通信及基础工程21

Unit5TextAInternetofThingsInternetofThingsTheInternetofthings[1](stylizedInternetofThingsorIoT)istheinternetworkingofphysicaldevices,vehicles(alsoreferredtoas"connecteddevices"and"smartdevices"),buildings,andotheritems—embeddedwithelectronics,software,sensors,actuators,andnetworkconnectivitythatenabletheseobjectstocollectandexchangedata.In2013theGlobalStandardsInitiativeonInternetofThings(IoT-GSI)definedtheIoTas"theinfrastructureoftheinformationsociety.”TheIoTallowsobjectstobesensedand/orcontrolledremotelyacrossexistingnetworkinfrastructure,creatingopportunitiesformoredirectintegrationofthephysicalworldintocomputer-basedsystems,(Tobecontinued)TextTextWordsNotesDiscussionHome(Continued)andresultinginimprovedefficiency,accuracyandeconomicbenefitinadditiontoreducedhumanintervention.WhenIoTisaugmentedwithsensorsandactuators,thetechnologybecomesaninstanceofthemoregeneralclassofcyber-physicalsystems,whichalsoencompassestechnologiessuchassmartgrids,smarthomes,intelligenttransportationandsmartcities.EachthingisuniquelyidentifiablethroughitsembeddedcomputingsystembutisabletointeroperatewithintheexistingInternetinfrastructure.ExpertsestimatethattheIoTwillconsistofalmost50billionobjectsby2020.TextTextWordsNotesDiscussionHomeTypically,IoTisexpectedtoofferadvancedconnectivityofdevices,systems,andservicesthatgoesbeyondmachine-to-machine(M2M)communicationsandcoversavarietyofprotocols,domains,andapplications.Theinterconnectionoftheseembeddeddevices(includingsmartobjects),isexpectedtousherinautomationinnearlyallfields,whilealsoenablingadvancedapplicationslikeasmartgrid,andexpandingtotheareassuchassmartcities.TextTextWordsNotesDiscussionHome"Things,"intheIoTsense,canrefertoawidevarietyofdevicessuchasheartmonitoringimplants,biochiptranspondersonfarmanimals,electricclamsincoastalwaters,automobileswithbuilt-insensors,DNAanalysisdevicesforenvironmental/food/pathogenmonitoringorfieldoperationdevicesthatassistfirefightersinsearchandrescueoperations.Legalscholarssuggestlookingat"Things"asan"inextricablemixtureofhardware,software,dataandservice".(Tobecontinued)TextTextWordsNotesDiscussionHome(Continued)Thesedevicescollectusefuldatawiththehelpofvariousexistingtechnologiesandthenautonomouslyflowthedatabetweenotherdevices.Currentmarketexamplesincludehomeautomation(alsoknownassmarthomedevices)suchasthecontrolandautomationoflighting,heating(likesmartthermostat),ventilation,airconditioning(HVAC)systems,andappliancessuchaswasher/dryers,roboticvacuums,airpurifiers,ovensorrefrigerators/freezersthatuseWi-Fiforremotemonitoring.TextTextWordsNotesDiscussionHomeAswellastheexpansionofInternet-connectedautomationintoaplethoraofnewapplicationareas,IoTisalsoexpectedtogeneratelargeamountsofdatafromdiverselocations,withtheconsequentnecessityforquickaggregationofthedata,andanincreaseintheneedtoindex,store,andprocesssuchdatamoreeffectively.IoTisoneoftheplatformsoftoday’sSmartCity[2],andSmartEnergyManagementSystems.TextTextWordsNotesDiscussionHomeTheconceptoftheInternetofThingswasinventedbyandtermcoinedbyPeterT.LewisinSeptember1985inaspeechhedeliveredataU.S.FederalCommunicationsCommission(FCC)[3]supportedsessionattheCongressionalBlackCaucus15thLegislativeWeekendConference.TextTextWordsNotesDiscussionHome1.ApplicationsAccordingtoGartner,Inc.(atechnologyresearchandadvisorycorporation),therewillbenearly20.8billiondevicesontheInternetofthingsby2020.ABIResearchestimatesthatmorethan30billiondeviceswillbewirelesslyconnectedtotheInternetofthingsby2020.Aspera2014surveyandstudydonebyPewResearchInternetProject,alargemajorityofthetechnologyexpertsandengagedInternetuserswhoresponded—83percent—agreedwiththenotionthattheInternet/CloudofThings,embeddedandwearablecomputing(andthecorrespondingdynamicsystems)willhavewidespreadandbeneficialeffectsby2025.TextTextWordsNotesDiscussionHomeAssuch,itisclearthattheIoTwillconsistofaverylargenumberofdevicesbeingconnectedtotheInternet.Inanactivemovetoaccommodatenewandemergingtechnologicalinnovation,theUKGovernment,intheir2015budget,allocated£40,000,000towardsresearchintotheInternetofthings.TheformerBritishChancelloroftheExchequerGeorgeOsborne,positedthattheInternetofthingsisthenextstageoftheinformationrevolutionandreferencedtheinter-connectivityofeverythingfromurbantransporttomedicaldevicestohouseholdappliances.TextTextWordsNotesDiscussionHomeIntegrationwiththeInternetimpliesthatdeviceswilluseanIPaddressasauniqueidentifier.However,duetothelimitedaddressspaceofIPv4(whichallowsfor4.3billionuniqueaddresses),objectsintheIoTwillhavetouseIPv6toaccommodatetheextremelylargeaddressspacerequired.ObjectsintheIoTwillnotonlybedeviceswithsensorycapabilities,butalsoprovideactuationcapabilities(e.g.,bulbsorlockscontrolledovertheInternet).Toalargeextent,thefutureoftheInternetofthingswillnotbepossiblewithoutthesupportofIPv6;andconsequentlytheglobaladoptionofIPv6inthecomingyearswillbecriticalforthesuccessfuldevelopmentoftheIoTinthefuture.TextTextWordsNotesDiscussionHomeTheabilitytonetworkembeddeddeviceswithlimitedCPU,memoryandpowerresourcesmeansthatIoTfindsapplicationsinnearlyeveryfield.Suchsystemscouldbeinchargeofcollectinginformationinsettingsrangingfromnaturalecosystemstobuildingsandfactories,therebyfindingapplicationsinfieldsofenvironmentalsensingandurbanplanning.TextTextWordsNotesDiscussionHomeOntheotherhand,IoTsystemscouldalsoberesponsibleforperformingactions,notjustsensingthings.Intelligentshoppingsystems,forexample,couldmonitorspecificusers’purchasinghabitsinastorebytrackingtheirspecificmobilephones.Theseuserscouldthenbeprovidedwithspecialoffersontheirfavoriteproducts,orevenlocationofitemsthattheyneed,whichtheirfridgehasautomaticallyconveyedtothephone.(Tobecontinued)TextTextWordsNotesDiscussionHome(Continued)Additionalexamplesofsensingandactuatingarereflectedinapplicationsthatdealwithheat,electricityandenergymanagement,aswellascruise-assistingtransportationsystems.OtherapplicationsthattheInternetofthingscanprovideisenablingextendedhomesecurityfeaturesandhomeautomation.Theconceptofan"Internetoflivingthings"hasbeenproposedtodescribenetworksofbiologicalsensorsthatcouldusecloud-basedanalysestoallowuserstostudyDNAorothermolecules.TextTextWordsNotesDiscussionHomeHowever,theapplicationoftheIoTisnotonlyrestrictedtotheseareas.OtherspecializedusecasesoftheIoTmayalsoexist.Anoverviewofsomeofthemostprominentapplicationareasisprovidedhere.Basedontheapplicationdomain,IoTproductscanbeclassifiedbroadlyintofivedifferentcategories:smartwearable,smarthome,smartcity,smartenvironment,andsmartenterprise.TheIoTproductsandsolutionsineachofthesemarketshavedifferentcharacteristics.TextTextWordsNotesDiscussionHome2.EnablingtechnologiesforIoTTherearemanytechnologiesthatenableIoT.CrucialtothefieldisthenetworkusedtocommunicatebetweendevicesofanIoTinstallation,arolethatseveralwirelessand/orwiredtechnologiesmayfulfill:TextTextWordsNotesDiscussionHome(1)Short-rangewireless—Bluetoothlowenergy(BLE)–SpecificationprovidingalowpowervarianttoclassicBluetoothwithacomparablecommunicationrange.—Light-Fidelity(Li-Fi)–WirelesscommunicationtechnologysimilartotheWi-Fistandard,butusingvisiblelightcommunicationforincreasedbandwidth.—Near-fieldcommunication(NFC)–Communicationprotocolsenablingtwoelectronicdevicestocommunicatewithina4cmrange.TextTextWordsNotesDiscussionHome—QRcodesandbarcodes–Machine-readableopticaltagsthatstoreinformationabouttheitemtowhichtheyareattached.—Radio-frequencyidentification(RFID)–Technologyusingelectromagneticfieldstoreaddatastoredintagsembeddedinotheritems.—Thread–NetworkprotocolbasedontheIEEE802.15.4standard,similartoZigBee,providingIPv6addressing.TextTextWordsNotesDiscussionHome—Wi-Fi–Widely-usedtechnologyforlocalareanetworkingbasedontheIEEE802.11standard,wheredevicesmaycommunicatethroughasharedaccesspoint.—Wi-FiDirect–VariantoftheWi-Fistandardforpeer-to-peercommunication,eliminatingtheneedforanaccesspoint.—Z-Wave–Communicationprotocolprovidingshort-range,low-latencydatatransferatratesandpowerconsumptionlowerthanWi-Fi.Usedprimarilyforhomeautomation.—ZigBee–CommunicationprotocolsforpersonalareanetworkingbasedontheIEEE802.15.4standard,providinglowpowerconsumption,lowdatarate,lowcost,andhighthroughput.TextTextWordsNotesDiscussionHome(2)Medium-rangewireless—HaLow–VariantoftheWi-Fistandardprovidingextendedrangeforlow-powercommunicationatalowerdatarate.—LTE-Advanced–High-speedcommunicationspecificationformobilenetworks.ProvidesenhancementstotheLTEstandardwithextendedcoverage,higherthroughput,andlowerlatency.TextTextWordsNotesDiscussionHome(3)Long-rangewireless—Low-powerwide-areanetworking(LPWAN)–Wirelessnetworksdesignedtoallowlong-rangecommunicationatalowdatarate,reducingpowerandcostfortransmission.—Verysmallapertureterminal(VSAT)–Satellitecommunicationtechnologyusingsmalldishantennasfornarrowbandandbroadbanddata.TextTextWordsNotesDiscussionHome3.Wired—Ethernet–Generalpurposenetworkingstandardusingtwistedpairandfiberopticlinksinconjunctionwithhubsorswitches.—MultimediaoverCoaxAlliance(MoCA)–Specificationenablingwhole-homedistributionofhighdefinitionvideoandcontentoverexistingcoaxialcabling.—Power-linecommunication(PLC)–Communicationtechnologyusingelectricalwiringtocarrypoweranddata.SpecificationssuchasHomePlugutilizePLCfornetworkingIoTdevices.TextTextWordsNotesDiscussionHomestylizev.程式化，风格化actuatorn.[计]执行机构；[电]（电磁铁）螺线管connectivityn.[数]连通性;互联互通interventionn.介入，干涉，干预，调解augmentvt.增强；增加；（使）扩张，扩大encompassvt.围绕，包围；包含或包括某事物；完成WordsWordsTextWordsNotesDiscussionHomegridn.高压输电线路网；地图坐标方格；格栅interoperaten.&v.交互操作consistvi.由…组成；在于；符合biochipn.生物芯片transpondern.发射机应答器，询问机，转发器pathogenn.病菌，病原体WordsTextWordsNotesDiscussionHomeinextricableadj.无法摆脱的；解不开的plethoran.过多，过剩；[医]多血，多血症accommodatevt.容纳；使适应；向…提供住处correspondingadj.对应的；通信的；符合的；一致的positvt.假定，设想，假设referencev.引用；参照WordsTextWordsNotesDiscussionHomeappliancen.器具；器械；装置trackvt.跟踪；监看，监测prominentadj.突出的，杰出的；突起的twistedadj.扭曲的；喝醉了的；古怪的specificationn.规格；详述；说明书WordsTextWordsNotesDiscussionHome[1]InternetofThings（IoT）字面意思是“物体组成的因特网”，常译为“物联网”。物联网（InternetofThings）又称传感网，简要讲就是互联网从人向物的延伸。它是指的是将各种信息传感设备，如射频识别装置、红外感应器、全球定位系统、激光扫描器等种种装置与互联网结合起来而形成的一个巨大网络。其目的是让所有的物品都与网络连接在一起，方便识别和管理。TextWordsNotesDiscussionNotesHome[2]Smartcity智慧城市就是运用信息和通信技术手段感测、分析、整合城市运行核心系统的各项关键信息，从而对包括民生、环保、公共安全、城市服务、工商业活动在内的各种需求做出智能响应。其实质是利用先进的信息技术，实现城市智慧式管理和运行，进而为城市中的人创造更美好的生活，促进城市的和谐、可持续成长。TextWordsNotesDiscussionHome[3]FederalCommunicationsCommission（FCC）指美国联邦通讯委员会。该机构直接对国会负责，通过控制无线电广播、电视、电信、卫星和电缆来协调国内和国际的通信，负责授权和管理除联邦政府使用之外的射频传输装置和设备。TextWordsNotesDiscussionHomeQuestionsfordiscussion1.WhatdoestheInternetofthingsmean?

2.WhatdoyouthinkofthefutureofIoT?3.Howmanytypescanmedium-rangewirelessfallinto?Whatarethey?

TextWordsNotesDiscussionHomeAnswerstoquestionsfordiscussionTextWordsNotesDiscussionHome1.WhatdoestheInternetofthingsmean?TheInternetofthings(stylizedInternetofThingsorIoT),atermcoinedbyPeterT.LewisinSeptember1985,whichisdefinedas"theinfrastructureoftheinformationsociety"bytheGlobalStandardsInitiativeonInternetofThings(IoT-GSI)in2013,referstotheinternetworkingofphysicaldevices,vehicles(alsoreferredtoas"connecteddevices"and"smartdevices"),buildings,andotheritem