which stands for medium-bit-rate DSL. Confused yet?
RADSL Rate Adaptive Digital Subscriber Line (RADSL) is any rate adaptive xDSL modem, but may specifically refer to a proprietary modulation standard designed by Globespan Semiconductor. It uses carrierless amplitude and phase modulation (CAP). T1.413 standard DMT modems are also technically RADSL, but generally not referred to as such. The uplink rate depends on the downlink rate, which is a function of line conditions and signal to noise ratio (SNR). SDSL Symmetric Digital Subscriber Line (SDSL) is a 2-wire implementation of HDSL. Supports T1/E1 on a single pair to a distance of 11,000 ft. The name has become more generic over time to refer to symmetric service at a variety of rates over a single loop. UDSL Universal DSL. See G.lite. VDSL Very High Bit-rate Digital Subscriber Line (VDSL) is proposed for shorter local loops, perhaps up to 3000 ft. Data rates exceed 10 Mb/s.
