Exclusive-Region Based Scheduling Algorithms for UWB WPAN

With the capability of supporting very high data rate services in a short range, ultra-wideband (UWB) technology is appealing to multimedia applications in future wireless personal area networks (WPANs) and broadband home networks. However, the WPAN medium access control (MAC) protocol in IEEE 802.15.3 standard was originally designed for narrowband communication networks, without considering any specific features of UWB. In this paper, we explore the unique characteristics of UWB communications from which a sufficient condition for scheduling concurrent transmissions in UWB networks is derived: concurrent transmissions can improve the network throughput if all senders are outside the exclusive regions of other flows. We also study the optimal exclusive region size for a UWB network where devices are densely and uniformly located. Since the optimal scheduling problem for peer-to-peer concurrent transmissions in a WPAN is NP-hard, the induced computation load for solving the problem may not be affordable to the network coordinator, commonly a normal UWB device with limited computational power. We propose two simple heuristic scheduling algorithms with polynomial time complexity. Extensive simulations with random network topology demonstrate that, by exploiting the unique characteristics of UWB communications and allowing concurrent transmissions appropriately, the proposed exclusive-region based scheduling algorithms can significantly increase the network throughput.