《物联网专业英语教程》课件第3章

Unit3ArchitectureandTechnologyofIoT[40]TextAArchitecture,Hardware,SoftwareandAlgorithmsofIoT[48]TextBTechnologyofIoT[55]参考译文物联网的体系、硬件、软件及算法

1.Architecture

TheInternetofThingsneedsanopenarchitecturetomaximizeinteroperabilityamongheterogeneoussystemsanddistributedresourcesincludingprovidersandconsumersofinformationandservices,whethertheybehumanbeings,software,smartobjectsordevices.Architecturestandardsshouldconsistofwell-definedabstractdatamodels,Architecture,Hardware,Softwareand

AlgorithmsofIoTinterfacesandprotocols,togetherwithconcretebindingstoneutraltechnologies(suchasXML,webservicesetc.)inordertosupportthewidestpossiblevarietyofoperatingsystemsandprogramminglanguages.

Thearchitectureshouldhavewell-definedandgranularlayers,inordertofosteracompetitivemarketplaceofsolutions,withoutlockinganyusersintousingamonolithicstackfromasinglesolutionprovider.Liketheinternet,theIoTarchitectureshouldbedesignedtoberesilienttodisruptionofthephysicalnetworkandshouldalsoanticipatethatmanyofthenodeswillbemobile,mayhaveintermittentconnectivityandmayusevariouscommunicationprotocolsatdifferenttimestoconnecttotheIoT.

IoTnodesmayneedtodynamicallyandautonomouslyformpeernetworkswithothernodes,whetherlocalorremoteandthisshouldbesupportedthroughadecentralized,distributedapproachtothearchitecture,withsupportforsemanticsearch,discoveryandpeernetworking.Anticipatingthevastvolumesofdatathatmaybegenerated,itisimportantthatthearchitecturealsoincludemechanismsformovingintelligenceandcapabilitiesforInternetofThings,patternrecognition,machinelearninganddecision-makingtoenabledistributedanddecentralizedprocessingoftheinformation,eitherclosetowheredataisgeneratedorremotelyinthecloud.Thearchitecturaldesignwillalsoneedtoenabletheprocessing,routing,storageandretrievalofeventsandallowfordisconnectedoperations(e.g.wherenetworkconnectivitymightonlybeintermittent).Effectivecaching,pre-positioningandsynchronizationofrequests,updatesanddataflowsneedtobeanintegralfeatureofthearchitecture.Bydevelopinganddefiningthearchitectureintermsofopenstandards,wecanexpectincreasedparticipationfromsolutionprovidersofallsizesandacompetitivemarketplacethatbenefitsendusers.

Issuestobeaddressed:

·Distributedopenarchitecturewithendtoendcharacteristics,interoperabilityofheterogeneoussystems,neutralaccess,clearlayeringandresiliencetophysicalnetworkdisruption.

·Decentralizedautonomicarchitecturesbasedonpeeringofnodes.

·Cloudcomputingtechnology,event-drivenarchitectures,disconnectedoperationsandsynchronization.

·Useofmarketmechanismsforincreasedcompetitionandparticipation.

2.Hardware

Theresearchonnano-electronicsdeviceswillbeusedforimplementingwirelessidentifiablesystemswiththefocusonminiaturization,lowcostandincreasedfunctionality.Polymerselectronicstechnologywillbedevelopedandresearchisneededondevelopingcheap,non-toxicandevendisposableelectronicsforimplementingRFIDtagsandsensorsthatincludelogicandanaloguecircuitswithnandptypeThinFilmTransistors(TFTs),powerconverters,batteries,memories,sensors,activetags.

SiliconICtechnologywillbeusedforsystemswithincreasedfunctionalityandrequirementsformorenonvolatilememoryusedforsensingandmonitoringambientparameters.Researchisneededonultra-lowpower,lowvoltageandlowleakagedesignsinsubmicronRFCMOStechnologies,onhigh-efficiencyDC-DCpower-managementsolutions,ultralowpower,lowvoltagecontrollablenon-volatilememory,integrationofRFMEMSandMEMSdevices.Thefocuswillbeonhighlyminiaturizedintegratedcircuitsthatwillinclude:

·MultiRF,adaptiveandreconfigurableFrontEnds;

·HF/UHF/SHF/EHF;

·Memory–EEPROM/FRAM/Polymer;

·ID128/256bits+othertypeID;

·MultiCommunicationProtocols;

·DigitalProcessing;

·Security,includingtamper-resistancecountermeasures,andtechnologytothwartsidechannelattacks.

BasedonthisdevelopmenttwotrendsareemergingforwirelessidentifiabledevicesforIoTapplications:

·Increasinguseofembeddedintelligence;

·Networkingofembeddedintelligence.

IoTwillcreatenewservicesandnewbusinessopportunitiesforsystemproviderstoservicethecommunicationdemandsofpotentiallytensofbillionsofdevices.Threemaintrendsareseentoday:

·Ultralowcosttagswithverylimitedfeatures.Theinformationiscentralizedondataserversmanagedbyserviceoperators.Valueresidesinthedatamanagement.

·Lowcosttagswithenhancedfeaturessuchasextramemoryandsensingcapabilities.Theinformationisdistributedbothoncentralizeddataserversandtags.Efficientnetworkinfrastructure.Valueresidesincommunicationanddatamanagement,includingprocessingofdataintoactionableinformation.

·Smartfixed/mobiletagsandembeddedsystems.Morefunctionsintothetagbringinglocalservices.Smartsystems(sensing/monitoring/actuating)ontags.Theinformationiscentralizedonthedatatagitself.Valueresidesinthecommunicationmanagementtoensuresecurityandeffectivesynchronizationtothenetwork.Smartdevicesenhancedwithinter-devicecommunicationwillresultinsmartsystemswithmuchhigherdegreesofintelligenceandautonomy.ThiswillenablethemorerapiddeploymentofsmartsystemsforIoTapplicationsandcreationofnewservices.

3.SoftwareandAlgorithms

OneofthemostpromisingmicrooperatingsystemsforconstraineddevicesisContiki.ItprovidesafullIPstack(bothIPv4andIPv6),supportsalocalflashfilesystemandfeaturesalargedevelopmentcommunityandacomprehensivesetofdevelopmenttools.

OneofchallengesinbuildingIoTapplicationsliesinthelackofacommonsoftwarefabricunderlyinghowthesoftwareinthedifferentenvironmentscanbecombinedtofunctionintoacompositesystemandhowtobuildacoherentapplicationoutofalargecollectionofunrelatedsoftwaremodules.Researchanddevelopmentisfocusingonserviceorientedcomputingfordevelopingdistributedandfederatedapplicationstosupportinteroperablemachinetomachineand"thing"to"thing"interactionoveranetwork.ThisisbasedontheInternetprotocols,andontopofthat,definesnewprotocolstodescribeandaddresstheserviceinstance.ServiceorientedcomputinglooselyorganizestheWebservicesandmakesitavirtualnetwork.

Issuestobeaddressed:

·Openmiddlewareplatforms;

·Energyefficientmicrooperatingsystems;

·Distributedselfadaptivesoftwareforselfoptimization,selfconfiguration,selfhealing(e.g.autonomic);

·Lightweightandopenmiddlewarebasedoninteractingcomponents/modulesabstractingresourceandnetworkfunctions;

·Bio-inspiredalgorithms(e.g.selforganization)andgametheory(toovercometherisksoftragedyofcommonsandreactiontomaliciousnodes);

·Selfmanagementtechniquestoovercomeincreasingcomplexities;

·Passworddistributionmechanismsforincreasedsecurityandprivacy;

·Energy-awareoperatingsystemsandimplementations.

1.IdentificationTechnology

ThefunctionofidentificationistomapauniqueidentifierorUID(globallyuniqueoruniquewithinaparticularscope),toanentitysoastomakeitwithoutambiguityidentifiableandretrievable.UIDsmaybebuiltasasinglequantityoroutofacollectionofattributessuchthatthecombinationoftheirvaluesisunique.TechnologyofIoTInthevisionoftheInternetofThings,thingshaveadigitalidentity(describedbyuniqueidentifiers),areidentifiedwithadigitalnameandtherelationshipsamongthingscanbespecifiedinthedigitaldomain.

Auniqueidentifierforanobjectcantranslatetoasinglepermanentassignednameforthelifeofanobject.However,IoTwillfacetheneedtoaccommodatemultipleidentifiersperobjects,aswellaschangestothoseidentifiers.Forexample,manyobjectswillhaveauniqueidentifierassignedbytheirmanufacturer.Somemayalsohavenetworkaddresses(suchasIPv6addresses),aswellastemporarylocalidentifierswithintransientad-hocclustersofobjects.Objectsmayalsohavesensorsandactuatorsphysicallyattachedtothem,witheachofthesesensorsandactuatorsalsobeingindividuallyaddressable;theiridentifiersmaybeconstructedasextensionsoftheIDoftheobjectorperhapsassociatedwiththeobject'sidentifierviaalookupinaregistry.Manyobjectsmaybecompositeobjectsorproductsthatconsistofreplaceablepartsthatareexchangedduringtheusagephaseorlifetimeoftheobject.ThesepartsmayalsohavetheirownuniqueidentifiersanditisimportantthattheinformationmodelsfortheIoTallowchangesofidentifier,changesofconfigurationandassociationsbetweenidentifierstoberecordedandqueried,bothintermsofkeepingtrackofchangestoparent-childrelationshipsaswellasold-newrelationships(e.g.whereanewpartisinstalledtoreplaceanoldpartthatiswornorfaulty).Furtherexamplesofassociationsbetweenidentifiersincludethebreakdownoflargequantitiesofbulkproduct(e.g.aspecificbatchoffoodproduct)intoanumberofindividualproductsorpackagesforretailpurposes,repackagingandre-labellingofproducts,aggregationofingredients,componentsandpartstoformcompositeproductsandassembliesorkits,suchasmedicalkits.

Combinationsofthingswillcreate"familytree"identificationschemeswherepartsandcomponentsthatareincorporatedwithincomposite/complexproductssuchascomputers,vehicles,andbuildingshavemanydifferentcomponents,eachwiththeirownuniqueIDandlifehistory.ThisisalsoreferredtoasaserialisedBillofMaterials.Thisisnecessaryinordertotracksetsofdifferentobjects(e.g.parentsorchildrenoftheoriginalobject)andtheframeworkforexpressingdatasharingrulesneedstobeabletosupportthis.

ByassigningeachthingparticipatingintheInternetofThingsauniqueidentityorpotentiallyseveraluniqueidentities,itispossibletorefertoeachthingasanindividual,eachhavingitsowncharacteristics,lifehistoryandinformationtrail,itsownflowpatternthroughtherealworldanditsownsequenceofinteractionswithotherthings.

Itisimportantthatsuchuniqueidentifiersforthingscanbegloballyuniqueandcanhavesignificantconsistencyandlongevity(ideallyforthelifeofthething),independentofthecurrentlocationofthethingorthecurrentnetworkconnectivityavailabletothething,inorderthatitispossibletogatherinformationaboutathingevenwhenthatinformationiscollectedandownedbyanumberofdifferententitiesandfragmentedacrossalargenumberofdatabasesandinformationsystems.

Manythingscanbeconsideredtobe(atleastatthetimeoftheircreation)near-identicalreplicasofeachother,perhapsbelongingtothesameproducttypeandsharinganumberofpropertiescommontoallinstanceswithinthesameclassofthings.Often,arequestororderforaparticularthingmightnotalwaysspecifytheexactuniqueIDthatmustberetrieved;insteadtherequestcanbesatisfiedbyanythingthatisamemberofaparticularclass.ItisthereforeimportantthattheInternetofThingssupportuniqueidentifiersinawaythatitisalsopossibletorefertoaparticularclassofthingsaswellasindividualthingswithinthatclass,inordertobeabletoretrieveorrefertoclass-levelinformationandservicesprovidedfortheclassofthingsaswellasserial-levelinformationandservicesprovidedforeachindividualthing.

Itisalsoimportantthatcitizens,companiesandotherorganisationscanconstructuniqueidentifiersforthingsaseasily,affordablyandautonomouslyastheycancreateuniqueidentifiersforwebpagesandotherinternetresources,whileensuringthatnotwoentitiescanclaimtobetheauthoritativecreatorofthesameuniqueID.IntheexistingInternet,thisistypicallyachievedthroughhierarchicalidentifierstructures,inwhicheachtierofthehierarchyisonlyresponsibleforensuringuniquenessamongthemembersofthetierbelow.

Familiarexamplesofsuchhierarchicallystructuredidentifiersincludetelephonenumbers,URIs,Internethostnamesandsubdomains,handles,digitalobjectidentifiersetc.Itwouldbeimportanttoaccommodatemorethanasinglehierarchicalnamespace;perhapssomeclassesof"things"wouldhavetheirownnamespace,suchastheWorldWideWebusingtheclass"IN"whosenamespaceismanagedbyICANN.Otherwaysthatanamespacecanbedescribedwouldbeasadominionorarealm.

However,therecanbegoodreasonswhytheInternetofThingsshouldalsosupport"opaque"identifiersandpseudonyms,inwhichtheinternalstructureofhierarchyisnotreadilyapparent;thisisparticularlyimportantwhenunauthorisedpartiesareabletoreadtheclassinformation(e.g.producttypeorobjecttype)andcouldjeopardisetheprivacyofacitizenorthesafetyandsecurityofsupplychains,subjectingthemtodiscriminatorytreatmentortargetedattack,onthebasisofwhattheidentifierrevealsaboutthethingswhicharebeingworn,carriedortransported.Therecouldbeanopaqueidentifiernamespacethatisnotpartofthehierarchicalnamespacestructureandrevealsabsolutelynoinformationabouttheobjectthatitisidentifying.Forexample,thiscouldhaveapplicationsinuniquelyidentifyingthemedicationthatapatientiscarrying,especiallywhenusingwirelessidentificationtechnologiesthatlackadequateprivacymeasures.

Werecognisethatmanyindustrysectorshavealreadybegunassigninguniqueidentifierstoobjectsandthatsignificantinvestmenthasbeenmadeininformationsystemsandcollectionofinformationaboutvariouskindsofthings,usingthoseexistinguniqueidentifiersaskeystolookupandretrievethatinformation.SuchestablishedUIDsaredifficulttodisplaceanditisthereforecriticalforsuccessfuldeploymentthatIoTtechnologycansupportsuchexistingUIDs,usingmappingprocesseswherenecessary.

Furthermore,asindicatedinISO15459,multipleestablishednameissuingauthoritiesexistanditisimportantthattheInternetofThingsrecognisestheirlegitimatebutnonexclusiveinvolvementintheconstructionofuniqueidentifiersforthingsandinhelpingtomanagedelegationofuniquenessoftheidentifierscreatedbytheirmembers,eachofwhomistherebygrantedtheautonomytocreateuniqueidentifierswithintheirownnamespace;itshouldalsobepossibleforanyonetouseUniformResourceIdentifiers(URI)asuniqueidentifiersforthings.

Itisimportanttounderstandthatidentifierscanrefertonamesandaddresses,butsincetherecanbemultipleaddressesofinformationandservicesrelatedtoanindividualthing,itisprobablymorehelpfultoensurethateachthingisgivenauniquenameandtouselookupmechanismsandreferralservicestoobtainaddressesofinformationandservices,includingthoseprovidedauthoritativelybythething'screatorandthosecontributedbyotherswhohaveinteractedwith

thethingatsometimeinitslife.Inthecaseoftheexistenceofmultipleidentifiersfora

singleobjectduetodifferentreasonsaschemeforIDdatatranslationanddynamiccompatibility/interoperabilitycheckisnecessary.

Furthermore,itisimportantthatidentifiersarenotconstrainedbycurrentchoicesoftechnologyforstoringandcommunicatinguniqueidentifiersortheircurrentlimitations,sinceweshouldexpectthatthedatacarriertechnologywillevolveovertimeandcurrentlimitations(suchasthoseonmemorycapacityavailableforidentifiers)willbecomemorerelaxed.

TodayvariousuniqueidentifierschemesexistandinteroperabilityisrequiredbetweenapplicationsusingdifferentschemeswhenthoseapplicationsareoperatedintheFutureInternetenvironment.

ThetrafficintheInternetofThingsnetworksforqueriesaboutuniqueidentifierswillbemanytimeshigherthanthatforDNSqueriesinthecurrentInternet.

InthiscontexttheInternetofThingsdeploymentwillrequirethedevelopmentofnewtechnologiesthatneedtoaddresstheglobalIDschemes,identitymanagement,identityencoding/encryption,authenticationandrepositorymanagementusingidentificationandaddressingschemesandthecreationofglobaldirectorylookupservicesanddiscoveryservicesforInternetofThingsapplicationswithvariousuniqueidentifierschemes.

2.CommunicationTechnology

TheapplicationsofInternetofThingsformanextensivedesignspacewithmanydimensionsthatinclude:

·Deployment—onetime,incrementalorrandom.

·Mobility—occasionalorcontinuousperformedbyeitherselectedorall"things"intheselectedenvironment.

·Cost,size,resources,andenergy—veryresourcelimitedtounlimited.

·Heterogeneity—asingletypeof"thing"ordiversesetsofdifferingpropertiesandhierarchies.

·Communicationmodality—Electromagneticcommunication—RadioFrequency,optical,acoustic,inductiveandcapacitivecoupledcommunicationhavebeenused.

·Infrastructure—differentapplicationsexclude,alloworrequiretheuseoffixedinfrastructure.

·Networktopology—singlehop,star,multihop,meshand/ormultitier.

·Coverage—sparse,denseorredundant.

·Connectivity—continuous,occasionalorsporadic.

·Networksize—rangingfromtensofnodestothousands.

·Lifetime—fewhours,severalmonthstomanyyears.

·Otherqualityofservicerequirements—realtimeconstraints,tamperresistance,unobtrusiveness

AnextensivedesignspacecomplicatesIoTapplicationdevelopmentinvariousways.Onecouldarguethatdesigningforthemostrestrictivepointinthedesignspace,e.g.minimum"thing"capabilities,highlymobile,etc.mightbeasolution.However,oftenthereisnosuchglobal"minimum"anditwillbedesirabletoexploitthecharacteristicsofthevariouspointsinthedesignspace.Thisimpliesthatnosinglehardwareandsoftwareplatformwillbesufficienttosupportthewholedesignspaceandheterogeneoussystemswillbeused.

Issuestobeaddressed:

·InternetofThingsenergyefficientcommunications;

·Multifrequencyradiofrontendsandprotocols;

·Communicationspectrumandfrequencyallocation;

·SoftwareDefinedRadios(SDRs);

·CognitiveRadios(CRs);

·Energyefficientwirelesssensornetworkswithinterprotocolcommunicationcapabilities.

3.NetworkTechnology

TheIoTdeploymentrequiresdevelopmentsinnetworktechnologywhichisessentialforimplementingthevisionreachingouttoobjectsinthephysicalworldandtobringthemintotheInternet.RFID,short-rangewirelesstechnologiesandsensornetworksareenablingthis,whileforexampleIPv6,withitsexpandedaddressspace,allowthatallthingscanbeconnected,andcanbetracked.

IntheIoTsecurity,scalability,andcrossplatformcompatibilitybetweendiversenetworkedsystemswillbeessential.

Inthiscontextthenetworktechnologieshastooffersolutionsthatreducedcoststhatcanoffertheviabilityofconnectingalmostanythingtothenetwork,andthisubiquityofaccesswillchangethewayinformationisprocessed.IPprovidestodayendtoendcommunicationbetweendevices,withoutintermediateprotocoltranslationgateways.

Protocolgatewaysareinherentlycomplextodesign,manage,anddeployandwiththeendtoendarchitectureofIP,therearenoprotocoltranslationgatewaysinvolved.

Newscalablearchitecturesdesignedspecificallyfortheubiquitoussensornetworkscommunicationswillallowfornetworksofbillionsofdevices.Improvementsintechniquesforsecureandreliablewirelesscommunicationprotocolswillenablemission-criticalapplicationsforubiquitoussensornetworksbasedonwirelessidentifiabledevices.

Issuestobeaddressed:

·Networktechnologies(fixed,wireless,mobileetc.);

·Ad-hocnetworks.

1.体系

物联网需要开放的体系来实现不同系统