Coverage Optimization in DSL Networks by Low-Complexity Discrete Spectrum Balancing

Spectrum balancing is an established optimization approach in multi-carrier digital subscriber line (DSL) systems. It has previously been applied to very different performance objectives such as sum-rate, min-rate, or fairness maximization and sum-power minimization. In this work we study the maximization of the service coverage, which will be defined as the number of DSL lines which can be granted an operator-specified high-bandwidth service. The proposed algorithm is based on a previously described mathematical decomposition framework. We extend this framework for our new problem and enhance its scalability by various low-complexity heuristics. Simulations demonstrate the applicability of our algorithm for DSL networks of realistic sizes. More precisely, our results obtained in thousand 25 user near-far DSL scenarios show an average gain in service coverage of more than 13% compared to state-of-the-art sum-rate maximizing spectrum balancing algorithms.