The first in our series of technology primers explains how DSL works and how you can get it. DSL connects your computer to the Internet at speeds as fast as 52 megabits per second, using the copper lines that already bring you phone service. And unlike cable modems, DSL connections are dedicated, so you don't have to share bandwidth with other users in your neighborhood. Regular voice signals travel over phone lines at frequencies ranging from 0 kHz to 4 kHz.
Standard modems use the same frequencies as voice.
But DSL uses frequencies between 25 kHz and 1 MHz. That extra bandwidth also means it can send more data. This broadband connection requires special hardware at both ends. On your end, a DSL modem modulates digital information from your computer to send it along phone lines. These signals are then translated by a Digital Subscriber Line Access Multiplexer located at the phone company's nearest central office.