Linear and Nonlinear Lagrange Relaxation Algorithms for Delay-Constrained Least-Cost QoS Routing ∗
Gang Feng, Kia Makki, Niki Pissinou, Non-members · 2002
SUMMARY The development of efficient quality of service (QoS) routing algorithms in a high-speed network environment is a very important and at the same time very difficult task due to the need to provide divergent services with multiple QoS requirements. Recently heuristic algorithms based on Lagrange relaxation techniques have been proposed to resolve the contradiction between the time complexity and the quality of solution. In this paper, we investigate the performance of two heuristic algorithms, LR DCLC and NR DCLC, for the delay-constrained least-cost (DCLC) routing problem. Algorithm LR DCLC is based on linear relaxation, while algorithm NR DCLC, which is proposed in this paper, is based on nonlinear relaxation. A large number of simulations demonstrate that even though both algorithms have very good performance, NR DCLC can obtain much better solutions than LR DCLC by running Dijkstra’s algorithm on average a fewmore times, especially in the case when the optimal solutions are hard to find.