Detailed description about wi-vi

1. ▪ By:-
▪ D.VAMSI
▪ 151fa04213
▪ CSE SEC-e
Wi-vi

2. contents
• History of WI-VI.
• Introduction.
• Operating principle.
• RADAR and SONAR imaging.
• Development.
• Futuristic uses.
• Advantages
• Disadvantages
• Conclusion

3. history
 Researchers at MIT's Computer and Artificial
Science Intelligence Laboratory.
 Dina Katabi , a professor in MIT’s Department of
Electrical Engineering and Computer Science,
. and hergraduate student Fadel Adib.

4. introduction
Previous attempts to track moving targets through
walls have done so using an array of spaced antennas.
Each capture the signal reflected off a person moving
through the environment.
This would be too expensive and bulky for use in a
handheld device.
So instead Wi-Vi uses just one receiver.

5. basic working
Based on the principle of RADAR and SONAR imaging.
WI-VI is potentially an X-RAY vision created with low
power Wi-Fi signals.
This tech uses reflected Wi-Fi signals to track the
movement of people behind walls.
See through movement behind walls.

6. principle
RADAR and SONAR work on the Doppler effect.
RADAR is an object detection system which
uses radio waves to determine the range, altitude,
direction, or speed of objects.
Depends on its own transmitted signal.

7.  Wi-Vi relies on a simple hardware of 2.4 GHz Wi- Fi
radios.
 Wi-Fi signals easily penetrate through walls.
 Small enough to be portably used.
 Integrated in hand held devices.

8. How it works?
WI-VI uses two transmitting antennas and
receiver.
a single
Transmitting signals are low power Wi-Fi signals.
The two antennas transmit almost identical signals,
except the second antenna's signal is the inverse of
the first, resulting in interference.

9. 180˚ inverse
DIRECTION OF
SIGNAL
ROUTER 1 ROUTER2
RECIEVER
obstacle

10.  Any static objects that the signals hit including the
wall create identical ref lections, they too are cancelled
out by this nulling effect.
 Only those reflections thatchange between the
two signals, such as those from a moving object,
arrive back at the reciever.

11. WI-VI setup

12.  As the person moves through the room, his or her
distance from the receiver changes, meaning the time
it takes for the ref lected signal to make its way back to
the receiver changes.
 The system then uses this information tocalculate
where the person is at any one time.

13. All reflections from static objects are cancelled out, and the
only thing registered by the device is the moving human.

14. Direction of motion

15. resolution
Wi-Vi delivers a more basic perspective
objects.
on moving
Relatively low resolution compared to a traditional
camera.
Wi-Vi delivers a more basic perspective on moving
objects. “Simple gestures” are also traceable.

17. Advantages
▪ Wi-vi require same bandwidth & operates in the
same range as wi-fi.
▪ Wi-vi can perform through wall imaging without
access to any device on the other side of the wall.
▪ Wi-vi employs signals whose wavelength are
12.5 cm.

18. Disadvantages
▪ Wi-vi employs signals whose wavelength are
12.5 cm.
▪ We cannot detect humans behind concrete
walls thicker
▪ than 8” .
• To achieve a narrow beam the human needs to
move by about 50cm.

19. applications
Possible use in smart phones as a hand
device.
held WI-VI
Monitoring situations in hospitals or a conspired
heist.
Disaster recovery.
Gaming.

20. conclusion
Smart hand held device which gives an insight vision
through walls.
Could prove to be very powerful and effective device
for defence purposes.
Possibly the next generation RADAR.

21. THANK YOU!