IOT NOTES BASED ON THE ENGINEERING ACADEMICS

IOT NOTES

1. Module 1: Introduction to IoT
•IntroductiontoIoT
‐DefiningIoT,
‐CharacteristicsofIoT,
‐PhysicaldesignofIoT,
‐LogicaldesignofIoT,
‐FunctionalblocksofIoT,
‐BriefreviewofapplicationsofIoT.
•SmartObject
‐Definition,
‐CharacteristicsandTrends
•Self-learningTopics:Hardwareandsoftwaredevelopmenttoolsfor-Arduino,NodeMCU,
ESP32,RaspberryPi,forimplementinginternetofthings,SimulatorsCircuit.io,Eagle,Tinkercad
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2. DefinitionofIoT
Adynamicglobalnetworkinfrastructurewithself-configuring
capabilitiesbasedonstandardandinteroperablecommunication
protocolswherephysicalandvirtual"things"haveidentities,physical
attributes,andvirtualpersonalitiesanduseintelligentinterfaces,and
areseamlesslyintegratedintotheinformationnetwork,often
communicatedataassociatedwithusersandtheirenvironments.
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3. CharacteristicsofIoT
1.Dynamicandself-Adapting:IoTdevicesandsystemsmayhavethecapabilityto
dynamicallyadaptwiththechangingcontextsandtakeactionsbasedontheir
operatingcondition.Ex:Surveillancecamerascanadapttheirmodesbasedon
whetheritisdayornight.
2.Self–Configuring:IoTdevicesmayhaveself-Configuringcapabilityallowingalarge
numberofdevicestoworktogethertoprovidecertainfunctionality.
3.Interoperablecommunicationprotocols:IoTDevicesmaysupportanumberof
interoperablecommunicationprotocolsandcancommunicatewithotherdevicesand
alsowiththeinfrastructure.
4.UniqueIdentity:EachIoTdeviceshasauniqueidentityandauniqueidentifier.IP
address,URI).IoTsystemsmayhaveintelligentinterfaceswhichadaptbasedonthe
context,allowcommunicationwithusersandtheenvironmentcontexts.
5.Integratedintoinformationnetwork:IoTdevicesareusuallyintegratedintothe
informationnetworkthatallowsthemtocommunicateandexchangedatawithother
devicesandsystems.
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4. PhysicalDesignofIoT
•The"Things"inIoTusuallyreferstoIoTdeviceswhichhaveuniqueidentitiesand
canperformremotesensing,actuatingandmonitoringcapabilities.
•IoTdevicescan:
‐Exchangedatawithotherconnecteddevicesandapplications(directly
orindirectly),or
‐Collectdatafromotherdevicesandprocessthedatalocallyor
‐Sendthedatatocentralizedserversorcloud-basedapplicationback-ends
forprocessingthedata,or
‐PerformsometaskslocallyandothertaskswithintheIoT
infrastructure,basedontemporalandspaceconstraints(s(i.e.
Memory,processingcalibrators,communicationlatenciesandspeed
anddeadlines).
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5. Genericblock diagramofan IoTDevice
•An IoT device may consist of several interfaces for connections to
other devices, bothwiredandwireless.
•I/Ointerfacesfor sensors
•Interfaces for Internet connectivity
•Memoryandstorage interfaces
•Audio/videointerfaces.
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6. PhysicalDesignofIoT: IoTProtocols
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7. 1.LinkLayer:
•LinkLayerprotocolsdeterminehowthedataisphysicallysentover
thenetworksphysicallayerormedium(examplecopperwire,
electricalcable,orradiowave).
•TheScopeofTheLinkLayeristheLastLocalNetworkconnectionsto
whichhostisattached.Hostonthesamelinkexchangedatapackets
overthelinklayerusingthelinklayerprotocol.
•Linklayerdetermineshowthepacketsarecodedandsignaledbythe
hardwaredeviceoverthemediumtowhichthehostisattached.
IoTProtocols: Link Layer
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8. •802.3Ethernet:802.3isacollectionsofwiredEthernetstandardsforthelinklayer.Forexample802.3
10BASE5Ethernetthatusescoaxialcableasasharedmedium,802.3.iisstandardfor10BASETEthernetover
coppertwistedpairconnection,Standardsprovidedataratesfrom10Mb/sto40gigabitspersecondand
thehigher.ThesharedmediuminEthernetcanbeacoaxialcable,twistedpairwireorandOpticalfiber.
Sharedmediumcarriesthecommunicationforallthedevicesonthenetwork.
•802.1-WI-FI:IEEE802.3isacollectionsofwirelessLocalareanetwork.(WLAN)communicationstandards,
includingextensivedescriptionsofthelinklayer.Forexample802.11aoperateinthe5GHzband,802.11b
and802.11goperateinthe2.4GHzband.802.11acoperatesinthe5Ghertzband.
•802.16wiMAX:IEEE802.16isacollectionofwirlessbroadbandandStandards,includingextensive
descriptionsforthelinklayeralsocalledWiMAXwimaxstandardprovidesadataratesfromfrom1.5Mb/s
to1Gb/stherecentupdateprovidesdataratesofhundredmegabitspersecondformobilestation.
•802.15.4LR-WPAN:IEEE802.15.4isacollectionsofstandardforlowratewirelesspersonalarea
network(LRWPAN).ThesestandardformthebasisofspecificationsforhighlevelcommunicationZigbee.LR-
WPANstandardsprovidedataratesfrom40kb/s.Thesestandardsprovidelowcostandlowspeed
Communicationsforpowerconstraineddevices.
•2G/3G/4Gmobilecommunications:Thesearethedifferentgenerationsofmobilecommunication
standardsincludingsecondgeneration(2GincludingGSMandCDMA).3rdGeneration(3GincludingUMTS
andCDMA2000)and4thgeneration4GincludingLTE.
IoTProtocols: Link Layer
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9. •ThenetworklayerareresponsibleforsendingofIPdatagramsfromthesourcenetworktothe
destinationnetwork.
•ThislayerPerformsthehostaddressingandpacketrouting.
•Thedatagramscontainsasourceanddestinationaddresswhichareusedtoroutethemfromthe
sourcetothedestinationacrossmultiplenetworks.
•HostIdentificationisdoneusingthehierarchyIPaddressingschemessuchasIPv4orIPv6.
‐IPv4:Internetprotocolversionsforopenparentsclose(IPv4)istheremostdeployedinternet
protocolthatisusedtoidentifythedeviceisonanetworkusingahierarchylatestschemes.
Ituses32bitaddressesschemethatallowstotalof2
32
address.Asmoreandmoredevices
gotconnectedtotheinternet.TheIPv4hassucceededbyIPv6.
‐IPv6:ItisthenewestversionsofinternetprotocolandsuccessortoIPv4.IPv6uses128bit
addressschemesthatarelosttotalof2
128
are3.4*10
38
address.
‐6LoWPAN:IPv6overlowpowerwirelesspersonalareanetworksbringsIPprotocoltothelow
powerdevicewhichhavelimitedprocessingcapabilityitoperateinthe2.4GHzfrequency
rangeandprovidethedatatransferrateoffto50kb/s.
IoTProtocols: Network/ internetlayer
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10. IoTProtocols: Transport layer
•TheTransportlayerprotocolsprovidesend-to-endmessagetransfercapabilityindependentofthe
underlyingnetwork.
•Themessagetransfercapabilitycanbesetuponconnections,eitherusinghandshakeorwithout
handshakeacknowledgements.
•Providesfunctionssuchaserrorcontrol,segmentation,flowcontrolandcongestioncontrol.
•TCP:Transmissioncontrolprotocolisthemostwidelyusedtotransportlayerprotocolthatis
usedbythewebbrowsersalongwithHTTP,HTTPSapplicationlayerprotocolsemailprogram
(SMTPapplicationlayerprotocol)andfiletransferprotocol.TCPisaconnectionOrientedand
statefulprotocolwhileIPprotocoldealswithsendingpackets,TCPensuresreliabletransmissions
ofpacketsinorder.TCPalsoprovideerrordeductioncapabilitysothatduplicatepacketscanbe
discardedandlowpacketsareretransmitted.Theflowcontrolcapabilityensuresthattherateat
whichthesendersincethedataisnowtotootohighforthereceivertoprocess.
•UDP:UserDatagramProtocolunlikeTCP,whichrequirescarryingoutaninitialsetupprocedure,
UDPisaconnectionlessprotocol.UDPisusefulfortimesensitiveapplicationtheyhaveverysmall
dataunitstoexchangeanddonotwanttheoverheadofconnectionsetup.UDPisatransactions
orientedandstatelessprotocol.UDPdoesnotprovideguaranteeddelivery,orderingofmessages
andduplicateeliminations.
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11. IoTProtocols: Applicationlayer
•Applicationlayerprotocoldefinehowtheapplicationinterfaceswith
thelowerlayerprotocolstosendthedataoverthenetwork.
•Dataaretypicallyinfiles,isencodedbytheapplicationlayerprotocol
andencapsulatedinthetransportlayerprotocol.
•Applicationlayerprotocolenableprocess-to-processconnectionusing
ports.
•Protocols:HTTP,COAP,Websocket,MQTT,XMPP,DDS,AMQP
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12. IoTProtocols: Applicationlayer
HTTP:
•HyperTextTransferProtocolistheapplicationlayerprotocolthatformsthefoundationsofworld
widewebhttpincludes,,commandssuchasGET,PUT,POST,DELETE,HEAD,TRACE,OPTIONSetc.
•Theprotocolfollowsarequest-responsemodelwhereareclientsendsrequesttoserverusingthe
http,commands.
•HTTPisastatelessprotocolandeachhttprequestisindependentotherrequest
CoAP:
•ConstrainedApplicationProtocolisanapplicationlayerprotocolformachinetomachine
applicationM2Mmeantforconstrainedenvironmentwithconstraineddevicesandconstrained
networks.
•LikehttpCoAPisawebtransferprotocolandusesarequest-responsemodel,howeveritrunson
thetopoftheUDPinsteadofTCPCoAPusesaclient–serverarchitecturewhereclient
communicatewithserverusingconnectionlessdatagrams.
•ItisdesignedtoeasilyinterfacewithHTTP.LikeHTTP,CoAPsupportsmethodsuchasGET,PUT,
DELETE.
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13. IoTProtocols: Applicationlayer
WebSocket:
•WebSocketprotocolallowsfullduplexcommunicationoverasinglesocketconnections
forsendingmessagebetweenclientandserver.
•WebSocketisbasedonTCPandAllowsstreamsofmessagestobesentbackandforth
betweentheclientandserverwhilekeepingtheTCPconnectionopen.
•Theclientcanbeabrowser,amobileapplicationandIoTdevice.
MQTT:
•MessageQueueTelemetryTransportitisalightweightmessageprotocolbasedon
public-subscribemodel.
•MQTTusesaclientserverArchitecturebytheclientssuchasanIoTdeviceconnectto
theserveralsocalledtheMQTTbrokerandpublishersmessagetotopicontheserver.
•ThebrokerforwardthemessagetotheclientssubscribedtotopicMQTTiswellsuitedfor
constrainedandenvironmentswheredeviceshavelimitedprocessingandmemory
resourcesandthenetworkbandwidthislow.
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14. IoTProtocols: Applicationlayer
XMPP:ExtensibleMessagingandPresenceProtocolitisaprotocolforreal-time
communicationandstreamingXMLdatabetweennetworkentities.XMPPpowerswide
rangeofapplicationsincludingmessaging,presence,datasyndication,gamingmultiparty
chatandvoice/voicecalls.XMPPAllowssendingsmallchunksofXMLdatafromone
networkentitytoanotherinrealtime.XMPPsupportsbothclienttoserverandserver–
clientcommunicationpath.
DDS:Datadistributionserviceisthedatecentricmiddlewarestandardfordevice-to-
deviceormachinetomachinecommunicationDDSusesapublishsubscribemodelwhere
publisher(exampledevicethatgeneratedata)createtopicstowhichsubscriberspercan
subscribepublisherisanobjectresponsiblefordatadistributionsandthesubscriber
responsibleforreceivingpublisheddata.DDSprovidequalityofservice(QoS)controland
configurablereliability
AMQP:AdvancedMessageQueuingprotocols.itisanopenapplicationlayerprotocolfor
businessmessaging.AMQPsupportpointtopointandpublish-subscribemodelrouting
andqueuing.AMQPbrokerreceivemessagefrompublishersexampledevicesor
applicationsthatgeneratedataandaboutthemoverconnectionstoconsumerspublishers
publishthemessagetoexchangewhichthendistributemessagecopiestoqueues.
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15. LogicalDesignofIoT
•LogicaldesignofanIoTsystem
referstoanabstract
representationoftheentities
andprocesseswithoutgoing
intothelow-levelspecificsof
theimplementation.
•AnIoTsystemcomprisesofa
numberoffunctionalblocks
thatprovidethesystemthe
capabilitiesforidentification,
sensing, actuation,
communication, and
management.
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16. The functional blocks
•Devices:AnIoTsystemcomprisesofthedevicesthatprovidesensing,actuation,
monitoringandcontrolfunction.
•Communication:communicationblockhandlethecommunicationsystems.
•Services:AnIoTsystemusesvarioustypesofIoTservicessuchasservicesfor
devicemonitoring,devicecontrolservices,datapublishingservicesandservices
fordeviceDiscovery.
•Management:FunctionalblocksprovidevariousfunctionstogoverntheIoT
system.
•Security:SecurityfunctionalblocksecurityIoTsystemandbyprovidingfunctions
suchasapplicationauthorizationmessageandcontentintegrityanddata
security.
•Application:IoTapplicationprovidesandinterfacethattheusercanusedto
controlandmonitorvariousaspectsoftheIoTsystem.Applicationalsoallow
userstoviewthesystemstatusandvieworanalyzetheprocessedtodata.
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17. Applications of IoT
1)Home
2)Cities
3)Environment
4)Energy
5)Retail
6)Logistics
7)Agriculture
8)Industry
9)Health & Life Style
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18. IoT communication model
•Request Response Communications Model
•Publish –Subscribe Communication Model
•Push Pull Communication Model
•Exclusive Pair Communication Model
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19. Request-Responsecommunicationmodel
•Request-Responseisacommunicationmodelinwhichtheclient
sendsrequeststotheserverandtheserverrespondstotherequests.
•Whentheserverreceivesarequest,itdecideshowtorespond,
fetchesthedata,retrievesresourcerepresentations,preparesthe
response,andthensendstheresponsetotheclient.
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20. Publish-Subscribecommunicationmodel
•Publish-Subscribe is a communication model that involves publishers, brokers
and consumers.
•Publishers are the source of data. Publishers send the data to the topics which
are managed by the broker. Publishers are not aware oftheconsumers.
•Consumers subscribe to the topics whicharemanagedbythebroker.
•When the broker receives data for atopicfromthepublisher,it sends the data to
all the subscribedconsumers.
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21. Push-Pullcommunicationmodel
•Push-Pullisacommunicationmodelinwhichthedataproducerspushthe
datatoqueuesandtheconsumerspullthedatafromthequeues.Producers
donotneedtobeawareoftheconsumers.
•Queueshelpindecouplingthemessagingbetweentheproducersand
consumers.
•Queuesalsoactasabufferwhichhelpsinsituationswhenthereisamismatch
betweentherateatwhichtheproducerspushdataandtheraterateatwhich
theconsumerspulldata.
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22. Exclusive Paircommunicationmodel
•ExclusivePair isa
bidirectional, fully duplex
communication model that
uses a persistent connection
betweentheclient and
server.
•Once the connection is setup
itremains openuntil the
clientsends arequest to
close theconnection.
•Clientandserver cansend
messages to each other after
connectionsetup.
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23. IoT communication APIs
•REST-based communication API:
•WebSocket based communication API:
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24. REST-basedCommunicationAPIs
•Representational State Transfer
(REST) is a set of architectural
principles by which you can design
web services and web APIs that
focus on a system’s resources and
howresourcestatesare
addressedandtransferred.
•REST APIs follow the request-
responsecommunicationmodel.
•The REST architectural constraints
apply to the components,
connectors, and data elements,
within a distributed hypermedia
system.
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25. WebSocket-basedCommunicationAPIs
•WebSocketAPIsallowbi-
directional, fullduplex
communication between
clientsandservers.
•WebSocket APIs follow the
exclusive pair
communicationmodel
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26. Smart Objects: Introduction
•Smartobjectsare,quitesimply,thebuildingblocksofIoT.
•Theyarewhattransformeverydayobjectsintoanetworkofintelligentobjectsthatareabletolearn
fromandinteractwiththeirenvironmentinameaningfulway.
•TherealpowerofsmartobjectsinIoTcomesfrombeingnetworkedtogetherratherthanbeing
isolatedasstandaloneobjects.
•Thisabilitytocommunicateoveranetworkhasamultiplicativeeffectandallowsforverysophisticated
correlationandinteractionbetweendisparatesmartobjects.
•Example
‐Ifasensorisastandalonedevicethatsimplymeasuresthehumidityofthesoil,itisinterestingand
useful,butitisn’trevolutionary.Ifthatsamesensorisconnectedaspartofanintelligentnetworkthat
isabletocoordinateintelligentlywithactuatorstotriggerirrigationsystemsasneededbasedonthose
sensorreadings,wehavesomethingfarmorepowerful.
‐Extendingthatevenfurther,imaginethatthecoordinatedsensor/actuatorsetisintelligently
interconnectedwithothersensor/actuatorsetstofurthercoordinatefertilization,pestcontrol,andso
on—andevencommunicatewithanintelligentbackendtocalculatecropyieldpotential.
‐ThisnowstartstolooklikeacompletesystemthatbeginstounlockthepowerofIoTandprovidesthe
intelligentautomationwehavecometoexpectfromsucharevolutionarytechnology.
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27. Smart Objects: A Definition
•ADefinitionHistorically,thedefinitionofasmartobjecthasbeena
bitnebulousbecauseofthedifferentinterpretationsoftheterm
byvaryingsources.
•Toaddtotheoverallconfusion,thetermsmartobject,despite
somesemanticdifferences,isoftenusedinterchangeablywith
termssuchassmartsensor,smartdevice,IoTdevice,intelligent
device,thing,smartthing,intelligentnode,intelligentthing,
ubiquitousthing,andintelligentproduct.
•Inordertoclarifysomeofthisconfusion,Asmartobject,isa
devicethathas,ataminimum,thefollowingfourdefining
characteristics.
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28. Smart Objects: A Definition
•Definingcharacteristics
1.Processingunit:
-Asmartobjecthassometypeofprocessingunitforacquiringdata,processing
andanalyzingsensinginformationreceivedbythesensor(s),coordinating
controlsignalstoanyactuators,andcontrollingavarietyoffunctionsonthe
smartobject,includingthecommunicationandpowersystems.
-Thespecifictypeofprocessingunitthatisusedcanvarygreatly,dependingon
thespecificprocessingneedsofdifferentapplications.
-Themostcommonisamicrocontrollerbecauseofitssmallformfactor,
flexibility,programmingsimplicity,ubiquity,lowpowerconsumption,andlow
cost.
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29. Smart Objects: A Definition
Definingcharacteristics
2.Sensor(s)and/oractuator(s):
-Asmartobjectiscapableofinteractingwiththephysicalworld
throughsensorsandactuators.
-Asensorlearnsandmeasuresitsenvironment,whereasan
actuatorisabletoproducesomechangeinthephysicalworld.
-Asmartobjectdoesnotneedtocontainbothsensorsand
actuators.Infact,asmartobjectcancontainoneormultiple
sensorsand/oractuators,dependingupontheapplication.
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30. Smart Objects: A Definition
Definingcharacteristics
3.Communicationdevice:
-Thecommunicationunitisresponsibleforconnectingasmart
objectwithothersmartobjectsandtheoutsideworld(viathe
network).
-Communicationdevicesforsmartobjectscanbeeitherwiredor
wireless.
-InIoTnetworkssmartobjectsarewirelesslyinterconnectedfora
numberofreasons,includingcost,limitedinfrastructure
availability,andeaseofdeployment.
-Therearemyriaddifferentcommunicationprotocolsforsmart
objects.
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31. Smart Objects: A Definition
Definingcharacteristics
4.Powersource:
-Smartobjectshavecomponentsthatneedtobepowered.
-Themostsignificantpowerconsumptionusuallycomesfromthecommunicationunitofasmart
object.Buttheotherthreesmartobjectbuildingblocks,thepowerrequirementsvarygreatlyfrom
applicationtoapplication.
-Typically,smartobjectsarelimitedinpower,aredeployedforaverylongtime,andarenoteasily
accessible.
-Thiscombination,especiallywhenthesmartobjectreliesonbatterypower,impliesthatpower
efficiency,judiciouspowermanagement,sleepmodes,ultra-lowpowerconsumptionhardware,
andsoonarecriticaldesignelements.
-Forlong-termdeploymentswheresmartobjectsare,forallpracticalpurposes,inaccessible,power
iscommonlyobtainedfromscavengersources(solar,piezoelectric,andsoon)orisobtainedina
hybridizedmanner,alsotappingintoinfrastructurepower.
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32. Characteristics of a Smart Object
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33. Trends in Smart Objects
•Sizeisdecreasing:Thereisacleartrendofever-decreasingsize.Somesmartobjectsaresosmall
theyarenotevenvisibletothenakedeye.Thisreducedsizemakessmartobjectseasiertoembed
ineverydayobjects.
•Powerconsumptionisdecreasing:Thedifferenthardwarecomponentsofasmartobject
continuallyconsumelesspower.Thisisespeciallytrueforsensors,manyofwhicharecompletely
passive.Somebatterypoweredsensorslast10ormoreyearswithoutbatteryreplacement.
•Processingpowerisincreasing:Processorsarecontinuallygettingmorepowerfulandsmaller.This
isakeyadvancementforsmartobjects,astheybecomeincreasinglycomplexandconnected.
•Communicationcapabilitiesareimproving:It’snobigsurprisethatwirelessspeedsarecontinually
increasing,buttheyarealsoincreasinginrange.IoTisdrivingthedevelopmentofmoreandmore
specializedcommunicationprotocolscoveringagreaterdiversityofusecasesandenvironments.
•Communicationisbeingincreasinglystandardized:Thereisastrongpushintheindustryto
developopenstandardsforIoTcommunicationprotocols.Inaddition,therearemoreandmore
opensourceeffortstoadvanceIoT.
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