电信(英)

Telecommunication¹

    Telecommunication refers to communication over long distances. In practice, something of the message may be lost in the process. Telecommunication covers all forms of distance and/or conversion² of the original communications, including radio, telegraphy, television, telephony, data communication and computer networking.

    The elements of a telecommunication system are a transmitter, a medium (line) and possibly a channel imposed upon the medium (see baseband and broadband as well as multiplexing), and a receiver. The transmitter is a device that transforms or encodes the message into a physical phenomenon; the signal. The transmission medium, by its physical nature, is likely to modify or degrade the signal on its path from the transmitter to the receiver. The receiver has a decoding³ mechanism⁴ capable of recovering the message within certain limits of signal degradation⁵. Sometimes, the final receiver is the human eye and/or ear (or in some extreme cases other sensory⁶ organs) and the recovery of the message is done by the brain (see psychoacoustics.)

    Telecommunication can be point-to-point, point-to-multipoint or broadcasting, which is a particular form of point-to-multipoint that goes only from the transmitter to the receivers.

    One of the roles of the telecommunications engineer is to analyse the physical properties of the line or transmission medium, and the statistical⁸ properties of the message in order to design the most effective encoding and decoding mechanisms⁹.

    When systems are designed to communicate through human sensory organs (mainly those for vision and hearing), physiological¹⁰ and psychological characteristics of human perception must be taken into account. This has important economic implications and engineers must research what defects can be tolerated in the signal and not significantly degrade the viewing or hearing experience.

    Examples of human (tele)communications

    In a simplistic example, consider a normal conversation between two people. The message is the sentence that the speaker decides to communicate to the listener. The transmitter is the language areas in the brain, the motor cortex, the vocal¹¹ cords, the larynx, and the mouth that produce those sounds called speech. The signal is the sound waves (pressure fluctuations¹² in air particles) that can be identified as speech. The channel is the air carrying those sound waves, and all the acoustic⁷ properties of the surrounding space: echoes, ambient noise, reverberation¹³. Between the speaker and the listener, there might be other devices that do or do not introduce their own distortions of the original vocal signal (for example a telephone, a HAM radio, an IP phone, etc.) The receiver is the listener's ear and auditory system, the auditory nerve, and the language areas in the listener's brain that will decode¹⁴ the signal into information and filter out background noise.

    All channels have. Another important aspect of the channel is called the bandwidth. A low bandwidth channel, such as a telephone, cannot carry all of the audio information that is transmitted in normal conversation, causing distortion and irregularities in the speaker's voice, as compared to normal, in-person speech.

1 telecommunication   

n.电信，远距离通信

参考例句：

• Telecommunication is an industry of service.电信业是一个服务型的行业。
• I only care about the telecommunication quality and the charge.我只关心通信质量和资费两个方面。

2 conversion   

n.转化，转换，转变

参考例句：

• He underwent quite a conversion.他彻底变了。
• Waste conversion is a part of the production process.废物处理是生产过程的一个组成部分。

3 decoding   

n.译码，解码v.译（码），解（码）( decode的现在分词 )；分析及译解电子信号

参考例句：

• We cannot add any other memory to this system without further decoding. 如果不增加译码，就不能使系统的存贮容量有任何扩展。 来自辞典例句
• Examples using the 8250 will be presented in hardware section to clarify full-decoding schemes. 在硬件一节中有应用说明全译码方案8250的例子。 来自辞典例句

4 mechanism   

n.机械装置；机构，结构

参考例句：

• The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
• The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。

5 degradation   

n.降级；低落；退化；陵削；降解；衰变

参考例句：

• There are serious problems of land degradation in some arid zones.在一些干旱地带存在严重的土地退化问题。
• Gambling is always coupled with degradation.赌博总是与堕落相联系。

6 sensory   

adj.知觉的，感觉的，知觉器官的

参考例句：

• Human powers of sensory discrimination are limited.人类感官分辨能力有限。
• The sensory system may undergo long-term adaptation in alien environments.感觉系统对陌生的环境可能经过长时期才能适应。

7 acoustic   

adj.听觉的，声音的；(乐器)原声的

参考例句：

• The hall has a fine acoustic.这个大厅的传音效果很好。
• Animals use a whole rang of acoustic, visual,and chemical signals in their systems of communication.动物利用各种各样的听觉、视觉和化学信号来进行交流。

8 statistical   

adj.统计的，统计学的

参考例句：

• He showed the price fluctuations in a statistical table.他用统计表显示价格的波动。
• They're making detailed statistical analysis.他们正在做具体的统计分析。

9 mechanisms   

n.机械( mechanism的名词复数 )；机械装置；[生物学] 机制；机械作用

参考例句：

• The research will provide direct insight into molecular mechanisms. 这项研究将使人能够直接地了解分子的机理。 来自《简明英汉词典》
• He explained how the two mechanisms worked. 他解释这两台机械装置是如何工作的。 来自《简明英汉词典》

10 physiological   

adj.生理学的，生理学上的

参考例句：

• He bought a physiological book.他买了一本生理学方面的书。
• Every individual has a physiological requirement for each nutrient.每个人对每种营养成分都有一种生理上的需要。

11 vocal   

adj.直言不讳的；嗓音的；n.[pl.]声乐节目

参考例句：

• The tongue is a vocal organ.舌头是一个发音器官。
• Public opinion at last became vocal.终于舆论哗然。

12 fluctuations   

波动，涨落，起伏( fluctuation的名词复数 )

参考例句：

• He showed the price fluctuations in a statistical table. 他用统计表显示价格的波动。
• There were so many unpredictable fluctuations on the Stock Exchange. 股票市场瞬息万变。

13 reverberation   

反响； 回响； 反射； 反射物

参考例句：

• It was green as an emerald, and the reverberation was stunning. 它就象翠玉一样碧绿，回响震耳欲聋。
• Just before dawn he was assisted in waking by the abnormal reverberation of familiar music. 在天将破晓的时候，他被一阵熟悉的，然而却又是反常的回声惊醒了。

14 decode   

vt.译（码），解（码）

参考例句：

• All he had to do was decode it and pass it over.他需要做的就是将它破译然后转给他人。
• The secret documents were intercepted and decoded.机密文件遭截获并被破译。