A simplified wivi presentation

2.  History
 Introduction
 What can Wi-Vi do?
 Why use Wi-Fi Signals?
 Wi-Vi Construction
 Basic principle
 Working
 Resolution
 Advantages
 Limitations
 Applications
 Future Scope
 Conclusion

3.  Wi-Vi was invented at MIT's Computer Science and Artificial
Intelligence Laboratory.
 Dina Katabi , a professor in MIT’s Department of Electrical
Engineering and Computer Science, and her graduate student
Fadel Adib invented this technology.
Dina Katabi Fadel Adib

4. Captures moving objects
behind the wall
Wireless Device
3 Antenna MIMO device(Two
Transmitter antenna and one
receiver antenna)
- Two modes of use:
- Image moving
objects behind the
wall
- Gesture based
interface
- Uses Wi-Fi signals in
ISM band(2.4Ghz)
- Typically Wi-Fi
Hardware
INTRODUCTION

5. • Detect the Number of Moving Humans in a Closed
Room.
• Determine the Relative Locations of Moving Humans.
• Enable Communication through a Wall without
Carrying a Wireless Device.
• Identify Simple Gestures from Behind a Wall.

6.  Wi-Fi signals can easily penetrate through walls.
 Wi-Vi relies on a simple hardware of 2.5 GHz Wi-Fi radios
 Small enough to be portably used.
 Integrated in hand held devices.
 Low power Wi-Fi signals are used.

7.  Wi-Vi like any other system essentially consists of
a transmitter and receiver.
 Two transmitting antennas.
 Single receiver.
Router 1 Router 2
Receiver
Moving objects

8. Wi-Vi
Device
Wall
Moving object
Transmitted
signal
Reflected signal

9.  WI-VI is Based on the principle of RADAR and SONAR
imaging which works on doppler effect.
 RADAR is an object detection system which uses radio
waves to determine the range, altitude, direction, or
speed of objects.
 It’s similar to the way radar and sonar work but without
the expensive, bulky gear and restricted frequencies that
radar requires.
 Depends on its own transmitting signal.

10. WORKING

11. Identifying & tracking
humans
Flash Effect

12. h2
αx
X
Y=h1x+αh2x
Static objects(Walls , chair
etc.) α=-h1/h2
Y=h1x+(-h1/h2)h2x= ZERO
Moving Objects
Y=h1x+αh2x= NOT ZERO
h1

13. Direction of
reflection
θ
Antenna Array
RF source

14. Direction of motion
Antenna array
θ
At any point in time, we have a
single measurement

15. Direction of motion
Antenna array
θ
θ

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

17. Gestures as detected by Wi-Vi Gestures as Angles

18. Tracking of 2 humans Tracking of 3 humans

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

20. Wi-Vi is relatively a low-power, low-cost, low-bandwidth, and low-
size
Wi-Vi requires same bandwidth & operates in the same range as wifi.
 It allowing us to detect objects in the dark or in smoke.
 Accurate detection and good accuracy

21.  We cannot detect the human if concrete walls thicker than 8".
 Display has very low resolution.
 To achieve a narrow beam the human needs to move by about
50cm.

22. Law enforcement
Personal Security
Emergency
situations
Smart Sensing

23. User Interface Design Intruder Detection
Gesture interface behind the wall

24. • Wi-Vi could be built into a Smartphone or a special
handheld device.
• Can be used in search-and-rescue missions and law
enforcement
• Evolution of seeing human beings with denser building
material with longer range.

25.  WI-VI a 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.