- DSL which stands for Digital Subscriber Line, used to report a range of communication services extended over the Public Switched Telephone Network (PSTN). The PSTN uses a pair of copper wires to connect our telephone service to the national telephony network. DSL technology enables high-speed communications over these same copper lines by arriving use of frequencies not utilized by voice communications.
- ADSL which stands for Asymmetric Digital Subscriber Line service and called as a asymmetric because the download and upload speeds are not symmetrical (download is faster than upload). ADSL2 (ITU G.992.3 and G.992.4) adds new features / functionality targeted at improving performance and interoperability and adds support for new applications and services. An increase in the distance ADSL can reach from the local telephone exchange, dynamic data rate adaptation, better resistance to noise, diagnostics, and a stand-by mode to save power.
- ADSL2 also reduces the initialisation time from more than 10 seconds (as is required for ADSL) to less than 3 seconds. ADSL2 has the same signal footprint as ADSL. ADSL2+ (ITU G.992.5) doubles the bandwidth used for downstream data transmission, effectively doubling the maximum downstream data rates, and achieving rates of 20 Mbps on telephone lines as long at 5,000 feet.
- ADSL2+ solutions will interoperate with ADSL and ADSL2, as well as with ADSL2+. ADSL2+ will include all the feature and performance benefits of ADSL2 while maintaining the capability to interoperate with legacy ADSL equipment.
- Frequency reach for telephone service is between 0kHz and 4kHz is used and 20kHz to 2.2MHz for DSL (ADSL or ADSL2) service.
Last updated: 02 October 2012
by BSNL TeleServices on
Broadband Technologies - DSL / ADSL / ADSL2 / ADSL2+