Optimal solution for the fixed margin problem in digital subscriber lines

Digital Subscriber Lines (DSL) are today one of the most important means for delivering high-speed data transmission. Dynamic Spectrum Management (DSM) is an emerging technique for dealing with crosstalk, one of the technology´s most harmful problems. DSM judiciously designs users´ power spectral densities so that the overall system performance is improved. This works aims at presenting a new insight in one of the most popular DSM schemes, the OSB. OSB is adapted to the Fixed Margin problem associated with DSL transmission. The result, presented and analyzed in this paper, is an algorithm that is able to operate in the whole area of feasible points in the rate region for a given DSL service. The algorithm is designed to use the minimum amount of power to serve a given set of rates in the system, an approach which saves power by using it more cleverly and is much closer to current market demands.