1. TinyViz Obstructed Radio Signal
Jeff Rupp
CS526
Dr. Chow
1/17/2019
Jeff Rupp CS526

2. Purpose Add to the TinyViz graphical mote simulator
Provide a tool for more accurate interior mote layout
Allow specification of varied Radio Signal obstructions
1/17/2019
Jeff Rupp CS526

3. GUI
1/17/2019
Jeff Rupp CS526

4. TinyViz Standard Java application
Uses a ‘plug-in’ architecture to allow for expansion
Wide array of existing plugins
Easy to expand
1/17/2019
Jeff Rupp CS526

5. Obstructions
Radio signals are obstructed by varying amounts by different materials
Formula for loss in free space over distance
wavelength = 300 / frequency in MHz
According to the Crossbow site, a 433MHz Mote has a range of about 1000ft, which says it can receive at an attenuation of about 70dB
1/17/2019
Jeff Rupp CS526

6. Assumptions
According to the measured values, the bit error rate becomes too high for decent transmission much sooner than 70dB
Based on this I made 60dB equate to a maximum bit error rate
Other website’s observations were that walls presented low attenuation, about 3-12dB
1/17/2019
Jeff Rupp CS526

7. Results
I was able to create my plug-in with a reasonable amount of code, about 400 lines
My plug-in is based in the Radio Model done by Nelson Lee at Berkeley
By varying attenuation of the walls, with the perfect signal mode, it is easy to see how motes connect.
1/17/2019
Jeff Rupp CS526

8. Usage Obstructions file is simple format:
net.tinyos.sim.plugins.LineObstruction,X1,Y1,X2,Y2,atten_dB
Specifying the class name allows for very simple addition of new obstruction classes (different shapes)
1/17/2019
Jeff Rupp CS526

9. References http://www.educatorscorner.com/media/Exp94e.pdf
1/17/2019
Jeff Rupp CS526