Enabling video transmission to be maintained at an acceptable level under unreliable and time-varying wireless channels in a non-trivial challenge. The main challenge in enabling video transmission over UWB WPAN lies on how to meet the QoS requirements (ie: delay, jitter, PSNR) under time-varying spectral resources, video frame dependencies, limited power and data rate and tight delay constraint. In this paper, capacity of UWB wireless networks supporting video application with IEEE802.15.3 MAC is analyzed by considering the overheads from different layers. Then, impact of channel conditions and retransmission limit to the (packet error rate) PER and JFR (job failure rate) are also studied. Round robin, shortest remaining processing time (SRPT) and constant bandwidth server (CBS) scheduling mechanisms are also compared. Video performance is investigate as a function of time slot allocations and number of users supported. BER, PER and JFR are used as performance parameters. Result showed that BER should be kept at 10-6 to maintain good PER and JFR below 10%. Optimal CTA allocation is crucial to ensure timely multimedia delivery as well as to minimize wasteful of resources.