.轮机英语（轮机长大管轮）Lesson 45 An Introduction to Shipboard Networks.ppt

Lesson45AnIntroductiontoShipboardNetworksNewWordsandExpressionsethernet [iθ?n?t]n.以太网LANLocalAreaNetworks局域网cable[ke?b(?)l] n.电缆，缆绳alternative[??lt??n?t?v]n.二中择一，供替代的选择popularity[p?pj?l?r?t?]n.普及，流行wirelessnetwork无线网络WANWideAreaNetworks 广域网airlinesystem 航线系统NewWordsandExpressionsmatured [m?t???d]v.成熟，到期（mature的过去分词）Megabit[meɡ?b?t]n.兆位，兆比特（缩写MB）Gigabit [g?g?b?t]n.千兆位，千兆比特（缩写GB）EthernetTopologiesandProtocols 以太网的拓扑结构和协bustopology总线构造，总线拓扑footer[f?t?]n.页脚bytes[baits]n.字节，字节数（byte的复数）broadcast [br??dkɑ?st]vt.播送，播放NewWordsandExpressionsadapter[?d?pt?] n.适配器hardware [hɑ?dwe?]n.计算机硬件preliminary[pr?l?m?n(?)r?]adj.初步的，开始的，预备的simultaneously[,s?mlte?n??sl?]adv.同时trade-off [treid?f] n.权衡，平衡，交换，交易algorithm [?lg?r?e(?)m]n.算法，运算法则random [r?nd?m]adj.随机的，任意的hub [h?b]n.集线器NewWordsandExpressionsrouter[ru?t?(r)] n.路由器console[k?ns??l] n.控制台，操纵台sophisticatedkit先进的装备migrate[ma?gre?t]vt.使移居，使移植terminal[t??m?n(?)l]n.终端机，末端，终点IntroductiontoEthernetEthernetisacomputernetworkingtechnologythattypicallyconnectsLANnetworks.LANstandsforLocalAreaNetworks,andreferstoanycomputernetworkthatinvolvesmorethanonecomputer.LANnetworksareusuallyconnectedusingEthernetcables.Ethernetisasystemofcablesusedtoconnectnetworks.ItwasinvestedbyBobMetcalfeandhasbeenaroundsince1973inoneformoranother.ItisbyfarthemostwidelyusedstandardusedtoconnectLANnetworks.ThereareotheralternativesbutEthernetistheclearleaderintermsofpopularity.EthernetCardsWearenowinthetimesofthewirelessnetwork,meaningthatinmanycaseslargenumbersofcablesarenotnecessary.LANconnectionsandinternetconnectioncanoftenbeachievedusingwirelesssystemsnow.Thismeansitispossibletogainaccesstothenetworkanywherewithinacertainarea,dependingonthereachof