Optimal quorumcast routing

Multicasting is the transmission of data packets from a source to multiple destinations, known as the multicast group. Quorumcasting, which is generalization of multicasting, is the sending of these data packets to only a subset of nodes in the multicast group, which we call the quorum group. The quorumcast routing problem is that of finding the least cost tree which spans the source node and a quorum group. This problem is known to be NP-complete. Therefore, exhaustive search algorithms are generally used to find a solution for the problem. We introduce the notion of a threshold value and show that how this value can be used to significantly reduce the running time of exhaustive search algorithms for the quorumcast routing problem.