DSL digital subscriber line Digital subscriber lines carry data at high speeds over standard copper telephone wires. With DSL, data can be delivered at a rate of 1.5 mbps (around 30 times faster than through a 56-kbps modem). Also, DSL users can receive voice and data simultaneously, so small offices can leave computers plugged into the Net without interrupting phone connections. Currently, DSL is expensive because specialized equipment--a splitter--needs to be installed at the subscriber's location. DSL Lite, the consumer-ready version of DSL, requires no such splitter, and promises comparable access speeds at a cheaper rate. xDSL is the collective term for different variations of DSL, such as ADSL and HDSL. See also: ADSL