專業(yè)英語datacom

1、Specialized English on TelecommunicationsYang Xiaoqingo Datan Analog: n Continuous value data n (sound, temperature)n Digital: n Discrete value n (text, integers, symbols)o Analog transmissionn attenuation overcome with amplifiersn signal is not regeneratedo Digital transmissionn uses repeaters rath

2、er than amplifiersn regenerates signal雙絞線雙絞線o 兩種n 非屏蔽雙絞線-Unshielded twisted-pair (UTP)n 屏蔽雙絞線-Shielded twisted-pair (STP)同軸電纜(Coaxial Cable) Data communication networkslPublic Switched Telephone Network (PSTN)lLocal Area Network (LAN)lLeased lineslPublic switched data network (PSDN)lIntegrated servi

3、ces digital network (ISDN)OSI reference ModelLayer 1Physical linkLayer 2Data link layerLayer 3Network layerLayer 4Transport layerLayer 5Session layerLayer 6Presentation layerLayer 7Application layer developed by ISOData Communications o Key terms:o using programming techniques to process a signal wh

4、ile in digital formo DSPo Digital signal processingo Digital signal processoro Parityo A common method of error detection.o States that the sample frequency must be at least twice the highest input frequency. o Nyquist rateo Thermoelectricityo Electricity generated by a flow of heat, as in a thermoc

5、ouple.o the study of the relationship between heat and electrical energyo Photovoltaico producing a voltage when exposed to radiant energy (especially light)o 光電的o Tubeo 管子，地鐵（英國），電子管（美國）o electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distanceo

6、 Loudspeakero 擴(kuò)音器o Cathode-ray oscillographo 陰極射線示波器o Printed circuito 印制電路o RADARo Radio detection and ranging11o Batteryo 電池o Active deviceso 有源器件o Passive deviceso 無源器件o PLCo Programmable logic controllero 可編程邏輯控制器o Magnetic resonance imagingo 磁共振成像12o Anodeo 陽極o Varactoro variable capacitoro 變?nèi)荻?/p>

7、極管o Substrateo 基底o(hù) Schottkyo 肖特基o Gunno 耿氏的2021-12-12通信與信息工程專業(yè)英語教程13othe number of bits that can be transmitted in one second.oBpsoBits per secondothe number of times per second that signal being transmitted changesoBaud rateoA form of data transmission in which the modulating wave shifts the output

8、 between two predetermined frequency.oFSK ofrequency shift keyingoHandshaking oProcedures allowing for orderly exchange of information between a central computer and remote siteso Method of data transmission in which data causes the phase of the carrier to shift by a predefined amount.o PSK o (phase

9、 shift keying)o Test configuration for a data link; the receiver takes the data and sends it back to the transmitter, where it is compared with the original data to indicate system performance.o Loopbacku allowing communication in only one direction at a time, or in telegraphy allowing only one mess

10、age over a line at a timeu Simplexu Either direction, but only one way at a timeu Half duplex u Both directions at the same time u Full duplexo QAM o Quadrature amplitude modulationo OSIo open-system-interconnectiono LANo Local area networkso AT&To American telephone and telegrapho CCITTo Intern

11、ational telegraph and telephone consultative committeeo Graphicso 圖示o Inventoryo 清單odata processing in which some of the functions are performed in different places and connected by transmission facilities o Teleprocessingo 遠(yuǎn)程處理，遙控處理o Constraino 約束o Multiaccesso 多路存取othe process in which part of the

12、 output of a system is returned to its input in order to regulate its further output o Feedbacko 反饋o Intelligenceo 智利，信息o Intermediateo 中間的o Elapseo 經(jīng)過，消失o Be called upon too 用來，（被）要求。o With the aid ofo 借助于o Appear aso 作為。出現(xiàn)o Be likely too 可能o Asynchronous transmissiono 異步傳輸o Synchronous transmissio

13、no 同步傳輸o Simultaneously o 同時(shí)地o Call upon o 請(qǐng)求o Airline reservation system o 航空預(yù)售票系統(tǒng)o Man-computer conversation o 人機(jī)對(duì)話o Data collection system o 數(shù)據(jù)采集系統(tǒng)o Meter reading o 儀表讀數(shù)orefer to sth. as o稱某物為oTele o 遠(yuǎn)，遠(yuǎn)距離oAccounting o會(huì)計(jì)學(xué)，帳目oFlexibility o適應(yīng)性, 機(jī)動(dòng)性，靈活性oFacility o設(shè)備，工具oSuffice o 足夠, 有能力，使?jié)M足oFacsimil

14、e o復(fù)制本，傳真oConvincing o令人信服的；能說服人的oExpedient o有用的；有利的oResearch findings o研究成果o electronic equipment connected by cable to the a computer o Peripheral o 外圍設(shè)備o a part of RAM used for temporary storage of data that is waiting to be sent to a device; used to compensate for differences in the rate of flow

15、 of data between components of a computer system o buffer store o 緩沖存儲(chǔ)器o the branch of computer science that deal with writing computer programs that can solve problems creatively o Artificial intelligence o 人工智能Passage B Characteristics of communication channelso Data communications is the electron

16、ic transmission including data, television pictures, sound and facsimiles.o 數(shù)據(jù)通信是包括數(shù)據(jù),電視圖像,聲音和傳真的電子傳輸.o It usually involves a computer, a modem, software, and a printer.o 數(shù)據(jù)傳輸中通常需要計(jì)算機(jī),調(diào)制解調(diào)器,軟件和打印機(jī).o With this equipment, you can communicate with a friend in St. Louis, Missouri, or Paris, France, send

17、ing and receiving anything from a manuscript to a simple message over the telephone lines.o 有了這些設(shè)備,你能通過電話線與一個(gè)在密蘇里州圣路易斯或者法國巴黎的朋友通信, 接收或者發(fā)送簡(jiǎn)單的信息或者手稿.o Using the same method, a home-bound child can interact with a teacher in the classroom, an office worker can work at home, and a doctor can access a re

18、mote computer for research data.o 用同樣的方法,一個(gè)回家的小孩能與一個(gè)在教室的老師進(jìn)行交流,一個(gè)工人能在家中工作,一個(gè)醫(yī)生能訪問遠(yuǎn)程計(jì)算機(jī)的研究數(shù)據(jù).o The reasons for using communications system are convincing. It is expedient and efficient, lessens job stress, decreases car pollution, saves time and money, allows home to serve as an office, and promotes

19、distant learning in which students can share information and computer research findings.o 用這樣的通信系統(tǒng)有讓人信服的原因,這個(gè)系統(tǒng)是便利高效的,減輕了工作壓力,降低了汽車的污染,節(jié)約時(shí)間和金錢,容許家里辦公,推進(jìn)了遠(yuǎn)程教育,學(xué)生能分享信息和計(jì)算機(jī)研究成果.o When you connect one computer to another, you use hardware and software.o 當(dāng)一個(gè)計(jì)算機(jī)與另外的連接的時(shí)候,要用到軟件和硬件.o In the majority of case

20、s, the hardware consists of equipment that sends the data over some type of communications line, such as a telephone line.o 在大多數(shù)情況下,硬件包括在一些類型的通信線路上,比如電話線上傳送數(shù)據(jù)的設(shè)備.o The software controls the flow of this data.o The necessary hardware consist of a modem and telephone lines.o 軟件控制這些數(shù)據(jù)的流動(dòng),硬件中調(diào)制解調(diào)器和電話線是必

21、須的.o The modem modulates the computer output to an acceptable signal for transmission and then demodulates the signal back for computer input.o 調(diào)制解調(diào)器調(diào)制計(jì)算機(jī)的輸出信號(hào)成為適合傳輸?shù)男问?然后將返回計(jì)算機(jī)的信號(hào)解調(diào)出來.o The modem on the transmitting computer converts the digital signals to modulated analog signal tones and transmit

22、s them over the telephone lines.o 發(fā)送端計(jì)算機(jī)的調(diào)制解調(diào)器把數(shù)字信號(hào)調(diào)制為模擬信號(hào),并通過電話線發(fā)送出去.o The receiving computers modem transforms the incoming analog signals back to their digital equivalents in order to understand them.o 為了便于理解,接收端計(jì)算機(jī)的調(diào)制解調(diào)器變化輸入模擬信號(hào)回到同等的數(shù)字形式.Transmission rateo The transmission rate of a communicatio

23、ns channel is determined by its bandwidth and its speed.o 信道的傳輸速率是由信道的帶寬和信息傳輸速率決定的.o The bandwidth is the range of frequencies that a channel can carry.o 帶寬是信道能運(yùn)載信息的的頻率范圍.o Since transmitted data can be assigned to different frequencies, the wider the bandwidth, the more frequencies, and the more da

24、ta can be transmitted at the same time.o 由于傳輸?shù)臄?shù)據(jù)被分配到不同的頻率進(jìn)行傳輸,因此,這將有更寬的帶寬,或者更多的傳輸頻率,也將有更多的數(shù)據(jù)被同時(shí)傳輸.o The speed at which data is transmitted is usually expressed as bits per second or as a baud rate.o 數(shù)據(jù)傳輸?shù)乃俾释ǔ１硎緸楸忍芈驶蛘卟ㄌ芈?o Bits per second (bps) is the number of bits that can be transmitted in one sec

25、ond.o Bps 一秒傳輸?shù)亩M(jìn)制碼元個(gè)數(shù).o Use a 10-bit byte to represent a character (7 data bits, 1 start, 1 stop, and 1 parity bit), a 2400 bps transmission would transmit 240 characters per second.o 用一個(gè)10位二進(jìn)制字節(jié)去代表一個(gè)字符(7個(gè)數(shù)據(jù)位,1個(gè)開始位,1個(gè)結(jié)束位,1個(gè)奇偶效驗(yàn)位), 2400bps的傳輸速率就意味著每秒傳輸240個(gè)字符.o At this rate, a 20-page, single-spaced

26、report would be transmitted in approximately five minutes.o 以這樣的速率傳輸一個(gè)單欄20頁的報(bào)告將大概需要5分鐘.o The baud rate is the number of times per second that signal being transmitted changes.o 波特率是每秒被傳輸信號(hào)的變化次數(shù).o With each change, one or more bits can be transmitted.o 每發(fā)生一次變化,都有1個(gè)或者更多的二進(jìn)制位被傳輸.o At speeds up to 2400

27、bps, usually only one bit is transmitted per signal change and, thus, the bits per second and the baud rate are the same.o 當(dāng)速率達(dá)到了2400bps,通常符號(hào)每變化一次只有一個(gè)二進(jìn)制數(shù)被傳輸,這時(shí),比特率和波特率是相等的.o To achieve speeds in excess of 2400bps, more than one bit is transmitted with each signal change and , thus, the bps will exc

28、eed the baud rate.o 當(dāng)速率超過了2400bps時(shí),當(dāng)符號(hào)每變化一次時(shí),有多余1比特的二進(jìn)制數(shù)被傳輸,因此,比特率將超過波特率.o Direction of transmissiono The direction of data transmission is classified as either simplex, half-duplex, or full-duplex.o 根據(jù)數(shù)據(jù)傳輸?shù)姆较蚍诸?傳輸有單工方式,半雙工方式和全雙工方式.o In simplex transmission, data flows in one direction only.o 在單工傳輸中

29、,數(shù)據(jù)僅僅向一個(gè)方向傳輸.o Simplex is used only when the sending device, such as a temperature sensor, never requires a response from the computer.o 單工方式僅僅用在發(fā)射裝置中,例如一個(gè)溫度傳感器,它不需要來自計(jì)算機(jī)的響應(yīng).o For example, if a computer is used to control temperature of a building, numerous sensors are placed throughout it.o 例如,假如計(jì)算

30、機(jī)用來控制建筑物的溫度,需要有很多的溫度傳感器貫穿其中.o Each sensor is connected to the computer with a simplex transmission line because the computer only needs to receive data from the temperature sensors and does not need to send data back to the sensors.o 每一個(gè)傳感器都通過一根單工傳輸線連接到計(jì)算機(jī)上,這是因?yàn)橛?jì)算機(jī)只需要接收來自于溫度傳感器的數(shù)據(jù),而不需要向傳感器發(fā)送數(shù)據(jù). o In

31、 half-duplex transmission, data can flow in both directions but in only one direction at a time.o 在半雙工傳輸中,數(shù)據(jù)可以向兩個(gè)方向傳輸,但是在同一時(shí)間只能向一個(gè)方向傳輸.o An example is a citizens band radio. The user can talk or listen but not do both at the same time. Half-duplex is often used between terminals and a central comput

32、er.o 一個(gè)例子是城市的無線電臺(tái),用戶能聽或者說,但是不能兩者同時(shí)進(jìn)行,半雙工方式經(jīng)常用于終端和中心計(jì)算機(jī)之間.o In full-duplex transmission, data can be sent in both directions at the same time.o 在全雙工傳輸方式中,數(shù)據(jù)能在兩個(gè)方向同時(shí)進(jìn)行傳輸.o A normal telephone line is an example of full-duplex transmission.o 一個(gè)普通的電話線就是一個(gè)全雙工傳輸?shù)睦?o Both parties can talk at the same time.

33、 Full-duplex transmission is used for most interactive computer applications and for computer-to-computer data transmission.o 所有的當(dāng)事人都能同時(shí)講話,全工傳輸方式被用于主要的計(jì)算機(jī)交互應(yīng)用和計(jì)算機(jī)之間的數(shù)據(jù)傳輸.o Transmission modes: asynchronous and synchronouso In asynchronous transmission mode (figure3.1), individual characters (made up of bits) are transmitted at irregular intervals , for example, when user enters data.o 在如圖3.1所示的異步傳輸模式中,由二進(jìn)制位構(gòu)成的單個(gè)字符被無規(guī)律的傳輸,例如,當(dāng)用戶輸入數(shù)據(jù)時(shí).o To distinguish where one character stops and another starts, the asynchronous communication mode uses a start and a