計算機英語Unit7計算機通信

1、Unit 7 Computer CommunicationsSection A Telecommunications and Computer第七單元：計算機通信 課文A：電信與計算機 Telecommunications allows people around the world to contact one another, to access information instantly, and to communicate from remote areas. Telecommunications usually involves a sender of information an

2、d one or more recipients linked by a technology, such as a telephone system, that transmits information from one place to another.Telecommunications devices converts different types of information, such as sound and video, into electronic signals. The signals can then be transmitted by means of medi

3、a such as telephone wires or radio waves. 電信使世界各地的人們得以互相聯(lián)系，即刻獲取信息，并從邊遠地區(qū)實施通信。電信通常涉及一個信息發(fā)送者和一個或多個接收者，他們通過電話系統(tǒng)等把信息從一地發(fā)送到另一地的技術(shù)相聯(lián)系。電信設(shè)備將不同類型的信息，如聲音和圖像，轉(zhuǎn)換成電子信號。然后，這些信號就可以通過電話線或無線電波等媒介進行發(fā)送。 When a signal reaches its destination, the device on the receiving end converts the electronic signal back into an

4、understandable message, such as sound over a telephone, moving images on a television, or words and pictures on a computer screen. Telecommunications enable people to send and receive personal messages across town, between countries, and to and from outer space. It also provides the key medium for n

5、ews, data, information, and entertainment. 信號到達目的地后，接收端的設(shè)備將電子信號轉(zhuǎn)換回可以理解的信息，如電話中的聲音、電視上的活動圖像或計算機屏幕上的文字和圖片。電信使人們能夠在城鎮(zhèn)不同地方、國家之間以及向外層空間和從外層空間發(fā)送和接收個人信息。電信也為新聞、數(shù)據(jù)、信息和娛樂提供了關(guān)鍵的媒介。 Telecommunications messages can be sent in a variety of ways and by a wide range of devices. The messages can be sent from one se

6、nder to a single receiver (point-to-point) or from one sender to many receivers (point-to-multipoint). Personal communications, such as a telephone conversation between two people or a facsimile (fax) message, usually involve point-to-point transmission. Point-to-multipoint telecommunications often

7、called broadcasts, provide the basis for commercial radio and television programming. 電信信息可通過各種方式和設(shè)備發(fā)送。信息可由一個發(fā)送者發(fā)送給一個接收者（點對點），或者由一個發(fā)送者發(fā)送給多個接收者（點對多點）。個人通信，如兩個人之間的電話對話或傳真信息，通常涉及點對點的傳輸。通常稱為廣播的點對多點電信傳輸，為商業(yè)無線電和電視節(jié)目播送提供了基礎(chǔ)。 Telecommunications begin with messages that are converted into electronic signals.

8、 The signals are then sent over a medium to a receiver, where they are decoded back into a form that the person receiving the message can understand. There are variety of ways to create and decode signals, and many different ways to transmit signals. 電信以信息轉(zhuǎn)換為電子信號為開端。然后，這些信號通過媒介發(fā)送到接收機，并在那里解碼，恢復(fù)為接收信息的

9、人能夠理解的形式。有各種方法可以生成并解譯信號，也有許多不同方法可以傳輸信號。 Devices such as the telegraph and telephone relay messages by creating modulated electrical impulses, or impulses that change in a systematic way. These impulses are then sent by wires, radio waves, or other media to a receiver that decodes the modulation. The

10、 telegraph, the earliest method of delivering telecommunications, works by converting the contacts (connections between two conductors that permit a flow of current) between a telegraph key and a metal conductor into electrical impulses. These impulses are sent along a wire to a receiver, which conv

11、erts the impulses into short and long bursts of sound or into dots and dashes on a simple printing device. 電報機與電話機等設(shè)備，通過生成調(diào)制電脈沖或以系統(tǒng)化方式變化的脈沖，來傳遞信息。接下來，這些脈沖通過導(dǎo)線、無線電波或其他媒介發(fā)送給接收機，并由其進行解調(diào)。電報機是最早的傳遞電信信息的方法，它通過將電報電鍵與金屬導(dǎo)體之間的接觸（使電流得以流動的兩個導(dǎo)體之間的連接）轉(zhuǎn)換成電脈沖而進行工作。這些脈沖沿著導(dǎo)線發(fā)送到接收機，而接收機則將這些脈沖轉(zhuǎn)換成長與短的聲音脈沖串，或者在簡單的打印設(shè)備上打印

12、出來的點與劃。 Specific sequences of dots and dashes represents letters of the alphabet. In the early days of the telegraph, these sequences were decoded by telegraph operators. In this way, telegraph operators could transmit and receive letters that spelled words. Later versions of the telegraph could dec

13、ipher letters and numbers automatically. Telegraphs have been largely replaced by other forms of telecommunications, such as fax machines and electronic mail (E-mail), but they are still used in some parts of the world to send messages. 特定的點與劃序列代表字母表中的字母。在早期的電報中，這些序列由電報機操作員進行解譯。這樣，電報機操作員就可以發(fā)送和接收可拼成詞

14、語的字母。后來的電報機能自動解譯字母和數(shù)字。電報機在很大程度上已被其他的電信形式所取代，如傳真機和電子郵件，但在世界有些地方，電報機仍然用來發(fā)送信息。 Telegraphs, telephones, radio, and television all work by modifying electronic signals, making the signals imitate, or reproduce, the original message. This form of transmission is known as analog transmission. Computers and

15、 other types of electronic equipment, however, transmit digital information. Digital technologies convert a message into electronic form first by measuring different qualities of the messages, such as the pitch and volume of a voice, many times. These measurements are then encoded into multiple seri

16、es of binary numbers, or 1s and 0s. 電報機、電話機、無線電和電視都是通過修改電子信號，使其模擬或再現(xiàn)原來的信息，來進行工作的。這種傳輸稱為模擬傳輸。然而，計算機和其他類型的電子設(shè)備是傳輸數(shù)字信號的。數(shù)字技術(shù)將信息轉(zhuǎn)換成電子形式。其方法首先是多次測量信息的不同特性，如語音的音高和音量。然后，這些測量值被編譯成多個系列的二進制數(shù)或1與0。 Finally, digital technologies create and send electrical impulses that correspond to the series of 1s and 0s. Dig

17、ital information can be transmitted faster and more clearly than analog signals, because the electrical impulses only need to correspond to two digits and not to the full range of qualities that compose the original message, such as the pitch and volume of a human voice. While digital transmissions

18、can be sent over wires, cables or radio waves, they must be decoded by a digital receiver. New digital telephones and televisions are being developed to make telecommunications more efficient. 最后，數(shù)字技術(shù)生成并發(fā)送與這些系列的1和0相對應(yīng)的電脈沖。與模擬信號相比較，數(shù)字信息可以更快、更清晰地傳輸，因為電脈沖僅需與兩個數(shù)字對應(yīng)，而不是構(gòu)成原信息的所有特性，如人的說話聲的音高和音量。數(shù)字信息可以通過導(dǎo)線、

19、電纜或無線電波傳輸，但必須由數(shù)字接收機進行解譯。新型數(shù)字電話和電視正在開發(fā)中，以提高電信的效率。 Most personal computers communicate with each other and with larger networks, such as the Internet, by using the ordinary telephone network. Since the telephone network functions by converting sound into electronic signals, the computer must first con

20、vert its digital data into sound. Computers do this with a device called a modem, which is short for modulator/demodulator. A modem converts the stream of 1s and 0s from a computer into an analog signal that can then be transmitted over the telephone network, as a speakers voice would. The modem of

21、the receiving computer demodulates the analog sound signal back into a digital form that the computer can understand. 大多數(shù)個人計算機通過使用普通電話網(wǎng)，來進行彼此間的通信以及與因特網(wǎng)等大型網(wǎng)絡(luò)的通信。因為電話網(wǎng)是通過將語音信號轉(zhuǎn)換成電子信號來工作的，計算機必須首先將其數(shù)字數(shù)據(jù)轉(zhuǎn)換成語音信號。計算機使用稱為調(diào)制解調(diào)器的設(shè)備來完成這項工作。調(diào)制解調(diào)器是調(diào)制器/解調(diào)器的縮略。調(diào)制解調(diào)器將計算機輸出的1和0數(shù)字流轉(zhuǎn)換成模擬信號，而模擬信號可隨后通過電話網(wǎng)傳輸，就像通話者的聲音那樣。接

22、收端計算機的調(diào)制解調(diào)器將模擬語音信號解調(diào)還原為計算機能理解的數(shù)字形式。 Telecommunications systems deliver messages using a number of different transmission media, including copper wires, fiber-optic cables, communication satellites, and microwave radio. One way to categorize telecommunications media is to consider whether or not the

23、media uses wires. Wire-based (or wireline) telecommunications provide the initial link between most telephones and the telephone network, and are a reliable means for transmitting messages. Telecommunications without wires, commonly referred to as wireless communications, using technologies such as

24、cordless telephones, cellular radio telephones, walkie-talkies, citizens band (CB) radios, pagers, and satellites. Wireless communications offer increased mobility and flexibility. 電信系統(tǒng)使用多種不同的傳輸媒介傳送信息，包括銅線、光纜、通信衛(wèi)星和微波無線電。劃分電信媒介的一種方法，是看媒介是否使用導(dǎo)線?；趯?dǎo)線（或有線）的電信提供了大多數(shù)電話與電話網(wǎng)之間的最初鏈路，是一種可靠的信息傳輸方式。沒有導(dǎo)線的電信，通常稱為

25、無線通信，使用無繩電話、蜂窩式無線電話、步話機、民用波段無線電臺、尋呼機和衛(wèi)星等技術(shù)。無線通信提高了機動性和靈活性。 Individual people, businesses, and governments use many different types of telecommunications systems. Some systems, like the telephone system, use a network of cables, wires, and switching stations for point-to-point communication. Other sy

26、stems, such as radio and television, broadcast signals through space, which can be received by anyone who has a device to receive them. Some systems make use of several types of media to complete a transmission. For example, a telephone call may travel by means of copper wire, fiber-optic cable, and

27、 radio waves as the call is sent from sender to receiver. All telecommunications systems are constantly evolving as telecommunications technology improves. 個人、企業(yè)和政府使用多種不同的電信系統(tǒng)。有些系統(tǒng)，如電話系統(tǒng)，使用由電纜、導(dǎo)線和交換臺組成的網(wǎng)絡(luò)，來進行點對點的通信。另外一些系統(tǒng)，如無線電臺與電視臺，通過空間播出信號，任何擁有接收設(shè)備的人都可以接收。有些系統(tǒng)利用數(shù)種媒介完成傳輸。例如，一個電話從打電話的人傳送到接電話的人，其間可能要通

28、過銅線、光纜和無線電波進行傳輸。隨著電信技術(shù)的發(fā)展，所有的電信系統(tǒng)都在不斷地演變。 Computer telecommunications, with the ability to send and receive audio, video, text, software, and multimedia, is one of the fastest growing segments of the telecommunications market. Computer telecommunications takes advantage existing telephone connection

29、s to transmit digital data. This type of transmission is frequently done over the Internet, a decentralized network of personal, business, government, and educational computers, and sources of information. Some computers connect directly to the digital portion of the telephone network using the Inte

30、grated Services Digital Network (ISDN), but this requires the installation of special devices and telephone line, called Digital Subscriber Line (DSL), is being developed to increase modem speed tremendously. 計算機遠程通信具有發(fā)送和接收音頻信號、視頻信號、文本、軟件和多媒體的能力，是電信市場發(fā)展最快的部分之一。計算機遠程通信利用現(xiàn)有的電話連接來傳輸數(shù)字數(shù)據(jù)。這種傳輸常常通過因特網(wǎng)進行，而

31、因特網(wǎng)是一個由個人、企業(yè)、政府和教育機構(gòu)所使用的計算機和信息源構(gòu)成的分散型網(wǎng)絡(luò)。有些計算機使用綜合業(yè)務(wù)數(shù)字網(wǎng)（ISDN）直接連接到電話網(wǎng)的數(shù)字部分，但這需要安裝專門設(shè)備和進行電話線調(diào)整。為了大幅度提高調(diào)制解調(diào)器的速度，目前正在開發(fā)一種供常規(guī)電話線使用的改進型調(diào)制解調(diào)器系統(tǒng)，稱為數(shù)字用戶線路（DSL）。 Electronic mail, or e-mail, is a key attraction of the Internet and a common form of computer telecommunications. E-mail is a text-based message del

32、ivery system that allows information such as typed messages and multimedia to be sent to individual computer users. Local e-mail messages (within a building or a company) typically reach addressees by traveling through wire-based internal networks. E-mail that must travel across town or across a cou

33、ntry to reach the final destination usually travels through the telephone network. Other computer telecommunications technologies that businesses frequently use include automated banking terminals and devices for credit card transactions that bill charges directly to a customers bank account. 電子郵件是因

34、特網(wǎng)吸引人的一個關(guān)鍵點，也是計算機遠程通信的一種常見形式。電子郵件是基于文本的信息傳輸系統(tǒng)，它能將鍵入的信息和多媒體信息等發(fā)送給個人計算機用戶。（一幢建筑或一家公司內(nèi)的）本地電子郵件通常經(jīng)由基于導(dǎo)線的內(nèi)部網(wǎng)傳送給收件人。必須橫穿城鎮(zhèn)或國家才能到達最終目的地的電子郵件，通常通過電話網(wǎng)進行傳輸。企業(yè)經(jīng)常使用的其他計算機遠程通信技術(shù)包括自動銀行終端及設(shè)備，用來處理將費用直接從顧客銀行帳戶上扣除的信用卡業(yè)務(wù)。 Personal computers have pushed the limits of the telephone system as more and more complex comput

35、er messages are being sent over telephone lines, and at rapidly increasing speeds. This need for speed has encouraged the development of digital transmission technology. Innovations in fiber-optic technology will hopefully keep up with the growing use of personal computers for telecommunications. Th

36、e next generation of cellular telephones, pagers, and televisions will also benefit from the speed and clarity of digital telecommunications. 隨著越來越復(fù)雜的計算機信息以快速提高的速度通過電話線發(fā)送，個人計算機拓展了電話系統(tǒng)的作用范圍。這種對速度的需要促進了數(shù)字傳輸技術(shù)的發(fā)展。光纖技術(shù)的革新有望跟上個人計算機在遠程通信方面不斷增長的使用。下一代蜂窩電話、尋呼機和電視機也將受益于數(shù)字遠程通信的速度和清晰度。 Telecommunications and i

37、nformation technologies are merging and converging. This means that many of the devices that we associate with only one function may evolve into more versatile equipment. This convergence is already happening in various fields. Some telephones and pagers are able to store not only phone numbers but

38、also names and personal information about callers. 電信和信息技術(shù)正在融合。這意味著，在我們只將其與一種功能聯(lián)系起來的設(shè)備中，有不少可能演變?yōu)槎嘤猛驹O(shè)備。這種融合已經(jīng)開始在各種領(lǐng)域發(fā)生。有些電話機和尋呼機不但能存儲電話號碼，而且還能存儲呼叫者的姓名和個人信息。 Advanced phones with keyboards and small screens are now in development that can access the Internet and send and receive e-mail. Personal computers can now access information and video entertainment a