Ultra-wideband (UWB) is a new technology that enables wireless connectivity with consistent high data rates across multiple devices, such as high-definition television (HDTV) receivers, PCs, printers and digital cameras, within the digital home, and the office. In this paper, we focus on UWB transmissions where multiple accesses to the channel are coordinated by the IEEE 802.15.3 medium access control mechanism proposed in the IEEE 802.15.3a task