Evaluating wireless mesh network performances has become a specific challenge since the emergence of ubiquitous computing. In this article, we consider the network capacity as the performance measure and study its behaviour under two different interference models: (i) usual IEEE 802.11 MAC layer with acknowledgments at each hop, and (ii) block acknowledgments reported at the transport layer that can be included in the IEEE 802.16 standard. We derive a linear program modeling crosslayer characteristics of the wireless mesh network that is solved using column generation. We quantify the capacity gain induced by the move of the MAC acknowledgments into the transport layer, and show that a better load distribution is also obtained.