In this paper, we investigate spectrum occupancy focusing on cellular and TV broadcasting bands. Recently, TV band has attracted much attention due to the potential to exploit the available white space, if any, to improve spectrum utilization opportunistically. TV white space is a portion of spectrum in the UHF/VHF bands which is not utilized based on time and location. For the sake of comparison, measurements have also been conducted to investigate spectrum occupancy in cellular band, which is normally assumed to be fully utilized. The findings in this paper are important to provide insight of the actual spectrum utilization in the TV and cellular bands in Malaysia as compared to studies conducted in other countries.

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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.