Multicast trees to provide message ordering in mesh networks

The objective of this work is to provide message ordering for mesh networks by constructing multicast trees. Two different graph models can be used to guarantee the message ordering properties. In the first one, a single global tree is built for all the nodes in overlapping groups, while in the second one, single trees are built only for overlapping nodes, and on top of these subtrees separate trees are built for each multicast group. Two problems are investigated to build such trees: finding an optimal root that minimizes the time of the multicast, and determining the routing to minimize both time and traffic. An algorithm to find a root node that minimizes the time is presented. An efficient heuristic routing algorithm which builds a shortest-path tree is also presented. It is shown that this algorithm builds a tree whose traffic has an upper bound of twice as much as that of an optimal multicast tree.