We study the problem of computing multicast trees with minimal bandwidth consumption in multi-hop wireless mesh networks. For wired networks, this problem is known as the Steiner tree problem, and it has been widely studied before. We demonstrate in this paper, that for multihop wireless mesh networks, a Steiner tree does not offer the minimal bandwidth consumption, because it neglects the wireless multicat advantage. Thus, we re-formulate the problem in terms of minimizing the numbrer of transmissions, rather than the edge cost of multicast trees. We show that the new problem is also NP-complete and we propose heuristics to compute good approximations for such bandwidthoptimal trees. Our simulation results show that the proposed heuristics offer a lower bandwidth consumption compared with Steiner trees.
Pedro M. Ruiz, Antonio F. Gómez-Skarmeta