Modems White Papers
Practical Guide to Analog Modems
Overview Modem is a word born out of the combination of two words: Modulator / Demodulator. These words were picked since they describe the actions a modem takes in the most precise way. Modems are no more than an extension to a computer, designed to use ordinary telephone lines to carry digital computer data. So what is Analog and what is Digital, and what is the advantage of one over the other? To explain the principle, we will look at the brightness of light bulbs. First, we will look at the Digital Light bulb. This one is hooked up to a switch. You can either turn it on, or turn it off. You cannot decide how bright the light will be; there is either light or no light. This makes things nice and simple if you wish to describe what the light bulb is doing: it is either glowing, or it is not. A light bulb hooked up to a dimmer, on the other hand, could be in many states. It can be off, or dim, or a little brighter, or very bright, and everything in-between! The light bulb on the switch has a defined number of states: It is ON or OFF. We call it Discrete which is saying it has a finite number of states, and Binary since it only has two states. This finite-state discrete object would be called digital. The light bulb on the dimmer would be called analog; we're never quite sure exactly where in the range from dark to light it is. All we know is the constraints of its range of possible states.
| Publisher | Niels Jonker | File Format | HTML |
|---|---|---|---|
| Date Published | August 2003 | Downloads | 2 |
| Format | White Papers | ||
| Topics | |||
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