Cross layer design is considered as an attractive strategy to enable multimedia transmission over cognitive ultra wide band (C-UWB) system experiencing time-varying channel conditions and traffic characteristics. The close dependency among various parameters across protocol stacks need to be addressed to determine the optimum cross layer approach. Hence, this paper highlights a MAC centric cross layer approach that is aware of sensing activity and channel conditions at the PHY layer, resource allocation at the MAC layer and MPEG-4 video at the APP layer. The cross layer actions are determined through optimal sensing scheduling and dynamic packet reception rate (PRR) based resource allocation to improve video transmission quality. Two important sensing approaches, local and cooperative OR-rule are also discussed in detail. Then, the impact of the proposed sensing scheduling and resource allocation to the video transmission are evaluated accordingly.