An Effective Randomized QoS Routing Algorithm on Networks with Inaccurate Parameters

This paper develops an effective randomized on-demand QoS routing algorithm on networks with inaccurate link-state information. Several new techniques are proposed in the algorithm. First, the maximum safety rate and the minimum delay for each node in the network are pre-computed, which simplify the network complexity and provide the routing process with useful information. The routing process is dynamically directed by the safety rate and delay of the partial routing path developed so far and by the maximum safety rate and the minimum delay of the next node. Randomness is used at the link level and depends dynamically on the routing configuration. This provides great flexibility for the routing process, prevents the routing process from overusing certain fixed routing paths, and adequately balances the safety rate and delay of the routing path. A network testing environment has been established and five parameters are introduced to measure the performance of QoS routing algorithms. Experimental results demonstrate that in terms of the proposed parameters, the algorithm outperforms existing QoS algorithms appearing in the literature. This work was supported by the China National Science Fund for Overseas Distinguished Young Scholars (No.69928201), Foundation for University Key Teachers by the Ministry of Education (2000]143). WANG Jianxin received his B.S. and M.S. degrees in computer science from the Central-South University, P. R. China, in 1992 and 1996, respectively, where he is currently a Ph.D. candidate. His research interests include routing algorithms, scheduling policies, and quality-of-service issues on the Internet and high-speed networks. CHEN Jian’er received his Ph.D. degree of computer science from New York University in 1987 and the Ph.D. degree in mathematics from Colombia University in 1990. Currently he is a chair professor in computer science and technology, Central-South University. His research interests include computer networks, computer graphics, computational optimization, and algorithms. CHEN Songqiao is currently a professor in computer science at the College of Information Engineering, Central-South University. His research interest is computer software.