Jump to navigation Jump to search “DSL” redirects here. DSL binary option no loss cable splitters, line conditions, and service-level implementation. The 1980s saw the development of techniques for broadband communications that allowed the limit to be greatly extended. A patent was filed in 1979 for the use of existing telephone wires for both telephones and data terminals that were connected to a remote computer via a digital data carrier system.
Lechleider’s contribution to DSL was his insight that an asymmetric arrangement offered more than double the bandwidth capacity of symmetric DSL. Until the late 1990s, the cost of digital signal processors for DSL was prohibitive. All types of DSL employ highly complex digital signal processing algorithms to overcome the inherent limitations of the existing twisted pair wires. A DSL connection can be deployed over existing cable.
Such deployment, even including equipment, is much cheaper than installing a new, high-bandwidth fiber-optic cable over the same route and distance. This is true both for ADSL and SDSL variations. In the case of ADSL, competition in Internet access caused subscription fees to drop significantly over the years, thus making ADSL more economical than dial up access. Telephone companies were pressured into moving to ADSL largely due to competition from cable companies, which use DOCSIS cable modem technology to achieve similar speeds. Early DSL service required a dedicated dry loop, but when the U. ILECs to lease their lines to competing DSL service providers, shared-line DSL became available.
By 2012, some carriers in the United States reported that DSL remote terminals with fiber backhaul are replacing older ADSL systems. Telephones are connected to the telephone exchange via a local loop, which is a physical pair of wires. The local loop connecting the telephone exchange to most subscribers has the capability of carrying frequencies well beyond the 3. Depending on the length and quality of the loop, the upper limit can be tens of megahertz. The underlying technology of transport across DSL facilities uses high-frequency sinusoidal carrier wave modulation, which is an analog signal transmission. DSL modems modulate frequencies from 4000 Hz to as high as 4 MHz. Because DSL operates above the 3.