What is HDSL (High-bit-rate Digital Subscriber Line)?

High-bit-rate Digital Subscriber Line innovation is a replacement for a T-1 repeatered line. It permits DS-1 signals to be transported over distances of up to 3700 meters at 1.544 Mbit/s and 2.048 Mbit/s, on unconditioned copper link, without a requirement for repeaters. It was the first digital subscriber line (DSL) innovation to utilize a higher recurrence range over copper, twisted pair cables. High-bit-rate digital subscriber line (HDSL) was normalized in 1994.