Resource optimization in QoS multicast routing of real-time multimedia

Moses Charikar, Joseph Naor, Baruch Schieber

Research output: Contribution to journalConference articlepeer-review

27 Scopus citations


We consider a network design problem, where applications require various levels of Quality-of-Service (QoS) while connections have limited performance. Suppose that a source needs to send a message to a heterogeneous set of receivers. The objective is to design a low cost multicast tree from the source that would provide the QoS levels (e.g, bandwidth) requested by the receivers. We assume that the QoS level required on a link is the maximum among the QoS levels of the receivers that are connected to the source through the link. In accordance, we define the cost of a link to be a function of the QoS level that it provides. This definition of cost makes this optimization problem more general than the classical Steiner tree problem. We consider several variants of this problem all of which are proved to be NP-hard. For the variant where QoS levels of a link can vary arbitrarily and the cost function is linear in its QoS level, we give a heuristic that achieves a multicast tree with cost at most a constant times the cost of an optimal multicast tree. The constant depends on the best constant approximation ratio of the classical Steiner tree problem. For the more general variant, where each link has a given QoS level and cost we present a heuristic that generates a multicast tree with cost O(min{log r, k}) times the cost of an optimal tree, where r denotes the number of receivers, and k denotes the number of different levels of QoS required. We generalize this result to hold for the case of many multicast groups.

Original languageEnglish (US)
Pages (from-to)1518-1527
Number of pages10
JournalProceedings - IEEE INFOCOM
StatePublished - 2000
Externally publishedYes
Event19th Annual Joint Conference of the IEEE Computer and Communications Societies - IEEE INFOCOM2000: 'Reaching the Promised Land of Communications' - Tel Aviv, Isr
Duration: Mar 26 2000Mar 30 2000

All Science Journal Classification (ASJC) codes

  • General Computer Science
  • Electrical and Electronic Engineering


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