Fair greening of broadband access: spectrum management for energy-efficient DSL networks

Abstract

Dynamic spectrum management (DSM) is recognized as a promising technology to reduce power consumption in DSL access networks. However, the correct formulation of power-aware DSM problem statements requires a proper understanding of greening, i.e., reducing power consumption. In this paper, we, therefore, investigate greening and show that it can be decomposed into two dimensions: the price of greening and the fairness of greening. We first analyze the price of greening, providing theoretical bounds on the power-rate trade-off and identifying the typical trends that can be expected in practice, with some particularly promising results. Then, we introduce the fairness dimension, where we show that fairness becomes crucial when reducing power consumption. We propose four different fair greening policies that can be used to obtain a favorable trade-off between fast, fair and green DSL operation. Finally, we evaluate and quantify the corresponding trade-offs for realistic DSL access networks.

Real-Time Dynamic Spectrum Management for Multi-User Multi-Carrier Communication Systems} \newcommandargmaxoperatornamewithlimits{argmax

“…In particular, when multiple users transmit simultaneously in a common frequency bandwidth, significant interference levels can be observed among them in practical systems. This can result in large data rate reductions [6]- [8], poor spectral and energy efficiency [9]- [15], unstable behaviour due to transient interference [16]- [19], unfairness due to unbalanced interference impact [20] and other performance degradations.…”

Spectrum optimization in multi-user multi-carrier systems with iterative convex and nonconvex approximation methods

“…It consists of the joint coordination of the transmit spectrum, i.e., transmit powers over all frequency carriers, of the interfering users so that the spectral efficiency is improved. This can lead to a maximization of the data rates for a given transmit power budget [3], a minimization of the transmit powers for mininum target data rates [4], [5], some fair trade-off between these objectives [6], or even a maximization of the signal to noise ratio (SNR) margin [7], [8]. We want to highlight here that our target system model considers spectrum optimization only, i.e., without any joint signal coordination at the transmitter or the receiver side.…”