Presentation on theme: "Wireless Location Technologies"— Presentation transcript:
1 Wireless Location Technologies Nobuo KawaguchiGraduate School of Eng.Nagoya University
2 About me Nobuo Kawaguchi Research Topics Associate Professor Dept. Engineering, Nagoya UniversityResearch TopicsWireless Location Systems ( )Scalable Adaptive Multicast (SAM), XCAST6UbiCompEnvironment and CommunicationMiddleware named “cogma”Mobile agent based system
3 Today’s Topic Wireless Location Technologies WiFi Location Database What is WiFi based PositioningHistoryCharacteristicsWiFi Location DatabaseWireless Location Information SystemsPlaceLabSkyhook Wireless LokiPlaceEngineLocky.jpApple iPhoneLocation Enhanced Services
4 Wireless Location Technologies Tech. for both Indoor / Outdoor is requiredOutdoorsGPSCellPhonePHSWireless LANEnvironmentRFIDUltra SonicUWBIndoors1m10m100mEstimation Accuracy
5 WiFi Everywhere Wireless LAN has become popular infrastructure RestaurantAirportWide spread of wireless LANHomeCompanyStationUniversityWiFi locationRSSIThis slide shows a background of our research.In recent years, wireless LAN has become popular infrastructure.In the old time, we could receive the signal of wireless LAN only in the university and the company.[Click] However, now, we can receive the signal of wireless LAN in a lot of places.As a result, a large number of position estimation system using wireless LAN have been developed.[Click] This figure shows, this positioning system needs one or more WiFi locations to estimation.[Click] WiFi location is set of BSSID, position of access point and RSSI.BSSID, Latitude, LongitudeWireless LAN has become popular infrastructureA large number of position estimation system using wireless LAN have been developed
6 WiFi Location Technology Every WiFi Access Point(AP) has followingsESSID (String)BSSID 6 byte vendor assigned unique address (MAC)Construct a database with BSSID and PositionOne 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
7 History of WLAN positioning Start around 2000 (MS RADER)nowTechnology2000:RADAR(Microsoft)Products2003:AirLocation(Hitachi)2000:EkahauService/Activities2006/3: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)
8 Positioning methods using WLAN Existing methods are classified into following three types.TriangulationLateration (RSSI or TDOA)RADAR (MS Research), WiPS (Kyusyu Univ. Japan)AirLocation (TDOA)(Hitachi)Angulation (AOA)ProximityGUIDE Project (Keith et al)Scene AnalysisRADAR(MS Research), Ekahau (Ekahau corp.)Place Lab (Intel Research)
9 Positioning Access Point Triangulation(Angulation)(Lateration)Using more than 2 reference points directionUsing more than 3 reference point’s distanceABEαβABCabcEReference PointEstimated PointReference Direction
10 Positioning Access Point ProximityConsider the position of most powerful AP as a current position.Transmission range of Wireless LAN is about 100 meters in the open airNot good accuracy but simple.Scene AnalysisConsiderDifficult to construct learning data as target area is spreadInappropriate for our objective
11 ProximityThis method consider communication area of AP as user’s position.Terminal’s locationAPn(xn,yn)AP1(x1,y1)AP2(x2,y2)Reference PointCommunication Area of Reference Point
12 Scene AnalysisThis 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 Room ALecture RoomBLecture RoomCLecture RoomDLecture RoomE
13 GPS vs WiFi LocationFrom , Delivering Real-World Ubiquitous Location Systems, C. ACM 2006.
14 WiFi Location: Characteristics WiFi characteristicsDifference of WLAN Adapter/AntennasDifference on OrientationWiFi Signal Strength DistribtionWiFi Positioning AcitivitiesLocky.jp ProjectWiFi AP positioning
17 Difference on Orientation 0ºWireless LAN Card AWireless LAN Card BWireless LAN Card C315º45º270º90º225º135º180º
18 Distribution Pattern of WiFi RSSI Received Signal Strength (dBm)Probability Density
19 WiFi Location Database Required for wide area location system.Acquisition MethodAccuracyEfficiencyHow to construct a large DatabaseLocky.jp
20 Acquisition MethodsVariety of acquisition methods with different transportationCar30km/hWalking5km/hBicycle15km/hThis slide shows the variety of acquisition methods with different transportation.In this research, we focused transportation for acquisition.We considered 4 acquisition methods by walking, bicycle, motorcycle, and car.Left side is low speed.It's not good to collect wide areas but movement is free.Right side is high speed.But it is influenced by traffic regulations.Near to the buildings and housesInfluenced by traffic jams and regulations
21 Cumulative estimation accuracy of evaluative data by walking Cumulative rateAccuracy(m)This slide shows the cumulative estimation accuracy of evaluative data by walking.Horizontal axis shows the accuracy of estimation system.Vertical axis shows cumulative rate.This figure shows, the position estimation using the learning data acquired by foot can make estimates at less than 30 m in 68% of the area.The estimation data by car is worse by about 5% in all ranges.Comparing the data by bicycle and by walking, there is about a 5% difference in the range of 10 m,but beyond 40 m, the bicycle data can estimate almost as well as that obtained by walking.Cumulative estimation accuracy of evaluative data by walkingThe position estimation using the learning data acquired by walking can make estimates at less than 30m in 63% of the areaThe estimation data by car is worse by about 5% in all rangesBeyond 40 m, the bicycle data can estimate almost as well as that obtained by walking
23 Result: Bicycle is more suitable than Others Table: Position Estimation of Experimental data （Walking, Proximity）Walking(5km/h)Bicycle(15km/h)Car(30km/h)All dataNo. of APs247269183Accuracy (m)24.326.729.6Coverage (%)86.887.883.3First-round data21420912231.323.226.072.274.668.2Strong signal APs(1st round) (RSSI > -90)1551784930.123.532.9188.8.131.52Now we can select a pre-acquisition method.This table shows the result of this experiment.“All data” is all collected WiFi locations.“First-round data” is collected WiFi locations in the first round of experiment.“Strong signal APs” is that data’s RSSI is stronger than -90 of the “First-round data”.If we simply require accuracy, “walking” may be the answer.However, we need also coverage and efficiency in the acquisition.If we only think about speed, “car” may be the answer.But the accuracy and coverage of the car data are always the worst.Additionally, the cost of the transportation and lack of freedom are not acceptable for our project.As a result, we selected pre-acquisition method using the bicycle.Bicycle has better efficiency than others
24 WarDriving using bycicle GPSNote PCWiFi Antenna / CardBatteryStumbler
26 Locky.jp Project WiFi Location Portal for Japan Begins July 2005 Data Collection of WiFi AP(BSSID) + LocationPlace InformationBegins July 2005Currently, we have collected369,045 APs currently
27 Environment full of wireless LAN Locky.jpEnvironment full of wireless LANUsersLocky.jpEffect on …Service areaEstimation accuracyInformation ServiceWiFi LocationDatabaseWiFi LocationWiFi LocationWiFi LocationWiFi LocationGoals of Locky.jpWide-area WiFi Location acquisition by collaboration with userCreation of position estimation system using WiFi Location databaseProducing Low-Cost positioning system for everywhere everybodyActivityResearch on positioning systemPublic relations of positioning systemCreation of acquisition assistance toolsLocky.jp is our location project.We are working on the Locky.jp to collect WiFi Location with user.Our goal is divided into three steps.First, we collect WiFi Locations in wide-area by collaboration with user.Next, we create positioning system using WiFi Location database.Finally, we produce low-cost positioning system for everywhere everybody.Figure shows collaboration between Locky.jp and user.[Click] User can get and use information services and applications from Locky.jp with no cost.[Click] If user discovered new access point,[Click] user can register in database.[Click] Registered WiFi location comes to be used to estimate next time.[Click] If users register a lot of WiFi locations,[Click] database grows more and more,[Click] and quality of service improves, too.In this way, Locky.jp grows up with the user.Our main activity is research and public relations of positioning systemand create acquisition assistance tools.
28 Collecting AP’s by Collaborators 300 over members collecting APMainly for Tokyo/Osaka/Nagoya- Ranking
29 Trend of No. of AP in Locky.jp Over 530,000 WiFi locations in JapanNo. of collaboratorNo. of APThis slide shows the current status of Locky.jp.Horizontal axis shows the time to the month.The left side vertical axis shows the number of collected WiFi locations.The right side vertical axis shows the number of collaborator.The blue line shows number of WiFi locations.The red line shows number of collaborator.Locky.jp collected about 200,000 WiFi locations in September 2006.Now, over WiFi locations are collected in Japan.Month
38 Wireless Location Lib for WLDB Locky ToolkitBy using Locky Toolkit, one can easily develop a WiFi Location ApplicationJust a few line of Java code.// Creation of LockyToolkit objectLockyToolkit lockyToolkit = new LockyToolkit();// Load a WiFi Location DBlockyToolkit.openDB();// Get Locky Code from current wireless measurementLockyCode lockyCode = lockyToolkit.getLockyCode();// Get latitide, Longitudedouble latitude = lockyCode.getLatitude();double longitude = lockyCode.getLongitude();Locky Toolkit example program （Java）
39 PlaceLab （２００３~ Intel Research) Bootstrapping Location-enhanced ComputingEnabling privacy-observant, wide scale, indoor & outdoor device positioning with low barriers to participationResearch AgendaPrevious research: small communities, high cost systemsOur goal: enable large communities by reducing barriers to adoptionProvide low-cost, highly convenient position-sensing technologyMake users comfortable with respect to their location privacyDevelop services and toolkits to make it easy to build location-aware applicationsUsage ModelClient devices cache snapshots of WiFi Beacon DatabasesApplications use location to provide customized, dynamic content and servicesDevices that hear WiFi beacons estimate location locally & privately. New beacons get added to user-contributed databaseUrban areas have dense WiFi coveragePlaceLab ApproachRely on increasing WiFi densities to provide low-cost device positioningBuild a public user-contributed data store to map RF beacons to geographic locationsImprove quality of positioning data via Bayesian filter and sensor fusion techniquesUnderstand privacy management tradeoffs by studying use of location-aware applicationsProvide a “PlaceLab” for educators with toolkits and curriculum for web and ubicomp coursesOffer developers a mechanism to use “place” abstractions in addition to low-level coordinates(Reference )
40 Skyhook wireless Loki http://loki.com/ 200 employee 8million APs Loki ToolbarBy using the Loki toolbar, one can locate the place of the terminal in major cities in U.S.
55 Applications of WLAN Positioning Beacon Print (Intel Research: UbiComp2005)Detect User’s Preferred PlacesDo not require pre-acquisitionNearMe (MS Research:UbiComp2004)Wireless ProximityDetect near person using BSSIDSelf organization of WLAN AP dataPlaceEngine uses this technology
56 WiFi Tagged Photo Exif for JPEG Date , Time , other photo dataadd WiFi BSSID..||Location Enhanced PhotoIf 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 databaseDigital camera with WiFi is now on Market
57 Utilization of WiFi Location System Location systems are widely spreadBut not for WiFi Location SystemGPS is primary location sourceA lot of GPS application are publicNMEA formatWe need integrate WLS with GPS
58 Implementation of Virtual GPS Virtual COM driverGPS ApplicationWiFiLocky VirtualGPSNMEA outputWLDBGet NMEA data from COM portCOM XCOM YVirtual COM Driver
59 Hybrid Positioning with GPS Virtual COM driverGPS ApplicationWiFiGPSSelection moduleLocky VirtualGPSNMEA outputWLDBGet NMEA data from COM portCOM XCOM YVirtual COM Driver
60 Indoor positioning for public area Outdoors data can be easily collectedLocky.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
63 We collected underground WiFi Map of undergroundUse 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.
64 Subway StumblerWe have developed a tool for indoors
65 How many data have we collected? Current Subway WiFi data.83 Nagoya Subway Stations30 person-day2000 Unique APs82500 point of locations
66 How many data have we collected? Current Subway WiFi data.83 Nagoya Subway Stations30 day collection2000 Unique APs82500 point of locationsOnly 30 day are required to collect subway data in Nagoya ( 2 million city )
67 It is not only a location information Location ProcessingSubway knowledgeTime tableArrival time can be estimateThere are shops in the station.RestroomsExchange stationIt is not only a location information
68 Possible Applications Train Navigation with “Time”Exit navigationIf you collect WiFi data every seconds,Your route is stored in the device.Station/Route can be estimated. → Train fee is easily calculated.
69 Underground Map of Nagoya ALPSLAB Underground(Since 2007/12)
70 We already collected WiFi Total UniqueSakae Area AP = Nagoya Station AP ：241
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