Approximating optimal multicast trees in wireless multihop networks

We study the problem of computing minimal cost multicast trees in multi-hop wireless mesh networks. This problem is known as the Steiner tree problem, and it has been widely studied in fixed networks. However, we show in this paper that in multi-hop wireless mesh networks, a Steiner tree is no longer offering the lowest bandwidth consumption. So, we re-formulate the problem in terms of minimizing the number of transmissions. We show that the new problem is also NP-complete and propose heuristics to approximate such trees. Our simulations results show that the proposed heuristics offer a lower cost than Steiner trees over a variety of scenarios.