The Single Source Two Terminal Network with Network Coding

We consider a communication network with a single source that has a set of messages and two terminals where each terminal is interested in an arbitrary subset of messages at the source. A tight capacity region for this problem is demonstrated. We show by a simple graph-theoretic procedure that any such problem can be solved by performing network coding on the subset of messages that are requested by both the terminals and that routing is sufficient for transferring the remaining messages.
Comment: 4 pages, appeared at the Canadian Workshop on Information Theory (CWIT), 2005