3. SINR Diagram- Theoretical Background Motivation Pilot Results Tmote Grid Sensor Network Experiment The Story Behind Our Experiment

5. SINR signal to interference and noise ratio – in our case the path-loss parameter α = 2 ( preliminary assumption) we can write the SINR function from the above definitions:

6. we have understood the SINR concept so the only question left……

7. Here is one example of 4 transmitting stations and one receiver:

8. Another example for SINR Diagram benefits come from the comparison between this model to the familiar Unit Disc Graph model (UDG) UDG is local model, represent by a graph whose vertices correspond to the stations, an edge connecting two vertices if the corresponding stations are at distance at most one from each other. Each reception zone in the UDG model is uniform circle shaped.

9. SINR Diagram is more realistic, in some cases in UDG receiver who locate in the congruence between two or more transmitters reception zones, won’t hear any of the transmitter while in SINR Diagram it might hear it- (there are also cased where the receiver won’t hear anyone in SINR and will hear someone in UDG)

10. After intense study of the SINR Diagram theory we wanted to get a true feeling of wireless network’s reception zones actual behavior We also wanted this project to be a modest contribution for the field researchers work Another benefit we hoped to get was getting an experience in planning and implementing an experimental system with the tools we got from 4 years of studying and also an experience in deploying and programing wireless network.

11. We decided to use TMOTE SKY sensors who include IEEE 802.15.4 wireless NIC that available in dr. Zvi Lotker sensors lab At first we planned to transmit signals simultaneously from 3 transmitters and sample the RSSI measurement in 22 receiving sensors antenna This plan failed because we discovered these sensors include inflexible MAC layer CSMA/CA protocol who prevent transmitting from more than one transmitter on the same time Another problem was that there is no possibility of separating each signal RSSI After reading in the sensors manual what will be the outcome of the RSSI sample we realized that our system is LTI and there for we can use superposition.

13. TMOTE SKY motes essential characteristic: Enables mobility. Includes 10KB RAM and 48KB Flash provides satisfying storage place Includes Chipcon CC2420 radio for wireless communications provide IEEE802.15.4 compliant radio providing the PHY and some MAC functions Get its power supply from two simple finger batteries or USB connection

14. TMOTE SKY motes essential characteristic: The motes antenna enables 50M indoor range and 125M outdoor. The antenna radiation pattern:

15. Sentilla mote software architecture: Sentilla work: a development workbench. Sentilla point: an operating environment that runs on the motes (runtime image). Sentilla server: a system service that provides connectivity between the motes (Sentilla Points + applications) and Sentilla Work. Our code was written with JAVA

16. We have created 25X25 meter grid network with 25 motes and gateway who controls our experiment operation

19. After running the experiment output is a text file includes all the RSSI measured in the experiment Using Matlab and Mathematica we will create from the results a reception map using this two methods: Approximate the reception zones using interpolation. Finding the signal wave spreading target function using mathematical optimization in order to understand the natural behavior of the wireless signal and the wireless reception nature

20. We have executed a pilot experiment with 16 sensors in 9X9 meter grid topology The pilot gallery:

21. 3D topographic Energy graph for transmitters located at: (3,3), (9,3), (9,9)

22. SINR topographic graph for transmitters located at: (3,3), (9,3), (9,9) Transmitter (9,9)Transmitter (9,3)Transmitter (3,3)

23. 3D topographic combine SINR graph for transmitters located at: (3,3), (9,3), (9,9) with β=7.5

24. Combined SINR contour graph β=1 β=1Transmitting Energy

25. Our project was based on: C. Avin, Y. Emek, E. Kantor, Z. Lotker, D. Peleg and L. Roditty SINR Diagrams: Towards Algorithmically Usable SINR Models of Wireless Networks, September 29,2009 Special tanks for: Dr. Zvi Lotker Michael Borokhovich Arik Sapojnik