Modem Types and Its Functions

Modem:

Modem stands for “Modulator-Demodulator“. It is a hardware component that allows a computer or another device, such as a router or switch, to connect to the Internet. It converts or “modulates” an analogue signal from a telephone or cable wire to digital data (1s and 0s) that a computer can recognize. Similarly, it converts digital data from a computer or other device into an analogue signal that can be sent over standard telephone lines.

The first modems were “dial-up“. It means that they had to dial a phone number to connect to an ISP. These modems operated over standard analogue phone lines and used the same frequencies as telephone calls, which limited their maximum data transfer rate to 56 Kbps. Dial-up modems also required full use of the local telephone line, meaning voice calls would interrupt the Internet connection.

Types of Modem:

Modems can be of several types and they can be categorized in three ways.
1. Directional capacity: Half Duplex Modem and Full Duplex Modem.
2. Connection to the line: 2-wire Modem and 4-wire Modem.
3. Transmission mode: Asynchronous Modem and Synchronous Modem.