通信专业英语电子备课包.doc

1 CONTENTS PART A DATA COMMUNICATION 数据通信数据通信 INTRODUCTION TO DATA COMMUNICATION 数据通信介绍 3 SWITCHING TECHNOLOGIES 交换技术 4 CARRIER FREQUENCIES AND MULTIPLEXING 载波和多路复用 6 DATA TRANSMISSION MEDIA 数据传输媒介 7 ATM 异步传输模式 9 DATA COMMUNICATIONS PROTOCOL 数据通信协议 13 LOCAL AREA NETWORKS PROTOCOL 局域网协议 14 INTERNET PROTOCOL TCP IP 因特网协议 TCP IP 15 WAP THE WIRELESS APPLICATION PROTOCOL WAP 无线应用协议 17 IPV6 PROTOCOL IPV6 协议 18 SDH Synchronous Digital Hierarchy 数字同步系列 22 FIBER OPTICS 光纤 23 Fiber to the Home 光纤到家 25 Wavelength Division Multiplexing 26 Ultra High Speed Fiber Optics 超高速光纤 26 Cellular Mobile Telephone System 蜂窝移动电话系统 30 GSM 移动通信 31 Code Division Multiple Access CDMA 码分多址 34 Introduction to 3G 3G 介绍 35 Satellite Communication 卫星通信 37 Bluetooth Technology 蓝牙技术 39 PSTN 公共交换电话网 42 Typical WAN Technology 典型的广域网技术 44 Access Network 接入网络 45 FAST ETHERNET 快速以太网 46 INTERNET 互联网 47 INTRODUCTION NGN 下一代网络介绍 49 2 Part A Data Communication 数据通信数据通信 3 Introduction to Data Communication 数据通信介绍 数据通信介绍 New Words Phrases and Abbreviations technique n 方法 技术 electromagnetic adj 电磁的 analog n 类似物 continuous adj 继续的 连续的 持续的 延伸的 discrete adj 离散的 分立的 不连续的 characteristic adj 表示特性的 典型的 特有的 frequency n 屡次 频繁 baud波特 发报速度单位 duplex adj 电信 计 双工的 双向的 simplex单工 interphone对讲机 asynchronous不同时的 电 异步的 synchronous adj 同时发生的 同步的 parity n 同等 平等 计 奇偶校验 serial adj 连续的 parallel adj 平行的 并行的 resemble vt 相似 simultaneously adv 同时地 Notes to the Text 1 Since transmitted data can be assigned to different frequencies the wider the bandwidth the more frequencies and the more data can be transmitted at the same time 句中 Since transmitted data can be assigned to different frequencies 是原因状语从句 the more the more 是一个双重比较级的句子 相当于汉语的 越 越 译文 因为传输的数据能被分配到不同频率 所以带宽越宽频率越多 同一时间能被传输 的数据就越多 2 To distinguish where one character stops and another starts the asynchronous communication mode used a start and a stop bit 句中 To distinguish where one character stops and another start 是不定式短语 在句中做状语 where one character stops and another starts 是宾语从句 做 to distinguish 的宾语 译文 为了辨别一个字符在什么地方停止而另一个字符在什么地方开始 异步通信模式使 用一个起始位和一个停止位 3 More technical names for the serial port are RS 232C connector and asynchronous communications port 句中RS 232C 的机械指标规定 RS 232C 接口通向外部的连接器 插针和插座 是一种标准的 D 型保护壳的 25 针连接器 目前微机的 RS 32C 接口多采用 D 型保护壳的 9 针连接器 译文 串行端口著名的技术是 RS 232C 连接器与异步通信接口 Exercises to the Text Translate the following words and phrases into English 1 信号 2 波特率 3 单工 4 同步 5 信道 6 模拟 7 数字 Text1 4 8 电磁的 9 串行口 10 带宽 Answer the following questions according to the text 1 Please give out some characteristics of communication channels 2 Please write out the difference between Bits per second bps and the baud rate 3 Please write out the difference between simplex and half duplex 4 How many types can the transmission mode be divided into 5 Please write out the difference between serial transmission and parallel transmission and give out one or more examples Translate the following words and phrases into Chinese 1 baud 2 asynchronous 3 full duplex 4 parallel 5 electromagnetic 6 discrete 7 simultaneously 8 parity Translate the following paragraph into Chinese Third is transmission mode The transmission mode includes Asynchronous and Synchronous In asynchronous transmission mode individual characters made up of bits are transmitted at irregular intervals for example when a user enters data To distinguish where one character stops and another starts the asynchronous communication mode used a start and a stop bit An additional bit called a parity bit is sometimes included at the end of each character Parity bits are used for error checking asynchronous transmission mode is used for lower speed data transmission and is used with most communications equipment designed for personal computers Switching Technologies 交换技术 交换技术 New Words Phrases and Abbreviations dedicated adj 计 专用的 destination n 目的地 终点 microphone n 麦克风 话筒 扩音器 亦作 mike guaranteed n 有保证的 被担保的 decrease vi vt 减少 变少 降低 comprise vt 包括 包含 构成 checksum检验 校验 和 核对和 outgoing adj 往外去的 即将离任的 好交往的 maximum n adj 最大量 的 最大值 的 multiplex adj 复合的 多重的 identification n 认明 识别 鉴定 concurrent adj 同时发生的 同时存在的 incurred招致 遭受 amortize vt 摊销 摊还 分期偿付 burst vt vi 爆炸 胀裂 constraint n 约束 限制 randomness随意 无安排 relatively adv 相对地 比较地 utilization n 利用 intermediate adj 中间的 居中的 whenever adv 随便什么时候 motivation动机 Text2 5 remainder n 剩余物 其余 的人 Notes to the Text 1 Circuit switched networks operate by forming a dedicated connection circuit between two points 本句后面括号内的 circuit 译为 线路 译文 电路交换网络运行时在两点之间形成一条专用连线 线路 2 a telephone call establishes a circuit from the originating phone through the local switching office across trunk lines to a remote switching office and finally to the destination telephone 句中 a telephone call 可译为 一个电话呼叫 译文 一个电话呼叫建立一条线路 从发起呼叫的电话机通过本地交换局 穿过中继线到 一个远程交换局 最后到达目的电话机 3 The sender is guaranteed that the samples can be delivered and reproduced because the circuit provides a guaranteed data path of 64 Kbps thousand bits per second the rate needed to send digitized voice 句中 guaranteed data path 译为 被保证的数据通路 路径 the rate needed 是 64Kbps 的同位语 digitized voice 译为 数字化语音 译文 发话方确信采样一定会被传输和重新生成 因为线路提供了一条被保证的 64KbPs 千比特每秒 数据路径 这个速率是发送数字化的语音所必需的 4 circuit costs are fixed independent of traffic 句中 independent of traffic 译为 与通信 话 量无关 译文 线路的费用是固定的 与通信量无关 5 The disadvantage of course is that as activity increases a given pair of communicating computers receives less of the network capacity 句中 as activity increases 译为 随着网络活动的增加 译文 它的缺点是 随着网络活动的增加 一对通信的计算机所获得的网络容量就会减少 6 That is whenever a packet switched network becomes overloaded computers using the network must wait before they can send additional packets 句中 before they can send additional packets 译为 在它们能够继续发送分组之前 译文 也就是说 每当一个分组交换网络超载 那么 使用这个网络的计算机在可以继续 发送分组之前 必须等待 Exercises to the Text Translate the following words and phrases into English 1 交换技术 2 存储转发技术 3 数据块 4 分组交换 5 电路交换 6 带宽 7 多路通信 8 面向连接 Answer the following questions according to the text 1 In general How many types can the communication networks be divided into 2 Please give out a brief description of packet switched 3 Please write out a brief description of circuit switched 4 Please write out the disadvantage of circuit switched 5 Nowadays packet switched have become extremely popular why give out your reason Translate the following paragraph into Chinese Packet switched networks the type usually used to connect computers take an entirely different approach In a packet switched network data to be transferred across a network is divided into small pieces called packets that are multiplexed onto high capacity intermachine connections A packet which usually contains only a few hundred bytes of data carries identification that enables the network hardware to know how to send it to the specified destination For example a large file 6 to be transmitted between two machines must be broken into many packets that are sent across the network one at a time The network hardware delivers the packets to the specified destination where software reassembles them into a single file again The chief advantage of packet switching is that multiple communications among computers can proceed concurrently with intermachine connections shared by all pairs of machines that are communicating Carrier Frequencies and Multiplexing 载波和多路复用载波和多路复用 New Words Phrases and Abbreviations multiplexing n 多路技术 modulated 已调整 制 的 被调的 video n 电视 录象 视频 intuition n 直觉 直觉的知识 fundamental adj 基础的 基本的 simultaneously adv 同时地 interference n 冲突 干涉 merely adv 仅仅 只不过 shorthand n 速记 oscillate v 振荡 subscriber n 订户 签署者 捐献者 principle n 法则 原则 原理 multiple vt vi 成为多重 倍 optical adj 光的 光学的 fiber n 纤维 纤维质 concept n 观念 概念 minimum adj 最小的 最低的 division n 分开 分割 区分 除法 公司 军事 师 分配 分界线 prompt adj 刺激 鼓动 怂恿 敦促 prohibit vt 禁止 阻止 exclusive adj 排外的 孤高的 唯我独尊的 独占的 唯一的 高级的 guarantee n 保证书 arbitrarily adv 武断地 任意地 专横地 Notes to the Text 1 In fact a channel number is merely shorthand for the frequency at which the station s carrier oscillates 译文 译文 实际上 频道号码就是电视台载波用的振荡频率的速记 2 A receiver configured to accept a carrier at a given frequency will not be affected by signal sent at other frequencies 句中 configured to 是过去分词短语 修饰前面的 receiver 译文 一个接收器被设置成接收给定频率的载波 它将不会受其他频率信号的影 响 或干扰 3 Frequency Division Multiplexing FDM is the technical term applied to a network system that uses multiple carrier frequencies to allow independent signals to travel through a mediun 句中 applied to 修饰前面的 term 译文 频分复用 FDM 是使用多个载波频率在一个介质中同时传输多个独立信 号的计算机网络系统术语 4 In practice however two carriers operating at almost the same frequency or at exact multiples of a frequency can interfere with one another 句中 at exact multiples of a frequency 译为 一频率的整数倍 译文 实际上 两个频率相近或频率成整数倍的载波会彼此干扰 5 The mandate for large gaps between the frequences assigned to carriers means that underlying hardware used with FDM can tolerate a wide range of frequencies Text3 7 句中 mandate for large gaps 译为 大间隔的要求 译文 在各载波的频率之间的大间隔意味着 FDM 所用的硬件能容纳很宽的频率范围 6 The general alternative to FDM is time division multiplexing TDM in which sources sharing a medium take turn 句中 general alternative to FDM 译为 与 FDM 不同的另一种服用形式 alternative 是 两 者挑一 可供选择的办法 方案 句中 sharing a medium t 修饰前面的 sources 发送源 译文 与 FDM 不同的另一种复用形式是时分多路复用 TDM 按这种方式各发 送源轮流使用共享的通信介质 Exercises to the Text Decide whether each of the following statements is true or false according to the text 1 Computer networks that use a modulated carrier wave to transmit data are similar to television stations that use a modulated carrier wave to broadcast video 2 Two or more signals that use different carrier frequencies can not be transmitted over a single media simultaneously without interference 3 Although a cable subscriber may have only one physical wire that connects to the cable company the subscriber receives many channels of information simultaneously The signal for one channel does not interfere with the signal for another 4 Computer networks use the principle of separate channels to permit multiple communications to share a single physical connection 5 Nowadays all computer networks use some form of time division multiplexing Translate the following words and phrases into English 1 载波 2 多路复用 3 载波震荡频率 4 频分复用 5 时间片轮转 6 时分复用 Translate the following paragraph into Chinese Dividing data into small packets ensures that all sources receive prompt service because it prohibits one source from gaining exclusive access for an arbitrarily long time In particular if one source has a few packets to send and another has many allowing both sources to take turns sending packets guarantees that the source with a small amount of data will finish promptly Data Transmission Media 数据传输媒介 数据传输媒介 New Words Phrases and Abbreviations electromagnetic adj 电磁的 pulse n 脉搏 coaxial adj 共轴的 同轴的 microwave n 微波 charge vt vi 常与 with 连用 责令 公开指责 控诉 常与 up 连用 使充电 unsheathed n 无覆盖的 insulator n 绝缘物 绝缘体 susceptible adj 与 to 连用 易受影响的 twisted弯的 diameter n 直径 interference n 物 干扰 garble vt vi 混淆 曲解 歪曲 intact adj 完整的 未动过的 nonconductive不传导的 绝缘的 bundle n 捆 束 包 Text4 8 extensively广阔地 curvature n 曲度 弯曲 弯曲部分 terrain n 地带 地域 地势 地形 vicinity n 周围地区 邻近地区 antenna n 天线 gigahertz千兆赫 geosynchronous与地球的相对位置不变的 transponder n 无线电发射机应答器 retransmit转播 转发 中继站发送 costly adj 价值高的 贵重的 owing adj 与 to 连用 由于 因为 compensating补偿 补助 修正 encrypted 修 加密 Notes to the Text 1The form or method of communications affects the maximum rate at which data can be moved through the channel and the level of noise that will exist 动词 affect 有两个并列的宾语 它们是 the maximum rate 和 the level of noise 各自后面都 有一个定语从句 译文 通信的形式或方法决定着数据可以通过信道传输的最大速度以及会出现的噪声等级 一 2 Obviously some situations require that data be moved as fast as possible others don t Require 后面跟的是 that 引导的宾语从句 其形式是 should 加动词原形 should 可以省去 译文 显然 有时要求数据传输得越快越好 有时则不然 3 Understanding how these media function will help you sort out the various rates and charges for them and determine which is the most appropriate in a given situation 本句主语部分是一个动词 ing 短语 Understanding how these media function 注意 understanding 后是一个 how 引出的从句 function 在这个从句中充当谓语动词 主句的基 本结构是 help sb do sth 有两个并列的不带 to 的动词不定式充当宾语的补足语 它们是 sort out 和 determine 译文 理解这些媒介的性能将帮助你区别不同的速率和费用并决定在一个特定的情况下哪 一种是最适合的 4 which limits the practical distance that data can be transmitted without being garbled Garble 这个动词的原义是 对 文章报告等 断章取义 篡改 歪曲 此处 be transmitted without being garbled 指的是 不失真传输 译文 这限制了数据不失真传输的实际距离 5 To be received intact digital signals must be refreshed every one to two miles through the use of an amplifier and related circuits which together are called repeaters To be received intact 指的是 digital signals 我们可以说 receive digital signals intact 即 receive digital signals which are intact intact 这个形容词后置 相当于定语从句 在被动语态中变成 了 Digital signals are received intact 就相当于 Digital signals intact are received 意思说的是 接受完整信号 译文 数字信号想要完整的接收 必须每 1 2 英里用放大器及相关电路重新放大 这种放 大装置称为增音器 6 The distance between the towers depends on the curvature of the surface terrain in the vicinity Surface terrain 指的是 地形 in the vicinity 是 附近地区 the curvature 是 弯曲程度 译文 两座塔之间的距离取决于附近地表的弯曲程度 7 Each tower facility receives incoming traffic boots the signal strength and sends the signal to the next station Traffic 在这儿的意思是 电信 跟后面的 signal 的意思相同 译文 每个塔上的设备接收过来的信号 加以放大 并把信号发送到下一个基站 8 However the saturation of the airwaves with microwave transmissions has reached the point where future needs will have to be satisfied by other communications methods such as fiber optic 9 cables or satellite systems 本句的主语是一个长长的名词短语 传输微波的空气波达到饱和状态 其核心词是 saturation has reached the point 即 已经达到这一点 接着是一个由 where 引出的一个定 语从句表示结果 译文 但是 当传输微波的空气波达到饱和状态时 将由其他的方式来满足将来的需要 例如光纤和卫星系统 Exercises to the Text Translate the following words and phrases into English 1 电磁波 2 同轴电缆 3 双绞线 4 微波系统 5 卫星系统 6 空气饱和度 Answer the following questions according to the text 1 Please write out the virtue of coaxial cable 2 Please give out a brief description of twisted pair wire 3 Please write out the difference between microwave system and satellite system 4 Please write out some problems of the satellite transmission Translate the following words and phrases into Chinese 1 unsheathed 2 insulator 3 susceptible 4 vicinity 5 curvature 6 antenna 7 gigahertz 8 nonconductive Translate the following paragraph into Chinese Instead of using wire or cable microwave systems can use the atmosphere as the medium through which to transmit signals These systems are extensively used for high volume as well as long distance communication of both data and voice in the form of electromagnetic waves similar to radio waves but in a higher frequency range Microwave signals are often referred to as line of sight signals because they cannot bend around the curvature of the earth instead they must be relayed from point to point by microwave towers or relay stations placed 20 to 30 miles apart The distance between the towers depends on the curvature of the surface terrain in the vicinity The surface of the earth typically curves about 8 inches every mile The towers have either a dish or a horn shaped antenna The size of the antenna varies according to the distance signals must cover A long distance antenna could easily be 10 feet or larger in size a dish of 2 to 4 feet in diameter which you often see on city buildings is large enough for small distances Each tower facility receives incoming traffic boots the signal strength and sends the signal to the next station ATM 异步传输模式 异步传输模式 New Words Phrases and Abbreviations intermittent adj 间歇的 断断续续的 scalable可攀登的 可升级的 megabit兆位 百万位 gigabit吉 咖 比特 irrespective adj 与 of 连用 不顾 的 不考虑 的 不论 的 Text5 10 identification n 认明 识别 鉴定 identifier标志 标识 识别 符 simplicity n 简单 简易 朴素 朴实 单纯 convey vt 运送 运输 approximation n 近似 近似值 overlaid覆盖 equivalent adj 常与 to 连用 相同的 同等的 proportion n 比例 比率 thereby adv 因此 从而 由此 infrastructure n 基本设施 considerable adj 相当大的 相当多的 telecommunication n 电信 远程通信 variable adj 易变的 不稳定的 preeminent adj 卓越的 杰出的 出类拔萃的 essential adj 必需的 基本的 optimum adj 最好的 最佳的 最有利的 underway起步的 进行中的 航行中的 upheaval n 动乱 剧变 Notes to the Text 1 ATM 本篇课文涉及宽带交换这一新技术领域 题目可译为 异步传输模式 2 it has in fact proved to be a universal technique for transporting and switching any type of digitized information at a wide variety of bit rates It 是代词 指前面的 ATM in fact 可看作是插入语 通常去掉插入语不会影响句子的主要 意思 插入语也经常用两个逗号分开 for transporting and switching 是介词短语 表示目的 介词后面不跟动词 所以这里用的是动名词 译文 事实却证明它是一种通用技术 可以用来传输和交换任何类型并具有各种比特率 的数字化信息 3 ATM transfers information in short packets called cells with a fixed length of 48 bytes plus five header bytes irrespective of the underlying type of transmission called 过去分词 由它及其分词短语作后置定语 修饰前面的词 irrespective of 形容词短 语 为了使译文简洁 后面的 underlying 也可不译 译文 无论传输的信息是什么 ATM 都以称作 信元 的短的分组来传送信息 信元是由 固定的 48 字节加上 5 字节的信头组成 4 On the other hand ATM retains all the flexibility of the packet mode enabling only required information to be conveyed offering a simple unique multiplexing method irrespective of the bit rates of the different information flows and allowing these bit rates to be varied On the other hand 意为 另一方面 此句主干为 ATM retains all the flexibility 后面三个并 列的分词短语 enabling offering allowing 都是对 flexibility 作进一步的说明 译文 另一方面 ATM 保留了分组方式所有的灵活性 只传送所需要的信息 提供简单 独特的复用方法而不管不同信息流的比特率 并且允许比特率变化 5 seen from the access 这是一个插入语 由逗号隔开 译文 从接入的角度看 6 The ability to construct virtual networks means that the physical network can be shared by many users dynamically and in real time That 引导 means 的宾语从句 be shared 被动句 译成 由 共享 dynamically 副词 这里 修饰动词 shared 译文 构成虚网络的能力意味着物理网络可以由许多用户动态实时地共享 7 Today ATM is the only transfer technique to offer the high bit rates and flexibility required by these services required by 过去分词短语作后置定语 译文 今天 ATM 是惟一能够提供这些业务所需的高比特率和灵活性的传输技术 8 ATM is special mainly due to its universal nature both in terms of bit rate and type of 11 information transferred in terms of 根据 按照 译文 ATM 主要由于其通用性 无论是比特率还是传输的信息类型都具有特殊的优点 9 ATM s specific features will make it the preeminent nature vehicle for multimedia services and especially for varying bit rate video and will make it one of the essential components of future information superhighways offering new services such as video on demand Features 有两个谓语 will make and will make offering new services 分词短语 修饰 superhighways 译文 ATM 的独特性将使它成为卓越的多媒体业务的自然载体 特别是对于可变比特率的 视频 并且使它成为能够提