1. Sri Naga Jahnavi Yeddanapudy
LAWS : Location Accuracy based on Wireless Signals Master Project Defense
Sri Naga Jahnavi Yeddanapudy

2. LAWS/Sri Naga Jahnavi Yeddanapudy
Outline of the talk
Introduction
Background
Related Work
Design
Implementation
Performance Evaluation
Challenges faced
Lessons learnt
Future Work
Conclusion
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

3. LAWS/Sri Naga Jahnavi Yeddanapudy
Introduction
Need For Location Accuracy
Disaster/Security, e.g. E-911
Better Direction
Geo-Fencing
Geo-Locking
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

4. LAWS/Sri Naga Jahnavi Yeddanapudy
Background
GPS information – Latitude , Longitude
Wi-Fi derived location information
Utilize the GPS locations of Wireless access points (AP)
BSSID can be used to identify uniquely the signal of an AP.
By correlating the strength of three AP signals we can estimate the location of a Wi-Fi receiver.
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

5. LAWS/Sri Naga Jahnavi Yeddanapudy
Signal Degrading over Distance and Trilateration
Free Space Path Loss - characterizes how the wireless signal degrades over distance (following an inverse square law):
Trilateration
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

6. LAWS/Sri Naga Jahnavi Yeddanapudy
Related Work
Improve GPS Positioning Accuracy with Context Awareness [Huang,2008]
Our work used only latitude and longitude values not the behavior of the context.
Task remainder based on location [Lin and Hung, 2014]
Utilized the GPS and Wi-Fi information like the mac address added to the database but not the distances.
Validating crowd sensed data using image processing [Talasila, 2013]
Our work differs by using GPS and Wi-Fi information.
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

7. Location Accuracy Based on Wireless Signals
Assumptions
End user must have Android Studio installed to deploy the application.
We assume that there are no hackers trying to change or spoof the GPS and Wi-Fi location information.
The Android applications that are developed serve the Android smart phones or tablets which have Minimum SDK API 15 : Android (Ice cream Sandwich)
LAWS System is provided to
Smart phone GPS application for determining the user location.
Wi-Fi application for providing the user location based on Wi-Fi and geolocation information.
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

8. LAWS/Sri Naga Jahnavi Yeddanapudy
LAWS Design
Design and develop Android app to compute the geolocation info of the receiver based on Google Client API and Location Manager API
Design and develop Android app to collect Wi-Fi signals based on Wi-Fi Manager API.
Design and develop Trilateration algorithm for calculating the geolocation of the receiver based on the available Wi-Fi signals
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

9. Evaluate Accuracy of Geolocations Computed by LAWS Software
Nine points in UCCS Alpine Soccer Field are chosen
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

10. LAWS/Sri Naga Jahnavi Yeddanapudy
Implementation
LAWS GPS Android Application
LAWS Wi-Fi Android Application
Location – Geo location -Google Client API
Wi-Fi Manager
Wi-Fi trilateration
Technologies used : Android Studio 1.5
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

11. LAWS/Sri Naga Jahnavi Yeddanapudy
LAWS GPS Application
Latitude and Longitude value is determined by using the Location Manager and Google Client CPI
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

12. LAWS Wi-Fi Application
Mac Address of Wifi Base station
Frequency in MHz
Distance in meters
Signal to Noise Ratio
SSID
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

13. Geolocation Determined with Wi-Fi Trilateration
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

14. Pseudo code of GPS Smart Phone application
Passing Lat, Lng values
Pseudo code of GPS Smart Phone application
Adds marker to the map along with lat, lng values
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

15. Pseudo code for Wi-Fi Scan
Distance calculation using Free space path loss
Pseudo code for Wi-Fi Scan
Scanning of Wi-Fi Base stations
Retrieves Mac Address, Signal to noise ratio, frequency, SSID
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

16. Pseudo code for Wi-Fi trilateration
Based on three distances and three Wi-Fi base stations GPS information
LAWS/Sri Naga Jahnavi Yeddanapudy
11/14/2018

17. Performance Evaluation
GPS Sample for Alpine soccer field
Wi-Fi Sample for Alpine center
High end Precision data for Alpine center
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

18. LAWS/Sri Naga Jahnavi Yeddanapudy
Error values
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

19. Average and Variance of nine points with 90 samples
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

20. Average and Variance of nine points
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

21. LAWS/Sri Naga Jahnavi Yeddanapudy
Analysis Results
Accuracy of GPS derived geolocation is 75% better than those of Wi-Fi derived information based on the 90 samples that were collected for the Smart Phone Data.
Based on the nine values of the smart phones geolocation data, the performance of the GPS is 50% better than the Wi-Fi derived information.
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

22. Offset Deviation in Google Earth surprise finding!
Collecting the High Precision Data for these points
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

23. Offset Deviation in Google Earth surprise finding!
Selected locations displayed as Pins by Google Earth
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

24. Difficult Bug in Wi-Fi Code
If the ex, ey ( unit vectors )are not determined properly it doesn’t generate the expected value.
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

25. LAWS/Sri Naga Jahnavi Yeddanapudy
Lessons learnt
Wi-Fi API and Google Client API are very useful.
Android programming using Android Studio is easy to learn.
It is challenging how to develop a user friendly application.
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

26. LAWS/Sri Naga Jahnavi Yeddanapudy
Future work
Design and develop E-911 Service
Integrate with Geolocation Verification Service.  
Provide real-time geolocation service
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

27. LAWS/Sri Naga Jahnavi Yeddanapudy
Conclusion
Designed and implemented system for Location Accuracy based on Wireless Signals
Provide user location information through GPS Application
Provide user location information through Wi-Fi application
Conducted experiments to investigate the location accuracy based on Wi-Fi and GPS information and LAWS systems results show that GPS approximately 50% more accurate than Wi-Fi.
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

28. LAWS/Sri Naga Jahnavi Yeddanapudy
References
Jiung-yao Huang, Chung-Hsien Tsai, “Improve GPS Positioning Accuracy with Context Awareness”, Ubi-Media Computing, First IEEE International Conference, Pages 94-99, July 31 – Aug
Chi-Yi Lin & Ming-Tze Hung, “A location-based personal task reminder for mobile users”, Pages , Personal and Ubiquitous Computing archive, Volume 18 Issue 2, February 2014.
Manoop Talasila, Reza Curtmola, and Cristian Borcea, “Improving Location Reliability in Crowd Sensed Data with Minimal Efforts”, Pages 1-8, Wireless and Mobile Networking Conference (WMNC), th Joint IFIP, April 2013.
11/14/2018
LAWS/Sri Naga Jahnavi Yeddanapudy

29. LAWS/Sri Naga Jahnavi Yeddanapudy
Q & A
LAWS/Sri Naga Jahnavi Yeddanapudy
11/14/2018