Zigbee無線傳感器網(wǎng)絡(luò)英文文獻(xiàn)與翻譯

1、ZigbeeWirelessSensorNetworkinEnvironmentalMonitoringApplicationsI.ZIGBEETECHNOLOGYZigbeeisawirelessstandardbasedonIEEE02.15.4thatwasdevelopedtoaddresstheuniqueneedsofmostwirelesssensingandcontrolapplications.Technologyislowcost,lowpower,alowdatarate,highlyreliable,highlysecurewirelessnetworkingproto

2、coltargetedtowardsautomationandremotecontrolapplications.It'sdepictstwokeyperformancecharacteristics-wirelessradiorangeanddatatransmissionrateofthewirelessspectrum.ComparingtootherwirelessnetworkingprotocolssuchasBluetooth,Wi-Fi,UWBandsoon,showsexcellenttransmissionabilityinlowertransmissionrate

3、andhighlycapacityofnetwork.A. ZigbeeFrameworkFrameworkismadeupofasetofblockscalledlayers.Eachlayerperformsaspecificsetofservicesforthelayerabove.AsshowninFig.1.TheIEEE802.15.4standarddefinesthetwolowerlayers:thephysical(PHY)layerandthemediumaccesscontrol(MAC)layer.TheAlliancebuildsonthisfoundationby

4、providingthenetworkandsecuritylayerandtheframeworkfortheapplicationlayer.Applicatton&profilesApphcatmnFramework&SecurityUayersMACLmyQrPHYLayerZlgHeespecificatIonIEEE802.15.4ApplJcatlQrfStackFig.1FrameworkTheIEEE802.15.4hastwoPHYlayersthatoperateintwoseparatefrequencyranges:868/915MHzand2.4GH

5、z.Moreover,MACsub-layercontrolsaccesstotheradiochannelusingaCSMA-CAmechanism.Itsresponsibilitiesmayalsoincludetransmittingbeaconframes,synchronization,andprovidingareliabletransmissionmechanism.B. Zigbee'sTopologyThenetworklayersupportsstar,tree,andmeshtopologies,asshowninFig2.Inastartopology,th

6、enetworkiscontrolledbyonesingledevicecalledcoordinator.Thecoordinatorisresponsibleforinitiatingandmaintainingthedevicesonthenetwork.Allotherdevices,knownasenddevices,directlycommunicatewiththecoordinator.Inmeshandtreetopologies,thecoordinatorisresponsibleforstartingthenetworkandforchoosingcertainkey

7、networkparameters,butthenetworkmaybeextendedthroughtheuseofrouters.Intreenetworks,routersmovedataandcontrolmessagesthroughthenetworkusingahierarchicalroutingstrategy.Meshnetworksallowfullpeer-to-peercommunication.StarNfttwarkNetworkNatworkRvli4bility|(UattRAMCoordinatorRgtiJFF。)EndDevicsFig.2Meshtop

8、ologiesFig.3isanetworkmodel,itshowsthatsupportsbothsingle-hopstartopologyconstructedwithonecoordinatorinthecenterandtheenddevices,andmeshtopology.Inthenetwork,theintelligentnodesarecomposedbyFullFunctionDevice(FFD)andReducedFunctionDevice(RFD).OnlytheFFNdefinesthefullfunctionalityandcanbecomeanetwor

9、kcoordinator.Coordinatormanagesthenetwork,itistosaythatcoordinatorcanstartanetworkandallowotherdevicestojoinorleaveit.Moreover,itcanprovidebindingandaddress-tableservices,andsavemessagesuntiltheycanbedelivered.Fig.3ZigbeenetworkmodelII.THEGREENHOUSEENVIRONMENTALMONITORINGSYSTEMDESIGNTraditionalagric

10、ultureonlyusemachineryandequipmentwhichisolatingandnocommunicatingability.Andfarmershavetomonitorcropsgrowthbythemselves.Evenifsomepeopleuseelectricaldevices,butmostofthemwererestrictedtosimplecommunicationbetweencontrolcomputerandenddeviceslikesensorsinsteadofwireconnection,whichcouldn'btestric

11、tlydefinedaswirelesssensornetwork.Therefore,bythroughusingsensornetworksand,agriculturecouldbecomemoreautomation,morenetworkingandsmarter.Inthisproject,weshoulddeployfivekindsofsensorsinthegreenhousebasement.Bythroughthesedeployedsensors,theparameterssuchastemperatureinthegreenhouse,soiltemperature,

12、dewpoint,humidityandlightintensitycanbedetectedrealtime.Itiskeytocollectdifferentparametersfromallkindsofsensors.Andinthegreenhouse,monitoringthevegetablesgrowingconditionsisthetopissue.Therefore,longerbatterylifeandlowerdatarateandlesscomplexityareveryimportant.Fromtheintroductionaboutabove,weknowt

13、hatmeettherequirementsforreliability,security,lowcostsandlowpower.A. SystemOverviewTheoverviewofGreenhouseenvironmentalmonitoringsystem,whichismadeupbyonesinknode(coordinator),manysensornodes,workstationanddatabase.Motenodeandsensornodetogethercomposedofeachcollectingnode.Whensensorscollectparameter

14、srealtime,suchastemperatureinthegreenhouse,soiltemperature,dewpoint,humidityandlightintensity,thesedatawillbeofferedtoA/Dconverter,thenbythroughquantizingandencodingbecomethedigitalsignalthatisabletotransmitbywirelesssensorcommunicatingnode.Eachwirelesssensorcommunicatingnodehasabilityoftransmitting

15、,receivingfunction.InthisWSN,sensornodesdeployedinthegreenhouse,whichcancollectrealtimedataandtransmitdatatosinknode(Coordinator)bythewayofmulti-hop.Sinknodecompletethetaskofdataanalysisanddatastorage.Meanwhile,sinknodeisconnectedwithGPRS/CDMAcanprovideremotecontrolanddatadownloadservice.Inthemonito

16、ringandcontrollingroom,byrunninggreenhousemanagementsoftware,thesinknodecanperiodicallyreceivesthedatafromthewirelesssensornodesanddisplaysthemonmonitors.B. NodeHardwareDesignSensornodesarethebasicunitsofWSN.Thehardwareplatformismadeupsensornodescloselyrelatedtothespecificapplicationrequirements.The

17、refore,themostimportantworkisthenodesdesignwhichcanperfectimplementthefunctionofdetectingandtransmissionasaWSNnode,andperformitstechnologycharacteristics.Fig.4showstheuniversalstructureoftheWSNnodes.Powermoduleprovidesthenecessaryenergyforthesensornodes.Datacollectionmoduleisusedtoreceiveandconverts

18、ignalsofsensors.Dataprocessingandcontrolmodule'functionsarenodedevicecontrol,taskscheduling,andenergycomputingandsoon.Communicationmoduleisusedtosenddatabetweennodesandfrequencychosenandsoon.Fig.4UniversalstructureofthewsnnodesInthedatatransferunit,themoduleisembeddedtomatchtheMAClayerandtheNETl

19、ayeroftheprotocol.WechooseCC2430astheprotocolchips,whichintegratedtheCPU,RFtransceiver,netprotocolandtheRAMtogether.CC2430usesan8bitMCU(8051),andhas128KBprogrammableflashmemoryand8KBRAM.ItalsoincludesA/Dconverter,someTimers,AES128Coprocessor,WatchdogTimer,32KcrystalSleepmodeTimer,PoweronReset,Browno

20、utDetectionand21I/Os.Basedonthechips,manymodulesfortheprotocolareprovided.Andthetransferunitcouldbeeasilydesignedbasedonthemodules.Asanexampleofasensorenddeviceintegratedtemperature,humidityandlight,thedesignisshowninFig.5.Fig.5ThehardwaredesignofasensornodeTheSHT11isasinglechiprelativehumidityandte

21、mperaturemultisensormodulecomprisingacalibrateddigitaloutput.Itcantestthesoiltemperatureandhumidity.TheDS18B20isadigitaltemperaturesensor,whichhas3pinsanddatapincanlinkMSP430directly.Itcandetecttemperatureingreenhouse.TheTCS320isadigitallightsensor.SHT11,DS18B20andTCS320arebothdigitalsensorswithsmal

22、lsizeandlowpowerconsumption.Othersensornodescanbeobtainedbychangingthesensors.Thesensornodesarepoweredfromonboardbatteriesandthecoordinatoralsoallowstobepoweredfromanexternalpowersupplydeterminedbyajumper.C. NodeSoftwareDesignTheapplicationsystemconsistsofacoordinatorandseveralenddevices.Thegenerals

23、tructureofthecodeineachisthesame,withaninitializationfollowedbyamainloop.Thesoftwareflowofcoordinator,uponthecoordinatorbeingstarted,thefirstactionoftheapplicationistheinitializationofthehardware,liquidcrystal,stackandapplicationvariablesandopeningtheinterrupt.Thenanetworkwillbeformatted.Ifthisnetha

24、sbeenformattedsuccessfully,somenetworkinformation,suchasphysicaladdress,netID,channelnumberwillbeshownontheLCD.Thenprogramwillstepintoapplicationlayerandmonitorsignal.Ifthereisenddeviceorrouterwanttojoininthisnet,LCDwillshownthisinformation,andshowthephysicaladdressofapplyingnode,andthecoordinatorwi

25、llallocateanetaddresstothisnode.Ifthenodehasbeenjoinedinthisnetwork,thedatatransmittedbythisnodewillbereceivedbycoordinatorandshownintheLCD.Thesoftwareflowofasensornode,aseachsensornodeisswitchedon,itscansallchannelsand,afterseeinganybeacons,checksthatthecoordinatoristheonethatitislookingfor.Itthenp

26、erformsasynchronizationandassociation.Onceassociationiscomplete,thesensornodeentersaregularloopofreadingitssensorsandputtingoutaframecontainingthesensordata.Ifsendingsuccessfully,enddevicewillstepintoidlestate;bycontrast,itwillcollectdataonceagainandsendtocoordinatoruntilsendingsuccessfully.D. Green

27、houseMonitoringSoftwareDesignWeuseVBlanguagetobuildaninterfaceforthetestandthisgreenhousesensornetworksoftwarecanbeinstalledandlaunchedonanyWindows-basedoperatingsystem.Ithas4dialogboxselections:settingcontrollingconditions,settingTimer,settingrelevantparametersandshowingcurrentstatus.Bysettingsomep

28、arameters,itcanperformthefunctionsofcommunicatingwithport,datacollectionanddataviewingZigbee無線傳感器網(wǎng)絡(luò)在環(huán)境檢測(cè)中的應(yīng)用1.Zigbee技術(shù)Zigbee是一種基于IEEEE802.15.4的無線標(biāo)準(zhǔn)上被開發(fā)用來滿足大多數(shù)無線傳感器和控制應(yīng)用的獨(dú)特需求。Zigbee技術(shù)是低成本，低功耗，低數(shù)據(jù)速率，高可靠性，高度安全的無線網(wǎng)絡(luò)協(xié)議實(shí)現(xiàn)自動(dòng)化和遠(yuǎn)程控制應(yīng)用的目標(biāo)。它描述了兩個(gè)關(guān)鍵的性能特點(diǎn)一無線射頻范圍和無線頻譜的數(shù)據(jù)傳輸速率。相較于其他如藍(lán)牙，Wi-Fi技術(shù)，超寬帶等無線網(wǎng)絡(luò)協(xié)議，Zigbee雖然傳輸

29、速率慢但傳輸容量大的特點(diǎn)向我們展示了他出色的傳輸能力。A. 技術(shù)框架Zigbee的框架是有一組層組成的。上訴層中每一層都要執(zhí)行一組特定的服務(wù)任務(wù)。如圖所示。在IEEE802.15.4標(biāo)準(zhǔn)定義了兩個(gè)較低層：物理層(PHY)和媒體接入控制(MAC)層。Zigbee聯(lián)盟建立在網(wǎng)絡(luò)層和安全層及應(yīng)用層框架提供的基礎(chǔ)上。圖1技術(shù)框架在IEEE802.15.4有兩個(gè)phy層，它們?cè)趦蓚€(gè)不同的頻率范圍操作：868/915兆赫和2.4GHz。此外,MAC子層控制訪問無線電頻道使用的CSMA-CA的機(jī)制。它的功能還可以包括信標(biāo)幀傳輸，同步，并開發(fā)一個(gè)可靠的傳輸機(jī)制。B. Zigbee技術(shù)的拓?fù)鋃igbee網(wǎng)絡(luò)層支

30、持星形，樹形和網(wǎng)狀拓?fù)浣Y(jié)構(gòu)，如圖2所示。在星型拓?fù)浣Y(jié)構(gòu)中，網(wǎng)絡(luò)是由一個(gè)叫做Zigbee協(xié)議器的單一設(shè)備控制的。Zigbee協(xié)議器負(fù)責(zé)發(fā)起和維護(hù)網(wǎng)絡(luò)上面的設(shè)備。所有其他設(shè)備，稱為終端設(shè)備，直接與Zigbee協(xié)議器連接。在網(wǎng)狀和樹狀拓?fù)浣Y(jié)構(gòu)中,Zigbee協(xié)議器的作用是啟動(dòng)網(wǎng)絡(luò)，并選擇一些重要的網(wǎng)絡(luò)參數(shù)，但是網(wǎng)絡(luò)可以通過Zigbee路由器擴(kuò)展。在樹狀網(wǎng)絡(luò)中，路由器將通過使用分層路由策略移動(dòng)數(shù)據(jù)和控制消息。網(wǎng)狀網(wǎng)絡(luò)允許完全對(duì)等的對(duì)等通信。圖2技術(shù)的拓?fù)鋱D3是一個(gè)Zigbee網(wǎng)絡(luò)模型，它表明Zigbee支持協(xié)議器中心的單挑星型拓?fù)浣Y(jié)構(gòu)和終端設(shè)備，以及網(wǎng)狀拓?fù)錁?gòu)造。在Zigbee網(wǎng)絡(luò)中，智能節(jié)電有全功能

31、設(shè)備（FFD）和精簡(jiǎn)功能設(shè)備（RFD）組成。只有FFN定義了完整的Zigbee功能，并且可稱為網(wǎng)絡(luò)協(xié)議器。協(xié)議器管理網(wǎng)絡(luò)，也就是說，協(xié)議器可以啟動(dòng)網(wǎng)絡(luò)，并允許其他設(shè)備加入或離開它，此外，它還可以提供綁定和地址表服務(wù)，并保存，直到它們能傳遞信息。圖3Zigbee網(wǎng)絡(luò)模型2.溫室環(huán)境監(jiān)測(cè)的系統(tǒng)設(shè)計(jì)傳統(tǒng)農(nóng)業(yè)只使用孤立的和沒有溝通能力的機(jī)器和設(shè)備。農(nóng)民們必須自己親自監(jiān)控顧作物的生長(zhǎng)。及時(shí)有些人用電氣設(shè)備，但他們中的大多數(shù)只限于控制計(jì)算機(jī)和終端設(shè)備的簡(jiǎn)單通信，此終端設(shè)備像傳感器而不是像線相連接的傳感器，嚴(yán)格意義上來說，不能被定義為無線傳感器網(wǎng)絡(luò)，因此，通過使用傳感器網(wǎng)絡(luò)和Zigbee,農(nóng)業(yè)可能變得更加自

32、動(dòng)化，更加的網(wǎng)絡(luò)化和智能化。在這個(gè)項(xiàng)目中，我們要在溫室的地下室部署5種傳感器。通過這些部署的傳感器，如溫室的溫度，土壤溫度，露點(diǎn)，濕度和光照強(qiáng)度的參數(shù)可以實(shí)時(shí)監(jiān)測(cè)。他的關(guān)鍵是從各種不同的傳感器來收集不同的參數(shù)。而在溫室，檢測(cè)蔬菜的長(zhǎng)勢(shì)是首要問題。因此，延長(zhǎng)電池的壽命，減少數(shù)據(jù)數(shù)率和降低復(fù)雜度是非常重要的。從上述關(guān)于Zigbee的介紹，我們知道Zigbee滿足了可靠性，安全性，低成本，低功耗的要求。A、系統(tǒng)概述溫度環(huán)境監(jiān)測(cè)系統(tǒng)是由一個(gè)接收器節(jié)點(diǎn)（協(xié)議器）。許多傳感器節(jié)點(diǎn)，工作點(diǎn)和數(shù)據(jù)庫(kù)采集組成的。模特節(jié)點(diǎn)和傳感器節(jié)點(diǎn)共同組成了每個(gè)收集節(jié)點(diǎn)。當(dāng)傳感器參數(shù)進(jìn)行實(shí)時(shí)采集，如溫室溫度，土壤溫度，露點(diǎn)，濕

33、度，光照強(qiáng)度，這些數(shù)據(jù)將提供給A/D轉(zhuǎn)換器，然后透過量化和編碼稱為數(shù)字信號(hào)，它能通過無線傳感器通信節(jié)點(diǎn)傳送。每一個(gè)無線傳感器通信節(jié)點(diǎn)有傳輸和接收的能力。在這種傳感器網(wǎng)絡(luò)中，傳感器節(jié)點(diǎn)部署在溫室，它可以采集實(shí)時(shí)數(shù)據(jù)和通過多條方式傳輸數(shù)據(jù)到接收器節(jié)點(diǎn)（協(xié)議器）。接收器節(jié)點(diǎn)完成另外數(shù)據(jù)分析和存儲(chǔ)的任務(wù)。同時(shí)，接收器節(jié)點(diǎn)與GPRS/CDMA連接可以提供遠(yuǎn)程控制和數(shù)據(jù)下載服務(wù)。在監(jiān)控室通過運(yùn)行溫室管理軟件，接收器節(jié)點(diǎn)可以定期收到來自無線傳感器節(jié)點(diǎn)和在監(jiān)視器上顯示這些數(shù)據(jù)。B、節(jié)點(diǎn)的硬件設(shè)計(jì)在傳感器節(jié)點(diǎn)是無線傳感器網(wǎng)絡(luò)的基本單元。硬件平臺(tái)是由密切相關(guān)的具體應(yīng)用要求的傳感區(qū)節(jié)點(diǎn)組成的。因此，最重要的工作是節(jié)點(diǎn)設(shè)計(jì)，可以完美執(zhí)行無線傳感器網(wǎng)絡(luò)的傳送和檢測(cè)功能，并體現(xiàn)Zigbee的技術(shù)特點(diǎn)，圖4顯示了無線傳感器網(wǎng)絡(luò)節(jié)點(diǎn)的普遍結(jié)構(gòu)。電源模塊為傳感器節(jié)點(diǎn)提供了必要的能量。數(shù)據(jù)采集模塊被用來接收和轉(zhuǎn)換傳感器的信號(hào)。數(shù)據(jù)處理和控制模塊的功能是節(jié)電設(shè)備控制，任務(wù)調(diào)度，能量計(jì)算等。通訊模塊被用來在節(jié)點(diǎn)和頻率選擇之間傳遞數(shù)據(jù)等。圖4無線