Ultra wideband (UWB) systems are currently an important wireless infrastructure for efficient shortrange communications. To improve the system efficiency while guaranteeing the radio link level quality of services, transmission rate and power of the mobile nodes can be dynamically adjusted by executing an optimization algorithm at the access points (APs). In this paper, we present a cross layer rate and power allocation algorithm based on the multilayer model of time hopping (TH) pulse position modulation (PPM) UWB multimedia networks. We consider the performance of the TCP protocol under the proposed cross layer allocation scheme in various realistic UWB based infrastructure networking scenarios.