专业英语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双绞线双绞线o 两种n 非屏蔽双绞线-Unshielded twisted-pair (UTP)n 屏蔽双绞线-Shielded twisted-pair (STP)同轴电缆(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 光电的o Tubeo 管子，地铁（英国），电子管（美国）o electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distanceo

6、 Loudspeakero 扩音器o Cathode-ray oscillographo 阴极射线示波器o Printed circuito 印制电路o RADARo Radio detection and ranging11o Batteryo 电池o Active deviceso 有源器件o Passive deviceso 无源器件o PLCo Programmable logic controllero 可编程逻辑控制器o Magnetic resonance imagingo 磁共振成像12o Anodeo 阳极o Varactoro variable capacitoro 变容二

7、极管o Substrateo 基底o Schottkyo 肖特基o Gunno 耿氏的2021-12-12通信与信息工程专业英语教程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 图示o Inventoryo 清单odata processing in which some of the functions are performed in different places and connected by transmission facilities o Teleprocessingo 远程处理，遥控处理o Constraino 约束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 反馈o Intelligenceo 智利，信息o Intermediateo 中间的o Elapseo 经过，消失o Be called upon too 用来，（被）要求。o With the aid ofo 借助于o Appear aso 作为。出现o Be likely too 可能o Asynchronous transmissiono 异步传输o Synchronous transmissio

13、no 同步传输o Simultaneously o 同时地o Call upon o 请求o Airline reservation system o 航空预售票系统o Man-computer conversation o 人机对话o Data collection system o 数据采集系统o Meter reading o 仪表读数orefer to sth. as o称某物为oTele o 远，远距离oAccounting o会计学，帐目oFlexibility o适应性, 机动性，灵活性oFacility o设备，工具oSuffice o 足够, 有能力，使满足oFacsimil

14、e o复制本，传真oConvincing o令人信服的；能说服人的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 外围设备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 缓冲存储器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 数据通信是包括数据,电视图像,声音和传真的电子传输.o It usually involves a computer, a modem, software, and a printer.o 数据传输中通常需要计算机,调制解调器,软件和打印机.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 有了这些设备,你能通过电话线与一个在密苏里州圣路易斯或者法国巴黎的朋友通信, 接收或者发送简单的信息或者手稿.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 用同样的方法,一个回家的小孩能与一个在教室的老师进行交流,一个工人能在家中工作,一个医生能访问远程计算机的研究数据.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 用这样的通信系统有让人信服的原因,这个系统是便利高效的,减轻了工作压力,降低了汽车的污染,节约时间和金钱,容许家里办公,推进了远程教育,学生能分享信息和计算机研究成果.o When you connect one computer to another, you use hardware and software.o 当一个计算机与另外的连接的时候,要用到软件和硬件.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 在大多数情况下,硬件包括在一些类型的通信线路上,比如电话线上传送数据的设备.o The software controls the flow of this data.o The necessary hardware consist of a modem and telephone lines.o 软件控制这些数据的流动,硬件中调制解调器和电话线是必

21、须的.o The modem modulates the computer output to an acceptable signal for transmission and then demodulates the signal back for computer input.o 调制解调器调制计算机的输出信号成为适合传输的形式,然后将返回计算机的信号解调出来.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 发送端计算机的调制解调器把数字信号调制为模拟信号,并通过电话线发送出去.o The receiving computers modem transforms the incoming analog signals back to their digital equivalents in order to understand them.o 为了便于理解,接收端计算机的调制解调器变化输入模拟信号回到同等的数字形式.Transmission rateo The transmission rate of a communicatio

23、ns channel is determined by its bandwidth and its speed.o 信道的传输速率是由信道的带宽和信息传输速率决定的.o The bandwidth is the range of frequencies that a channel can carry.o 带宽是信道能运载信息的的频率范围.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 由于传输的数据被分配到不同的频率进行传输,因此,这将有更宽的带宽,或者更多的传输频率,也将有更多的数据被同时传输.o The speed at which data is transmitted is usually expressed as bits per second or as a baud rate.o 数据传输的速率通常表示为比特率或者波特率.o Bits per second (bps) is the number of bits that can be transmitted in one sec

25、ond.o Bps 一秒传输的二进制码元个数.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 用一个10位二进制字节去代表一个字符(7个数据位,1个开始位,1个结束位,1个奇偶效验位), 2400bps的传输速率就意味着每秒传输240个字符.o At this rate, a 20-page, single-spaced

26、report would be transmitted in approximately five minutes.o 以这样的速率传输一个单栏20页的报告将大概需要5分钟.o The baud rate is the number of times per second that signal being transmitted changes.o 波特率是每秒被传输信号的变化次数.o With each change, one or more bits can be transmitted.o 每发生一次变化,都有1个或者更多的二进制位被传输.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 当速率达到了2400bps,通常符号每变化一次只有一个二进制数被传输,这时,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 当速率超过了2400bps时,当符号每变化一次时,有多余1比特的二进制数被传输,因此,比特率将超过波特率.o Direction of transmissiono The direction of data transmission is classified as either simplex, half-duplex, or full-duplex.o 根据数据传输的方向分类,传输有单工方式,半双工方式和全双工方式.o In simplex transmission, data flows in one direction only.o 在单工传输中

29、,数据仅仅向一个方向传输.o Simplex is used only when the sending device, such as a temperature sensor, never requires a response from the computer.o 单工方式仅仅用在发射装置中,例如一个温度传感器,它不需要来自计算机的响应.o For example, if a computer is used to control temperature of a building, numerous sensors are placed throughout it.o 例如,假如计算

30、机用来控制建筑物的温度,需要有很多的温度传感器贯穿其中.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 每一个传感器都通过一根单工传输线连接到计算机上,这是因为计算机只需要接收来自于温度传感器的数据,而不需要向传感器发送数据. o In

31、 half-duplex transmission, data can flow in both directions but in only one direction at a time.o 在半双工传输中,数据可以向两个方向传输,但是在同一时间只能向一个方向传输.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 一个例子是城市的无线电台,用户能听或者说,但是不能两者同时进行,半双工方式经常用于终端和中心计算机之间.o In full-duplex transmission, data can be sent in both directions at the same time.o 在全双工传输方式中,数据能在两个方向同时进行传输.o A normal telephone line is an example of full-duplex transmission.o 一个普通的电话线就是一个全双工传输的例子.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 所有的当事人都能同时讲话,全工传输方式被用于主要的计算机交互应用和计算机之间的数据传输.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 在如图3.1所示的异步传输模式中,由二进制位构成的单个字符被无规律的传输,例如,当用户输入数据时.o To distinguish where one character stops and another starts, the asynchronous communication mode uses a start and a