ADSL Asymetric Digital Subscriber Line
ADSL Asymmetric Digital Subscriber Line, or DSL for short is a high-speed Internet access service that utilizes existing copper telephones lines to send and receive data at speeds that far exceed conventional dial-up modems. The fastest dial-up modems are rated at 57 kilobits per second and usually operate at about 53 Kbps under good conditions. By comparison, ADSL allows datastream speeds from 1.5 to 8 megabits per second depending on the grade of ADSL service purchased. ADSL uses standard telephone lines to transmit upstream and downstream data on a digital frequency, which sets these datastreams apart from the analog signals telephones and fax machines use. Because the ADSL signal is operating on a frequency that is inaudible to humans, the telephone can be used normally, even when surfing the Web with the ADSL service.