ANSI Standard Contribution 2003-325: On the Optimality of Iterative Waterfilling in DSL

The iterative waterfilling algorithm was recently presented and demonstrates the large gains that can be achieved through the use of Dynamic Spectrum Management (DSM). In this contribution we evaluate the optimality of iterative waterfilling in various scenarios by comparison with the Optimal Spectrum Management (OSM) algorithm. OSM determines the theoretically optimal transmit spectra for the modems within a network thereby allowing them to achieve the maximum possible bitrates. We show that in many scenarios, the potential benefits of DSM can be even larger than those already demonstrated by iterative waterfilling. This demonstrates the huge potential of DSM and motivates further work in the area