Wireless Location Technologies

1. Wireless Location Technologies Nobuo Kawaguchi Graduate School of Eng. Nagoya University

2. Today’s Topic • Wireless Location Technologies • What is WiFi based Positioning • History • Characteristics • WiFi Location Database • Wireless Location Information Systems • PlaceLab • Skyhook Wireless Loki • PlaceEngine • Locky.jp • Apple iPhone • Location Enhanced Services

3. Wireless Location Technologies • Tech. for both Indoor / Outdoor is required GPS Outdoors Cell Phone PHS Wireless LAN Environment RFID Ultra Sonic UWB Indoors 1m 10m 100m Estimation Accuracy

4. WiFi Everywhere Airport Restaurant University Station WiFi location Company Home • Wireless LAN has become popular infrastructure • A large number of position estimation system using wireless LAN have been developed Wide spread of wireless LAN RSSI BSSID, Latitude, Longitude

5. WiFi Location Technology • Every WiFi Access Point(AP) has followings • ESSID(String) • BSSID6 byte vendor assigned unique address (MAC) • Construct a database with BSSID and Position • One can estimate the position just receive a WiFi BSSID. • A lot of WiFi APs are already exist in the Wild. • One can easily add new APs by oneself. • Can increase accuracy by adding APs. • Each AP do not requires network access for positioning. Important Points

6. History of WLAN positioning now Start around 2000 (MS RADER) Technology 2000:RADAR (Microsoft) Products 2003:AirLocation (Hitachi) 2000:Ekahau Service/Activities 2006/3:Loki (Skyhook Wireless) 2003:PlaceLab (Intel) 2005/7:Locky.jp (Nagoya Univ) 2008/1:iPhone (Apple) 2006/7:PlaceEngine (Sony CSL) 2007/9:Digial Camera (Sony)

7. Positioning methods using WLAN Existing methods are classified into following three types. • Triangulation • Lateration (RSSI or TDOA) RADAR (MS Research), WiPS (Kyusyu Univ. Japan) AirLocation (TDOA)(Hitachi) • Angulation (AOA) • Proximity • GUIDE Project (Keith et al) • Scene Analysis • RADAR(MS Research), Ekahau (Ekahau corp.) • Place Lab (Intel Research)

8. Positioning Access Point α A B β A B a b E Reference Direction E Reference Point c Estimated Point C • Triangulation (Angulation) (Lateration) • Using more than 2 reference points direction • Using more than 3 reference point’s distance

9. Positioning Access Point • Proximity • Consider the position of most powerful APas a current position. • Transmission range of Wireless LAN is about 100 meters in the open air • Not good accuracy but simple. • Scene Analysis • Consider • Difficult to construct learning data as target area is spread • Inappropriate for our objective

10. Proximity • This method consider communication area of AP as user’s position. Terminal’s location APn(xn,yn) AP1(x1,y1) AP2(x2,y2) Reference Point Communication Area of Reference Point

11. Scene Analysis • This method use pre-observation wireless information called radio map. • Most system use Monte Carlo family method (ex. Bayesian filter, particle filter) and radio map. Lecture RoomA Lecture Room B Lecture Room C Lecture Room D Lecture Room E

12. GPS vs WiFi Location From , Delivering Real-World Ubiquitous Location Systems, C. ACM 2006.

13. WiFi Location: Characteristics • WiFi characteristics • Difference of WLAN Adapter/Antennas • Difference on Orientation • WiFi Signal Strength Distribtion • WiFi Positioning Acitivities • Locky.jp Project • WiFi AP positioning

14. Difference on WLAN Adapter

15. Distribution Difference

16. Difference on Orientation Wireless LAN Card A 0º Wireless LAN Card B Wireless LAN Card C 45º 315º 90º 270º 225º 135º 180º

17. Distribution Pattern of WiFi RSSI Probability Density Received Signal Strength (dBm)

18. WiFi Location Database Required for wide area location system. • Acquisition Method • Accuracy • Efficiency • How to construct a large Database • Locky.jp

19. Acquisition Methods • Variety of acquisition methods with different transportation Car 30km/h Walking 5km/h Bicycle 15km/h Near to the buildings and houses Influenced by traffic jams and regulations

20. Estimation Accuracy Cumulative rate • The position estimation using the learning data acquired by walking can make estimates at less than 30m in 63% of the area • The estimation data by car is worse by about 5% in all ranges • Beyond 40 m, the bicycle data can estimate almost as well as that obtained by walking Accuracy(m) Cumulative estimation accuracy of evaluative data by walking

21. Accuracy of WiFi location Bicycle Motor Bike Car

22. Result: Bicycle is more suitable than Others Table: Position Estimation of Experimental data （Walking, Proximity） Bicycle has better efficiency than others

23. WarDriving using bycicle GPS Stumbler WiFi Antenna / Card Note PC Battery

24. Locky.jp Project

25. Locky.jpProject • WiFi Location Portal for Japan • Data Collection of WiFi AP(BSSID) + Location • Place Information • Begins July 2005 • Currently, we have collected 369,045 APs currently

26. Locky.jp Environment full of wireless LAN Users Locky.jp • Effect on … • Service area • Estimation accuracy Information Service WiFi Location Database WiFi Location WiFi Location WiFi Location WiFi Location • Goals of Locky.jp • Wide-area WiFi Location acquisition by collaboration with user • Creation of position estimation system using WiFi Location database • Producing Low-Cost positioning system for everywhere everybody • Activity • Research on positioning system • Public relations of positioning system • Creation of acquisition assistance tools

27. Collecting AP’s by Collaborators • 300 over members collecting AP Mainly for Tokyo/Osaka/Nagoya - Ranking

28. Trend of No. of AP in Locky.jp • Over 530,000 WiFi locations in Japan No. of collaborator No. of AP Month

29. Tokyo area ( over 50000 AP)

30. Tokyo APs plotted on GoogleEarth

31. View from Tokyo-Castle

32. Nagoya Area , Over 40000APs

33. Access Points in Nagoya City Area 1km Square 878 APs Center of Nagoya JAPAN 1km Access Point Total 878 8.8 unit / 100m×100m

34. APs in Residential Area Access Point Total 278 3.5 unit /100m×100m Residential area Height is restricted 278 APs in 1km square area 1km Residential Area

35. Locky.jp upload page

36. Tools for Locky.jp • Locky Stumbler • KML converter • Log→ KML (Google Earth)

37. Wireless Location Lib for WLDB // Creation of LockyToolkit object LockyToolkit lockyToolkit = new LockyToolkit(); // Load a WiFi Location DB lockyToolkit.openDB(); // Get Locky Code from current wireless measurement LockyCode lockyCode = lockyToolkit.getLockyCode(); // Get latitide, Longitude double latitude = lockyCode.getLatitude(); double longitude = lockyCode.getLongitude(); • Locky Toolkit • By using Locky Toolkit, one can easily develop a WiFi Location Application • Just a few line of Java code. Locky Toolkit example program （Java）

38. PlaceLab （２００３~ Intel Research) Research Agenda • Previous research: small communities, high cost systems • Our goal: enable large communities by reducing barriers to adoption • Provide low-cost, highly convenient position-sensing technology • Make users comfortable with respect to their location privacy • Develop services and toolkits to make it easy to build location-aware applications Usage Model • Client devices cache snapshots of WiFi Beacon Databases • Devices that hear WiFi beacons estimate location locally & privately. New beacons get added to user-contributed database • Urban areas have dense WiFi coverage • Applications use location to provide customized, dynamic content and services PlaceLab Approach • Rely on increasing WiFi densities to provide low-cost device positioning • Build a public user-contributed data store to map RF beacons to geographic locations • Improve quality of positioning data via Bayesian filter and sensor fusion techniques • Understand privacy management tradeoffs by studying use of location-aware applications • Provide a “PlaceLab” for educators with toolkits and curriculum for web and ubicomp courses • Offer developers a mechanism to use “place” abstractions in addition to low-level coordinates Bootstrapping Location-enhanced Computing Enabling privacy-observant, wide scale, indoor & outdoor device positioning with low barriers to participation (Reference http://www.placelab.org/ )

39. Skyhook wireless http://loki.com/ • Loki 200 employee 8million APs Loki Toolbar By using the Loki toolbar, one can locate the place of the terminal in major cities in U.S.

41. PlaceEngine by Sony CSL • You can upload theWiFi Info to PlaceEngine Serverusing Web Service

42. PlaceEngine • Web service for WLAN location • 200,000 access point in Tokyo area. (Reference http://www.placeengine.com/ )

43. PlaceEngine • 150,000 access point in Tokyo area. (Reference http://www.placeengine.com/ )

44. Mash up with PlaceEngine • PlaceEngine can be used as a Web parts. Your PC Web Service Web Browser PE button PlaceEngineWeb DB PlaceEngine Client

45. PlaceEngine×Station Info. • PlaceEngine can be used as a Web parts.

46. PlaceEngine × Restaurant Search

47. PlaceEngine × Restaurant Search Asked to send “location” to Web Application

48. PlaceEngine × Restaurant Search

49. Apple iPhone Apple iPhone utilize WiFi Positioning System by Skyhook Wirelessand GSM Location System by Google.

50. Google Maps for Mobile • "My Location" Technology http://www.google.com/intl/en/press/annc/20071128_maps_mobile_my_location.html • Adds a GSM Location technology ontomobile phones • Do not require GPS (only 15% of mobile phone has GPS)