PHYSICAL LAYER AND TRANSMISSION MEDIA
INTRODUCTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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fiber optics
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switch
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modulator
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modem
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Detailed explanation-1: -A modulator is a device that performs modulation. A demodulator (sometimes detector or demod) is a device that performs demodulation, the inverse of modulation. A modem (from modulator–demodulator) can perform both operations.
Detailed explanation-2: -A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio.
Detailed explanation-3: -Modulation: the process of transforming digital information (1’s an 0’s) into analog (perceived as sound) signals. In the case of modems, capable of being transmitted over telephone lines. Demodulation: the process of transforming analog signals, previously modulated, back into digital information.