无线局域网-计算机毕业论文外文翻译

毕业设计(论文)外文资料翻译系：信息工程学院专业：计算机科学与技术姓名：学号：(用外文写)(用外文写)s[M].London:Spring--Verlag,2008.8-13.附件：1.外文资料翻译译文；2.外文原文。指导教师评语：签名：年月日注：请将该封面与附件装订成册。

附件1：外文资料翻译译文无线局域网为何使用无线局域网络对于局域网络管理主要工作之一，对于铺设电缆或是检查电缆是否断线这种耗时的工作，很容易令人烦躁，也不容易在短时间内找出断线所在。再者，由于配合企业及应用环境不断的更新与发展，原有的企业网络必须配合重新布局，需要重新安装网络线路，虽然电缆本身并不贵，可是请技术人员来配线的成本很高，尤其是老旧的大楼，配线工程费用就更高了。因此，架设无线局域网络就成为最佳解决方案。什么情形需要无线局域网络无线局域网络绝不是用来替代有限局域网络，而是用来弥补有线局域网络之不足，以达到网络延伸之目的，下列情形可能须要无线局域网络。无固定工作场所的使用者有线局域网络架设受环境限制作为有线局域网络的备用系统无线局域网络存取技术目前厂商在设计无线局域网络产品时，有相当多种存取设计方式，大致可分为三大类：窄频微波技术、展频(SpreadSpectrum)技术、及红外线(Infrared)技术，每种技术皆有其优缺点、限制及比较，接下来是这些技术方法的详细探讨。技术要求由于无线局域网需要支持高速、突发的数据业务，在室内使用还需要解决多径衰落以及各子网间串扰等问题。具体来说，无线局域网必须实现以下技术要求：可靠性：无线局域网的系统分组丢失率应该低于10-5，误码率应该低于10-8。提供常用的导航回退功能。点餐系统点餐系统利用软件的全自动信息化手段，实现点菜、配菜、炒菜到传菜的全部管理过程；完成点菜单计算机管理、点菜单前端收银台与各厨房的同步打印；实现菜单无纸化操作；后台经理查询；仓库进销存管理等。除此之外，点餐系统还可以对客户资料进行有效的管理，存档和备查，杜绝酒楼“漏单”、“跑单”现象；帮助酒楼利用计算机强大的数据处理能力和流程优化能力，实现自动化管理，简化酒楼的工作流程，减少浪费及人为管理的疏漏现象，重新优化配置企业资源，把经营成本降低到最低。功能强大的点餐系统除支持一般的单机和局域网应用之外，还支持总店/分店多级架构的远程联网应用于分店使用POS系统实现前台销售收银、即时打印销售小票、销售日结、上报销售数据和接收新菜品信息等功能。目前点餐系统共有三种实现模式：触摸屏点菜模式：它利用了目前最为流行的触摸式电脑实现点菜过程，即点菜员可以根据软件的画面提示，只需用手指点击画面就可以完成整个点菜过程，方便快捷，这种模式适用于菜式和做法丰富大型的酒楼、酒家和菜馆等。无线PDA点菜模式：它利用了无线WiFi技术，通过PDA显示点菜界面，使用触摸笔完成点菜过程，真正实现随时随地点菜实时响应，这种模式适用于菜式和做法较为简单的西餐厅、特色菜馆和特具情调的中高级餐厅等。无线点菜宝模式：它使用了ISM频段，可以在有楼层或其它障碍物阻挡的情况下无缝覆盖达10米之远，而信号依然稳定，这是其比之无线PDA点菜模式最大的优势，这种模式适用于菜式和做法较为简单及其它要求较少的快餐店、火锅店等。

附件2：外文原文WLANWhyuseWLANForoneofthemainlocalareanetworkmanagement,forthelayingofcables,orcheckthecableisdisconnectedthistime-consumingwork,itiseasytoupset,noteasytobreakinashorttimetofindoutwhere.Furthermore,forthebusinessandapplicationenvironmentconstantlyupdatinganddevelopmentofenterprisenetworkmustbematchedwiththeoriginalre-layout,needtore-installthenetworklines,althoughthecableitselfisnotexpensive,butrequestedthetechnicalstafftothehighcostofwiring,especiallytheoldbuilding,wiringprojectcostsevenhigher.Therefore,theconstructionofwirelesslocalareanetworkhasbecomethebestsolution.WhatconditionsneedtouseWLANWLANisnotlimitedtoalternativelocalareanetwork,buttomakeupforlackofwiredlocalareanetworks,inordertoachievethepurposeofextendingthenetwork,thefollowingcircumstancesmayhavewirelesslocalareanetwork.nofixedworkplaceuserswiredlocalareanetworksetupbytheenvironmentalconstraintsAsawiredlocalareanetworkbackupsystemWLANaccesstechnologyCurrentlymanufacturersinthedesignofwirelesslocalareanetworkproducts,therearequiteavarietyofaccessdesignmethodscanbedividedintothreecategories:narrowbandmicrowave,spreadspectrum(SpreadSpectrum)technology,andinfraredhavetheiradvantagesanddisadvantages,limitations,andmore,followedbydetaileddiscussionofthesetechniques.(Infrared)technology,eachtechniquehastheiradvantagesanddisadvantages,limitations,andmore,followedbydetaileddiscussionofthesetechniques.TechnicalrequirementsAswirelesslocalareanetworkneedstosupporthigh-speed,burstdataservices,needtobeaddressedintheindooruseofmultipathfading,aswellasissuessuchascrosstalksubnets.Specifically,wirelesslocalareanetworkmustachievethefollowingtechnicalrequirements:Reliability:WirelessLANsystempacketlossrateshouldbelowerthan10-5,theerrorrateshouldbelowerthan10-8.Compatibility:Forindooruseofwirelesslocalareanetwork,soasfaraspossiblewiththeexistingwiredLANnetworkoperatingsystemandnetworksoftwarecompatible.Datarate:Inordertomeettheneedsoflocalareanetworktraffic,wirelessLANdatatransferrateshouldbemorethan1Mbps.Theconfidentialityofcommunications:Asthedatatransmittedintheairviawirelessmedia,wirelesslocalareanetworksatdifferentlevelsmusttakeeffectivemeasurestoimprovecommunicationsecurityanddatasecurity.Mobility:supportforallmobilenetworksorsemi-mobilenetwork.EnergyManagement:Whenreceivingorsendingdatatothesitewhenthemachineisinsleepmode,whenactivatedagainwhenthedatatransceivertoachievethesavingsinpowerconsumption.smallsizeandlowprice:Thisisthekeytothepopularityofwirelesslocalareanetworkcanbe.Electromagneticenvironment:wirelessLANshouldconsiderthehumanbodyandthesurroundingelectromagneticenvironmenteffects.AndroidGoogleAndroidisaLinux-basedplatformfordevelopingopen-sourcephoneoperatingsystem(registeredtrademarkinChinacalled"Achi;).Itincludesoperatingsystems,userinterfaceandapplications-mobilephoneworkrequiredbythesoftware,butthereisnopast,theexclusiverighttoimpedeinnovationandbarrierstomobileindustry,calledmobileterminalisthefirsttocreateatrulyopenandcompletemobilesoftware.GoogleandOpenHandsetAlliancetodeveloptheAndroid,thealliancebyincludingChinaMobile,Motorola,QualcommandT-Mobile,includingmorethan30technologyandthecompositionofaleaderinwirelessapplications.Googlewithoperators,equipmentmanufacturers,developersandotherinterestedpartiestoformdeep-levelpartnerships,hopingtoestablishastandardized,opensoftwareplatformformobilephonesinthemobileindustrytoformanopenecosystem.Itusessoftwarestacklayers(softwarestack,alsoknownasthesoftwarestack)architecture,isdividedintothreeparts:thecoreoftheunderlyingLinux-basedlanguagedevelopedbythec,onlybasicfunctions.Middlelayerconsistsoflibrary.LibraryandVirtualMachineVirtualMachine,developedbytheC+.Atthetopareavarietyofapplications,includingthecallprocedures,SMSprocedures,applicationsoftwareisdevelopedbythecompaniesthemselvestowritejava.Topromotethistechnology,Google,anddozensofotherphonecompanyhasestablishedtheOpenHandsetAlliance(OpenHandsetAlliance).CharacteristicapplicationframeworktosupportcomponentreuseandreplacementDalvikvirtualmachinespecificallyformobiledevicesisoptimizedInternalintegratedbrowser,thebrowser-basedopen-sourceWebKitengineoptimizationof2Dand3Dgraphicslibraryincludesgraphicslibrary,3DgraphicslibrarybasedonOpenGLES1.0(hardware-acceleratedoptional)#SQLiteforstructureddatastorageMultimediasupportincludesthecommonaudio,videoandstaticimagefileformats(suchasMPEG4,H.264,MP3,AAC,AMR,JPG,PNG,GIF)GSMphone(dependingonhardware)BluetoothBluetooth,EDGE,3G,andWiFi(hardwaredependent)Camera,GPS,compass,andaccelerometer(hardwaredependent)Richdevelopmentenvironmentincludingadeviceemulator,debugger,memoryandperformanceanalysischarts,andtheEclipseintegrateddevelopmentenvironmentplug-insApplicationsAcoreAndroidapplicationpackagetogetherwiththereleaseoftheapplicationpackage,includingemailclient,SMSshortmessagingprogram,calendar,maps,browser,contactmanagementprocedures.AllapplicationsarewrittenusingJAVA.AndroidApplicationFrameworkDevelopershavefullaccesstocoreapplicationsusedbytheAPIframework.Theapplicationframeworkdesignedtosimplifythereuseofsoftwarecomponents;anyapplicationcanpublishitsfunctionalblocksandanyotherapplicationscanusethefunctionblockitsrelease(butmustfollowtheframeworkofsecurityrestrictions).Reusemechanismallowstheapplicationformcanbeuserreplaced.Allofthefollowingapplicationsbythecompositionofarangeofservicesandsystems,including:anexpandedview(Views)canbeusedtobuildapplications,includingalistof(lists),grid(grids),textboxes(textboxes),buttons(buttons),andevenanembeddablewebbrowser.ContentManager(ContentProviders)allowsapplicationstoaccessdatafromanotherapplicationprogram(suchasthecontactdatabase),ortosharetheirowndata.Aresourcemanager(ResourceManager)toprovideaccesstonon-coderesources,suchaslocalstrings,graphics,andhierarchicalfile(layoutfiles).Anotificationmanager(NotificationManager)allowsapplicationstocustomersinthestatusbardisplaynotificationinformation.AnactivityclassManager(ActivityManager)tomanagetheapplicationlifecycleandprovidescommonnavigationrollbackfeature.OrderingthesystemOrderingthesysteminformationusingautomatedsoftwaretoolstoachievelacarte,sidedishes,stirfryvegetablestothetransferofallmanagementprocesses;completionpoint,thecomputermanagementmenu,pointthemenuandthekitchen,front-endcheckoutsynchronizationprint;achievedwithoutthemenupaper-basedoperation;backstagemanagerofinquiry;warehouseinventorymanagementandsoon.Inaddition,orderingthesystemcanalsoeffectivelymanagecustomerdata,archivingandfuturereference,putanendtotherestaurant"leakageList","runlist"phenomenon;helprestaurantsusingcomputerdataprocessingcapabilityandpowerfulabilitytoprocessoptimizationtoachieveautomatedmanagement,streamlineworkflowrestaurant,reducewasteandman-madephenomenonofmanagementoversight,re-optimalallocationofcorporateresources,theoperatingcoststoaminimum.Powerfuladditiontoorderingthesystemtosupportthegeneralapplicationofstand-aloneandLANinadditiontosupportheadoffice/branchofmulti-levelframeworkusedforremotenetworkusingthePOSsystemtoachievefrontstoresalescashier,salesofsmall-ticketinstantlyprintsalesday-end,reportingsalesdataandreceiveinformationofnewfeaturesdishes.Therearethreecurrentlyorderingthesystemtoachievemode:First,thetou