Industrial Internet and the need for guarantees - WINCOM...•IEEE Std802.1TM for the Professional...
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Industrial Internet and the need for guarantees (6TiSCH) Gopi Garge [email protected] Fellow, IPv6 Forum & Director, SmartLancs Ltd., UK
Transcript of Industrial Internet and the need for guarantees - WINCOM...•IEEE Std802.1TM for the Professional...
IndustrialInternetandtheneedforguarantees
(6TiSCH)
Gopi [email protected]
Fellow,IPv6Forum&
Director,SmartLancs Ltd.,UK
Agenda• IndustrialIoT• PerformanceRequirementsofIIoT?• TimeSensitive/DeterministicNetworking• TSCH• 6TiSCH• Conclusion• Callformemberships– IEEEP1931.1WG
IndustrialIoT(IIoT)• Industry4.0• Multiplesectors,applicationdomains• Severalimplementations• Estimatedmarket– USD934Bby2025• IIoT – 55%marketshare
IndustrialIoT(IIoT)• Industry4.0• Multiplesectors,applicationdomains• Severalimplementations• Estimatedmarket– USD934Bby2025• IIoT – 55%marketshare
IndustrialIoT• SensorsandactuatorsdeployedbeforeIoT• Communicationssystemsbasedon• WirelessHART• FoundationFIELDBUS• Profibus• ControllerAreaNetworkCAN
• PushforIP-basedstandardisation (last3decades)• Stringenttimeandperformancerequirement• Time-constrainedcommunications(boundede-to-edelays)
• Otherrequirements• Boundedlatency,highreliability,energyefficiency
IndustrialIoT
• SensorsandactuatorsdeployedbeforeIoT• Communicationssystemsbasedon
• WirelessHART• FoundationFIELDBUS• Profibus• CAN
• PushforIP-basedstandardisation (last3decades)• Stringenttimeandperformancerequirement
• Time-constrainedcommunications(boundede-to-edelays)
• Otherrequirements• Boundedlatency,highreliability,energyefficiency
IndustrialIoT• Closedloopindustrialautomation• Front-endsarewirelesssensor-actuatornetworks• Back-endsarecloudsattheedgeandthecore
• Realtimeoperation,withlatencybounds• Technologysupport• DeterministicNetworking(DetNet)• Focusonflowefficiency(resourceefficiencyintheInternet)• Whatarethedifferences?
• Dependablecontrol• Realtime(back-endsrealtime?)• Resilience• Controlperformance
IndustrialIoT• Closedloopindustrialautomation• Front-endsarewirelesssensor-actuatornetworks• Back-endsarecloudsattheedgeandthecore
• Realtimeoperation,withlatencybounds• Technologysupport• DeterministicNetworking(DetNet)• Focusonflowefficiency(resourceefficiencyintheInternet)• Whatarethedifferences?
PacketLossandLatencies
Best-effort
CBR
Deterministic
DetNet Features• Timesync’ed nodes– IEEE1588PTP- requiredbymostDetNet applications• Contractsbetweentransmittersandthenetworktogovernindividualflows• Flexiblecontracts• Nocongestionloss,boundedlatency• Veryreliablepacketdelivery• Co-existencewithbest-effortservices(singleinfrastructure)
• Requirestightcontrolofphysicaloperationsandschedulingofrealbuffersandqueues,receiving,shapingandresendingpacketsatprecisetimes
Layer2• DetNet operationatLayer3willrequireservicesfromlowerlayerstoachievetherequiredpropertiesend-to-end• IEEEStd 802.1TMfortheProfessionalMediaNetworks(FirstgenerationEthernet-basedstandards,calledAudio/VideoBridging(AVB)).• WithTimeSlottedChannelHopping(TSCH),IEEEStd802.15.4evolvedintoahighlypredictable,quasi-deterministicMediumAccessControl(MAC)technology.• WirelessHART(HART7),ISA100useTSCH
• TheTime-SensitiveNetworking(TSN)TaskGroup(TG)attheIEEEandtheDeterministicNetworking(DetNet)WorkingGroup(WG)attheIETFarenowgeneralizingthosemethodstotransportdeterministicflowsacrossEthernetbridgesandoverIPnetworks,respectively.
Whatwewant– WirelessDetnets• Radioandchannelrelatedissuesimpactdeterminism• Channel• CongestedISMband• Varyingchannelconditions• Fixedchannelsnotfeasible– Channelagility
• Radio• Co-channelinterferenceandmulti-pathfading• Channelaccess– contentiondelays,back-offs
• TimeSlottedChannelHopping(TSCH)• Scheduletransmissions• Timeandfrequencydiversities
Whatwewant– WirelessDetnets• Radioandchannelrelatedissues
impactdeterminism
• Channel• CongestedISMband• Varyingchannelconditions• Fixedchannelsnotfeasible–
Channelagility
• Radio• Co-channelinterferenceand
multi-pathfading• Channelaccess– contention
delays,back-offs
• TimeSlottedChannelHopping(TSCH)• Scheduletransmissions• Timeandfrequencydiversities
CoAP (2014)
RPL(2012)
6LoWPAN(2011)
802.15.4TimeSlottedChannelHopping(TSCH)- 2012
IPConnectivity• Web-likeservices• Easeofuse
IndustrialDeployments• Performance• Reliability• Lowmaintenance
IEEE802.15.4• Standardforlow-rate,low-power,andlow-costPersonalAreaNetworks(PANs)• Networktopologiesarestar(single- hop),cluster-treeandmesh(multi-hop)• A beaconenabled(BE)modeandanon-beaconenabled(NBE)mode• TheactiveperiodisdenotedasSuperframeDuration(SD)dividedintoaContentionAccessPeriod(CAP)andaContentionFreePeriod(CFP)• CAP=slottedCSMA/CAforchannelaccess,CFP=TDMAusinganumberofGuaranteedTimeSlots(GTSs),pre-assignedtoindividualnodes
LimitationsofIEEE802.15.4• UnboundedDelay.CSMA/CAcannotprovideanyboundonthemaximumdelay• Limitedcommunicationreliability.BEmodehasverylowPDR;NBEmodewhenalargenumberofnodesstarttransmittingsimultaneously(e.g.,inevent-drivenapplications)• Noprotectionagainstinterferences/fading• EnergyConsumptionRelaynodesinamulti-hoptopologyrequiretokeeptheirradioON,always
IEEE802.15.4eTSCH• TimeSlotted(TSCH)• Timeisdividedinslots• Allmotesaresynchronized toagivenslotframe (groupofslotswhichrepeatsovertime)• Numberofslotsinaslotframe isconfigurable
• ChannelHopping(TSCH)• 16channels,2.4GHzband• Eachslotusedbyanynode=IncreasedNetworkcapacity• Thechanneloffsetistranslatedintoafrequency(i.e.,arealchannel)• Nodesusedifferentchannelsforeachpacket=minimiseInterferenceandmultipathfading
timeslot
slotframe
2 3 41 2 3 41 2 3 41
IEEE802.15.4eTSCH• Schedulingtransmissions• Eachnodefollowsaschedule(acellmatrix)• Eachcellinthescheduleisassignedtoapairforone-waycommunication• Ascheduleisbuilteithercentrallyordistributedwithapplicationrequirements(latency,bandwidth,energyconsumption,etc.)• Acellcanbebothdedicatedorshared(TSCH-CSMA/CA)
ChannelDistribution/Usage• Switching• framecanbeswitchedbasedontheparticulartimeandtheparticularchannelatwhichitwasreceived
• ChannelDistribution/UsageMatrix(CDU)• Globaltonetwork• Cells,eachofacertaintimeslot
channe
lOffset
–Max16
slotOffset,0..N
10-15ms
Cell(slotOffset,channelOffset
Slotframe
CDU• AChunkisalistofcellswithsimilarproperties,welldistributedintimeandfrequency• Anodegetstheownershipofachunkanddecideswhichtransmissionswilloccuroverthecellsinthechunk• Applicationflowsfromasinglenodecanbescheduledondifferentframeswithdifferentpriorities,tosupportconcurrentoperations(Rx,Tx)• Bundle– groupofcellsscheduledforthesamepurpose.Representsahalf-duplexlinkwithabandwidthofthetotalcellsinthebundle
Tracks&LinksB
IEEE802.15.4eTSCH• Schedule:based on specific application requirements -latency,bandwidth,energy consumption,etc.• Approaches tobuild aschedule
• Centralized• PCEresponsibleforbuildingandmaintainingtheschedule• Efficientforstatic networks
• Distributed(MPLS-like)• Nodesdecidelocally whichcellstheywilluseforcommunicatingwiththeirneighbors
• Suitableformobile networkswithmanygateways
Centralised Scheduling1.NodessendperiodicinformationtoPathComputationElement(PCE)• Connectivity• Trafficrequirements
2.PCEcomputestheTSCHschedule
3.PCEcommunicateswithnodestoconfiguretheschedule(CoAP)
DistributedScheduling• AsendsapacketalongtheAàBàDàEmulti-hoppath(circuit?)• Ateachhop,neighbormotesnegotiatewithoneanothertoaddcellsintotheirTSCHschedule(bandwidth)• 6topmonitoringprocessrecoversfromtopologicalchangesandcollisionsbyreschedulingbadlyperformingcells
D
C
B
A
E
TSCH- Performance
• NodeshavethesamemaximumnumberofpossiblechannelaccessattemptsmaxA inbothprotocols• TSCHproviderhigherreliabilityaswellasahigherlatency(!)
DeGuglielmo,D.,AlNahas,B.,Duquennoy,S.,Voigt,T.andAnastasi,G.,2017.AnalysisandexperimentalevaluationofIEEE802.15.4eTSCHCSMA-CAalgorithm.IEEETransactionsonVehicularTechnology, 66(2),pp.1573-1588.
Whatwewant– WirelessDetnets• Radioandchannelrelatedissues
impactdeterminism
• Channel• CongestedISMband• Varyingchannelconditions• Fixedchannelsnotfeasible–
Channelagility
• Radio• Co-channelinterferenceand
multi-pathfading• Channelaccess– contention
delays,back-offs
• TimeSlottedChannelHopping(TSCH)• Scheduletransmissions• Timeandfrequencydiversities
CoAP (2014)
RPL(2012)
6LoWPAN(2011)
802.15.4TimeSlottedChannelHopping(TSCH)- 2012
IPConnectivity• Web-likeservices• Easeofuse
IndustrialDeployments• Performance• Reliability• Lowmaintenance
Stackingthelayers• Time-sensitiveIPv6traffic(OTtraffic)• Use802.15.4deterministicmodewithTSCH• IETF6TiSCHWG– 2013
IEEE
IETF
The6TiSCHStack
6top(6TiSCHoperationsub-layer)
6TiSCH
The6TiSCHOperationsublayer(6top)isasublayerofaLogicalLinkControl(LLC)thatprovidestheabstractionofanIPlinkoveraTSCHMACandschedulespacketsoverTSCHcells
/6LoRH
Summary• BothwiredandwirelessnetworksareevolvingtowardsmoredeterminismneededbyIIoT• OperationalTechnologies(OT)requireaspecificperformance,vastlydifferentfromtraditionalIT• OTandIThavetoconvergeonasharednetwork;CurrentOTnetworksareseparatenetworks• 6TiSCHprovidesameanstoevolvetowardsthisconvergence• Deterministicandbest-efforttraffic• Bestaveragedeliverytimeandlowestenergyconsumption
On-goingworkintheIETF• 6topProtocol(6P)-draft-ietf-6tisch-6top-protocol-09• 6Pispartofthe6topsub-layer,thelayerabovetheIEEEStd802.15.4TSCHMAClayer.A6topSchedulingFunction(SF)decideswhentoadd/deletecells,andtriggers6PTransactions.
• 6TiSCH6topSchedulingFunctionZero- draft-ietf-6tisch-6top-sfx-00• "SchedulingFunctionZero"(SF0)dynamicallyadaptsthenumberofscheduledcellsbetweenneighbornodes,basedontheamountofcurrentlyallocatedcellsandtheneighbornodes'cellrequirements.SF0usesthe6Psignalingmessagestoadd/deletecellsintheschedule.
• AnArchitectureforIPv6overtheTSCHmodeofIEEE802.15.4- draft-ietf-6tisch-architecture-12• Networkarchitecturethatprovideslow- latency,low-jitterandhigh-reliabilitypacketdelivery.
• TerminologyinIPv6overtheTSCHmodeofIEEE802.15.4edraft-ietf-6tisch-terminology-09
On-goingworkattheIETF
• MinimalSecurityFrameworkfor6TiSCHdraft-ietf-6tisch-minimal-security-03• The minimal mechanisms required to support secureenrollment of a pledge, a device being added to a6TiSCH network. The goal of this configuration is to setlink-layer keys, and to establish a secure end-to-endsession between each pledge and the join registrar whomay use that to further configure the pledge
• 6tischZero-TouchSecureJoinprotocoldraft-ietf-6tisch-dtsecurity-zerotouch-join-00• a zero-touch mechanism to enroll a new device (the"pledge") into a IEEE802.15.4 TSCH network using the6tisch signaling mechanisms.
References• Hsieh,C.EnergyEfficiencyandReliabilityonWirelessSensorActuatorNetwork,KIT,Germany
• www.iot-analytics.com
• Lu,C.Real-timeInternetofThings.Cyber-Physicalsystemslaboratory,WashingtonUniversity
• Finn,N.2017.Time-sensitiveandDeterministicNetworking.HuaweiTechnologiesCo.Ltd.
• Rodenas-Herraiz,D.,Garcia-Sanchez,A.J.,Garcia-Sanchez,F.andGarcia-Haro,J.,2013.Currenttrendsinwirelessmeshsensornetworks:Areviewofcompetingapproaches. Sensors, 13(5),pp.5958-5995.
• DeGuglielmo,D.,Brienza,S.andAnastasi,G.,2016.IEEE802.15.4e:Asurvey. ComputerCommunications, 88,pp.1-24.
• ETSI2017.IPv6-basedIndustrialInternetleveraging6TiSCHtechnology.GroupReport- ETSIGRIP6009V1.1.1(2017-03)
•
RoofComputing• Real-timeOn-siteOperationsFacilitation(ROOF)
Roofvs. Fogvs. Cloud
IEEEStandardsDevelopmentWorkingGroup,ROOF– RoofComputing
https://standards.ieee.org/develop/wg/ROOF.html
CallingformembershipstotheWG:Contact
Dr.P.Ambika,[email protected]
Thankyou
