Zipper VDSL: A Solution for Robust Duplex Communication Over Telephone Lines
This paper presents an overview of a digital duplex scheme called Zipper, intended for DMT-based VDSL systems. The Zipper multi-carrier duplex scheme represents a breakthrough toward digital implementation of frequency-division duplexing. A duplex scheme is a method to divide the capacity of a line between the upstream and downstream directions. Zipper divides the available bandwidth by assigning different sub-carriers for the different directions.