modem
n. device which allows the transfer of data through a telephone line from one computer to another (Computers) | ||||
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Modems definition was found in categories: Computer & Internet(1) Language, Idioms & Slang(2) Entertainment & Music(1) Encyclopedia(1)
Modems Definition from Computer & Internet Dictionaries & Glossaries
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modem
<hardware, communications> (Modulator/demodulator) An electronic device for converting between serial data (typically EIA-232) from a computer and an audio signal suitable for transmission over a telephone line connected to another modem. In one scheme the audio signal is composed of silence (no data) or one of two frequencies representing zero and one.
Modems are distinguished primarily by the maximum data rate they support. Data rates can range from 75 bits per second up to 56000 and beyond. Data from the user (i.e. flowing from the local terminal or computer via the modem to the telephone line) is sometimes at a lower rate than the other direction, on the assumption that the user cannot type more than a few characters per second.
Various data compression and error correction algorithms are required to support the highest speeds. Other optional features are auto-dial (auto-call) and auto-answer which allow the computer to initiate and accept calls without human intervention. Most modern modems support a number of different protocols, and two modems, when first connected, will automatically negotiate to find a common protocol (this process may be audible through the modem or computer's loudspeakers). Some modem protocols allow the two modems to renegotiate ("retrain") if the initial choice of data rate is too high and gives too many transmission errors.
A modem may either be internal (connected to the computer's bus) or external ("stand-alone", connected to one of the computer's serial ports). The actual speed of transmission in characters per second depends not just the modem-to-modem data rate, but also on the speed with which the processor can transfer data to and from the modem, the kind of compression used and whether the data is compressed by the processor or the modem, the amount of noise on the telephone line (which causes retransmissions), the serial character format (typically 8N1: one start bit, eight data bits, no parity, one stop bit).
See also acoustic coupler, adaptive answering, baud barf, Bulletin Board System, Caller ID, SoftModem, U.S. Robotics, UUCP, whalesong.
Usenet newsgroup: news:comp.dcom.modems.
(2002-05-04)
<hardware, communications> (Modulator/demodulator) An electronic device for converting between serial data (typically EIA-232) from a computer and an audio signal suitable for transmission over a telephone line connected to another modem. In one scheme the audio signal is composed of silence (no data) or one of two frequencies representing zero and one.
Modems are distinguished primarily by the maximum data rate they support. Data rates can range from 75 bits per second up to 56000 and beyond. Data from the user (i.e. flowing from the local terminal or computer via the modem to the telephone line) is sometimes at a lower rate than the other direction, on the assumption that the user cannot type more than a few characters per second.
Various data compression and error correction algorithms are required to support the highest speeds. Other optional features are auto-dial (auto-call) and auto-answer which allow the computer to initiate and accept calls without human intervention. Most modern modems support a number of different protocols, and two modems, when first connected, will automatically negotiate to find a common protocol (this process may be audible through the modem or computer's loudspeakers). Some modem protocols allow the two modems to renegotiate ("retrain") if the initial choice of data rate is too high and gives too many transmission errors.
A modem may either be internal (connected to the computer's bus) or external ("stand-alone", connected to one of the computer's serial ports). The actual speed of transmission in characters per second depends not just the modem-to-modem data rate, but also on the speed with which the processor can transfer data to and from the modem, the kind of compression used and whether the data is compressed by the processor or the modem, the amount of noise on the telephone line (which causes retransmissions), the serial character format (typically 8N1: one start bit, eight data bits, no parity, one stop bit).
See also acoustic coupler, adaptive answering, baud barf, Bulletin Board System, Caller ID, SoftModem, U.S. Robotics, UUCP, whalesong.
Usenet newsgroup: news:comp.dcom.modems.
(2002-05-04)
Modems Definition from Language, Idioms & Slang Dictionaries & Glossaries
| WordNet 2.0 |
modem
Noun
1. (from a combination of MOdulate and DEModulate) electronic equipment consisting of a device used to connect computers by a telephone line
(hypernym) electronic equipment
(hyponym) acoustic modem
Noun
1. (from a combination of MOdulate and DEModulate) electronic equipment consisting of a device used to connect computers by a telephone line
(hypernym) electronic equipment
(hyponym) acoustic modem
| hEnglish - advanced version |
Modems Definition from Entertainment & Music Dictionaries & Glossaries
| Guitar Glossary |
Modem
A data communications device whose name derives from its function: modulator/demodulator. The modem converts digital signals from a computer to analog signals (modulation) for transmission over telephone lines, and vice versa (demodulation).
A data communications device whose name derives from its function: modulator/demodulator. The modem converts digital signals from a computer to analog signals (modulation) for transmission over telephone lines, and vice versa (demodulation).
Modems Definition from Encyclopedia Dictionaries & Glossaries
| Wikipedia English - The Free Encyclopedia |
Democratic Movement (France)
The Democratic Movement (Mouvement démocrate, MoDem) is a centrist and pro-European French political party that was founded by centrist politician François Bayrou to succeed his Union for French Democracy (UDF) and to contest the 2007 legislative election, after his strong showing in the 2007 presidential election.
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Modem
Modem (from modulate and demodulate) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. Modems can be used over any means of transmitting analog signals, from driven diodes to radio. Experiments have even been performed in the use of modems over the medium of two cans connected by a string.
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