Basestation mote sends information to network

10. Chris Elliott10 TinyOS Developed to act as a generic environment Event based Uses a set of Components –Commands –Events –Fixed frame size –Tasks Task Scheduler –FIFO –Switches processor between sleep and active mode

11. Chris Elliott11 TinyOS Set of commands –Requests made to lower level components Event Handlers –Events received from lower level components –At lowest level triggers processor to wake up Commands used Events signaled –Passed to higher level components Operate on its state

12. Chris Elliott12 Research This will be done by: –Developing system architecture Using 3 motes, one as a basestation –Developing code to implement reconfiguration Using C code and TinyOS C compiler Using debugger and simulator that comes with TinyOS

13. Chris Elliott13 Conclusion Current Work Topics Covered –Hardware –TinyOS –Wireless Communication –Smart Dust –How the research will be undertaken Relevance of Research