How modem works

Modem is a communication device that enables a computer to transfer data over the telephone or cable lines. The word Modem is a short form for Modulator/Demodulator.

Working of a Modem:

A modem is a device that is used for modulation and demodulation of information. The working of a modem includes the following steps :

1. Software such as Auto Dialers in the computer activates the modem, which listens for the dial tone on the phone line.

2. Once the dial tone is available, the modem dials a specified number.

3. The modem at the receiving end answers the call and sends out a signal to the modem at the sending end. This results in establishing a connection.

4. The modem at the sending end converts digital signals from a computer to analog signals that can pass over the telephone line.

5. The modem at the receiving end converts analog signals back to digital signals that can be used by the computer.

6. The step 4 and 5 keep repeating during the online session.

7. Once the online session is over, the computer issues a command to disconnect the session.

Shows the working of a modem

At the sending end ------ Telephone lines------------------------At the receving end

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Modem Modem

Sending computer Receving computer