Presentation on theme: "Wireless Location Technologies Nobuo Kawaguchi Graduate School of Eng. Nagoya University."— Presentation transcript:
Wireless Location Technologies Nobuo Kawaguchi Graduate School of Eng. Nagoya University
About me Nobuo Kawaguchi Associate Professor Dept. Engineering, Nagoya University Research Topics Wireless Location Systems ( )http://locky.jp Scalable Adaptive Multicast (SAM), XCAST6 UbiCompEnvironment and Communication Middleware named cogma Mobile agent based system
Todays 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
1m 10m100m Estimation Accuracy Environment PHS GPS Outdoors Indoors Cell Phone Ultra Sonic RFID UWB Wireless LAN Wireless Location Technologies Tech. for both Indoor / Outdoor is required
WiFi Everywhere Wireless LAN has become popular infrastructure A large number of position estimation system using wireless LAN have been developed Station Home Restaurant Airport Wide spread of wireless LAN RSSI BSSID, Latitude, Longitude University Company WiFi location
WiFi Location Technology Every WiFi Access Point(AP) has followings ESSID (String) BSSID 6 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
now 2000:RADAR (Microsoft) 2000:Ekahau 2005/7:Locky.jp (Nagoya Univ) 2006/7:PlaceEngine (Sony CSL) History of WLAN positioning Start around 2000 (MS RADER) 2006/3:Loki (Skyhook Wireless) 2003:AirLocation (Hitachi) 2003:PlaceLab (Intel) Service/Activities Products Technology 2007/9:Digial Camera (Sony) 2008/1:iPhone (Apple)
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) Existing methods are classified into following three types. Positioning methods using WLAN
Positioning Access Point Triangulation Using more than 3 reference points distance Using more than 2 reference points direction A B C a b c E A B E α β (Lateration) (Angulation) Reference Point Estimated Point Reference Direction
Positioning Access Point Proximity Consider the position of most powerful AP as 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
Terminal s location AP n (x n,y n ) AP 2 (x 2,y 2 ) Reference Point AP 1 (x 1,y 1 ) Communication Area of Reference Point This method consider communication area of AP as users position. Proximity
Lecture Room A Lecture Room B Lecture Room C Lecture Room D Lecture Room E 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. Scene Analysis
GPS vs WiFi Location From, Delivering Real-World Ubiquitous Location Systems, C. ACM 2006.
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
Difference on WLAN Adapter
0º0º 45º 315º 225º 135º 90º 270º 180º Wireless LAN Card A Wireless LAN Card B Wireless LAN Card C Difference on Orientation
Received Signal Strength (dBm) Probability Density Distribution Pattern of WiFi RSSI
WiFi Location Database Required for wide area location system. Acquisition Method Accuracy Efficiency How to construct a large Database Locky.jp
Acquisition Methods Variety of acquisition methods with different transportation Car 30km/h Bicycle 15km/h Walking 5km/h Near to the buildings and houses Influenced by traffic jams and regulations
Estimation Accuracy 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 Cumulative estimation accuracy of evaluative data by walking Accuracy(m) Cumulative rate
Car Motor Bike Bicycle Accuracy of WiFi location
Result: Bicycle is more suitable than Others Bicycle has better efficiency than others Walking (5km/h) Bicycle (15km/h) Car (30km/h) All data No. of APs Accuracy (m) Coverage (%) First-round data No. of APs Accuracy (m) Coverage (%) Strong signal APs (1 st round) (RSSI > - 90) No. of APs Accuracy (m) Coverage (%) Table: Position Estimation of Experimental data Walking, Proximity
GPS Note PC WiFi Antenna / Card Battery Stumbler WarDriving using bycicle
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
Locky.jp 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 Locky.jp Environment full of wireless LAN Users WiFi Location Database Information Service WiFi Location Effect on … Service area Estimation accuracy WiFi Location
Collecting APs by Collaborators 300 over members collecting AP Mainly for Tokyo/Osaka/Nagoya - Ranking
Trend of No. of AP in Locky.jp Over 530,000 WiFi locations in Japan Month No. of collaborator No. of AP
Tokyo area ( over AP)
Tokyo APs plotted on GoogleEarth
View from Tokyo-Castle
Nagoya Area, Over 40000APs
Access Point Total unit / 100m×100m 1km Access Points in Nagoya City Area 1km Square 878 APs Center of Nagoya JAPAN
Access Point Total unit /100m×100m Residential Area APs in Residential Area 1km Residential area Height is restricted 278 APs in 1km square area
Wireless Location Lib for WLDB Locky Toolkit By using Locky Toolkit, one can easily develop a WiFi Location Application Just a few line of Java code. // 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 example program Java
Bootstrapping Location-enhanced Computing Enabling privacy-observant, wide scale, indoor & outdoor device positioning with low barriers to participation 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 Applications use location to provide customized, dynamic content and services Devices that hear WiFi beacons estimate location locally & privately. New beacons get added to user- contributed database Urban areas have dense WiFi coverage 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 (Reference )http://www.placelab.org/ PlaceLab ~ Intel Research)
Skyhook wireless 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.
PlaceEngine by Sony CSL You can upload the WiFi Info to PlaceEngine Server using Web Service
(Reference )http://www.placeengine.com/ PlaceEngine Web service for WLAN location 200,000 access point in Tokyo area.
(Reference )http://www.placeengine.com/ PlaceEngine 150,000 access point in Tokyo area.
Mash up with PlaceEngine PlaceEngine can be used as a Web parts. PlaceEngine Client Web Browser PlaceEngine Web DB Web Service PE button Your PC
PlaceEngine×Station Info. PlaceEngine can be used as a Web parts.
PlaceEngine × Restaurant Search
Asked to send location to Web Application
PlaceEngine × Restaurant Search
Apple iPhone Apple iPhone utilize WiFi Positioning System by Skyhook Wireless and GSM Location System by Google.
Google Maps for Mobile "My Location" Technology _maps_mobile_my_location.html Adds a GSM Location technology onto mobile phones Do not require GPS (only 15% of mobile phone has GPS)
Community: War Driving Community 12,886,129 points from 796,376,798 person (2008/01/23) Mostly for use WiFi Hotspot. Not for positioning.
Applications of WLAN Positioning Beacon Print (Intel Research: UbiComp2005) Detect Users Preferred Places Do not require pre-acquisition NearMe (MS Research:UbiComp2004) Wireless Proximity Detect near person using BSSID Self organization of WLAN AP data PlaceEngine uses this technology
WiFi Tagged Photo Exif for JPEG Date, Time, other photo data add WiFi BSSID.. || Location Enhanced Photo If you put photos on Flickr with BSSID, You can find the closer photos. With WiFi tag, and WiFi Location DB, You can find the photo using Place. This does not require offline WiFi location database Digital camera with WiFi is now on Market
Utilization of WiFi Location System Location systems are widely spread But not for WiFi Location System GPS is primary location source A lot of GPS application are public NMEA format We need integrate WLS with GPS
Implementation of Virtual GPS Virtual COM driver GPS Application Get NMEA data from COM port Virtual COM Driver Locky VirtualGPS WiFi WLDB COM X COM Y NMEA output
Hybrid Positioning with GPS Virtual COM driver GPS Application Get NMEA data from COM port Virtual COM Driver Locky VirtualGPS WiFi WLDB COM X COM Y NMEA output GPS Selection module
Indoor positioning for public area Outdoors data can be easily collected Locky.jp tool (GPS+ WiFi) How to collect data for indoor area. There is no way to locate position. We need some tool for data acquisition. Which place we should collect? Public place with WiFi
Subway of Nagoya
We have WiFi on all stations
We collected underground WiFi Map of underground Use a photo of floor map. Plot a location by Hand on the photo. Any place can be collected with this tool. Other data can be offered with Photo.
Subway Stumbler We have developed a tool for indoors
How many data have we collected? Current Subway WiFi data. 83 Nagoya Subway Stations 30 person-day 2000 Unique APs point of locations
How many data have we collected? Current Subway WiFi data. 83 Nagoya Subway Stations 30 day collection 2000 Unique APs point of locations Only 30 day are required to collect subway data in Nagoya ( 2 million city )
Location Processing Subway knowledge Time table Arrival time can be estimate There are shops in the station. Restrooms Exchange station It is not only a location information
Possible Applications Train Navigation with Time Exit navigation If you collect WiFi data every seconds, Your route is stored in the device. Station/Route can be estimated. Train fee is easily calculated.
Underground Map of Nagoya ALPSLAB Underground(Since 2007/12)
We already collected WiFi Total Unique Sakae Area AP = 160 Nagoya Station AP 241
Experiment with iPod Touch
FriendMap Shows the position of Friends and Chat