location-aware computing · apis for location-based services 28 q geocoding is the process of...

Location-aware Computing APIs for Location-based Services

Prof. Marco Di Felice Department of Computer Science and Engineering

University of Bologna

Context-Aware Systems

http://www.cs.unibo.it/difelice/

APIs for Location-based services

2APPLICATIONLAYERINTERFACES(API)FORLOCATION-BASEDSERVICES

MARCODIFELICE

COMPONENTSofLOCATION-BASEDSERVICESARCHITECTURE

Source:http://geoawesomeness.com/

Ø  Wewillstillfocusonthepositioningtechnologies,butconsideringavailablelocalizationAPIs.

Location-aware services

3

GeoDataACQUISITION

GeoDataMODELING

GeoDataSTORAGE

GeoDataVISUALIZATION

GeoDataAnalytics

APPLICATIONLAYERINTERFACES(API)FORLOCATION-BASEDSERVICESMARCODIFELICE


4LOCATIONINTELLIGENCE&SPATIALDATAANALYSIS

MARCODIFELICE

APIsforOUTDOORLOCALIZATION(ANDGEO-INFORMATIONRETRIEVAL)

WEBSERVICES


5

q  SeveralgeoservicesandgeolocationAPIsareavailable(atleastforoutdoorscenarios).



6

q  GeolocationAPIsforlocation-basedservices


http://www.programmableweb.com/news/61-geolocation-apis-panoramio-google-gears-and-yahoo/2012/03/14

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q  RepresentationalStateTransfer(REST)!setofarchitecturalprinciplesfordistributedsystems.1.  ClientServeràInteractionsbasedonarequest-response

communicationpattern.2.  UniformInterfacesàUnambigousstandardinterfacefor

accessingtheresources(e.g.theURI).3.  Statelessàclientcontextandstatearenotstoredontheserver.4.  Cacheableàdataarecachedbyclientsandintermediaries.5.  LayeredSystemàintermediatecomponentscanhidewhatis

behindthem(e.g.contentdeliverynetworks).


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q  W3CGeolocationAPIisaneffortbytheWorldWideWebConsortium(W3C)tostandardizeaninterfaceforretrievingthegeographicallocationinformationforaclient-side(Web)device.²  HTML5GeolocationAPIissupportedbymostofthebrowser²  Geolocationdata:latitude,longitude,accuracy,altitude,

altitude,altitudeAccuracy,speed,heading,timestamp²  Mainmethods:getCurrentPosition()andwatchPosition()



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q  HTML5GeolocationAPIcodeexample


interfaceGeolocation{voidgetCurrentPosition(PositionCallbacksuccessCallback,optionalPositionErrorCallbackerrorCallback,optionalPositionOptionsoptions);longwatchPosition(PositionCallbacksuccessCallback,optionalPositionErrorCallbackerrorCallback,optionalPositionOptionsoptions);voidclearWatch(longwatchId);};

Documentationandsourcecodeavailableat:http://www.w3schools.com/html/html5_geolocation.asp


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<script>varx=document.getElementById("demo");functiongetLocation(){if(navigator.geolocation){navigator.geolocation.getCurrentPosition(showPosition);}else{x.innerHTML="Geolocationisnotsupportedbythisbrowser.";}}functionshowPosition(position){x.innerHTML="Latitude:"+position.coords.latitude+"<br>Longitude:"+position.coords.longitude;}</script>



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q  GoogleMapsAPI

²  HTTP-basedWebserviceAPI

² WebclientAPI(Javascript)

²  ProgramminglanguageAPI(Java,Python)

² MobileOSAPI(Android,iOS)


Documentationandsourcecodeavailableat:https://developers.google.com/maps/web-services/


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q  GoogleMapswebservicesareacollectionofHTTPinterfacestoGoogleservicesprovidinggeographicdataformap-relatedapplications.²  RESTfulservices;resourcesareidentifiedbyaidentifier,and

manipulatedbyusingacommonsetofHTTPmethods.²  OutputsarereturnedinJSON/XMLformats.²  Aregistrationkeyisneededtoaccesstheservices.

https://console.developers.google.com




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q MainGoogleMapswebservices²  GoogleMapsGeolocationAPI²  GoogleMapsElevationAPI²  GoogleMapsGeocodingAPI²  GoogleMapsDirectionsAPI²  GoogleMapsRoadsAPI²  GoogleMapsTimeZoneAPI²  GooglePlacesAPI




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q  TheGoogleMapsGeolocationAPIprovidesthecurrentlocation(plustheaccuracyradius)

²  Geolocationisperformedbyconsideringfingerprinting/triangulationtechniques,basedoncellulartowersandWiFinetworkstheuserscandetectattheirlocations(providedasinputs).

²  Requests/responsesareformattedinJSON,andtransmittedusingPOSTmethodsoverHTTPS.

²  TheAPIkeyisneededtoidentifytheapplication(andthequota)


https://www.googleapis.com/geolocation/v1/geolocate?key=YOUR_API_KEY



18

q  TherequestbodymustbeformattedinJSON.


{"homeMobileCountryCode":310,"homeMobileNetworkCode":410,"radioType":"gsm","carrier":"Vodafone","considerIp":"true","cellTowers":[//CellTowerObjects.],"wifiAccessPoints":[//WiFiAccessPointObjects.]}

HOMENETWORKCOUNTRYCODE

HOMENETWORKNETWORKCODE

MOBILERADIOTYPE:gsm,lte,cdma,wcdma

UseIPaddresswhenwirelessnetworkinfoarenotavailable

Networkprovidername



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{"cellTowers":[{"cellId":42,"locationAreaCode":415,"mobileCountryCode":310,"mobileNetworkCode":410,"age":0,"signalStrength":-60,"timingAdvance":15}]}

CELLTOWERSOBJECTEXAMPLE

TIMEOFARRIVALfrommobilenodetothebasestation

RECEIVEDSIGNALSTRENGTH(indbm)

UniqueCELLIDENTIFIER(mandatory)

AreaandNetworkIdentifiers(mandatory)



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"wifiAccessPoints":[{"macAddress":"01:23:45:67:89:AB","signalStrength":-65,"age":0,"channel":11,"signalToNoiseRatio":40}]

WIFIOBJECTEXAMPLE

NOISEoverRECEIVEDSIGNAL(indb)

WIFIchannelusedbytheAP

MACADDRESSoftheAP(mandatory)

ReceivedSignalStrength(RSS)indbm



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q  TheresponsebodymustbeformattedinJSON.


{"location":{"lat":51.0,"lng":-0.1},"accuracy":1200.4}

Estimatedlatitudeandlongitudeoftheuser(indegrees)

Localizationerror,definedasaradius(inmeters)ofacirclecenteredattheestimatedlocationreturnedabove.



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q  TheGoogleMapsElevationAPIallowsdeterminingelevationdataforalllocationsonthesurfaceoftheearth,includingdepthlocationsontheoceanfloor.²  Elevationdataareavailablethroughmeasurementsorinterpolation.

²  Requests/responsesareformattedinJSONorXML,andtransmittedusingPOSTmethodsoverHTTPS.

²  Requestscanbeissuedforfordiscretelocationsorforanorderedpath


https://maps.googleapis.com/maps/api/elevation/outputFormat?parameters



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q  Positionalrequestsareindicatedthroughuseofthelocationsparameter,indicatingelevationrequestsforthespecificlocations(latitude/longitudevalues).


https://maps.googleapis.com/maps/api/elevation/json?locations=39.7391536,-104.9847034&key=YOUR_API_KEY

{"results":[{"elevation":1608.637939453125,"location":{"lat":39.73915360,"lng":-104.98470340},"resolution":4.771975994110107}],"status":"OK”} Minimumdistanceofinterpolation(inmeters)



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q  Positionalrequestscanrefertotheelevationdataalongapathatspecifiedintervals.


https://maps.googleapis.com/maps/api/elevation/json?path=36.578581,-118.291994|36.23998,-116.83171&samples=3&key=YOUR_API_KEY

² Pathisacoupleoflatitude/longitudeofthestartandendpoint² Sampleisthenumberofsamplepointsalongapathforwhichtoreturnelevationdata



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q  Positionalrequestscanrefertotheelevationdataalongapathatspecifiedintervals.


{"results":[{"elevation":4411.941894531250,"location":{"lat":36.5785810,"lng":-118.2919940},"resolution":19.08790397644043},

{"elevation":1381.861694335938,"location":{"lat":36.41150289067028,"lng":-117.5602607523847},"resolution":19.08790397644043},{"elevation":-84.61699676513672,"location":{

"lat":36.239980,"lng":-116.831710},"resolution":19.087903}],"status":"OK"}



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q  Geocodingistheprocessofconvertingaddressesintogeographiccoordinates(latitude/longitude).

²  Reversegeocodingistheprocessofconvertinggeocoordinates(latitude/longitude)intosymbolicaddresses(e.g.nation,city,address).


https://maps.googleapis.com/maps/api/geocode/output?parameters

² OutputcanbeJSONorXML² Parametersaredifferentforgeocodingandreversegeocoding



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q  Geocodingistheprocessofconvertingaddressesintogeographiccoordinates(latitude/longitude)


PARAMETERSOFTHEGEOCODINGSERVICE

² Address!Thestreetaddressintheformatusedbythenationalpostalservice² ComponentsàAcomponentfilterofthegeocodingrequest

ü  routematcheslongorshortnameofaroute.ü  localitymatchesagainstbothlocalityandsublocalitytypes.ü  administrative_areamatchesalltheadministrative_arealevels.ü  postal_codematchespostal_codeandpostal_code_prefix.ü  countrymatchesacountrynameoratwoletterISO3166-1countrycode.




MARCODIFELICE

https://maps.googleapis.com/maps/api/geocode/json?address=1600+Amphitheatre+Parkway,+Mountain+View,+CA&key=YOUR_API_KEY

{"results":[{…"formatted_address":"1600AmphitheatreParkway,

MountainView,CA94043,USA","geometry":{"location":{"lat":37.4224764,"lng":-122.0842499},"location_type":"ROOFTOP”,

"viewport":{"northeast":{"lat":37.4238253802915,"lng":-122.0829009197085},"southwest":{"lat":37.4211274197085,"lng":-122.0855988802915}}…



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q  GoogleMapsDirectionsAPIallowscalculatingdirectionsbetweenlocations(non-trackingservice).

²  Directionsmayspecifyorigins,destinationsandwaypoints²  Result(JSON/XML)containalistofwaypoints²  Directionscanbeprovidedforseveralmodesoftransportation,

includingtransit,driving,walkingorcycling.²  Timeintrafficcanbeestimated.²  Preferencesfortransitroutes(less_walkingorfewer_transfers)

canbeprovidedasinput.APPLICATIONLAYERINTERFACES(API)FORLOCATION-BASEDSERVICES

MARCODIFELICE



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q  GoogleMapsDirectionsAPIallowscalculatingdirectionsbetweenlocations(non-trackingservice).


https://maps.googleapis.com/maps/api/directions/json?origin=Toronto&destination=Montreal&avoid=highways&mode=cycling&key=YOUR_API_KEY

origin/destinationàaddressorgeocoordinatesmodeàdriving,walking,cycling,transitwaypointsàarrayofwaypoints,expressedascoordinatesoraddressesavoidàtolls,highways,ferriesorindoorarrival_time/departure_timeàusedfortransitdirectionstransit_modeàpreferredmodesoftransit(bus,subway,train,tram,rail)unitsàdistanceunittodisplayresults…

SOMEPARAMETERS



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q  GoogleMapsRoadsAPIallowsmappingGPScoordinatestothegeometryoftheroad,andtodeterminethespeedlimitalongtheroadsegments.


https://roads.googleapis.com/v1/speedLimits?parameters&key=YOUR_API_KEY

² path!Listofcoordinates(latitude/longitude),separatedbycommas² placeIdàplaceIDoftheroadsegment,returnedbythesnapToRoadsmethod

² unitsàspeedlimitsinkilometersormilesperhour.




MARCODIFELICE

https://roads.googleapis.com/v1/speedLimits?placeId=ChIJ1Wi6I2pNFmsRQL9GbW7qABM&placeId=ChIJ58xCoGlNFmsRUEZUbW7qABM&key=YOUR_API_KEY

"speedLimits":[{"placeId":"ChIJ1Wi6I2pNFmsRQL9GbW7qABM","speedLimit":60,"units":"KPH"},{"placeId":"ChIJ58xCoGlNFmsRUEZUbW7qABM","speedLimit":60,"units":"KPH"},}]



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q  TheGoogleMapsTimeZoneAPIallowsrequestingthetimezoneforalocationontheearth,aswellasthatlocationtimeoffsetfromtheUTC


https://maps.googleapis.com/maps/api/timezone/outputFormat?parameters

²  location!comma-separatedlat,lngtuple(eg.location=-33.86,151.20)² timestamp!desiredtimeassecondssincemidnight,January1,1970UTC.



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q  TheGoogleMapsTimeZoneAPIallowsrequestingthetimezoneforalocationontheearth,aswellasthatlocationtimeoffsetfromtheUTC


https://maps.googleapis.com/maps/api/timezone/json?location=39.6034810,-119.6822510&timestamp=1331161200&key=YOUR_API_KEY

{"dstOffset":0,"rawOffset":-28800,"status":"OK","timeZoneId":"America/Los_Angeles","timeZoneName":"PacificStandardTime"}



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q  TheGooglePlacesAPIreturnsinformationaboutplaces,definedasestablishments,geographiclocations,orprominentpointsofinterest.


² PlaceSearchesreturnalistofplacesbasedonauser'slocationorsearchstring.² PlaceDetailsrequestsreturninformationaboutaspecificPlace(e.g.reviews)

² PlaceAddallowaddingdatatotheGooglePlacesdatabase² PlacePhotosgivesaccesstothePlacerelatedphotosstoredinGoogle'sPlacedatabase.² PlaceAutocompletecanbeusedtoautomaticallyfillinthenameand/oraddressofaplace² QueryAutocompletecanbeusedtoprovideaquerypredictionservicefortext-based

geographicsearches,byreturningsuggestedqueriesasyoutype.



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q  TheGooglePlacesAPIreturnsinformationaboutplaces,definedasestablishments,geographiclocations,orprominentpointsofinterest.


https://maps.googleapis.com/maps/api/place/nearbysearch/jsonlocation=-33.8670522,151.1957362&radius=500&type=restaurant&name=Italia&key=YOUR_API_KEY

https://maps.googleapis.com/maps/api/place/radarsearch/json?location=51.503186,-0.126446&radius=5000&type=museum&key=YOUR_API_KEY

https://maps.googleapis.com/maps/api/place/textsearch/json?query=restaurants+in+Sydney&key=



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q  GoogleMapsAPI

²  HTTP-basedWebserviceAPI

² WebclientAPI(Javascript)

²  High-levelProgramminglanguageAPI(Java,Python)

² MobileOSAPI(Android,iOS)




MARCODIFELICE

APIsforOUTDOORLOCALIZATION

MOBILEAPPLICATIONS(ANDROIDOS)



MARCODIFELICE

²  GPSmodulesmightpresentaseriousbatterydrainproblemduetotheirhighcomputationload

KleomenisKatevas,HamedHaddadi,LaurissaTokarchuk,SensingKit:EvaluatingtheSensorPowerConsumptioniniOSdevices,https://arxiv.org/abs/1606.05576



MARCODIFELICE


Per-phaseconsumption Consumptionfordifferentaccuracies

KongyangChen,GuangTan,andMingmingLu,ImprovingtheEnergyPerformanceofGPSReceiversforLocationTrackingApplications,2017IEEEConferenceonComputerCommunicationsWorkshops(INFOCOMWKSHPS):2017IEEEInfocomMiseNetWorkshop



MARCODIFELICE


MeeyeonLee,Deok-KiKimandJung-WonLee,AnalysisofCharacteristicsofPowerConsumptionforContext-AwareMobileApplications,Information2014,5,612-621;doi:10.3390/info5040612

OUTDOOR(GPS)

INDOOR(WI-FI)

OUTDOOR(GPS)



MARCODIFELICE

APIvsmeterbasedconsumptionvalues

ImmanuelKönig,AbdulQudoosMemon,KlausDavid,EnergyconsumptionofthesensorsofSmartphones,TenthInternationalSymposiumonWirelessCommunicationSystems2013



MARCODIFELICE

HOWtogetthecurrentpositioninAndroid?

LOCATIONMANAGER

GPSprovider Wi-Fiprovider Cellularprovider

LOCATIONLISTENER

Locationchanged!

[interface]

NETWORKPROVIDER



MARCODIFELICE

q  InAndroid,thebatteryconsumptionofLocation-awareapplicationscanbemanagedbyproperlysettingthreeconfigurationparametersofthemobileapp:

https://developer.android.com/guide/topics/location/battery

²  Accuracy:Theprecisionofthelocationdata.Ingeneral,thehighertheaccuracy,thehigherthebatterydrain.

²  Frequency:Howoftenlocationiscomputed.Themorefrequentlocationiscomputed,themorebatteryisused.

²  Latency:Howquicklylocationdataisdelivered.Lesslatencyusuallyrequiresmorebattery.



MARCODIFELICE



²  Accuracy:Theprecisionofthelocationdata.Ingeneral,thehighertheaccuracy,thehigherthebatterydrain.

LocationRequestmLocationRequest=newLocationRequest();mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

PRIORITY_HIGH_ACCURACY,PRIORITY_BALANCED_POWER_ACCURACY,PRIORITY_LOW_POWER,PRIORITY_NO_POWER

Usesalllocationproviders

Passivelocalization,itexploitslocalizatioupdatesfromotherapps



MARCODIFELICE



²  Frequency:Howoftenlocationiscomputed.Themorefrequentlocationiscomputed,themorebatteryisused.

LocationRequestmLocationRequest=newLocationRequest();mLocationRequest.setInterval(10000);mLocationRequest.setFastestInterval(5000);

Intervalatwhichlocationcomputedforotherappsisdeliveredtothecurrentapp



MARCODIFELICE



²  Latency:Howquicklylocationdataisdelivered.Lesslatencyusuallyrequiresmorebattery.

LocationRequestmLocationRequest=newLocationRequest();mLocationRequest.setInterval(10000);mLocationRequest.setMaxWaitTime(50000);

Thisvalueshouldbeconsiderablelargerthantheinterval



MARCODIFELICE



1.  RemoveLocationUpdatesifnotneeded2.  Setatimeoutofwhenthelocationupdateshouldstop3.  Usepassivelocationupdatesandproperlysettheupdateparameters

LocationRequestrequest=newLocationRequest();request.setInterval(15*60*1000);request.setFastestInterval(2*60*1000);



MARCODIFELICE

Documentationandsourcecodeavailableat:http://developer.android.com/training/location/index.html

q  FusedlocationproviderAndroidAPIs.²  Itmergesthelocalizationoutputsofdifferentlocalization

providersforbetteraccuracy.²  Itmanages/hidestheunderlyinglocationtechnology(i.e.

GPS,cellularbasedorWiFibased).²  Itallowstheusertospecifyrequirementsatahighlevel,

likehighaccuracyorlowpower.²  Itsupportsgeofencingandactivityrecognition.


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q  STEP1-Requestlocationpermissions


<manifestxmlns:android="http://schemas.android.com/apk/res/android"package="com.google.android.gms.location.sample.basiclocationsample"><uses-permissionandroid:name="android.permission.ACCESS_COARSE_LOCATION"/><uses-permissionandroid:name="android.permission.ACCESS_FINE_LOCATION"/></manifest>

ANDROIDMANIFEST.XML



57

q  STEP2–ConnecttoGooglePlayservices


if(mGoogleApiClient==null){mGoogleApiClient=newGoogleApiClient.Builder(this).addConnectionCallbacks(this).addOnConnectionFailedListener(this).addApi(LocationServices.API).build();}…mGoogleApiClient.connect();



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q  STEP3–Getthelastknownlocation


publicvoidonConnected(BundleconnectionHint){mLastLocation=

LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);if(mLastLocation!=null){

mLatitudeText.setText(String.valueOf(mLastLocation.getLatitude()));mLongitudeText.setText(String.valueOf(mLastLocation.getLongitude()));}}



59

q  STEP4–Createalocationrequest


LocationRequestmLocationRequest=newLocationRequest();mLocationRequest.setInterval(10000);mLocationRequest.setFastestInterval(5000);mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

LocationSettingsRequest.Builderbuilder=newLocationSettingsRequest.Builder().addLocationRequest(mLocationRequest);

Interval–inmilliseconds-ofupdates

PRIORITY_BALANCED_POWER_ACCURACY,PRIORITY_HIGH_ACCURACY,PRIORITY_LOW_POWER,PRIORITY_NO_POWER



60

q  STEP5–ReceiveLocationupdates


LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient,mLocationRequest,this);

publicclassMainActivityextendsActionBarActivityimplementsConnectionCallbacks,OnConnectionFailedListener,LocationListener{...@OverridepublicvoidonLocationChanged(Locationlocation){mCurrentLocation=location;

…}



61

q  Geofencingisatechniquetodefinevirtualboundariesofageographicarea,andtolocalizeauseroverit.


Geofenceàpoint(latitude/longitude)plusaradiusAneventistriggeredeachtimetheuserentersorexitsthegeofence,ordwellslongerthanagivenintervaloftime.Eachgeofenceisassociatedtoanexpirationtime



62

q  STEP1–Createageofenceobject


mGeofenceList.add(newGeofence.Builder()//SettherequestIDofthegeofence..setRequestId(entry.getKey()).setCircularRegion(entry.getValue().latitude,entry.getValue().longitude,Constants.GEOFENCE_RADIUS_IN_METERS).setExpirationDuration(Constants.GEOFENCE_EXPIRATION_IN_MILLISECONDS).setTransitionTypes(Geofence.GEOFENCE_TRANSITION_ENTER|Geofence.GEOFENCE_TRANSITION_EXIT).build());



63

q  STEP2–Definetheinitialtriggerevents


mGeofenceList.add(newGeofence.Builder()//SettherequestIDofthegeofence..setRequestId(entry.getKey()).setCircularRegion(entry.getValue().latitude,entry.getValue().longitude,Constants.GEOFENCE_RADIUS_IN_METERS).setExpirationDuration(Constants.GEOFENCE_EXPIRATION_IN_MILLISECONDS).setTransitionTypes(Geofence.GEOFENCE_TRANSITION_ENTER|Geofence.GEOFENCE_TRANSITION_EXIT).build());



64

q  STEP3–AddgeofencesandIntents


LocationServices.GeofencingApi.addGeofences(mGoogleApiClient,mGeofenceList,getGeofencePendingIntent())

privatePendingIntentgetGeofencePendingIntent(){Intentintent=newIntent(this,GeofenceTransitionsIntentService.class);returnPendingIntent.getService(this,0,intent,PendingIntent.FLAG_UPDATE_CURRENT);}




MARCODIFELICE

APIsforINDOORLOCALIZATION(BASEDONWIRELESSTECHNOLOGIES)

APIs for Indoor Localization

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q  IndoorAtlas(https://www.indooratlas.com)


SDKavailableat:https://www.indooratlas.com

q Localizationbygeomagnetictechnology(i.e.analysisoftheEarth’smagneticfield)

q Supportsindoornavigation,geo-fencingandway-finding.


67




q Client-serverarchitecture,basedonfoursteps

1.  CreateLocationandAddmapfloor(throughaWebapplication)

2.  Setwaypoints(throughamobileapp)3.  Walkthroughthewaypoints,andautomatically

gathersensordata(e.g.magnetometer)4.  Importthemap,andaddlocation-based

featuresthroughthemobileapplication


68




q SDKforAndroidandIOSoperatingsystemsLocationupdatesareprovidedbytheIALocationListenerinterfaceandtheonLocationChanged()callbackmethod,andareexpressedasabsolutecoordinates(LAT;LONG).

privateIALocationListenermIALocationListener=newIALocationListener(){@OverridepublicvoidonLocationChanged(IALocationlocation){

Log.d(TAG,"Latitude:"+location.getLatitude());Log.d(TAG,"Longitude:"+location.getLongitude());

}};


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q  ESTIMOTE(http://developer.estimote.com/android/)


Furtherinformationavailableat:http://developer.estimote.com/android/

Android/IOSSDKforindoorlocalizationandLocalizationbasedservicesthroughBeaconsq Defineindoorgeofenceregions

q MonitortheBLEsignal

q TriggercorrespondingactionbasedondetectedBeacon


70

q  ESTIMOTE(http://www.i-locate.eu/the-virtual-hub/)



EachBeaconisidentifiedbythreevalues:

²  UUID,commonlyrepresentedasastring,e.g.“B9407F30-F5F8-466E-AFF9-25556B57FE6D”

²  majornumber,anunsignedshortinteger,i.e.,anintegerrangingfrom1to65535,(0isareservedvalue)

²  minornumber,alsoanunsignedshortinteger,likethemajornumber.


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beaconManager=newBeaconManager(getApplicationContext());//addthisbelow:beaconManager.connect(newBeaconManager.ServiceReadyCallback(){@OverridepublicvoidonServiceReady(){beaconManager.startMonitoring(newRegion("monitoredregion",UUID.fromString("B9407F30-F5F8-466E-AFF9-25556B57FE6D"),22504,48827));}});

DEFINETHEREGION


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beaconManager.setMonitoringListener(newBeaconManager.MonitoringListener(){@OverridepublicvoidonEnteredRegion(Regionregion,List<Beacon>list){ DOSOMETHING}@OverridepublicvoidonExitedRegion(Regionregion){ DOSOMETHING}});

DEFINETHEACTION



MARCODIFELICE

INDOORLOCALIZATIONDEMOTHROUGHBLEBEACONS

location-aware computing · apis for location-based services 28 q geocoding is the process of...

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