Wireless sensor networks in Internet of Things

Wireless Sensor Networks

1. WirelessSensorNetworks:
ASurvey

2. Outline
•Introduction
•WirelessSensorNetworksApplications
•FactorsInfluencingSensorNetworkDesign
•SensorNodeComponents
•SensorNetworksCommunicationArchitecture
•SensorNetworkProtocols
•SensorNetworksOperatingSystems
•SensorNetworksSimulators
•Conclusion
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3. Introduction
•sensor
–Atransducer
–convertsphysicalphenomenone.g.heat,light,motion,
vibration,andsoundintoelectricalsignals
•sensornode
–basicunitinsensornetwork
–containson-boardsensors,processor,memory,
transceiver,andpowersupply
•sensornetwork
–consistsofalargenumberofsensornodes
–nodesdeployedeitherinsideorveryclosetothe
sensedphenomenon
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4. WirelessSensorNetworksApplications
MilitaryApplications
•Monitoringfriendlyforces,equipment,
andammunition
•Battlefieldsurveillance
•Reconnaissanceofopposingforcesandterrain
•Targeting
•Battledamageassessment
•Nuclear,biological,andchemicalattack
detection
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5. WirelessSensorNetworks
Applications
EnvironmentalApplications
•Forestfiredetection
•Bio-complexitymappingofenvironment
•Flooddetection
•PrecisionAgriculture
•Airandwaterpollution
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6. WirelessSensorNetworks
Applications
HealthApplications
•Telemonitoringofhumanphysiologicaldata
•Trackingandmonitoringdoctorsand
patientsinsideahospital
•Drugadministrationinhospitals
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7. WirelessSensorNetworks
Applications
HomeandOfficeApplications
•Homeandofficeautomation
•Smartenvironment
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8. WirelessSensorNetworks
Applications
AutomotiveApplications
•Reduceswiringeffects
•Measurementsinchambersandrotatingparts
•Remotetechnicalinspections
•Conditionsmonitoringe.g.atabearing
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9. WirelessSensorNetworks
Applications
AutomotiveApplications
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10. WirelessSensorNetworksApplications
OtherCommercialApplications
•Environmentalcontrolinofficebuildings
(estimatedenergysavings$55billionper
year!)
•Interactivemuseums
•Detectingandmonitoringcarthefts
•Managinginventorycontrol
•Vehicletrackinganddetection
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11. UnderwaterAcousticSensor
Networksref.GeorgiaInstituteof
Technology
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12. FactorsInfluencingWSN
Design
•Faulttolerance
•Scalability
•Productioncosts
•Hardwareconstraints
•Sensornetworktopology
•Environment
•Transmissionmedia
•PowerConsumption
–Sensing
–Communication
–Dataprocessing
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13. SensorNodes
WorldsensInc.SensorNodeCrossbowSensorNode
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15. SensorNodeComponents
•SensingUnit
•ProcessingUnit
•TransceiverUnit
•PowerUnit
•LocationFindingSystem(optional)
•PowerGenerator(optional)
•Mobilizer(optional)
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16. WSNCommunicationArchitecture
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17. WSNProtocolStack
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18. AFewWSNProtocols
•Sensormanagementprotocol
–Providessoftwareoperationsneededtoperform
administrativetaskse.g.movingsensornodes,turning
themonanoff
•Sensorqueryanddatadisseminationprotocol
–Providesuserapplicationswithinterfacestoissuequeriesand
respondtoqueries
–Sensorqueryandtaskinglanguage(SQTL)
•Directeddiffusion
•SensorMAC(S-MAC)
•IEEE802.15.4
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19. Data-CentricRouting
•Interestdisseminationisperformedto
assignsensingtaskstosensornodes
–Sinksbroadcasttheinterest
–Sensornodesbroadcastanadvertisementforavailable
data
•Requiresattribute-basednaming
–Usersaremoreinterestedinqueryingtheattribute
ofthephenomenon,ratherthanqueryingan
individualnode
–E.g.thesensornodesintheareawhere
temperatureisgreaterthan75F
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20. DataAggregationin
WSNs
•Datacomingfrommultiple
sensornodesare
aggregatediftheyare
aboutthesameattribute
ofthephenomenonwhen
theyreachthesame
routingnodeontheway
backtothesink
–Solvesimplosionandoverlap
problem
–Energyefficient
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21. WSNOperating
Systems
•TinyOS
•Contiki
•MANTIS
•BTnut
•SOS
•Nano-RK
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22. Communication
HardwareAbstractions
CommunicationSensingActuating
Application(UserComponents)
Main(includesScheduler)
TinyOS
•Event-drivenprogrammingmodel
insteadofmultithreading
•TinyOSanditsprogramswritteninnesC
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23. TinyOSCharactersitics
•Smallmemoryfootprint
–non-preemptableFIFOtaskscheduling
•PowerEfficient
–Putsmicrocontrollertosleep
–Putsradiotosleep
•Concurrency-IntensiveOperations
–Event-drivenarchitecture
–EfficientInterruptsandeventhandling
•NoReal-timeguarantees
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24. MICASensorMote
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25. MICAMoteSpecifications
•4MHzATMEGA103LMicroprocessor
•128KBofFlashProgramMemory
•4KBRAM
•10bitAnalogtoDigitalConverter(ADC)
•3HardwareTimers
•SerialPeripheralInterface(SPI)bus
•ExternalUART
•AcoprocessorAT90LS2343(tohandlewirelessreprogramming)
•DS2401siliconserialnumber(providesuniqueIDtonodes)
•RFMonolithicsTR1000transceiver
•External4MbitAtmelAT45DB041BSerialFlashChip(forpersistent
data
storage)
•Maxim1678DC-DCConverter(providesaconstant3.0Vsupply)
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26. SmartDustMoteSpecifications
•4MHzAtmelAVR8535Microprocessor
•8KBInstructionFlashMemory
•512BytesRAM
•512BytesEEPROM
•TotalStoredEnergyapprox.1Joule
•TinyOSOperatingSystem(OS)with3500
bytesOScodespaceand4500bytes
availablecodespace
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27. WSNDevelopmentPlatforms
•Crossbow
•DustNetworks
•SensoriaCorporation
•EmberCorporation
•Worldsens
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28. •NS-2
WSNSimulators
•GloMoSim
•OPNET
•SensorSim
•J-Sim
•OMNeT++
•Sidh
•SENS
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29. WSNEmulators
•TOSSIM
•ATEMU
•Avrora
•EmStar
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30. Conclusion
•WSNspossibletodaydueto
technologicaladvancementinvarious
domains
•Envisionedtobecomeanessentialpartofour
lives
•DesignConstraintsneedtobe
satisfiedforrealizationofsensor
networks
•Tremendousresearcheffortsbeing
madeindifferentlayersofWSNs
protocolstack
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31. References
•I.F.Akyildiz,W.Su,Y.Sankarasubramaniam,
andE.Cayirci,“WirelessSensorNetworks:A
Survey”,ElsevierComputerNetworks,volume38,
Issue4,pp.393-422,March2002.
•Dr.VictorLeung,LectureSlideson“Wireless
SensorNetworks”,UniversityofBritish
Columbia,Canada
•D.Curren,“ASurveyofSimulationinSensor
Networks”
•Wikipedia,[AvailableOnline]
http://en.wikipedia.org/wiki/Wireless_Sensor_Net
works

32. References
•Dr.ChenyangLuSlideson“BerkeleyMotesand
TinyOS”,WashingtonUniversityinSt.Louis,USA
•J.HillandD.Culler,“AWirelessEmbedded
SensorArchitectureforSystem-Level
Optimization”,TechnicalReport,U.C.
Berkeley,2001.
•X.Su,B.S.Prabhu,andR.Gadh,“RFIDbased
GeneralWirelessSensorInterface”,Technical
Report,UCLA,2003.
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33. Thankyou!
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