外文翻译-采用Android手机操作系统的基于位置的服务

外文文献原文LocationBasedServicesusingAndroidMobileOperatingSystemAmitKushwaha1,VineetKushwaha21DepartmentofElectronics&CommunicationEngineeringIIMTEngineeringCollege,Meerut-250001,I2DepartmentofInformationTechnologyIndianInstituteofInformationTechnology,Allahabad-211012,IAbstractThemotivationforeverylocationbasedinformationsystemis:“Toassistwiththeexactinformation,atrightplaceinrealtimewithpersonalizedsetupandlocationsensitiveness”.InthiserawearedealingwithpalmtopsandiPhones,whicharegoingtoreplacethebulkydesktopsevenforcomputationalpurposes.Wehavevastnumberofapplicationsandusagewhereapersonsittinginaroadsidecafneedstogetrelevantdataandinformation.SuchneedscanonlybecateredwiththehelpofLBS.Theseapplicationsincludesecurityrelatedjobs,generalsurveyregardingtrafficpatterns,decisionbasedonvehicularinformationforvalidityofregistrationandlicensenumbersetc.Averyappealingapplicationincludessurveillancewhereinstantinformationisneededtodecideifthepeoplebeingmonitoredareanyrealthreatoranerroneoustarget.Wehavebeenabletocreateanumberofdifferentapplicationswhereweprovidetheuserwithinformationregardingaplaceheorshewantstovisit.Buttheseapplicationsarelimitedtodesktopsonly.Weneedtoimportthemonmobiledevices.Wemustensurethatapersonwhenvisitingplacesneednotcarrythetravelguideswithhim.Alltheinformationmustbeavailableinhismobiledeviceandalsoinusercustomizedformat.KeywordsAndroid;LBS;GPS;LCS;GoogleMaps1INTRODUCTIONLocationbasedservice(LBS)isemergingasakillerapplicationinmobiledataservicesthankstotherapiddevelopmentinwirelesscommunicationandlocationpositioningtechnologies.Userswithlocation-awarewirelessdevicescanqueryabouttheirsurroundings(e.g.,findingthenearestrestaurantorallshoppingmallswithin5miles)atanyplace,anytime.Whilethisubiquitouscomputingparadigmbringsgreatconvenienceforinformationaccess,theconstraintsofmobileenvironments,thespatialpropertyoflocation-dependentdata,andthemobilityofmobileusersposeagreatchallengefortheprovisionoflocation-basedservicestomobileusers.Alocation-basedservice(LBS)isamobileapplicationthatisdependentonthelocationofamobiledevice,likemobilephone.Virrantausetal1definedLBSservicesasfollows:“Informationservicesaccessiblewithmobiledevicesthroughthemobilenetworkandutilizingtheabilitytomakeuseofthelocationofthemobiledevice“OpenGeospatialConsortium”2definedLBSservicesimilarly:“Awireless-IPservicethatusesgeographicinformationtoserveamobileuser,anyapplicationservicethatexploitsthepositionofamobileterminal.”ALocationBasedService(LBS)isaninformationandentertainmentservice,accessiblewithmobiledevicesthroughthemobilenetworkandutilizingtheabilitytomakeuseofgeographicalpositionofthemobiledevice.ALBSservicescanbeusedinavarietyofcontexts,suchashealth,work,personallife,etc.LBSincludeservicestoidentifythelocationofapersonorobject,suchasdiscoveringthenearestbankingcashmachineorthewhereaboutofafriendoremployee.LBSservicesincludeparceltrackingandvehicletrackingservices.LBShavetwomajoractions,thatis:1.Obtainingthelocationofuser2.Utilizingthisinformationtoprovideaservice.These2actionsareusedtoanswerthese4questions(below)foramobileuserinanew,fast,andmoreaccurateway,toformthebasisforLBS:WhereamI.?Whereisthenearest.?Whereismy.?Howdolgetthere.?LBSservicescanbecategorizedastriggeredLBSservices(pushservices)anduser-requestedLBSservices(pullservices)3.Inatriggered(push)LBSservice,thelocationofusersmobiledeviceisretrievedwhenaconditionsetinadvanceisfulfilled.Forexample,acalltoemergencycentercanautomaticallytriggeralocationrequest3.Advertisementmessagescanbedeliveredtouserswhoenteraspecificareainashoppingmall,andwarningmessagescanbedeliveredtouserswhoareintheareawhereweatherconditionswillchange(e.g.hurricane,rain).Inauser-requested(pull)LBSservice,theuserdecideswhetherandwhentoretrievethelocationofhis/hermobiledeviceanduseitintheservice.User-requestedLBSservicecaninvolvepersonallocation(i.e.findingthecurrentlocationoftheuser)orserviceslocation(i.e.findingthelocationofthenearestrestaurantorbank).NavigationanddirectionsystemisanexampleofpullLBSservices3.2LBSCOMPONENTSInordertomakeLBSservicespossible,someinfrastructureelementsarenecessary,includingmobiledevices,applications,communicationnetwork,positioningcomponent,andserviceservers4.MobiledevicesaretoolsusedbyuserstoaccessLBSservices,tosendrequestsandretrieveresults.Suchdevicescanbeportablenavigationdevices(PNDs),PersonalDataAssistants(PDAs),laptops,mobilephones,andsoon.ApplicationistheinterfaceforuserstoaccesstheLBSservice.Itisusuallysoftwaredevelopedbyanapplicationprovider,downloadedandinstalledonusersmobiledevice.AspecificapplicationisusuallydevelopedforaspecificLBSservice.Duetotherestrictionsofmobiledevices(smallscreensize,limitedprocessorpowerandmemory,batterycapacity),LBSapplicationsneedtobelightweightandbatterysaving.Communicationnetworkreferstothemobilenetworkwhichtransfersservicerequestfromusertoserviceprovider,andrequestedinformationbacktotheuser.GlobalSystemforMobilecommunications(GSM)iscurrentlythemostcommonstandardformobilenetworkandisusedbymajorityofmobilephonesglobally.Mobilenetworksareusuallycontrolledandmaintainedbyoperatorswhoprovideconnectivityformobileusersandchargethemfordataandvoicetransmission.ApositioningcomponentisusuallyneededinaLBSapplicationtodeterminethelocationofusersmobiledevice.MostofthecurrentLBSservicesdonotrequireuserstoinputlocationmanually,likegivingzipcodeorstreetname.Insteaduserslocationcanbeobtainedbyusingsomepositioningtechnologies,suchassatellitepositioning,cellularnetworkpositioning,WLANstationsorradiobeacons5.ServiceprovidersmaintainserviceserverswhichofferdifferentkindsofLBSservicestousersandareresponsibleforprocessingservicerequestsandsendingbackrequestresults.Serverscalculatepositions,searchforaroute,orsearchspecificinformationbasedonusersposition.Serviceprovidersusuallydonotstoreandmaintainalltheinformationrequestedbyusers.Instead,contentprovidersareresponsibleforcollectingandstoringgeographicdata,location-basedinformation,andotherrelateddata.Thesedatawillberequestedandprocessedbyserviceserversandthenreturnedtousers.3DISCUSSIONLBSscontainanumberofcomponentsincludingmapsandGeographicInformationSystem(GIS)information,locationcollectionservices,andLBSapplication-specificsubcomponents.(1)LBSApplicationThisrepresentsaspecificapplicationsuchasa“findmyfriends”application.ThisconsistsofaSmartphonecomponent,whichhasanumberofsensors,andpotentiallyaservercomponentthatincludesapplication-specificdata(suchaslocation-taggedinformation(2)LBSMiddlewareThiswrapsaccesstoCoreLBSFeatures(LocationTracking,GISProviderandLocationCollectionServices)toprovideaconsistentinterfacetoLBSapplications.(3)LocationTrackingThiscomponentstoresthelocationtraceofindividualusers.Thisrepresentsafundamentalcomponentinnext-generationLBSasitcontainsthedatathatallowsausersroutetobedeterminedandpotentiallypredicted.Inparticular,thiscomponentwouldtypicallysupportthefollowingfunctionality:1.Keeprecordsonuserscurrentandpastlocations.2.Notifyothercomponentswhenaspecificuserhasmoved,orwhentheymoveinoroutofanarea.Thissupportslocation-basednotificationsbeingsenttousers.3.Determinewhichusersarewithinadefinedlocationthissupportsgeocastingfeatures.4.Queriesoflocationtracetogenerateusermovementmodels(4)GISProviderThiscomponentprovidesgeospatialfunctionalityformanyLBSsincludingmapinformation,mapvisualizationanddirectoryservices.GoogleMapswithitsAPIcanbeconsideredaGISprovider.(5)LocationCollectionServiceThiscomponentperformslocationcollectiontogetalatitudeandlongitudeforaspecificuser.Dependingonthetechnology,thiscomponentmaybeaccessedviatheLBSMiddleware(e.g.,mobilenetworktriangulationviaaserviceprovider)ordirectly(e.g.,viaGPSreceiverintheSmartphone).AndroidprovidesaccesstotheabovecomponentstofacilitatetheimplementationofLBSservicesthroughthehelpoffollowingclasses;1.LocationManager2.LocationProvider3.Geocoding4.Google-Map(6)LocationManagerLocationManagerClassofandroidispresenttomanageallothercomponentsneededtoestablishaLBSsystem.Locationproviderrepresentsthetechnologytodeterminethephysicallocationi.e.tohandleGIS.LocationProvidercomponentofAndroidapplicationisapresenttofacilitatethedeterminationofavailableproviderandselectionofsuitableone.FindingtheListofAvailableLocationProvider.Togetalistofnamesforalltheprovidersavailableonthedevice,callgetProviders,usingaBooleantoindicateifyouwantall,oronlytheenabled,providerstobereturned:booleanenabledOnly=true;Listproviders=locationManager.getProviders(enabledOnly);InadditiontothisGPSproviderandNetworkprovidercanbeaccesseddirectlybyusingthestaticvariablesdefinedintheLocationManagerclass:LocationManager.GPS_PROVIDERLocationManager.NETWORK_PROVIDERFurthermoreforfindingtheprovideronthebasisofsomecriteriawecanusethecriteriaclassandthencanfindthebestproviderfordefinedcriteriausingtheBestProviderMethodasshownisthefollowingcodesnaps:Criteriacriteria=newCriteria();criteria.setAccuracy(Criteria.ACCURACY_COARSE);criteria.setPowerRequirement(Criteria.POWER_LOW);/morecriteriahereStringbestProvider=locationManager.getBestProvider(criteria,true);Ifmorethanoneproviderisavailablefulfillingthegivencriteriathentheonewithbestperformanceisreturned.OntheotherhandifnoproviderisfoundforthedefinedcriteriathencriteriaareloosenedinorderPoweruse,Accuracy,Abilitytoreturnbearing,speed,andaltitude.(7)GeocodingReversegeocodingprovidesawaytoconvertgeographicalcoordinates(longitude,latitude)intostreetaddressandforwardgeocodingprovidesameantogetgeographicalcoordinatedfromstreetaddress.ForforwardgeocodingweusegetLatitude()andgetLongitude()methodasshownisthefollowingcodeBlockdoublelatitude=location.getLatitude();doublelongitude=location.getLongitude();ForreversegeocodingweusegetFromLocationmethodwithgeocodervariableasshownisthefollowingcodeblock/geocodisgeocodervariableaddresses=geocod.getFromLocation(latitude,longitude,10);GoogleMapinAndroidAndroidprovidesanumberofobjectstohandlemapsinLBSsystemlikeMapViewwhichdisplaysthemap.TohandlethisaMapActivityclassisthere.Toannotatemapitprovidestheoverlaysclass.Evenitprovidescanvasbywhichonecaneasilycreateanddisplaymultiplelayersoverthemap.Moreover,sufficientprovisionsaretheretozoomthemap,localizethemapbymeansofMapController.Followingcode-lineshowstheMapHandlinginAndroid:/mapcontrollerMapControllermapController=myMapView.getController();mapController.setCenter(point);mapController.setZoom(1);/ListofpresentoverlaysListoverlays=mapView.getOverlays();/addinganewoverlaysMyOverlaymyOverlay=newMyOverlay();overlays.add(myOverlay);mapView.postInvalidate();4GPSINANDROID1.Built-inGPSreceiver.2.Requires2linesofcodes.3.Requires1XMLfileforproperties.4.Systemisresponsibleforupdatinglocationchange.5USEOFLBSLocation-basedservicesorLBSrefertoasetofapplicationsthatexploittheknowledgeofthegeographicalpositionofamobiledeviceinordertoprovideservicesbasedonthatinformation.”2Theycanbeclassifiedinthreecategories:1.Publicsafetyoremergencyservices:Sincethelocationofthesubscribercanbeprovidedbythecarrier,themobilephoneisavaluableaccesspointinthetimesofemergency.IntheUS,EuropeandJapan,itismandatorybylawforcarrierstobeabletoprovidesuchinformation.2.Consumerservices:(1)Navigation-usersgetroutemapstoaparticulardestination,realtimetrafficroutingthattakesintoaccountactualcongestionpatternsetc.(2)Locationbasedadvertising-advertisementsofdiscountsoroffersfromastoreastheusercomeswithinthevicinity.(3)Locationbasedreminders-userscanenterinto-dolists,whoselocationinformationisactivatedwhentheuserpassesby,forinstance,pickupshoppingorlaundryetc.(4)Familyandfriendfinder-allowsuserstokeeptrackofthelocationoftheirchildren,relativesorfriends,withtheinformedconsentofthesesubscribers.(5)Locationbasedsearch-allowsuserstoaccesslocalservices,orfindevenmoredetailedinformationsuchaslistingsandratingsofmoviesplayingintheatersnearbyetc.(6)Locationbasedmobilegamingwhichbeganadecadeagohaslargerscopenowaspositioningandhandsettechnologyhaveimprovedconsiderably.3.Enterpriseservices:LBSenablesfirmsinfleetandassettracking,fieldservicedispatching,routeanddeliveryoptimization,andmobileworkforcemanagement.Thishasprovedtobeextremelyusefulforsmallandmediumbusinesses.6ANDROIDADVANTAGE&LIMITATIONSAdvantagesofanAndroidarelistedas:(1)Timeforachange.(2)Androidscalestoeverydevice.(3)Itssupportedbysomehardwaremanufacturersandmoretocomeinthefuture.(4)Opensource.(5)Thirdpartydevelopmentisencouraged.IncontrasttoadvantagesAndroidhasfollowinglimitations:(1)NotsupportedbyanybigcompanyyetexceptHTC.(2)DoesnotsupportsomeapplicationslikeFirefox.(3)Somelimitationsexistinbluetooth.7CONCLUSIONInitiallymobilephonesweredevelopedonlyforvoicecommunicationbutnowdaysthescenariohaschanged,voicecommunicationisjustoneaspectofamobilephone.Thereareotheraspectswhicharemajorfocusofinterest.TwosuchmajorfactorsarewebbrowserandGPSservices.Bothofthesefunctionalitiesarealreadyimplementedbutareonlyinthehandsofmanufacturersnotinthehandsofusersbecauseofproprietaryissues,thesystemdoesnotallowtheusertoaccessthemobilehardwaredirectly.Butnow,afterthereleaseofandroidbasedopensourcemobilephoneausercanaccessthehardwaredirectlyanddesigncustomizednativeapplicationstodevelopWebandGPSenabledservicesandcanprogramtheotherhardwarecomponentslikecameraetc.TheLBSapplicationcanhelpusertofindhospitals,school,gasfillingstationoranyotherfacilityofinterestindicatedbyuserwithincertainrange.JustlikeaGPSdeviceitslocationwillalsobeupdatedassoonasuserchangeshis/herposition.外文文献译文采用Android手机操作系统的基于位置的服务阿米特Kushwaha1，VINEETKushwaha2电子与通信工程教研室IIMT工程学院，密拉特-250001，印度信息技术教研室信息技术，阿拉哈巴德-211012，印度的印度理工学院摘要为每个基于信息系统的位置定位的动机是：“为帮助用户获取准确的信息，在正确的位置实时提供个性化的设置和位置的敏感性“。在这个时代，我们正在处理掌上电脑和iPhone手机，这是要替代笨重的台式电脑，甚至于计算的目的。我们有大量的应用程序，一个人坐在路边的咖啡馆需要得到相关的数据和信息。这种需求只能迎合LBS的帮助。这些应用包括安全相关的工作，关于交通模式的一般调查，车辆信息的有效性决定注册及牌照号码等。一个非常有吸引力的应用程序包括瞬间的监控信息来决定是否被监视的人是任何真正的威胁或一个错误的目标。我们已经能够建立向用户提供信息的多个不同的应用，不管他或她想要访问任何地方。但这些应用仅限于桌面。我们需要把它们导入到移动设备上。我们必须确保一个人的时候参观的地方不需要携带旅行引导。在他的移动设备中所有的信息必须是可用的，并以用户自定义的格式。关键词机器人；LBS；GPS；LCS；谷歌地图1引言基于位置的服务（LBS）是一种新兴的杀手级的移动数据服务由于飞速发展的无线通信和位置定位技术。拥有位置感知无线设备的用户可以在任何地方、任何时间查询他们周围的环境（例如，寻找最近的餐厅或8公里之内的所有商场）。虽然这种无处不在的计算模式带来了信息的获取，移动环境的制约，位置相关数据的空间属性，但是移动用户正面临着巨大的挑战就是基于位置服务的保护性。我们来看一下基于位置的服务：基于位置的服务（LBS）是移动应用程序，它依赖于移动设备的位置，如移动电话。Virrantaus等人1中定义的LBS服务，开放地理空间联盟“通过移动网络和移动设备的位置使用的能力使信息服务更容易获取”2与定义的LBS服务类似：”使用地理信息的无线IP服务的移动用户，它可以利用移动终端位置的任何应用程序服务。基于位置的服务（LBS）是通过移动网络和利用移动设备的地理位置的使用能力的信息和娱乐服务，用于移动设备访问。一个LBS服务可以在各种情况下使用，如健康，工作，包括识别一个人或物体的位置，如发现最近的银行取款机或与地方有关的朋友或员工。LBS服务包括包裹跟踪和车辆跟踪服务。LBS有两个主要的操作，即：1.获取用户的位置。2.利用该信息来提供服务。这两个动作是用来回答这些问题，从而形成基础的LBS：我在哪里.？哪里是最近的.？哪里是我的.？如何升到达那里.？LBS服务可以分为触发LBS服务（推送服务）以及用户要求的LBS服务（拉服务）3。在触发（推）的LBS服务，用户的移动设备的位置被检索时须满足预先的设置。例如，呼叫急救中心可以自动触发位置请求3。广告信息可以传递到谁在商场进入特定区域，警告信息可以传递到用户所在地的天气情况将发生变化（如飓风，雨水）。在一个用户请求（拉）的LBS服务，用户决定是否及何时取回他/她的移动设备的位置，并使用它的服务。用户请求的LBS服务可能会涉及个人位置（即发现该用户的当前位置）或位置的服务（即找到的位置最近的餐馆或银行）。导航和方向系统是拉LBS服务的例子3。2LBS组件为了使LBS服务成为可能，一些基础设施元素是必要的，包括移动设备，应用程序通信网络，定位部件和服务器4。移动设备是用户访问LBS服务，发送请求和检索结果的工具。这样的设备可以是便携式导航设备（PND），个人数据助理（PDA），笔记本电脑，移动电话，等等。应用程序是用户访问LBS服务的接口。它通常是由一个应用程序提供商开发并下载安装到用户的移动设备上的软件。一个具体的应用程序通常是开发特定的LBS服务。由于移动设备的限制（小屏幕尺寸，有限的处理器能力和内存，电池容量），LBS应用需要是重量轻，省电。通信网络指的是从用户传送服务请求给移动网络服务供应商，并要求信息返回给用户。全球移动系统通信系统（GSM）是目前用于移动网络中最常见的标准，并用于大多数全球性手机。移动网络中，通常控制并保持由谁运营商为移动用户提供连接，并收取他们的数据和语音传输。一种定位组件，通常需要在一个LBS应用里，以确定用户的位置。当前大多数的LBS服务不要求用户输入手动位置，如提供邮政编码或街道名称。用户的位置可以通过使用一些定位技术，如卫星定位，蜂窝网络的定位，WLAN站或无线电信标5。服务供应商保持业务服务器提供不同类型的LBS服务给用户和负责处理服务请求和回送请求的结果。服务器计算出位置，搜索路线，或搜索基于用户位置的具体信息。服务供应商通常不存储和维护所有用户请求的信息。相反，内容提供商负责收集和存储地理数据，基于位置的信息，以及其他相关数据。这些数据将被请求到处理服务的服务器，然后返回给用户。3讨论LBSS包含许多组件，包括地图和地理信息系统（GIS）信息，位置收集服务，和LBS应用程序特定的子组件。（1）LBS应用这是一个特定的应用程序，如“找朋友”应用程序。这包括一个智能部件，它具有多个传感器，并且可能包含应用程序特定数据。（2）LBS中间件这个包装访问核心LBS功能（位置跟踪，地理信息系统提供商和地点收集服务），以提供一个一致的接口LBS应用。（3）位置跟踪此组件存储单个用户的位置跟踪。这代表了下一代LBS一个基本组成部分，因为它包含允许用户的路径被确定，并可能预测数据。尤其是，该组件通常支持以下功能：1.保持对用户的当前和过去的位置记录。2.通知其他组件时，一个特定的用户移动时，或者当它们移动区域的缩小。这支持被发送到基于用户位置的通知。3.确定哪些用户是在一个定义的位置，支持geocasting功能。4.位置跟踪的查询生成用户的运动车型。（4）地理信息系统提供商该组件提供地理空间功能为许多LBSS包括地图信息，地图可视化和目录服务。谷歌地图与它的API可以被认为是一个地理信息系统提供商。（5）地点收集服务该组件为特定用户进行位置集合以获取经度和纬度。根据该技术，该组件可以经由LBS中间件（例如，通过一个服务提供商的移动网络三角）或直接（例如，通过在智能手机GPS接收器）来访问。Android提供了访问上述成分以促进LBS服务，通过下面的类的帮助下实施;1.位置管理器2.位置提供者3.地理编码4.谷歌地图（6）位置管理器机器人的位置管理类存在管理建立了LBS系统所需的所有其他组件。位置提供的位置信息提供代表该技术来确定的物理位置，即处理地理信息系统。Android应用程序的位置提供组件是一个礼物，以方便适合的供应商可提供和选择的决心。寻找可用的位置提供者的名单要获取名称为设备上可用的所有供应商的列表，调用get提供商，使用一个布尔值来表示，如果你想返回所有的，或只启用供应商：布尔enabledOnly=TRUE;Listproviders=locationManager.getProviders（enabledOnly）;除了这种GPS，提供商和网络提供商可以通过使用LocationManager类定义的静态变量直接进行访问：LocationManager.GPS_PROVIDERLocationManager.NETWORK_PROVIDER另外寻在找提供者的一些标准的基础上，我们可以使用标准的类：Criteriacriteria=newCriteria();criteria.setAccuracy(Criteria.ACCURACY_COARSE);criteria.setPowerRequirement(Criteria.POWER_LOW);/morecriteriahereStringbestProvider=locationManager.getBestProvider(criteria,