Friday, June 24, 2011



Modem is short for modulator-demodulator. Modems are required so that various computers can communicate with each other over a network. They convert the analog signals, which a computer receives over a telephone or cable television line into the digital signals.

When the use of Modem began in 1970’s most of them were used to connect computers to a Bulletin Board Systems (BBS). Initially 300 BAUD Modems were used which could transmit 30 characters per second. But nowadays modems available in the market transfer the data at a much faster rate thus allowing you to download huge amounts within few minutes

Types of Modem

Dial-up Modems- These modems were widely used in the late 1990’s. Dial-up modems used standard telephone line to connect to the Internet Service Provider (ISP). When developed these modems had the data transfer capability of 56 Kbps but the major drawback of using the dial-up technology was that a user couldn’t use telephone line while using the Internet.
Cable Modems – These types of modems allow computer systems and networks to communicate over the cable television infrastructure networks. These networks use co-axial cable media to communicate. Cable modems are generally used for broadband based Internet access.
Wireless Modems – Wireless modem is a network device which connects to wireless network. It attaches directly to your notebook or a computer. Wireless modem interfaces include Compact Flash, USB and Serial Port.
Voice Modems- Voice modems are just like standard modems that are capable of recording or playing audio over the telephone line. They are used for telephony applications.
ADSL/DSL Modems – ADSL stands for Asymmetric Digital subscriber line. However unlike dial up one can receive and make phone calls while simultaneously using the Internet. The reason why this is termed as asymmetric is because while using the ADSL modems user has much higher download speeds as compared to the upload speed.

On the other hand DSL (Digital Subscriber Line) modems give equal speed while both downloading and uploading the content on the Internet.

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