Improved approximation algorithms for the Capacitated Multicast Routing Problem

Abstract

Two models for the Capacitated Multicast Routing Problem are considered, which are the Multicast k-Path Routing and the Multicast k-Tree Routing. Under these models, two improved approximation algorithms are presented, which have worst case performance ratios of 3 and (2 + ρ), respectively. Here ρ denotes the best approximation ratio for the Steiner Minimum Tree problem, and it is about 1.55 at the writing of the paper. The two approximation algorithms improve upon the previous best ones having performance ratios of 4 and (2.4 + ρ), respectively. The designing techniques developed in the paper could be applicable to other similar networking problems. © Springer-Verlag Berlin Heidelberg 2005.