【英文标准名称】:Publictransport-Serviceinterfaceforreal-timeinformationrelatingtopublictransportoperations-Communicationsinfrastructure
【原文标准名称】:公共运输.与公共运输操作相关的实时信息服务接口.通信基础设施
【标准号】:BSDDCEN/TS15531-2-2007
【标准状态】:现行
【国别】:英国
【发布日期】:2007-07-31
【实施或试行日期】:2007-07-31
【发布单位】:英国标准学会(BSI)
【起草单位】:BSI
【标准类型】:()
【标准水平】:()
【中文主题词】:数据;数据通信;数据模型;数据处理;数据传送;信息交换;信息系统;基础设施;摩托车;客运;公共运输;公共事业;实时;实时系统;道路运输;道路车辆;远程信息管理;远程处理;交通业务;交通管制;交通量调查;交通流量;交通信息;传输协议
【英文主题词】:
【摘要】:SIRIusesaconsistentsetofgeneralcommunicationprotocolstoexchangeinformationbetweenclientandserver.Thesamepatternofmessageexchangemaybeusedtoimplementdifferentspecificfunctionalinterfacesassetsofconcretemessagecontenttypes.Twowell-knownspecificpatternsofclientserverinteractionareusedfordataexchangeinSIRI:Request/ResponseandPublish/Subscribe.?Request/Responseallowsfortheadhocexchangeofdataondemandfromtheclient.?Publish/SubscribeallowsfortherepeatedasynchronouspushofnotificationsanddatatodistributeeventsandSituationsdetectedbyaReal-timeService.TheuseofthePublish/SubscribepatternofinteractionfollowsthatdescribedinthePublish-SubscribeNotificationforWebServices(WS-PubSub)specification,andasfaraspossible,SIRIusesthesameseparationofconcernsandcommonterminologyforpublish/subscribeconceptsandinterfacesasusedinWS-PubSub.WS-PubSubbreaksdowntheserverpartofthePublish/Subscribepatternintoanumberofseparatenamedrolesandinterfaces(forexample,Subscriber,Publisher,NotificationProducer,andNotificationConsumer):inanactualSIRIimplementation,certainofthesedistinctinterfacesmaybecombinedandprovidedbyasingleentity.AlthoughSIRIisnotcurrentlyimplementedasafullWS-PubSubwebservice,theuseofaWS-PubSubarchitecturemakesthisstraightforwardtodoinfuture.Forthedeliveryofdatainresponses(tobothrequestsandsubscriptions),SIRIsupportstwocommonpatternsofmessageexchange,asrealisedinexistentnationalsystems:?Aonestep‘DirectDelivery’,aspertheclassicclient-serverparadigm,andnormalWS-PubSubpublishsubscribeusage;and;?Atwostep‘FetchedDelivery’whichelaboratesthedeliveryofmessagesintoasequenceofsuccessivemessagespairstofirstnotifytheclient,andthentosendthedatawhentheclientisready.FetchedDeliveryisastatefulpatterninitsownright.Eachdeliverypatternallowsdifferenttrade-offsforimplementationefficiencytobemadeasappropriatefordifferenttargetenvironments.ASIRIimplementationmaysupporteitherorbothdeliverymethods;inordertomakethemostefficientuseoftheavailablecomputationalandcommunicationresources.Thedeliverymethodmayeitherbepreconfiguredandstaticforagivenimplementation,oreachrequestorsubscriptionmayindicatethedeliverymethodrequiredbytheclientdynamicallyaspartoftherequestpolicy,andtheservermayrefusearequestifitdoesnotsupportthatmethod,givinganappropriateerrorcode.TheInteractionpatternsandtheDeliverypatternsareindependentaspectsoftheSIRIprotocolandmaybeusedinanycombinationindifferentimplementations.ForagivenSIRIFunctionalServicetype(ConnectionMonitoring,StopMonitoringetc),themessagepayloadcontentisthesameregardlessofwhetherinformationisexchangedwithaRequest/ResponseorPublish/Subscribepattern,orwhetheritisreturnedbyDirectorFetchedDelivery.TheSIRIPublish/SubscribeProtocolprescribesparticularmediationbehaviourforreducingthenumberofnotificationsandtheamountofnetworktrafficarisingfromsubscriptions.ThemediationgroupsthevarioussubscriptionsfromasubscriberintooneormoreSubscriberChannels,andisabletomanagenotificationsandupdatesfortheaggregate.Onlypartialupdatestothedatasetsincethelastdeliveryforthesubscriptionneedbesent.TheSIRICommunicationprotocolsaredesignedtofailgracefully.Considerationsforresilienceandrecoveryarecoveredbelow.
【中国标准分类号】:R07
【国际标准分类号】:35_240_60
【页数】:88P;A4
【正文语种】:英语