High data rate Wireless Personal Area Networks (WPANs) operate in a limited space with emphasis on supporting multi-media applications. The requirements for different types of voice and video codecs vary and therefore the resource allocation should be done accordingly. The efficient utilization of high data rate WPAN superframe is determined by the number of devices and the channel time allocated to them to support their respective applications. Since the MAC layer for high data rate WPANs is TDMA based, there is an upper limit on the practical data rate that can be supported considering fair utilization of the superframe. This paper discusses communication in a high data rate WPAN including various overheads imposed by different layers. It analyses the capacity of the superframe considering several application requirements at different transmitter data rates. The paper concludes by discussing some potential optimizations for fair utilization of the superframe and time allocation in WPANs.