Abstract-- UWB and 802.11n have both been touted as technologies for next generation wireless networks. UWB exploiting a large bandwidth, and 802.11n utilizing MIMO, demonstrate high data rates in single links. However, in real world applications these two technologies will not operate as isolated single links, but in a network environment characterized by interference. Through the application of a formal optimization theoretic framework, we demonstrate that their relative network performance is very different from a physical layer comparison. The interference handling capabilities of UWB and 802.11n cause this significant network performance result. We explore practical effects that alter the perceived interference and so, relative network performance. Further, recommendations for the use of multiple antennas in 802.11n radios are presented.