电信专业英英词典M-3

　　Multimode Optical Fiber¹(S)

　　Multimode fibers², with much wider cores than single mode fibers, allow light to enter at various angles, and reflect (bounce off of) core-clad boundaries as electromagnetic (light) wave propagates from transmitter to receiver. From a technical performance trade-off point of view, single mode fiber exhibits bandwidths of up to 100,000 MHz (MHz = 1,000,000 hertz or cycles per second = one megahertz) while multimode band width is in the range of 1,000 to 2,000 MHz (1,000 MHz = one billion hertz = one gigahertz = 1 GHz). See optical fiber(s); single modefiber(s).

　　Multiplexing

　　Multiplexing is a technique that enables a number of communications channels to be combined into a single broadband signal and transmitted over a single circuit. At the receiving terminal, demultiplexing of the broadband signal separates and recovers the original channels. Multiplexing makes more efficient use of transmission capacity to achieve a low per channel cost. Two basic multiplexing methods used in telecommunications systems, are frequency division multiplexing (FDM) and time division multiplexing (TDM).

　　Major Trading Area (MTA) - An area defined by the U.S. government and used by the Federal Communications Commission (FCC) to designate personal communications services market areas.

　　Mbps - Megabytes per second (MB is also used as an abbreviation for Megabyte).

　　Megabyte (MB)- A million bytes or a thousand kilobytes.

　　Miscellaneous Taxes - Like many other consumer goods and services, certain telephone services are taxed by federal, state, and local governments. These charges may appear as a ※gross receipts§ tax.

　　Modem³ - A device for converting digital signals from your computer into analog⁴ signals for transmission over a phone line (modulation) and also converts the analog signals from the phone into digital signals that your computer can read (demodulation).

1 fiber   

n.纤维，纤维质

参考例句：

• The basic structural unit of yarn is the fiber.纤维是纱的基本结构单元。
• The material must be free of fiber clumps.这种材料必须无纤维块。

2 fibers   

光纤( fiber的名词复数 )； （织物的）质地； 纤维，纤维物质

参考例句：

• Thesolution of collagen-PVA was wet spined with the sodium sulfate as coagulant and collagen-PVA composite fibers were prepared. 在此基础上，以硫酸钠为凝固剂，对胶原-PVA共混溶液进行湿法纺丝，制备了胶原-PVA复合纤维。
• Sympathetic fibers are distributed to all regions of the heart. 交感神经纤维分布于心脏的所有部分。

3 modem   

n.调制解调器

参考例句：

• Does your computer have a modem?你的电脑有调制解调器吗？
• Provides a connection to your computer via a modem.通过调制解调器连接到计算机上。

4 analog   

n.类似物，模拟

参考例句：

• The analog signal contains high-frequency video information,which helps make up the picture.模拟信号包括有助于构成图像的高频视频信息。
• The analog computer measures continuously,without proceeding step by step.模拟计算机不是一步一步地进行，而是连续地进行量度。