DSL, Digital Subscriber Line, is a high-speed Internet service over ordinary phone lines using broadband modem technology. DSL technology allows Internet and telephone service to work over the same phone line without requiring customers to disconnect either their voice or Internet connections.
DSL works by transferring voice and data simultaneously over the existing twisted-pair copper telephone lines by using different frequency ranges on the same line. A DSL modem at the customer residence sends data over the phone line to a DSLAM at the CO. The DSLAM is what terminates and aggregates incoming ADSL lines. The DSLAM redirects voice to the PSTN and data to the Internet backbone connection.
terminology
- DSL - Digital Subscriber Line
- ADSL - Asymmetric Digital Subscriber Line
- CO - Central Office (service provider)
- DSLAM - DSL Access Multiplexer
- PSTN - Public Switched Telephone Network
- FDM - Frequency Division Multiplexing
- POTS - Plain Old Telephone Service
- CAP - Carrierless Amplitude Phase
- DMT - Discrete MultiTone
- QAM - Quadrature Amplitude Modulation
- DWMT - Discrete Wavelet MultiTone
- R-ADSL - Rate-Adaptive Digital Subscriber Line
- HDSL - High Bit-Rate Digital Subscriber Line
- VDSL - Very High Bit-rate Digital Subscriber Line