Information dissemination in trees with nonuniform edge transmission times

The information dissemination process in a tree is considered. It is assumed that a vertex can either transmit or receive a message and an informed vertex can transmit it to only one of its neighbors at a time. For the case of uniform edge transmission times, P. Slater et al. (1981) showed that a simple ordering policy achieves the minimum broadcast time and presented an algorithm which determines a set of broadcast centers. It is shown that a simple ordering policy is still optimal for the case of nonuniform edge transmission times, and modifications of the algorithm that enables it to solve this general problem within O(N log N) time are suggested