On the properties of capacity regions in multi-user networks

Motivated by work by Yeung (1994) on the convexity of capacity regions for a multi-user channel, we formulate the general properties of the capacity region for any network of users. In particular, in addition to the usual properties of dominance and convexity, we also consider the bit masking property that a message could be sent to a larger number of receivers than necessary. We derive a general inner bound on the capacity region of a multiuser network without feedback using these properties.