III.LOCATORFUNCTIONALREQUIREMENT Locatorfunctionalrequirementsshouldhavethefollowingbasicfeatures:3.1self-checkingfunction Locatorwilltestitselfwhenthedeviceworkinthepower,andself-testresultsreportedtothebackstagemanagementsystem. 3.2Real-timemonitoringfunctionLocatorcansendreal-timelocationinformationaccordingtopre-establishedtimeintervaltothebackofficesystems;thecontentincludingtime,longitude,latitude,direction,status.Theminimumtimeintervalcanbesetas:30seconds,maximumintervaltime:30minutes。 3.3E-fencemanagementBackgroundmanagementsystemcanbepre-positioning4electronicfences(rectangulararea)intheinternalstorage,whenthemovingtargetleavetheelectronicfence,thepositioningsystemwillalarmtomanagementback-systeminitiatively. 3.4EmergencyfeaturesIfthemovingtargetisinanemergencysituation,pressthelocatorbuttonontheemergency,thepositioningsystemwillautomaticallydialoneoffourpre-storedrelatives contacttelephonenumbers,andemergencyinformationwillbesenttothebackgroundmanagementsystem. 3.5VoiceMonitorFunctionIfthemovingtargetisinanemergencysituation,pressthelocatorbuttonontheemergency,thepositioningsystemwillopenon-sitevoicemonitoringfunctionautomatically,whichcanclearlyhearamovingtargeton-sitevoiceinthebackgroundmanagementsystem. 3.6DeadzonecompensationwhenthelocaterisinnoGPRSsignalareaandlocationinformationcannotbeuploaded,locatorwilluploadandsavetheinformationinaccordancewithapre-minedintervaloftime.Whenthelocatorleavestheblind,itwilluploadtheinformationaccordancewithxsecondsinfirsttime. 3.7Low-voltagewarningfunctionLocators voltagedropsbelowthreshold,thepositioningsystemwilltaketheinitiativetoreportthelow-voltagewarningmessagetothebackstagemanagementsystem,whilepositioningsystemvoiceprompts,suchas:powerisnotenough,pleasecharge! 3.8Openandclosethee-fencefunctionBackgroundmanagementsystemcanbeconfiguredtoopenandcloselocator selectronicfencefunction. 3.9ModifytheCenterAddressOnlineFunctionAdminmodifythesystemthroughthewirelesscenterlocatoraddress(IPandport),theparameterissettorestartafterthepositioningdevice,totakeeffect. 3.10Emergencycallset-upfunctionItcansetupemergencycallinsidethelocatorbywirelessmode;thenumberofcallsistofour.Whenamovingtargetisinanemergencysituation,thesetelephonenumbersareusedforcontacting. 3.11Centernumberset-upfunctionItcansetupacenternumberforlocatorbywirelessmode,(i.e.,SIMcardnumber),afterthesuccess,thelocatorcanonlyacceptandresponsethecontrolinstructionsfromthisnumber. 3.12PointqueryfunctionLocatorcanacceptthelocationrequestfromemergencycalls(4),receivedlocationqueryrequest,thepositioningsystemwillsetitsowncurrent(orlasttimevalidlocation)messagestotheotherphone. 3.13CommunicationsDataEncryptionThecommunicationoflocatorandsystemdatatransmitinaccordanceoftheprovisionsencryption. 3.14Two-centermodelLocatorsupporttwo-centerconnectionmode,whichispre-storingthetwocentersaddressinonelocator. 3.15Dual-channeltransmissionLocatorsupportsdual-channeltransmission,inthedefaultstate,theupstreaminformationdual-channeluploadtocentralseversinGPSmeans.Downlinkinformation(allkindsofset-instructions)canbesentthroughGPRSmode,andcanalsobesenttolocatorviaSMSmode. IV.TELECOMMUNICATIONTRANSMISSIONAGREEMENTCommunicationagreementincludingtwotypesworkingways,ittransmitsinTCPmode; 1.Locatorsendsdatapacketstothebackstagemanagementsystem,referredasupstream. 2.Backmanagementsystemsendcontrolinstructionstolocator,referredasdownlink. V.AGREEMENTFORMATOFUPSTREAMANDDOWNLINK