lADSL

lADSL, short for low-rate ADSL, is a non-standard term used by some telecommunications providers to describe a reduced-speed variant of Asymmetric Digital Subscriber Line services delivered over the same copper telephone lines used for voice. It is not part of formal ITU-T DSL specifications; rather, it is a marketing label applied to a purpose-built, lower-bandwidth profile of the general ADSL technology. Vendors and operators may implement lADSL by restricting the number of active subcarriers, reducing modulation order, or otherwise tuning the downstream/upstream balance to achieve lower speeds and improved reach on marginal lines.

As with standard ADSL, lADSL uses a single copper pair and frequency-division multiplexing to separate voice from data, with data carried on higher-frequency bands. A DSL access multiplexer at the central office or remote terminal negotiates a profile with the customer premises equipment to determine achievable rates. The performance of lADSL depends heavily on line length, line quality, and shared network conditions; because it is designed for basic connectivity, downstream speeds are typically lower and may be asymmetrical, with slower upstream.

Deployment and usage: lADSL has been used in markets where a cheaper, easier-to-deploy service is desired or where customers are unable to obtain higher-speed ADSL due to line quality. In many regions, it has declined as providers migrated to standardized profiles such as ADSL2 and ADSL2+ (and, later, VDSL variants). Today, lADSL is largely a historical or regional label rather than a widely supported technology.