1. Work in Progress for Wireless Sensor Networks Yonghe Liu yonghe@cse.uta.edu Dept. of Computer Science and Engineering The University of Texas at Arlington Partially supported by NSF CNS-0721951, NSF IIP 0712433, and Texas ARP

2. 10/22/2007 2 Current efforts Develop sensor networks that are Energy efficient – multiple years operation Easy to use – as web applications to users Easy to program -- drag and drop Easy to clean up physically – no one left behind

3. 10/22/2007 4/25/2007 3 An easier route Focus on applications that are less demanding Temperature, humidity, light sensing, etc. Low data rate at several bytes/node/minute often sufficient Typical hardware platform: TelosB 250Kbps bandwidth (Zigbee) 8MHz Microcontroller 10KB ram 1MB flash And an extensive set of overlaying solutions Over Kill

4. 10/22/2007 4 Hardware Pseudo-RFID module on board Use RFID writing No backscattering though Semi-passive for long range Enable asynchronous communication among nodes Transmitter directly excites and writes into receiver memory Always “ON” receiver Transmit whenever desired No periodic wakeup/sleep, simplified MAC operation

5. 10/22/2007 4/25/2007 5 Network: asynchronous communication pattern Overall a store and forward, asynchronous communication architecture Benefit Utilize the whole time line Transmission anytime, not in a time window No-need of CSMA/CD MAC Low rate of data Avoid heavy collisions Avoid idle listening No wakeup synchronization overhead Energy Efficiency

6. 10/22/2007 6 Cleaning up If backscattering enabled, True RFID capability Locating and identifying node corpses

7. 10/22/2007 7 Onboard software Simplified to be necessary Using standard Zigbee stack if possible Quite powerful Open source

8. 10/22/2007 8 PC/Sink software Simplified but limited programming Drag and drop Like labview Web based visual/management tools

9. 10/22/2007 9 Advanced topics due to asynchronism Signal processing Delay reduction Joint synchronous and asynchronous design