Polynomial time approximation algorithms for multi-constrained QoS routing

We study the multi-constrained Quality-of-Service (QoS) routing problem where one seeks to find a path from a source to a destination in the presence of K 2 additive end-to-end QoS constraints. This problem is NP-hard and is commonly modeled using a graph with n vertices and m edges with K additive QoS parameters associated with each edge. For the case of K = 2, the problem has been well studied, with several provably good polynomial time approximation algorithms reported in the literature, which enforce one constraint while approximating the other. We first focus on an optimization version of the problem where we enforce the first constraint and approximate the other K - 1 constraints. We present an O(mn log log log n + mn/ ) time (1 + )(K - 1)-approximation algorithm and an O(mn log log log n + m(n )K-1 ) time (1 + )approximation algorithm, for any > 0. When K is reduced to 2, both algorithms produce an (1 + )-approximation with a time complexity better than that of the best-know...

• Type: Journal
• Year: 2008
• Where: TON
• Authors: Guoliang Xue, Weiyi Zhang, Jian Tang, Krishnaiyan Thulasiraman
• Keywords: Additive End-to-end Qos, Additive Qos Parameters, Algorithms, TON 2008