Wireless Network Location Verification

Presented by Wosen Agedie and Samuel WalkerMentor: Dr. Beex

The purpose of this project is to come up with a model to accurately locate where a transmitting device is indoors where Global Positioning Systems cannot by using an indoor wireless network.

Project Background

1. 9-1-1 Emergency Personnel who need to locate a victim trapped in a building

2. Parents who need to locate their child in a crowded, large building (mall,

museum, etc.)3. Locate lost personal items (cell phone,

keys, etc.)

Future Applications

Cognitive Radio Network Testbed

Gigabit Ethernet: interface between USRP2 (installed in the ceiling) and the processing platform.

12 nodes per floor for a total of 48 wireless nodes, each node is connected to a server

1. Signal Function Generator2. Cone-shaped antenna3. USRP2 w/ WBX Daughterboard4. Power Meter 5. NX Client6. MATLAB7. Microsoft Excel

Equipment/Software Used

Signal Function Generator

Setup Configuration

USRP2 WBX Daughterboard

Universal Software Radio Peripheral (USRP)

Provide hardware platform for software radio

It connects with the host computer using USB ot Gigabit Ethernet

Usually used with GNU radio software tool.

Has a motherboard wich provide the folowing subsystem:

FPGA ( field-programmable gate array) ADC ( analog-to-digital converter )

DAC (digital-to-analog converter )

clock generation

Power Meter

Calibration Method

Signal Generator

USRP Laptop

Rx Calibration Diagram

Laptop USRP Power Meter

Tx Calibration Diagram

Calibration Graphs

-80 -75 -70 -65 -60 -55 -50 -45 -400

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

f(x) = NaN x^NaNR² = NaN

f(x) = 71287.5126493625 exp( 0.229567784673106 x )R² = 0.999329076712998

Rx Calibration

Signal Generator Power (dBm)

Rece

ived P

ow

er

of

USR

P (

dW

)

0 5 10 15 20 25 30

-30

-25

-20

-15

-10

-5

0

5

10

f(x) = 0.0000416494 x⁵ − 0.0027469 x⁴ + 0.0678599 x³ − 0.861548 x² + 7.35998 x − 34.4997R² = 0.992683052961027

Tx Calibration

Transmitter Gain (dB)

Po

we

r M

ete

r M

ea

sure

d P

ow

er

(dB

m)

Testing Results

0 5 10 15 20 25 30 35 40

-75

-70

-65

-60

-55

-50Frequency: 766 MHz and Power Level: -1 dBm

Node #

Pow

er

Level (d

Bm

)

Third FloorFirst Floor Second Floor

When each power level from nodes are plotted in order from 1-48:We can easily spot the highest peak

between the four floors of the buildingThe floor with the highest peak is where the

transmitting device is locatedThe nodes with the highest power levels

shows the vicinity of where the transmitter is located

Localization Model

1. Transmitter power level is very important in order to locate a transmitter. The lower the power level, the harder it is accurately pinpoint the vicinity of the transmitter.

2. The position and number of nodes used to locate a transmitter is very important. The more nodes that are utilized, the more accurate the transmitter’s location.

Things Learned

Find the minimum power level required to accurately locate a transmitter

Find the minimum number of nodes and the distances between each one to accurately locate a transmitter

Future Work

Dr. Beex and Tamoghna Roy (Mentors)Dan Depoy (CORNET Administrator)Dr. Dietrich (Hardware and Supplies)

“Designing and Deploying a Building-Wide Cognitive Radio Network Testbed” Authors: Timothy R. Newman, S. M. Shajedul Hasan, Daniel DePoy, Tamal Bose, and Jeffrey H. Reed, Virginia TechPublished by IEEE Communications Magazine

Mentors and References

???Questions???

Floor 2 (ICTAS Building)