Rate-Adaptive_Digital_Subscriber_Line
Rate-adaptive digital subscriber line (RADSL) is a pre-standard asymmetric digital subscriber line (ADSL) solution.[1] RADSL was introduced as proprietary technology by AT&T Paradyne, later GlobeSpan Technologies Inc.,[2] in June 1996.[3] In September 1999, RADSL technology was formally described by ANSI in T1.TR.59-1999.[4][5] RADSL supports downstream data rates of up to approximately 8 Mbit/s, upstream data rates up to approximately 1 Mbit/s, and can coexist with POTS voice on the same line.[5]
RADSL allows rate-adaptation while the connection is in operation — rate-adaptation during connection setup is possible in many other DSL variants, including G.dmt and its successors. Rate-adaptation while the connection is in operation is specified as an option in ADSL2, ADSL2+, and VDSL2, under the name seamless rate adaptation (SRA).[6]