计算机英语专业外语第三版UNIT 7

UNIT 7 Computer Communications

Section A Telecommunications and Computers

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 and one or more recipients linked by a technology, such as a telephone system, that transmits information from one place to another.

电信使世界各地的人们得以互相联系，即刻获取信息，并在边远地区进行通信。电信通常涉及一个信息发送者和一个或多个接收者，他们通过将信息从一地发送到另一地的技术联在一起，如电话系统。

Telecommunications devices convert different types of information, such as sound and video, into electronic signals. The signals can then be transmitted by means of media such as telephone wires or radio waves.

电信设备将不同类型的信息，如声音和图像，转换成电子信号。然后，这些信号就可以通过电话线或无线电波等媒介进行发送。

When a signal reaches its destination, the device on the receiving end converts the electronic signal back into an understandable message, such as sound over a telephone, moving images on a television, or words and pictures on a computer screen.

信号到达其目的地后，接收端的设备将电子信号转换回可以理解的信息，如电话中的声音、电视上的活动图像或计算机屏幕上的文字和图片。

Telecommunications enables people to send and receive personal messages across town, between countries, and to and from outer space. It also provides the key medium for news, data, information and entertainment.

电信使人们能够在城市不同之处、国家之间以及和外层空间之间发送和接收个人信息。

电信也为新闻、数据、信息和娱乐提供了关键的媒介。

Telecommunications messages can be sent in a variety of ways and by a wide range of devices. The messages can be sent from one sender to a single receiver (point-to-point) or from one sender to many receivers (point-to-multipoint).

电信信息可通过各种方式和设备发送。信息可由一个发送者发送给一个接收者（点对点），或者由一个发送者发送给多个接收者（点对多点）。

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 called broadcasts, provide the basis for commercial radio and television programming.

个人通信，如两个人之间的电话对话或传真信息，通常涉及点对点的传输。点对多点的电信传输，通常称为广播，为商业广播和电视节目的播送提供了基础。

Telecommunications begin with messages that are converted into electronic signals. 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 a variety of ways to create and decode signals, and many different ways to transmit signals.

电信以信息转换为电子信号为开端。然后，这些信号通过媒介发送到接收机，并在这里解码，恢复为接收信息的人能够理解的形式。有各种方法可以产生并解译信号，也有许多不同的方法传输信号。

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.

电报机与电话机等设备，通过产生调制电脉冲或以系统化方式变化的脉冲，来传递信息。接下来，这些脉冲通过导线、无线电波或其他媒介发送给接收机，并由其进行解调。