Issue No. 09 - Sept. (2012 vol. 61)

ISSN: 0018-9340

pp: 1270-1283

DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TC.2011.145

Costas Busch , Louisiana State University, Baton Rouge

Rajgopal Kannan , Louisiana State University, Baton Rouge

Athanasios V. Vasilakos , University of Western Macedonia, Psychiko

ABSTRACT

A classic optimization problem in network routing is to minimize C+D, where C is the maximum edge congestion and D is the maximum path length (also known as dilation). The problem of computing the optimal C^{\ast}+D^{\ast} is NP-complete even when either C^{\ast} or D^{\ast} is a small constant. We study routing games in general networks where each player i selfishly selects a path that minimizes C_i + D_i the sum of congestion and dilation of the player's path. We first show that there are instances of this game without Nash equilibria. We then turn to the related quality of routing (QoR) games which always have Nash equilibria. QoR games represent networks with a small number of service classes where paths in different classes do not interfere with each other (with frequency or time division multiplexing). QoR games have O(\log^4 n) price of anarchy when either C^{\ast} or D^{\ast} is a constant. Thus, Nash equilibria of QoR games give poly-log approximations to hard optimization problems.

INDEX TERMS

Algorithmic game theory, congestion game, routing game, Nash equilibrium, price of anarchy.

CITATION

Costas Busch, Rajgopal Kannan, Athanasios V. Vasilakos, "Approximating Congestion + Dilation in Networks via "Quality of Routing” Games",

*IEEE Transactions on Computers*, vol. 61, no. , pp. 1270-1283, Sept. 2012, doi:10.1109/TC.2011.145